JP2004068571A

JP2004068571A - Fish run-up structure and water passage member for use in the same

Info

Publication number: JP2004068571A
Application number: JP2002282263A
Authority: JP
Inventors: Norio Kurohashi; 黒橋　典夫; Tokiji Ueno; 上野　世司; Kenji Hata; 端　憲二; Takashi Tanahashi; 棚橋　尚; Osamu Nobe; 野辺　脩; Hiroshi Yoshida; 吉田　浩; Shoichi Ishimoto; 石本　昭一
Original assignee: Shiga Prefectural Government.; National Institute for Rural Engineering; Hokukon Co Ltd; Showa Concrete Industry Co Ltd; Maruei Concrete Industry Co Ltd; Kurimoto Concrete Industries Ltd
Current assignee: Shiga Prefectural Government.; National Institute for Rural Engineering; Hokukon Co Ltd; Showa Concrete Industry Co Ltd; Maruei Concrete Industry Co Ltd; Kurimoto Concrete Industries Ltd
Priority date: 2002-06-12
Filing date: 2002-09-27
Publication date: 2004-03-04
Anticipated expiration: 2022-09-27
Also published as: JP3721455B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fish run-up structure for efficiently constructing a fish-way allowing the natural run-up of fishes from a drainage to a rice field. <P>SOLUTION: A plurality of water passage members 7 in a U-grooved shape are placed in stages to gradually rise from the side of the drainage 2 to the side of the rice field 3a. A joint portion 12 of the water passage member installed on the upstream side is fitted to a joint fitting portion 13 of the water passage member installed on the downstream side. A weir plate 23 for bank raising water in the water passage is detachably mounted on a portion of each water passage member on the downstream side of the water passage. An overflow portion 24 of the weir plate 23 is set to be higher enough for fishes to run up than a water level on the downstream side. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、排水路と、それよりも水位の高い水田や休耕田、溜め池、親水公園の池等としての貯水池との間に設けられ、該排水路から貯水池に無理なく魚類を遡上可能とする貯水池への魚類遡上構造に関するものであり、又該魚類遡上構造を構成する水路部材に関するものである。
【０００２】
【従来の技術】
近年、水田や休耕田等の貯水池への、鮒、鯉、鯰等の魚類の遡上を可能として、水田等を魚類の産卵繁殖・育成の場として活用することにより、生態系保全を達成せんとする試みが成されている。本出願人の一人も、特開２０００−１２００５２号において、淡水貯留池への魚類の遡上システムを提案した。
【０００３】
該遡上システムを構成する魚道は、図６７に示すように、淡水貯留池側ａが淡水貯留池ｂの水位より低位で且つ水路側ｃが水路ｄの水位より低位にある床部ｅと、この床部ｅの両側から夫々上方に立ち上がり且つ淡水貯留池ｂと水路ｄとを連通させる水の通路を形成する側壁ｆと、前記床部ｅと両側壁ｆ，ｆとにより構成される空間ｇ内に設けられ且つ上流側と下流側とを隔てると共に上流側の水を溢流させる越流部ｈとが設けられた隔壁ｊとを具える構成のものであった。
【０００４】
前記遡上システムは、その出願明細書に記載の通り、各隔壁の越流部を、下流側の水位に対して魚類が遡上可能な高さとなるように設計し、淡水貯留池の水位を略所定のレベルに維持して、水路側から淡水貯留池側に魚類を遡上させるようにしていたため、水路側から淡水貯留池側に魚類を容易に遡上させることができ、淡水貯留池における生物保全機能を向上させ、ビオトープに多様な生物を生息させることができるという大きな効果を奏するものであった。
【０００５】
【特許文献１】
特開２０００−１２００５２号公報（第４−７頁、第３図）
【０００６】
【非特許文献１】
「農業用排水路の生態系配慮型工法」、滋賀県農林土木コンクリート製品協会、平成１３年１２月２１日、Ｐ．２−６
【０００７】
【発明が解決しようとする課題】
しかしながら前記遡上システムによるときは、魚道の床部とこの床部の両側から立ち上がる側壁を、水路と淡水貯留池とを繋ぐように一連に形成していたため、魚道の構築が、現場打ち施工を主体としたものとなり、畦部等の幅や落差に応じた個別的な施工に多くの手間を要し施工コストの上昇を招くばかりか、工期が長引く問題があった。更に、前記一連構築の魚道によるときは、屈曲した魚道は構築しにくいことから、水路と淡水貯留池との間の落差が大きい場合、屈曲魚道によりこれに対応せんとしても、その施工が容易でない問題もあった。
【０００８】
又、前記床部ｅとその両側から夫々立ち上がる側壁ｆ，ｆとが一体のＵ字溝状ブロックとして構成される場合は、施工現場に応じた所定長さのブロックを個別的に設計製造しなければならず、型枠が高騰して製造コストの著しい上昇を招くことになる。加えて、長さの長いＵ字溝状ブロックは重量が大きくなり、施工現場への搬送が容易でなく又施工性を悪化させる問題も発生させることになる。
【０００９】
本発明は、主としてかかる問題点に鑑みて開発されたものであり、低水位の排水路から高水位の貯水池への魚類の遡上を容易に行わせ得るのはもとより、排水路の水位と貯水池の水位間の落差の程度に応じた適切な魚道を容易に形成できて施工能率の向上と施工コストの低減を期し得る、貯水池への魚類遡上構造の提供を課題とするものである。
【００１０】
又、魚類の遡上を可能とする越流部の高さ調整を施工現場に応じて適切に行うことのできる魚類遡上構造の提供を課題とするものであり、更に、魚類の遡上を誘発し易い魚類遡上構造の提供を課題とするものである。加えて、かかる魚道を合理的に構成できる水路部材の提供を課題とするものである。
【００１１】
【課題を解決するための手段】
前記課題を解決するため、本発明は以下の手段を採用する。
即ち本発明に係る魚類遡上構造は、排水路と、該排水路の水位よりも高い水位を有する貯水池に魚類を遡上させるための魚道を含み、該魚道を、水路部材の複数を順次接合して構成した貯水池への魚類遡上構造であって、前記水路部材は、その水路の上流側部と下流側部に、上流側開口と下流側開口を具え、上流側に設置された該水路部材の下流側開口が、下流側に設置された該水路部材の上流側開口に連通するように水路部材相互が接合されると共に、最上流側に設置された前記水路部材の上流側開口が前記貯水池に連通され、且つ最下流側に設置された前記水路部材の下流側開口が前記排水路に連通されている。又、前記水路部材の水路の下流側部位に、水路水を嵩上げする堰板が着脱可能に装着され、該堰板の越流部を、下流側の水位に対して魚類が遡上可能な高さに設定したことを特徴とするものである。
【００１２】
前記魚類遡上構造において、前記水路部材は、上端開放で且つ上流端から下流端に向かう連続する水路を有したＵ字溝状に形成すると共に、その上流側の水路幅を拡大し、該水路部材の下流側をなす接合部を嵌め入れるための接合嵌合部とし、該接合部が該接合嵌合部に嵌め入れられた状態において、前記接合部の前記接合嵌合部に対する、水路部材の長さ方向で見た挿入量を調節可能となし、又該水路部材の水路の下流側部位に、前記堰板を着脱可能に嵌め入れるためのガイド部を設け、上流側に設置された水路部材の前記接合部が、下流側に設置された水路部材の前記接合嵌合部に嵌め入れられたものとし、又前記ガイド部に前記堰板が嵌め入れられたものとするのがよい。
【００１３】
前記魚類遡上構造において、前記水路部材の上流側の部分の水路の底部に、上流側に設置された水路部材の前記接合部の下面を下方から支持する支持台を突設するのがよい。
【００１４】
本発明に係る魚類遡上構造のより好ましい態様は、排水路と、該排水路の水位よりも高い水位を有する貯水池に魚類を遡上させるための魚道を含み、該魚道を、水路部材の複数を順次接合して構成した貯水池への魚類遡上構造であって、前記水路部材は、上端開放で且つ上流端から下流端に向かう連続する水路を有したＵ字溝状に形成されると共に、その上流側の水路幅が拡大され、該水路部材の下流側をなす接合部を嵌め入れるための接合嵌合部とされている。又該水路部材の水路の下流側部位の対向側面と底面に、水路水を嵩上げする堰板を着脱可能に嵌め入れるための嵌入溝が設けられ、又、前記水路部材の上流側の部分の水路の底部に、上流側に設置された水路部材の前記接合部の下面を下方から支持する支持台が突設され、更に、前記水路部材の水路の上流側部位の対向側面と底面に、前記貯水池の水を嵩上げする堰板を着脱可能に嵌め入れるための嵌入溝が設けられている。又、上流側に設置された水路部材の前記接合部が、下流側に設置された水路部材の前記接合嵌合部に、該接合部を前記支持台に載せた状態で嵌め入れられると共に、最上流側に設置された前記水路部材の上流側開口が前記貯水池に連通され、且つ最下流側に設置された前記水路部材の下流側開口が前記排水路に連通されている。又、前記各嵌入溝に嵌め入れられた堰板の越流部を、下流側の水位に対して魚類が遡上可能な高さに設定したことを特徴とするものてある。
【００１５】
支持台を有する前記魚類遡上構造において、該支持台を、前記水路部材の上流側の部分の水路の底部に、水路の長さ方向の前後に所要間隔を置いて突設し、より上流側に位置する支持台を、その下流側に位置する支持台よりも低い高さに設定するのがよい。
【００１６】
支持台を有する前記魚類遡上構造において、前記支持台を前記水路部材と別体に形成し、該支持台を水路部材に後付けすることがある。該後付けされる支持台は、所要高さの支持台片を複数段に積重して構成されることがある。
【００１７】
前記水路部材をＵ字溝状に形成する場合、該水路部材の水路の下流側部位に前記堰板を着脱可能に嵌め入れる際、該堰板の外周面の下流端側が、前記水路の下流端の内周面に当接し、該堰板の下流側の面が前記水路部材の下流端面と面一となるように構成するのがよい。
【００１８】
本発明に係る魚類遡上構造の他の態様は、排水路と、該排水路の水位よりも高い水位を有する貯水池に魚類を遡上させるための魚道を含み、該魚道を、水路部材の複数を順次接合して構成した貯水池への魚類遡上構造であって、前記水路部材は、上端開放で且つ周方向の壁部で閉じられた有底の箱状に形成されると共に、該壁部の上流側部の所要部位と下流側部の所要部位に、上流側開口と下流側開口が設けられており、上流側に設置された水路部材の前記下流側開口が、下流側に設置された水路部材の前記上流側開口に連通するように水路部材相互が接合され、該両開口の連通部分に、水路水を嵩上げする堰板が着脱可能に装着されている。又、最上流側に設置された前記水路部材の上流側開口が前記貯水池に連通され、且つ最下流側に設置された前記水路部材の下流側開口が前記排水路に連通されており、前記堰板の越流部を、下流側の水位に対して魚類が遡上可能な高さに設定したことを特徴とするものである。
【００１９】
前記魚類遡上構造において、上端開放で且つ周方向の壁部で閉じられた有底の箱状を呈する前記水路部材の前記上流側開口に、上流側に設置された前記水路部材の下流側部分を挿入し、その挿入量を調節可能となすと共に、前記水路部材の前記下流側開口に、下流側に設置された前記水路部材の上流側部分を挿入し、その挿入量を調節可能となすのがよい。
【００２０】
上端開放で且つ周方向の壁部で閉じられた有底の箱状を呈する前記水路部材を具える前記魚類遡上構造において、該水路部材の水路に、前記上流側開口と前記下流側開口間を仕切るように、水路水を嵩上げする中間の堰板を着脱可能に装着し、該中間の堰板の越流部を、下流側の水位に対して魚類が遡上可能な高さに設定するのがよい。
【００２１】
上端開放で且つ周方向の壁部で閉じられた有底の箱状を呈する前記水路部材を具える前記魚類遡上構造において、該水路部材の水路に、前記上流側開口と前記下流側開口間を複数に仕切るように、水路水を嵩上げする中間の堰板の複数を着脱可能に装着し、該各中間の堰板の越流部を、下流側の水位に対して魚類が遡上可能な高さに設定するのがよい。
【００２２】
上端開放で且つ周方向の壁部で閉じられた有底の箱状を呈する前記水路部材を具える前記各魚類遡上構造において、該水路部材の前記上流側開口と下流側開口は、該両開口を通過する水の流れ方向が屈曲するように前記壁部に設けるのがよい。
【００２３】
前記各魚類遡上構造において、前記越流部の下流側を円弧面に形成するのがよい。又前記各魚類遡上構造において、前記越流部の下流側を１３〜６０度の角度で下方に傾斜する傾斜面に形成するのがよい。
【００２４】
本発明に係る魚類遡上構造のその他の態様は、排水路と、該排水路の水位よりも高い水位を有する水田に魚類を遡上させるための魚道を含む魚類遡上構造であって、該魚道は、水路部材の複数を、前記排水路と前記水田との間をなす畦部の延長方向に順次接合して魚道本体を形成すると共に、該魚道本体を構成するために最下流側に設置された水路部材に設けた下流側開口に、前記排水路に連通され且つ地下埋設されたパイプ状の水路部材の上流側の端部分が接合される一方、前記魚道本体を構成する最上流側に設置された水路部材の上流側開口に、水田に結果的に連通される水路部材の下流側の端部分が接合されており、又、前記魚道本体を構成する前記水路部材の夫々に、水路水を嵩上げする堰板が着脱可能に装着され、該堰板の越流部を、下流側の水位に対して魚類が遡上可能な高さに設定したことを特徴とするものである。
【００２５】
本発明に係る魚類遡上構造のその他の態様は、排水路と、該排水路の水位よりも高い水位を有する水田に魚類を遡上させるための魚道を含む魚類遡上構造であって、該魚道は、水路部材の複数を、前記排水路と前記水田との間をなす畦部の延長方向に順次接合して魚道本体を形成すると共に、該魚道本体を構成するために最下流側に設置された水路部材に設けた下流側開口に、前記排水路に連通され且つ地下埋設されたパイプ状の水路部材の上流側の端部分が接合される一方、前記魚道本体を構成する最上流側に設置された水路部材の上流側開口に、水田に結果的に連通され且つ地下埋設されたパイプ状の水路部材の下流側の端部分が接合されており、又、前記魚道本体を構成する前記水路部材の夫々に、水路水を嵩上げする堰板が着脱可能に装着され、該堰板の越流部を、下流側の水位に対して魚類が遡上可能な高さに設定したことを特徴とするものである。
【００２６】
これらの場合、前記パイプ状水路部材は、例えば円形パイプ状に形成し、又、略水平に配設するのがよい。
【００２７】
前記各魚類遡上構造において、前記堰板に、前記魚道を流れる水に漂う魚類誘導用の紐状物の上端側を取り付けるのがよい。
【００２８】
前記各魚類遡上構造において、前記堰板を、水路部材に着脱可能に装着される堰板本体と該堰板本体に付設されるスライド調整板とから構成し、該堰板本体は、上端開放の切欠部が設けられたものとし、前記スライド調整板は、前記切欠部の下側部分を覆うように前記堰板本体に当接状態に且つ上下方向でスライド可能に付設し、又該スライド調整板の上端を前記越流部とし、該越流部が、下流側の水位に対して魚類が遡上可能な高さとなるように、該スライド調整板の上下方向のスライド状態を調整できるものとし且つ該調整状態で該スライド調整板を前記堰板本体に固定可能とするのがよい。
【００２９】
前記各魚類遡上構造において、前記魚道を遡上する魚類が魚道の外に飛び出すのを防止すると共に、遡上中の魚類が鳥類に捕食されるのを防止するために、魚道の上側を防止ネットや透明被覆材で覆うのがよい。この場合、該防止ネット又は透明被覆材は、前記水路部材に立設状態に設けた支持枠に被せて、前記魚道の上側を覆うように構成するのがよい。
【００３０】
又前記各魚類遡上構造において、前記排水路に、該排水路を流れる水を嵩上げする隔壁を着脱可能に装着し、該隔壁を、前記排水路に着脱可能に装着される隔壁本体と該隔壁本体に付設される調整板とから構成し、該隔壁本体は、上端開放の切欠部が設けられると共に、前記調整板は、前記切欠部の下側部分を覆うように前記隔壁本体に当接状態に且つ上下方向でスライド可能に付設されるものとし、又、該調整板の上端を前記越流部とし、該越流部が、下流側の水位に対して魚類が遡上可能な高さとなるように、該調整板の上下方向のスライド状態を調整でき且つ該調整状態で該調整板を前記隔壁本体に固定可能とするのがよい。
【００３１】
又前記各魚類遡上構造において、前記排水路に、該排水路を流れる水を嵩上げする隔壁を装着し、該隔壁は、前記排水路における水の流れ方向に延長し且つ前記排水路の幅に略等しい幅を有する底板の上流側の端部に前板が立設されると共に、該底板の下流側の端部に後板が立設されてなる洗掘防止ブロックの該前板を以って形成し、該前板の一部分を、下流側の水位に対して魚類が遡上可能な高さに設定された越流部とするのがよい。
【００３２】
この場合、前記隔壁となる前板を、その一部をなす隔壁本体と、該隔壁本体に付設される調整板とから構成し、該隔壁本体は、上端開放の切欠部が設けられると共に、前記調整板は、前記切欠部の下側部分を覆うように前記隔壁本体に当接状態に且つ上下方向でスライド可能に付設されるものとし、又該調整板の上端を前記越流部とし、該越流部が、下流側の水位に対して魚類が遡上可能な高さとなるように、該調整板の上下方向のスライド状態を調整でき且つ該調整状態で該調整板を前記隔壁本体に固定可能とするのがよい。
【００３３】
又前記各魚類遡上構造において、前記排水路に、前記魚道の下流側に位置させて洗掘防止ブロックを配設し、該洗掘防止ブロックは、前記排水路における水の流れ方向に延長し且つ前記排水路の幅に略等しい幅を有する底板の上流側の端部に、該排水路を流れる水を嵩上げする隔壁として機能する前板が立設されると共に、該底板の下流側の端部に後板が立設されたものとし、該前板の一部分を、下流側の水位に対して魚類が遡上可能な高さに設定された越流部とし、且つ前記前板と後板との間をなす空所に濾過材を収容するのがよい。
【００３４】
隔壁が着脱可能に装着された前記魚類遡上構造において、前記越流部の下流側を円弧面に形成するのがよい。又該魚類遡上構造において、前記越流部の下流側を、１３〜６０度の角度で下方に傾斜する傾斜面に形成するのもよい。
前記隔壁を洗掘防止ブロックの前板を以って構成する場合、該前板を、排水路に装着される、上端開放の切欠部が設けられた隔壁本体と、該隔壁本体に付設される調整板とから構成する場合、該切欠部の下流側の縁部分を、１３〜６０度の角度で拡大するように、下流側に向けて傾斜する傾斜面に形成するのがよい。
【００３５】
前記堰板を堰板本体とスライド調整板とで構成する場合、前記切欠部の下流側の縁部分を円弧面に形成するのがよい。或いは、該切欠部の下流側の縁部分を、１３〜６０度の角度で拡大するように、下流側に向けて傾斜する傾斜面に形成するのがよい。
【００３６】
又前記隔壁を隔壁本体と調整板とで構成する場合、前記切欠部の下流側の縁部分を円弧面に形成するのがよい。或いは、該切欠部の下流側の縁部分を、１３〜６０度の角度で拡大するように、下流側に向けて傾斜する傾斜面に形成するのがよい。
【００３７】
排水路が隔壁を具える前記魚類遡上構造において、前記越流部の下側に位置させて水抜き孔を設けるのがよい。
【００３８】
前記各魚類遡上構造において、前記排水路に、その幅方向に適宜間隔で、産卵育成用の水草状紐体を配置するのがよい。この場合、該水草状紐体は、紐状体の一端に重りが設けられると共にその他端に浮きが設けられたものとし、該紐状体を、紐片の周面に５０〜１００ｍｍ程度の長さを有する毛片が多数設けられたものとし、前記重りを前記排水路の底部に設置する。
【００３９】
本発明に係る魚類遡上構造に用いる水路部材（以下水路部材という）は、排水路の水位よりも高い水位を有する貯水池に魚類を遡上させるための魚道を構成する水路部材であって、上端開放で且つ上流端から下流端に向かう連続する水路を有したＵ字溝状に形成されると共に、その上流側の水路幅が拡大され、その下流側をなす接合部の全部又は一部を嵌め入れるための接合嵌合部が形成されており、又前記水路の下流側部位に、水路水を嵩上げする堰板を着脱可能に嵌め入れるためのガイド部が設けられ、又、前記水路の上流側の底部に、上流側に設置された水路部材の前記接合部の下面を下方から支持する支持台が突設されていることを特徴とするものである。
【００４０】
本発明に係る水路部材のより好ましい態様は、排水路の水位よりも高い水位を有する貯水池に魚類を遡上させるための魚道を構成する水路部材であって、上端開放で且つ上流端から下流端に向かう連続する水路を有したＵ字溝状に形成されると共に、その上流側の水路幅が拡大され、その下流側をなす接合部の全部又は一部を嵌め入れるための接合嵌合部が形成されており、又前記水路の下流側部位に、その対向側面と底面に、水路水を嵩上げする堰板を着脱可能に嵌め入れるための嵌入溝が設けられ、又、前記水路の上流側の底部に、上流側に設置された水路部材の前記接合部の下面を下方から支持する支持台が突設されていることを特徴とするものである。
【００４１】
本発明に係る水路部材の他の態様は、排水路の水位よりも高い水位を有する貯水池に魚類を遡上させるための魚道を構成する水路部材であって、上端開放で且つ周方向の壁部で閉じられ、その内部が水路とされた有底の箱状に形成されると共に、該壁部の上流側の所要部位と下流側の所要部位に、上流側開口と下流側開口が設けられ、該上流側開口と下流側開口の内面に、水路水を嵩上げする堰板を着脱可能に嵌め入れるためのガイド部が設けられており、又、前記水路の内面に、前記上流側開口と下流側開口間を仕切るように、水路水を嵩上げする中間の堰板を着脱可能に嵌め入れるためのガイド部が設けられており、前記各堰板の越流部が、下流側の水位に対して魚類が遡上可能な高さに設定されていることを特徴とするものである。
【００４２】
この場合、前記上流側開口と前記下流側開口間を複数に仕切るように、その対向側面と底面に、水路水を嵩上げする中間の堰板の複数を着脱可能に嵌め入れるためのガイド部を設け、前記各堰板の越流部を、下流側の水位に対して魚類が遡上可能な高さに設定するのがよい。
【００４３】
本発明に係る水路部材のその他の態様は、排水路の水位よりも高い水位を有する貯水池に魚類を遡上させるための魚道を構成する水路部材であって、上端開放で且つ周方向の壁部で閉じられ、その内部が水路とされた有底の箱状に形成されると共に、該壁部の上流側の所要部位と下流側の所要部位に、上流側開口と下流側開口が設けられ、該上流側開口と下流側開口の、対向側面と底面に、水路水を嵩上げする堰板を着脱可能に嵌め入れるための嵌入溝が設けられており、又、前記水路の、対向側面と底面に、前記上流側開口と下流側開口間を仕切るように、水路水を嵩上げする中間の堰板を着脱可能に嵌め入れるための嵌入溝が設けられており、前記各堰板の越流部が、下流側の水位に対して魚類が遡上可能な高さに設定されていることを特徴とするものである。
【００４４】
この場合、前記上流側開口と前記下流側開口間を複数に仕切るように、その対向側面と底面に、水路水を嵩上げする中間の堰板の複数を着脱可能に嵌め入れるための嵌入溝を設け、前記各堰板の越流部を、下流側の水位に対して魚類が遡上可能な高さに設定するのがよい。
【００４５】
前記各水路部材において、前記上流側開口と前記下流側開口は、該両開口を通過する水の流れ方向が屈曲するように前記壁部に設けるのがよい。
【００４６】
又前記各水路部材において、前記堰板の越流部の下流側を円弧面に形成するのがよい。或いは、前記堰板の越流部の下流側を、１３〜６０度の角度で下方に傾斜する傾斜面に形成するのがよい。
【００４７】
又前記各水路部材において、前記堰板は、水路部材に着脱可能に装着される堰板本体と該堰板本体に付設されるスライド調整板とから構成し、該堰板本体は、上端開放の切欠部が設けられると共に、前記スライド調整板は、前記切欠部の下側部分を覆うように前記堰板本体に当接状態に且つ上下方向でスライド可能に付設されるものとし、該スライド調整板の上端を前記越流部とし、該越流部が、下流側の水位に対して魚類が遡上可能な高さとなるように、該スライド調整板の上下方向のスライド状態を調整でき且つ該調整状態で該スライド調整板を前記堰板本体に固定可能するのがよい。
【００４８】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて説明する。
〔第１の実施の形態〕
図１において本発明に係る魚類遡上構造１は、河川や湖等に連なる排水路２と、該排水路２の水位よりも高い水位を有する水田３ａとしての貯水池３に魚類を遡上させるための魚道６を含むものである。そして該魚道６は、前記水田３ａと前記排水路２との間をなす畦部５に、水路部材７の複数を直線状に段違いに順次接合して構成されており、排水路２の水位と水田３ａとしての貯水池３の水位間の落差が比較的小さい場合に好都合に対応できる。今、畦部５の幅（図３にＬ１で示す）が約１９００ｍｍで、且つ排水路２の水位と水田３ａの水位間の落差（図２にＬ２で示す）が約６５０ｍｍである場合を想定する。
【００４９】
前記水路部材７は、本実施の形態においては図４〜５に示すように、上端が開放され且つ上流端から下流端に向かう連続した水路９を有したＵ字溝状に形成されており、該水路９の上流端が上流側開口１０とされると共に、下流端が下流側開口１１とされている。又該水路部材７の上流側の部分は、水路幅が拡大されて、該水路部材７の下流側の部分をなす接合部１２を略密接に嵌め入れるための接合嵌合部１３とされている。該水路部材７の主要部の寸法を例示すれば、その全長が約６００ｍｍに設定されると共にその水路深さが約５００ｍｍに設定され、前記上流側の部分の水路幅が約６１０ｍｍに設定され、前記下流側の部分の水路幅が約５００ｍｍに設定されている。
【００５０】
又、前記水路部材７の前記上流側の部分の底部１５には、図５、図７に示すように、その全幅に亘って、上流側に設置された水路部材７の接合部１２の下面１６を下方から支持する支持台１７が突設されている。該支持台１７は、その上面１９が水平面に形成され、その高さは約１００ｍｍに設定されている。且つ、該支持台１７の上面１９と前記水路部材の下面１８との間の距離Ｌ３（図７）が、魚類が遡上可能な水位差に略等しい約１５０ｍｍに設定されている。
【００５１】
又図４〜７に示すように、前記水路部材７の水路９の下流側部位の対向側面２１，２１と底面２２に、水路水を嵩上げし、且つその越流部２４（図４、図９）で水を下流側に向けて越流させる堰板２３を嵌め入れるための嵌入溝２５が連続して設けられている。そして前記水路９の上流側部位には、前記支持台１７に近接する状態で、その上流側部位の対向側面２６，２６と底面２７に、前記貯水池３の水を嵩上げし、且つその越流部２４（図４、図９）で水を下流側に向けて越流させる堰板２３を嵌め入れるための嵌入溝２９が連続して設けられている。
【００５２】
又前記堰板２３には図４に示すように、その上端の中央部に、台形状や円弧状、矩形状、Ｖ字状等をなし且つ下端が前記越流部２４となる越流切欠部３０が設けられている。その形状や幅、深さは、前記魚道６を遡上する魚類の大きさや魚道６を流れる水量等を考慮して、該越流切欠部３０において必要な越流幅や越流水深が得られように設定される。例えば、越流幅が小さく且つ越流水深が浅い場合は、小型魚類は遡上させ得ても大型魚類は遡上させ得ないことになり、限られた魚類しか遡上させ得ないことになる。そこで本実施の形態においては、大型魚類も遡上させ得るように、前記越流切欠部３０を、上端幅Ｌ４が約１５０ｍｍで深さＬ５が約１００ｍｍの台形状に形成している。又前記越流切欠部３０の上端の下流側は、図８に拡大して示すように円弧面２８に形成し、遡上する魚類が引っ掛かりにくくしている。
【００５３】
然して、かかる構成を有する水路部材７を用いて前記魚類遡上構造１を構成するには、図１〜３に示すように、排水路２と水田３ａとの間をなす畦部５を、該排水路２の流れ方向と略直交する直線状の傾斜状態で掘削し、該掘削部３１で、４個の水路部材７，７，７，７を、直線状に段違いに順次接合するのであるが、その際、図７に示すように、下流側に設置された水路部材７ａの前記接合嵌合部１３に、上流側に設置された水路部材７ｂの前記接合部１２を嵌め入れ、該接合部１２を、前記下流側の水路部材７ａの支持台１７に載せ、各水路部材を略水平状態にして設置する。これにより、前記接合部１２の下面１６が前記支持台１７の上面１９に当接し、該接合部１２が接合嵌合部１３に嵌め入れられた状態となる。このようにして水路部材７，７相互を接合すると、前記魚道６が形成される。なお、上流側に設置された水路部材７ｂの接合部を、下流側に設置された水路部材７ａの接合嵌合部１３に嵌め入れる構成を採用するため、水路部材相互の接合部分３２（図７）に特別な漏水対策を施す必要がない。図９は魚道６の拡大斜視図であり、図１０は魚道の拡大断面図である。
【００５４】
前記接合の際、前記接合嵌合部１３に対する前記接合部１２の挿入長さを、前記畦部５の幅と水路部材７の使用個数を考慮して所要に設定し、魚道の全長を、畦部の幅に合わせて適切に調節する。図２、図７においては、前記接合部１２の端部３３が、前記支持台１７よりも下流側に突出し、例えば７ｃｍ程度の重なり代を有し、接合部の該突出した部分３５の下面３６と前記接合嵌合部１３の前記底面１５との間に空隙部３７が形成されている。
【００５５】
そして図２に示すように、最上流側に設置された水路部材７ｃの前記上流側開口１０が前記水田３ａに連通されると共に、最下流側に設置された水路部材７ｄの前記下流側開口１１が、前記排水路２に連通されている。又、各水路部材７に設けられた前記下流側の嵌入溝２５，２５，２５，２５と、最上流側に設置された水路部材７ｃの前記上流側の嵌入溝２９に、前記堰板２３が夫々、着脱可能に嵌め入れられている。
【００５６】
今説明の便宜上、図９、図１０において、前記４個の水路部材を上から順に、第１水路部材７Ａ、第２水路部材７Ｂ、第３水路部材７Ｃ、第４水路部材７Ｄといい、又、前記嵌入溝に嵌め入れられた５枚の堰板を上から順に、第１堰板２３Ａ、第２堰板２３Ｂ、第３堰板２３Ｃ、第４堰板２３Ｄ、第５堰板２３Ｅという。更に、前記堰板により嵩上げされた各水路部材内の貯水を上から順に、第１貯水３９Ａ、第２貯水３９Ｂ、第３貯水３９Ｃ、第４貯水３９Ｄといい、該貯水を溜める部分を第１溜め部４０Ａ、第２溜め部４０Ｂ、第３溜め部４０Ｃ、第４溜め部４０Ｄという。
【００５７】
又前記排水路２は、本実施の形態においては図１〜２、図１１〜１２に示すように、コ字状支持枠４１を所要間隔を置いて並設すると共に、排水路２の長さ方向で隣り合う立上がり片４２，４２間で側板４３を複数段に支持させて構成され、複数段に支持された該側板４３によって水路壁４４が形成されている。そして、隔壁５０（図１〜３、図１１〜１２）によって排水路２の水位が所要に嵩上げされている。
【００５８】
該隔壁５０は、排水路２の勾配や該排水路２を流れる水量に応じて、魚類が排水路２を遡上できるように、所要間隔で設置される。例えば図１〜２に示すように、その両端の縁部分５０ａ，５０ａが、例えば１〜２ｍ間隔で選択されたコ字状支持枠４１の内面に設けられた挿入溝４９（図１）に挿入せしめられ、該隔壁５０によって排水路２の水位を所要に嵩上げし、該隔壁に設けた上端開放の越流切欠部５２で水が下流側に越流するようになされ、該越流切欠部５２の下端としての越流部５４が、下流側の水位に対して魚類が遡上可能な高さ（例えば５０〜１５０ｍｍ）に設定されている。該越流切欠部５２は、排水路２の長さ方向で見て一直線上で並設されることの他、例えば図１１〜１２に示すように千鳥配置で設けられることもある。そして図１１においては、隔壁間のコーナ部分５３に魚類の遊泳場所が形成されている。
【００５９】
又、前記水路壁４４に欠切形成した開口３８に、前記最下流側の水路部材７Ｄの下流側開口１１が連通される。その際、図１０に示すように、該開口３８の底面３８ａと該下流側開口１１の底面４８が略面一状態になされている。
【００６０】
該排水路２は、部分的に、例えば図１２に示すように、一方の水路壁４４ａの一部分が畦側に拡大され、必要に応じ底部も掘り下げられて、魚介類の産卵や生息、避難に適した淀み部分、深み部分が設けられている。又、該拡大した部分４５の底部から上端に亘って、階段状やスロープ状の、適宜凹凸が設けられた傾斜部材４６が配設されており、昆虫類や両生類、爬虫類が該傾斜部材４６を上り下りして排水路２と、畦部表面４７や水田３ａとの間を行き来できるようになされている。なお前記拡大した部分は、双方の水路壁４４，４４に設けられてもよい。
【００６１】
次に、このように構成された魚類遡上構造１の作用を図９〜１０に基づいて説明する。即ち、前記構成の魚道６によるときは、図示しないポンプを介して水田に淡水が供給されると、その水位が、最上流側に設置された前記水路部材７Ａの第１堰板２３Ａによって嵩上げされ、該淡水は、該越流切欠部３０の下端としての前記越流部２４を越流して第１溜め部４０Ａ内に流入する。該第１溜め部４０Ａに流入した水路水は、前記第２堰板２３Ｂによって嵩上げされ、該第２堰板２３Ｂに設けた越流切欠部３０の下端としての越流部２４を越流した水路水が、前記第２溜め部４０Ｂ内に流入する。そして、該第２溜め部４０Ｂに流入された水路水は、前記第３堰板２３Ｃで嵩上げされ、該堰板の越流切欠部３０の下端としての越流部２４を越流して前記第３溜め部４０Ｃ内に流入する。該第３溜め部４０Ｃ内に流入した水路水は、前記第４堰板２３Ｄで嵩上げされ、該堰板の越流切欠部３０の下端としての越流部２４を越流して前記第４溜め部４０Ｄ内に流入する。そして該第４溜め部４０Ｄ内に流入した水路水は、前記第５堰板２３Ｅで嵩上げされ、該堰板の越流切欠部３０の下端としての越流部２４を越流して、前記排水路２内に流出する。
【００６２】
そして、排水路の水位５６と第４貯水３９Ｄの水位５７との間、第４貯水３９Ｄの水位５７と第３貯水３９Ｃの水位５９との間、第３貯水３９Ｃの水位５９と第２貯水３９Ｂの水位６０との間、第２貯水３９Ｂの水位６０と第１貯水３９Ａの水位６１との間に、夫々、魚類が遡上可能な５０〜１５０ｍｍ程度の水位差、例えば１００ｍｍ程度の水位差が設けられている。又、水田の水位６２と、該最上流側の水路部材７Ａにおける水位６１との間にも、７０ｍｍ程度の水位差が設けられている。そして、前記各越流部（越流水深は３０〜５０ｍｍ程度）２４において魚類が遡上できる。
【００６３】
従って本発明に係る魚類遡上構造１によるときは、鮒や鯉、鯰等の魚類を、河川や湖等から排水路２に進入させ、前記隔壁５０の越流切欠部５２を遡上させて前記魚道６が存する場所に至らせることができる。その後、該魚道６を遡上させ得る。具体的には、水面が階段状である前記第４貯水３９Ｄ、第３貯水３９Ｃ、第２貯水３９Ｂ、第１貯水３９Ａに順に遡上させて水田３ａに至らせ、水田で産卵させることができる。これにより水田３ａを、魚類の産卵、繁殖、育成の場として活用でき、自然と共生した稲作を展開できることとなる。
【００６４】
なお図９、図１３に示すように、前記堰板２３の例えば上端側６６に、魚類誘導用の紐状物６７の一端側６８を、ビス止め等の手段で固定したり、該一端側を、堰板２３等に設けた被掛着部に掛着させる等して取り付けるのがよい。取り付けた紐状物６７に魚類誘導の機能をもたせることができる限り、前記上端側６６は、前記越流切欠部３０の下側や、越流切欠部３０の周辺（側方部位等）として設定できる。
【００６５】
該紐状物６７は、魚道６の使用時期が終わった時点における最終処分を考慮し、有機性素材を用いて、例えば荒縄（５〜２０ｍｍ程度の直径のもの）や綿素材等を用いて形成するのが好ましいが、樹脂製とされてもよい。図１４は、該紐状物６７の具体的な一例を示しており、１〜３ｍｍ程度の太さを有する紐片６７ａの周面に５０〜１００ｍｍ程度の長さを有する毛片６７ｂを、放射状に多数に設けてなる。
【００６６】
該紐状物６７は、前記のように、各堰板２３に一端側６８が取り付けられ、その他端６９が、下流側に設置された水路部材に至る程度に、例えば３０〜５０ｃｍ程度と比較的短く長さ設定されることの他、図１０に破線で示すように、一端側６８が最上段の堰板２３Ａに取り付けられて、水田３ａ側から排水路２側にまで垂れ流されるように長さ設定されることもある。或いは、複数の水路部材に亘って垂れ流されるように長さ設定されることもある。
【００６７】
このように取り付けられた該紐状物６７は、自然界の河川における水草のように、水流に乗って、下流側に流れる状態で揺れ動くため、魚類の遡上を誘発できることとなる。
【００６８】
貯水池３が水田である場合、水田への魚類の産卵遡上時期が田植え時期に略合致しているため、この時期において前記堰板２３を装着すると、前記魚道６における一定量の排水を行わせつつ水田の水位を一定に保つことができる。逆に、中干しや稲刈り前等の水位を下げる必要のあるときは（この時期には魚道が必要でない）、図１５に示すように、前記全ての堰板を取り外し、水路６４を通して水田の水を排水路２に排水する。又、このように堰板を取り外すことによって、魚道６の掃除を容易に行うことができる。
【００６９】
又本実施の形態においては、上流側に設置された水路部材の前記接合部１２の下面１６を、下流側に設置された水路部材の前記支持台１７で下方から支持させる構成であり、且つ、各水路部材の下流側部位に堰板２３が装着されているため、図１０、図７に示すように、各水路部材の底部には泥溜め７２が形成される。従ってこの泥溜め７２において、魚道を流下する水路水に含有されている水田からの有機物を沈殿させることができ、排水路２への有機物の流出をそれだけ防止できる。更に、該泥溜め７２に堆積した土から水草等が生え、これが水路水の有機物を捕捉して水質浄化を図ることも期待できる。これ等により河川の汚染防止に寄与できる。又図７に示すように、前記水路部材７の底面部７３を、更には側面部７５を、自然石が露出した面に形成することにより、該自然石面に藻類を繁殖させることが可能になり、水路の底部を、小魚類や底生生物の餌場ともなし得え、その生息場を提供できることとなる。
【００７０】
又水路部材相互を接合するに際して、図２、図７に示すように、接合嵌合部１３内に突出した接合部１２の突出部分の下面３６と接合嵌合部１３の底面１５との間に前記空隙部３７が形成されているため、この場所に藻を生やすことができ、該空隙部３７を、陰を好む底生生物の生息場所となし得、又、稚魚の非難場所ともなし得る。
【００７１】
本実施の形態においては図１６に示すように、魚道６を遡上する魚類が魚道の外に飛び出すのを防止したり、遡上中の魚類が鳥類に捕食されるのを防止するするために、該魚道６の上側を覆うように、支持枠７６を介して、例えば樹脂製の防止ネット７７を取り付けることとしている。該防止ネット７７の網目は、例えば、一辺長が３０ｍｍ程度の菱形に形成される。
【００７２】
前記支持枠７６は、例えば、上下方向で接合された前記４個の水路部材７，７，７，７の夫々に取り付けられるものであり、図１７〜１８に示すように、上端高さが略等しい逆Ｕ字状をなす３本の枠片７９ａ，７９ｂ，７９ｃを間隔を置いて配置すると共に、該３本の枠片の上端水平部８０，８０，８０を、その下面の両側で、２本の直線状連結片８１，８１により一体に連結してなり、前記水路部材７の上流端側に位置する枠片７９ａは、残りの枠片７９ｂ，７９ｃよりも稍幅広に形成されている。そしてこれらの枠片は、例えば、直径１０ｍｍ程度の中空パイプや中実棒材（金属製や樹脂製）を所定長さに切断し、これを逆Ｕ字状を屈曲して形成されており、水路部材７の上端からの最大高さは、例えば３００〜４００ｍｍ程度に設定されている。
【００７３】
かかる構成の支持枠７６を前記水路部材７に取り付けるには、前記幅広の枠片７９ａの両下端部分８２，８２を、該水路部材７の前記接合嵌合部１３の上面の長さ方向の略中央に設けられた支持孔８３，８３に密接に挿入させると共に、中間の枠片７９ｂの両下端部分８２，８２を、前記水路部材７の上面の長さ方向の略中央（前記接合嵌合部１３と前記接合部１２との接続部分）に設けた支持孔８３，８３に密接に挿入させ、又、水路部材７の下流端側に位置する前記枠片７９ｃの両下端部分８２，８２を、前記水路部材７の下流端側の上面に設けた支持孔８３，８３に密接に挿入させて行う。このようにして各支持枠７６を各水路部材に立設状態に取り付けて後、前記防止ネット７７を、これらの支持枠７６，７６，７６，７６の上面部と両側部を覆うように且つ各水路部材７，７，７，７の側面部の上側部分を覆うように被せると、図１６に示すように、魚道６の上側が防止ネット７７で、上に突の半円形蒲鉾状に覆われた状態となる。これらの支持枠７６や防止ネット７７は、魚道の不用時期には取り外すことができる。なお、水路部材７に設ける前記支持孔８３は、便宜上、図１６〜１８においてのみ示している。
【００７４】
図１９〜２０は、Ｕ字溝状に形成された図２１に示す水路部材７を上下方向で順次接合して構成した魚道６を示すものであり、前記実施の形態におけるものとは、水田３ａとしての貯水池３の水を嵩上げする堰板（以下第１の堰板という）２３ａと、水路水を嵩上げする堰板（以下第２の堰板という）２３ｂの構成が異なる。又、該水路部材７の上流側部位に設けた嵌入溝２９の溝幅が若干広く形成されている。
【００７５】
貯水池３の水を嵩上げする前記第１の堰板２３ａは、図２０〜２２に示すように、前記嵌入溝２９に嵌め入れられる堰板本体８５と、該堰板本体８５に付設される落とし込み調整板８６とからなり、該堰板本体８５は、一側に寄せて、上端から前記水路部材７の底面近傍に至る縦長の矩形状切欠部８７（図２２）が設けられている。該矩形状切欠部８７の上端幅Ｌ６は約１５０ｍｍに設定されると共に、該矩形状切欠部の対向側面８９，９０と底面９１に、貯水池３の水を嵩上げする前記落とし込み調整板８６を嵌め入れるための装着溝９２が連続して設けられている。
【００７６】
そして該第１の堰板２３ａの上流側の面の下端部分は、前記支持台１７の下流側の傾斜面９３と当接し得る傾斜面９５として形成されており、該傾斜面９５の上端で上方に延長する面９６は、前記支持台１７の上面１９と直角に交わる。又、前記装着溝９２に嵌め入れられる前記落とし込み調整板８６は、本実施の形態においては、上下高さの異なる２枚を用いている。そして、上段の落とし込み調整板の上端の上側に、図２１に示すような矩形状の越流切欠部３０が形成され、該上端として越流部２４が、下流側の水位に対して魚類が遡上可能な高さ（例えば５０〜１５０ｍｍ）に設定され、該越流部２４における越流水深は、例えば３０〜５０ｍｍ程度に設定される。
【００７７】
又前記第２の堰板２３ｂは、本実施の形態においては図２０〜２１、図２３に示すように、水路部材７の下流側部位に設けられた前記嵌入溝２５に嵌め入れられる堰板本体９７と、該堰板本体９７に当接状態に付設されるスライド調整板９９とからなり、該堰板本体９７は、その外周面１００の上流端側に、前記嵌入溝２５に嵌め入れられる突条部１０１が設けられている。そして、該突条部１０１が前記嵌入溝２５に嵌め入れられた状態で、図２０に示すように、外周面１００の下流端側１０２が前記水路の下流端の内周面１０３に当接し、この状態で、図２０、図２４に示すように、第２の堰板２３ｂの下流側の面１０５が前記水路部材７の下流端面１０６と面一となるように構成されている。
【００７８】
又、前記第１の堰板２３ａにおけると同じ側に稍寄せて、上端幅Ｌ７が約１５０ｍｍで深さが２７０ｍｍ程度の矩形状切欠部１０７が設けられている。本実施の形態においては該矩形状切欠部１０７の周縁部分１０９が、下流側に向けて拡大するように面取りされている。該面取りは、遡上する魚類が該周縁部分に引っ掛かりにくくするために設けられるものであり、その傾斜角度は１３〜６０度程度に、好ましくは３５〜４５度程度に、更に好ましくは４５度程度に設定される。又、該矩形状切欠部１０７の下流側の面１１０の両側において、上下３段で、前記スライド調整板９９をボルト固定するためのインサート１１１，１１１，１１１、１１１，１１１，１１１が埋設されている。
【００７９】
又前記スライド調整板９９は、前記矩形状切欠部１０７を、その上流側又は下流側で覆うことによって（図１９〜２０においては下流側で覆っている）、該スライド調整板９９の上端の上側に、図２１に示すような矩形状の越流切欠部３０を形成するために用いられるものである。そして該上端としての越流部２４は、下流側の水位に対して魚類が遡上可能な高さ（例えば５０〜１５０ｍｍ）に設定されると共に、該越流部２４における越流水深は、３０〜５０ｍｍ程度に設定される。
【００８０】
又、該スライド調整板９９の上端１１２の下流側１０８は、図２３に示すように、例えば１３〜６０度程度に、好ましくは３５〜４５度程度に傾斜する傾斜面に、更に好ましくは４５度程度に傾斜する傾斜面に形成されており、遡上する魚類が引っ掛かりにくくしている。又該スライド調整板９９の両側には、前記インサート１１１に捩じ込まれるボルト１１２を挿通させるための上下に長い調整孔１１３，１１３が設けられている。
【００８１】
図２４は、下２段のインサート１１１，１１１、１１１，１１１を用いてスライド調整板９９を前記堰板本体９７に固定した状態を示すものであり、越流部２４が、下流側の水位に対して５０〜１５０ｍｍ程度に設定されると共に、該越流部２４における越流水深が３０〜５０ｍｍ程度に設定される。又図２５は、上２段のインサート１１１，１１１、１１１，１１１を用いてスライド調整板９９を堰板本体９７に固定した状態を示すものであり、越流部２４の高さと越流水深は前記と同様に設定されている。
【００８２】
なお図２６に示すように、前記スライド調整板９９を付設しないで、矩形状切欠部１０７の下端を越流部２４とすることもある。
【００８３】
なお前記第１、第２の堰板２３ａ、２３ｂは、重量のある例えばコンクリ─ト製とされ、又前記落とし込み調整板８６や前記スライド調整板９９は、例えば木製や樹脂製、金属製等とされる。
【００８４】
図１９は、前記構成を有する第１、第２の堰板２３ａ，２３ｂが装着された水路部材７を用いて構成された魚類遡上構造１を示すものであり、水路部材７，７相互を接合して魚道６を構成する要領は前記と同様である。即ち該魚道６は、排水路２と水田３ａとの間をなす畦部５を、該排水路２の流れ方向と略直交する直線状の傾斜状態で掘削し、該掘削部３１で、３個の水路部材７，７，７を、直線状に段違いに順次接合して構成されている。その際、前記実施の形態におけると同様に、下流側に設置された水路部材の前記接合嵌合部１３に、上流側に設置された水路部材の前記接合部１２を嵌め入れ、該接合部１２を、前記下流側の水路部材７の支持台１７に載せ、各水路部材を略水平にして設置する。これにより、前記接合部１２の下面１６が前記支持台１７の上面１９に当接し、該接合部１２が接合嵌合部１３に嵌め入れられた状態となる。水路部材７，７相互がこのように接合されて前記魚道６が形成されている。
【００８５】
そして図１９に示すように、最上流側に設置された水路部材７ｇの前記上流側開口１０が前記水田３ａに連通されると共に、最下流側に設置された水路部材７ｅの前記下流側開口１１（越流切欠部３０）が、前記排水路２に連通されている。又、各水路部材７に設けられた前記下流側の嵌入溝２５，２５，２５に前記第２の堰板２３ｂが着脱可能に嵌め入れられると共に、最上流側に設置された水路部材７ｇの前記上流側の嵌入溝２９に、前記第１の堰板２３ａが着脱可能に嵌め入れられている。
【００８６】
そして該第１の堰板２３ａ及び第２の堰板２３ｂ，２３ｂ，２３ｂの夫々に関し、前記矩形状切欠部８７，１０７においての越流部２４の高さと越流水深は、前記排水路２と前記水田３ａの水位間の落差Ｌ２と、前記畦部５の幅Ｌ１に応じて、前記落とし込み調整板８６及び前記スライド調整板９９の調整により、魚類の遡上を可能とするように所要に設定されるものである。この設定要領は前記した通りである。
【００８７】
本実施の形態においては、前記第１の堰板２３ａが、水田の土が魚道側に移動するのを防止する土留としても機能する。又、上下に位置する第２の堰板２３ｂ，２３ｂ間に形成された空所１１５及び、最上流側の水路部材７ｇにおける、第１、第２の堰板２３ａ，２３ｂ間の空所１１６に、図１９に散点を付して示すように、濾過材１１７を納めることができる。このように濾過材１１７を納めることにより、水田より越流した水に含まれている汚泥などの微粒子を濾過し、排水路２に流れ込む排水の水質浄化を図ることができる。なお濾過材１１７としては、その最終処分を考慮して、藁や籾殻等の有機性の材質からなるものを用いるのが好ましい。又前記と同様にして、図１９に示すように、各水路部材７に支持枠７６を装着して防止ネット７７を被せるのがよい。又、図９や図１０に示すと同様にして、第１、第２の堰板２３ａ，２３ｂに、水草状の紐状物６７を取り付けるのがよい。図１９は、水田３ａ側から排水路２側にまで垂れ流される長い紐状物６７を取り付けた場合を示している。
【００８８】
図２７は、Ｕ字溝状を呈する前記水路部材７を用いて構成した魚道６のその他の態様を示すものであり、畦の天端１１８や、畦の法面下端と排水路との間を成す畦道１１９に一輪車等を障害無く走行させたい場合に設けられて好都合である。
【００８９】
該魚道６は、図２７〜２８に示すように、４個の水路部材７，７，７，７を、前記畦道６と畦の法面部１２０の境界部分において畦の長さ方向に順次接合して魚道本体１２１を形成するものである。そのために、下流側に設置された水路部材７ｊの前記接合嵌合部１３に、上流側に設置された水路部材７ｋの前記接合部１２を嵌め入れ、該接合部１２を、前記下流側の水路部材７ｊの前記支持台１７に載せ、各水路部材を略水平状態に設置して構成されている。そして最上流側に設置された水路部材７ｍの上流端側の嵌入溝２９と、最下流側に設置された水路部材７ｊの下流端側の嵌入溝２５に、図２７、図３０、図３２に示すように、前記のような矩形状切欠部８７，１０７を有さない端面板１２２，１２３を嵌め入れてなる。又、最下流側の水路部材を除く各水路部材の下流側の嵌入溝２５，２５，２５に、前記第２の堰板２３ｂと同様構成の堰板２３，２３，２３を嵌め入れてなる。そして各堰板の越流切欠部３０は、例えば図２０に示すと同様にして、スライド調整板９９のスライド操作により、所要高さの越流部２４と越流水深が得られるように設定される。
【００９０】
又前記魚道６は、図２７〜３０に示すように、最下流側に位置する水路部材７ｊの、排水路２に面する側の側面部１２５の下端側に、例えば円形孔としての下流側開口１１が設けられており、該下流側開口１１に、前記排水路２に連通される、例えば内径１５０〜２００ｍｍ程度で、長さが畔道幅程度（６０〜２００ｃｍ程度）の塩化ビニール製パイプとして形成され且つ略水平に地下に埋設された水路部材７ｎの上流側の端部分１２７が挿入状態に接合されている。
【００９１】
加えて図２７、図３１〜３２に示すように、最上流側に位置する前記水路部材７ｍの、水田３ａに面する側面部１２９の下端側に、例えば円形孔としての上流側開口１０が設けられており、前記畦の水田側の部位に設けられた枡部材としての水路部材７ｐに連通する、例えば内径１５０〜２００ｍｍ程度の塩化ビニール製パイプとして形成され且つ略水平に地下に埋設された水路部材７ｑの下流側の端部分１３０が挿入状態に接合されている。
【００９２】
該枡部材としての水路部材７ｐは、前記魚道６の一構成要素であり、例えば図３１〜３２に示すように角筒状に構成され、パイプ状をなす前記最上流側に位置する水路部材７ｑの上流側の端部分１３１を挿入状態に接合するための下流側開口１１が、前記魚道本体１２１に面する側面部１３２の下端側に設けられている。そして該枡部材（水路部材）７ｐの水田側は、全体が開口されており、該開口部１３３の対向側面１３５，１３５と底面１３６に、前記水田３ａの水を嵩上げする堰板１３７を嵌め入れるための嵌入溝１３９が連続して設けられている。そして該堰板１３７は、図２２に示す堰板におけると同様にして、堰板本体１３８に設けた矩形状切欠部１３８ａの有する嵌入溝１３８ｂに落とし込み調整板１３８ｃの所要枚数を装着して構成されている。
【００９３】
該魚類遡上構造１によるときは、前記排水路２から前記下側のパイプ状の水路部材７ｎに進入した魚類は、各Ｕ字溝状の水路部材７を、前記堰板２３，２３，２３の越流切欠部３０を通して遡上でき、最上流側に存するＵ字溝状の水路部材７ｍに至る。その後、上に位置するパイプ状の水路部材７ｑ内に進入して前記枡部材（水路部材）７ｐに至り、該枡部材７ｐに設けられた前記堰板１３７の越流切欠部１４０を通して水田３ａに至ることができる。
【００９４】
なお、下に位置するパイプ状の水路部材７ｎの敷設高さは、該水路部材７ｎ内への魚類の進入を容易とするために、該水路部材内が常時満水状態となるように設定するのがよい。なお前記上下のパイプ状水路部材７ｎ，７ｑは、魚類の進入路として機能する他、例えば昼間において、魚類の避難場所としても機能し得る。
【００９５】
なお、前記と同様に設けられる支持枠７６や防止ネット７７、紐状物６７、濾過材１１７は、魚道の不要時期には取り外すことができる。
【００９６】
なお、前記Ｕ字溝状の水路部材を、畦を横断するように接合して魚道本体を形成し、この魚道本体の下流端側にだけ、又は上流端側にだけ、パイプ状の水路部材を接合して魚道を構成する場合もある。
【００９７】
図１９、図３３〜３７は、本発明に係る魚類遡上構造１を構成する排水路２の他の態様を示すものであり、前記と同様構成のコ字状支持枠４１を所要間隔を置いて並設すると共に、排水路２の長さ方向で隣り合う立上がり片４２，４２間で側板４３を複数段に支持させ、複数段に支持された該側板４３によって水路壁４４を形成することとしている。そして、選択されたコ字状支持枠４１の内面に設けられた挿入溝４９に、例えばコンクリート製の隔壁５０の両端の縁部分５０ａ，５０ａを挿入させることにより、排水路２の水位を所要に嵩上げさせている。又該隔壁５０の一方の端部側に、図３４、図３５に示すように、上端開放の矩形状切欠部１４０を設け、調整板１４１を、該矩形状切欠部１４０の例えば上流側の面において、上下方向にスライド可能に当接状態に設けることとし、該調整板１４１の上側に越流切欠部５２を形成している。そして該越流切欠部５２の周縁部分１４２が、下流側に向けて拡大するように面取りされている。なお該越流切欠部５２の開口幅は例えば１５０ｍｍと設定されると共に、深さは例えば１８０ｍｍに設定されている。
【００９８】
又図３６に示すように、前記隔壁５０の上流側の面に、前記矩形状切欠部１４０の両側に位置させて、上下３段に、前記調整板１４１を固定するためのインサート１４３，１４３，１４３、１４３，１４３，１４３を埋設している。
【００９９】
該調整板１４１は、木製、樹脂製又は金属製等として形成されており、横長矩形板状を呈し、その両側に、上下方向に長い調節孔１４４，１４４が設けられている。図１９、図３４、図３７は、上２段のインサート１４３，１４３、１４３，１４３にねじ込まれるボルト１４５を用いて、調整板１４１を隔壁５０に固定した状態を示し、又図０は、下２段のインサート１４３，１４３、１４３，１４３にねじ込まれるボルト１４５を用いて、前記調整板１４１を隔壁５０に固定した状態を示すものである。これらにおいて、排水路２における流水量に応じ、該調整板１４１の上端としての越流部５４が下流側の水位に対して魚類が遡上可能な高さ（例えば５０〜１５０ｍｍ程度の高さに設定され、該越流部５４における越流水深は、例えば３０〜５０ｍｍ程度に設定される。なお流水量によっては、前記調整板を外して、矩形状切欠部１４０の下端を越流部５４とすることもある。
【０１００】
又本実施の形態においては、前記隔壁５０の下端側において、前記矩形状切欠部１４０の下側（例えば、矩形状切欠部１４０の幅方向略中央）と、隔壁の他方の端部側に水抜き孔１４６，１４６を設けている。該水抜き孔１４６は、例えば、５０〜１００ｍｍの直径を有する円形孔（図１９、図３４においては直径５０ｍｍ程度の円形孔）として形成されており、排水路２の水路底１４７（図３７）から、３０〜５０ｍｍ程度浮き上がるように設けられる。そして該水抜き孔１４６は、図３８に示すように、嵌着やネジ込み等の手段によって、栓体１４８で閉塞可能となされている。
【０１０１】
前記矩形状切欠部１４０の下側に設けられた水抜き孔１４６ａ（図１９、図３４、図３７）にあっては、これを開放して水を放出させることにより、前記越流切欠部５２からの落水Ｆ１（図３７）に加えて該水抜き孔１４６ａからの水の放出Ｆ２（図３７）が加わるため、それらの流れを感じて魚類が越流切欠部５２に向けて誘導されやすくなる効果が期待できる。
【０１０２】
又、前記他端側の水抜き孔１４６ｂ（図１９）をも開放させる場合は、該水抜き孔１４６ｂからの水の排出による流れ作用によって、該水抜き孔１４６ｂの周辺において、流水の上側に比較的遅い流れ部分を形成できると共に下側に比較的速い流れ部分を形成でき、これらによって、澱みのある場所と流れのある場所を混在させることができ、魚類の生態環境に適した生育場所を形成できることになる。
【０１０３】
なお前記水抜き孔１４６は、前記スライド式の調整板１４１が最下降位置においても該調整板１４１で覆われることのないように設けられる。
【０１０４】
なお、排水路２における水嵩が予想外の降雨量によって異常に増した場合に、前記水抜き孔１４６を開放して放流させることにより、隔壁５０を取り外さなくても、排水路２の水位を調整できる場合がある。このような目的のために、設ける水抜き孔の数を増やしたり、その径をより大きくすることもある。
【０１０５】
又、魚類や貝類が、前記水抜き孔１４６ａ，１４６ｂを通して隔壁５０の反対側に移動できる効果もある。
【０１０６】
なお本実施の形態においては、図３７に示すように、前記排水路２に適宜間隔で、産卵育成用の水草状紐体１４９を配置することとしている。該水草状紐体１４９は、図３７に示すように、樹脂製の紐状体１５０の一端に、石やコンクリート隗等の重り１５１を設けると共に、その他端に、発泡スチロールや浮袋等の浮き１５２を設けてなる。該紐状物１４９は、直径が１〜３ｍｍ程度の紐片１５３の周面に、長さが５０〜１００ｍｍ程度の長さを有する毛片１５４を、放射状に多数設けた構成を有しており、その長さは、前記排水路２の水深に合わせて、例えば１００〜１３０ｃｍ程度に設定される。かかる構成の水草状紐体１４９は、前記重り１５１を排水路２の水路底１４７に載せて、水路幅方向に適宜間隔で配設され、排水路２の底部分に水草が生えているような状態を形成するもので、魚類の産卵や育成の補助具として機能する。
【０１０７】
例えば図３７に示すように、隔壁５０に設けた越流切欠部５２を通して下流側で落水した場合、該落水によって水路底が洗掘される場合が生ずる。そこで図３９〜４２においては、かかる洗掘を防止し得る機能を具えた洗掘防止ブロック１５６を用いて前記隔壁５０を構成している。
【０１０８】
該洗掘防止ブロック１５６は、例えばプレキャストコンクリート製であり、図３９、図４２に示すように、前記排水路２の幅に略等しい幅を有し、且つ該排水路２の水の流れ方向に延長して設けられた底板１５７の上流側の端部に、隔壁５０として機能する前板１５９を立設すると共に該底板１５７の下流側の端部に後板１６０を立設した、両側端が開放した構成を有しており、該後板１６０の高さは、その上端１６１が水路底１４７と略面一となるように設定されている。なお、該洗掘防止ブロック１５６の前記底板１５７の前後方向の長さは例えば８２０ｍｍに設定されると共に、前板１５９の高さは例えば４４０ｍｍに、又後板１６０の高さは例えば１９０ｍｍに設定されており、前板１５９と後板１６０との間に、７００ｍｍ程度の幅を有する空所１６３が形成されている。
【０１０９】
かかる構成の洗掘防止ブロック１５６は、隔壁５０となる前記前板１５９が、排水路２を構成するコ字状支持枠４１の下流側の面１６４に当接する状態で、下側部分１６５が排水路２の底部に埋設されて設置され、前記洗掘防止ブロック１５６の開放した両端１６６，１６６は、図４２に示すように例えば側板１６７，１６７で塞がれ、或いは土嚢で塞がれる。そして、前記隔壁５０となる前板１５９に、上端開放の矩形状切欠部（約１５０ｍｍの開口幅を有する）１６９が設けられると共に、該矩形状切欠部１６９の両側において、上下３段にインサート１７０が埋設されている。そして、前記と同様に構成されたスライド式の調整板１４１の両側に上下方向で設けられた調整孔１７１，１７１を挿通するボルト１７２を所要のインサート１７０に捩じ込むことによって、該調整板１４１を前板１５９に固定可能となされている。これにより、該調整板１４１の上側に越流切欠部５２を形成でき、前記と同様にして、魚類の遡上を可能とする越流部５４を形成している。
【０１１０】
このように構成した場合は、前記隔壁（前板１５９）５０の下流側に底板１５７が存するため、前記越流切欠部５２を通して落水しても、水路底が該底板１５７で保護されていることから、水路底の洗掘を防止できる。又、越流切欠部５２の下流側に、水路底がより掘り下げられた深み部１７２（図４０）が形成されるため、前記越流切欠部５２を魚類が遡上する際、その深みによって、勢いをつけて容易に遡上できる利点がある。
【０１１１】
加えて、該洗掘防止ブロック１５６の、前板１５９と後板１６０との間の前記空所１６３が泥溜めとなるため、前記魚道６を通して水田から排水路２に流入する等した、肥料成分等の有機物を含んだ微粒土を堆積させ、水質浄化を図り得ることともなる。
【０１１２】
なお、該洗掘防止ブロック１５６の前記空所１６３に、藁や籾殻等の濾過材１７３を収容することにより、排水路２における水質浄化効果を向上させることができる。又本実施の形態においても、前記と同様の機能を有する水抜き孔１４６を、矩形状切欠部１６９の例えば両側に設けている。又前記と同様にして、前記調整板１４１や前記矩形状切欠部１６９の周辺に、魚類誘導用の紐状物６７を取り付けることができる。
【０１１３】
〔第２の実施の形態〕
図４３〜４５は、本発明に係る魚類遡上構造１の他の態様を示すもので、排水路２の水位と、水田３ａとしての貯水池３の水位との間をなす畦部５に、該排水路２から貯水池３に向けて魚類を遡上させるための魚道６を形成するものであり、排水路２の水位と水田３ａとしての貯水池３の水位間の落差が大きい場合に好都合に対応できる。今、畦部５の幅（図４５にＬ１で示す）が約１９００ｍｍで且つ排水路２の水位と水田３ａとしての貯水池３の水位間の落差（図４４にＬ２で示す）が約９００ｍｍである場合を想定する。
【０１１４】
該水路部材７は、図４６〜４７に示すように、上端開放で且つ周方向の壁部１８０で閉じられ、その内部が水路９とされた有底の直方体箱状に構成され、平面視で、長辺長さが約１１００ｍｍ、短辺長さが約６００ｍｍ、上下高さが約８６０ｍｍに設定されている。そして図４７に示すように、一方の長辺側壁部１８０ａの一方の短辺寄り部位に、上端から下端側に至る上下に長い、幅が約３００ｍｍで深さが約６００ｍｍの矩形状の下流側開口１１が設けられると共に、他方の長辺側壁部１８０ｂの他方の短辺寄り部位には、図４６に示すように、前記下流側開口１１と同幅で且つその半分程度の深さを有する正方形状の上流側開口１０が設けられている。
【０１１５】
そして該下流側開口１１の対向する内側面１８１，１８１と底面１８２に、水路水を嵩上げする堰板２３を嵌め込むための嵌入溝１８３が連続して設けられると共に、前記上流側開口１０の対向する内側面１８５，１８５と底面１８６に、水路水を嵩上げする堰板２３を嵌め入れるための嵌入溝１８７が連続して設けられている。又、両長辺側壁部１８０ａ，１８０ｂの中央部には、対向する内側面１８９，１８９と水路部材の底面１９０に、水路水を嵩上げする堰板２３を嵌め入れるための中間の嵌入溝１９１が連続して設けられている。そして、前記各堰板２３には、その上端中央部に、前記と同様の越流切欠部３０が設けられている。
【０１１６】
そして図４５に示すように、上流側に設置された水路部材７の前記下流側開口１１が、下流側に設置された水路部材７の前記上流側開口１０に連通されるように水路部材７，７相互が接合され、該上流側開口１０と下流側開口１１の連通部分において、いずれか一方の開口に設けた嵌入溝に、堰板２３が嵌め入れられて、該堰板の上流側における水路水の嵩上げが行われている。
【０１１７】
然して、前記構成の水路部材７を用いて魚類遡上構造１を構成するには、図４３〜４５に示すように、排水路２と水田３ａとの間をなす畦部５を掘削し、該掘削部で、上から順に３個の水路部材７Ｅ，７Ｆ，７Ｇを略水平状態にして、段違いに順次接合するのであるが、その際、図４３に示すように最下流側に位置する水路部材７Ｇの前記下流側開口１１を、前記と同様構成の排水路２の水路壁４３に設けた開口３８に連通させる。そして図４８に示すように、該開口３８の底面３８ａと前記下流側開口１１の底面４８を略面一状態にする。
【０１１８】
又図４９に示すように、中段に位置する水路部材７Ｆの下流側開口１１の底面４８を、最下流側に設置された前記水路部材７Ｇの前記上流側開口１０の底面１９２と略面一状態にする。
【０１１９】
又図５０に示すように、最上流側に位置する水路部材７Ｅの前記下流側開口１１の底面４８を、中段に位置する水路部材７Ｆの上流側開口１０の底面１９２と略面一状態にする。そして最上流側に設置された水路部材７Ｅの上流側開口１０を前記水田３ａに連通させる。なお、上下隣り合う水路部材７，７相互を例えば図４５に示すアングル部材１９３を用いて連結する。図５１は、魚道６の拡大斜視図である。
【０１２０】
そして図４５に示すように、前記最下流側の水路部材７Ｇにおける下流側開口１１に設けた嵌入溝１８３と前記中間の嵌入溝１９１、前記中段の水路部材７Ｆにおける下流側開口１１に設けた嵌入溝１８３と該水路部材の中間の嵌入溝１９１、又、前記最上流側に設置された水路部材７Ｅにおける下流側開口１１の嵌入溝１８３と該水路部材における中間の嵌入溝１９１、該水路部材における上流側開口１０の嵌入溝１８７の夫々に堰板２３を嵌め入れる。該堰板２３には、前記と同様構成の越流切欠部３０が設けられている。
【０１２１】
今説明の便宜上、図４５及び図４５のＡ−Ａ断面図を示す図５２、図５１において、前記のように嵌め入れられた７枚の堰板を上から順に、第１堰板２３Ｅ、第２堰板２３Ｆ、第３堰板２３Ｇ、第４堰板２３Ｈ、第５堰板２３Ｉ、第６堰板２３Ｊ、第７堰板２３Ｋという。又、前記第２〜７の堰板により嵩上げされた貯水を上から順に、第１貯水３９Ｅ、第２貯水３９Ｆ、第３貯水３９Ｇ、第４貯水３９Ｈ、第５貯水３９Ｉ、第６貯水３９Ｊといい、該貯水を溜める部分を、第１溜め部４０Ｅ、第２溜め部４０Ｆ、第３溜め部４０Ｇ、第４溜め部４０Ｈ、第５溜め部４０Ｉ、第６溜め部４０Ｊという。
【０１２２】
然して、かかる魚類遡上構造１によるときは、水田３ａに供給された水の水位が前記第１堰板２３Ｅで嵩上げされ、その越流切欠部３０から前記第１溜め部４０Ｅに流入する。又、第１溜め部４０Ｅに流入した水は前記第２堰板２３Ｆで嵩上げされてその越流切欠部３０から第２溜め部４０Ｆに流入する。同様にして、該第２溜め部４０Ｆに流入した水は前記第３堰板２３Ｇで嵩上げされてその越流切欠部３０から第３溜め部４０Ｇに流入し、該第３溜め部４０Ｇに流入した水は前記第４堰板２３Ｈで嵩上げされてその越流切欠部３０から第４溜め部４０Ｈに流入し、該第４溜め部４０Ｈに流入した水は前記第５堰板２３Ｉで嵩上げされてその越流切欠部３０から第５溜め部４０Ｉに流入し、該第５溜め部４０Ｉに流入した水は前記第６堰板２３Ｊで嵩上げされてその越流切欠部３０から第６溜め部４０Ｊに流入し、該第６溜め部４０Ｊに流入した水は前記第７堰板２３Ｋで嵩上げされてその越流切欠部３０から前記排水路２内に流出する。そして図５２においては、隣り合う貯水の水位間に、魚類が遡上可能な５０〜１５０ｍｍ程度の水位差、例えば１００ｍｍ程度の水位差を設けられ、又、水田３ａの水位と第１貯水３９Ｅの水位との間にも、同程度の水位差が設けられている。そして、前記した各越流切欠部３０の下端としての越流部（越流水深は、例えば３０〜５０ｍｍ程度）２４において、魚類が遡上できる。
【０１２３】
従って本発明に係る魚類遡上構造１によるときは、鮒や鯉、鯰等の魚類を、河川や湖等から排水路２に進入させ、前記隔壁５０の越流切欠部５２を遡上させて前記魚道６が存する場所に至らせることができる。その後、該魚道６を遡上させ得る。具体的には、水面が階段状である前記第６貯水３９Ｊ、第５貯水３９Ｉ、第４貯水３９Ｈ、第３貯水３９Ｇ、第２貯水３９Ｆ、第１貯水３９Ｅを、前記越流部２４で順に遡上させて、水田３ａに至らせ、水田で産卵させることができる。そして、各堰板２３を取り外すことによって、水田の水を排水路２に円滑に排水できる。
【０１２４】
なお、前記堰板２３の越流切欠部３０の下流側を円弧面に形成し、又、堰板２３に魚類誘導用の紐状物６７を取り付ける構成は、前記実施の形態におけると同様である。そして、水路部材７の底部側に泥溜めを形成でき、これを前記実施の形態におけると同様に機能させ得る。
【０１２５】
前記堰板２３は、排水路２の水位と水田３ａの水位との落差や、畦部の幅に応じた適切な越流部２４を形成できるようにするために、前記実施の形態におけると同様に構成するのがより好ましい。即ち、最上流側に位置する堰板２３として、所要高さの落とし込み調整板８６の所要枚数を装着溝９２に順次に積み上げる構成の図２２に示す第１の堰板２３ａを採用し、それ以外の堰板２３として、図２３に示すような、スライド調整板９９を有する前記第２の堰板２３ｂを採用するのがよい。
【０１２６】
〔第３の実施の形態〕
図５３〜５４は、本発明に係る魚類遡上構造１の水田３ａと排水路２間をなす畦部５の幅（図５４にＬ１で示す）が比較的小さいのに対して、排水路２の水位と水田３ａとしての貯水池３の水位間の落差（図５８にＬ２で示す）が比較的大きい場合に好都合に対応できる。該屈曲した魚道６は、円筒状をなす第１の水路部材７ＨとＵ字溝状をなす第２の水路部材７Ｉの２種類の水路部材を用い、これらの水路部材を所要に接合して形成するものである。今、畦部５の幅が約１７００ｍｍで且つ排水路２の水位と水田３ａの水位間の落差が約５８０ｍｍである場合を想定する。
【０１２７】
前記第１の水路部材７Ｈは、図５５〜５６に示すように、上端開放で且つ周方向の壁部１８０で閉じられた有底の円筒箱状に構成され、平面視で、内径が約９００ｍｍで上下高さが約７２０ｍｍに形成されると共に、その壁部１８０の上流側部の所要部位と下流側部の所要部位に、上流側開口１０と下流側開口１１が設けられている。本実施の形態においては、該上流側開口１０と下流側開口１１は、上端が下端よりも稍拡大した上端開放の矩形状開口として形成され、該両開口１０，１１を通過する水の流れが略直角に屈曲するように設けられている。そして、該上流側開口１０及び下流側開口１１の上端幅は約６１０ｍｍに形成されると共に、該上流側開口１０の深さは約３６０ｍｍに形成され、下流側開口１１の深さはそれよりも稍深く、約５６０ｍｍに形成されている。
【０１２８】
又前記第２の水路部材７Ｉは、図５５、図５７に示すように、Ｕ字溝状に構成されており、その水路の上流端部が上流側開口１０とされると共に下流端部が下流側開口１１とされている。又、水路内面の上流側部位と下流側部位に、その対向側面１９７，１９７と底面１９９に、水路水を嵩上げする堰板２３を嵌め入れるための嵌入溝２０１，２０２が連続して設けられている。本実施の形態においては、その全長が約６００ｍｍに設定されると共にその水路深さが約５００ｍｍに設定されている。
【０１２９】
然して、該第１、第２の水路部材７Ｈ，７Ｉを用いて魚類遡上構造１を構成するには、図５４〜５５に示すように、前記畦部５を所要に掘削し、前記排水路２の延長方向に沿わせて上流側と下流側に、前記第１の水路部材７Ｈを配設する。そして、前記第１の水路部材７Ｈの下流側開口１１に、下流側に略水平状態にして設置された前記第２の水路部材７Ｉの上流側部分２０３を、弾性止水材を介在させて嵌合状態に挿入すると共に、該第２の水路部材７Ｉの下流側開口１１を、前記排水路２の水路壁４４に設けた開口３８に連通させる。
【０１３０】
又、隣り合う第１の水路部材７Ｈ，７Ｈ間を、Ｕ字溝としての前記第２の水路部材７Ｉで繋ぐのであるが、その際、該第２の水路部材７Ｉの下流側部分２０６を、下流側に設置された前記第１の水路部材７Ｈの上流側開口１０に、弾性止水材を介在させて嵌合状態に挿入すると共に、該第２の水路部材７Ｉの上流側部分２０３を、上流側に設置された前記第１の水路部材７Ｈの下流側開口１１に、弾性止水材を介在させて嵌合状態に挿入する。又、上流側に設置された第１の水路部材７Ｈの上流側開口１０に、前記第２の水路部材７Ｉの下流側部分２０６を、同様に嵌合状態に挿入する。そして該第２の水路部材７Ｉの上流側開口１０を水田３ａに連通させる。
【０１３１】
又、前記第２の水路部材７Ｉの夫々において、その上流側の嵌入溝２０１と下流側の嵌入溝２０２に堰板２３，２３を着脱可能に嵌め入れる。これらの堰板２３には越流切欠部３０が設けられている。
【０１３２】
今説明の便宜上、図５４及び図５４のＢ−Ｂ断面図を示す図５８、図５５において、前記のように嵌め入れられた６枚の堰板を上から順に、第１堰板２３Ｌ、第２堰板２３Ｍ、第３堰板２３Ｎ、第４堰板２３Ｐ、第５堰板２３Ｑ、第６堰板２３Ｒという。又、前記第２〜５の堰板により嵩上げされた貯水部を上から順に、第１貯水３９Ｌ、第２貯水３９Ｍ、第３貯水３９Ｎ、第４貯水３９Ｐ、第５貯水３９Ｑといい、該貯水を溜める部分を第１溜め部４０Ｋ、第２溜め部４０Ｌ、第３溜め部４０Ｍ、第４溜め部４０Ｎ、第５溜め部４０Ｐという。
【０１３３】
然して、かかる魚類遡上構造１によるときは、水田３ａに供給された水の水位が前記第１堰板２３Ｌで嵩上げされ、その越流切欠部３０から前記第１溜め部４０Ｋに流入する。又、該第１溜め部４０Ｋに流入した水は前記第２堰板２３Ｍで嵩上げされてその越流切欠部３０から第２溜め部４０Ｌに流入する。同様にして、該第２溜め部４０Ｌに流入した水は前記第３堰板２３Ｎで嵩上げされてその越流切欠部３０から第３溜め部４０Ｍに流入し、該第３溜め部４０Ｍに流入した水は前記第４堰板２３Ｐで嵩上げされてその越流切欠部３０から第４溜め部４０Ｎに流入し、第４溜め部４０Ｎに流入した水は前記第５堰板２３Ｑで嵩上げされてその越流切欠部３０から第５溜め部４０Ｐに流入し、最後に、第５溜め部４０Ｐから前記排水路２内に流出する。そして図５８においては、隣り合う水位間に、魚類が遡上可能な５０〜１５０ｍｍ程度の水位差、例えば１００ｍｍ程度の水位差を設けられている。そして、前記した各越流切欠部３０の下端としての越流部（越流水深は、例えば３０〜５０ｍｍ程度）において、魚類が遡上できる。
【０１３４】
従って本発明に係る魚類遡上構造１によるときは、鮒や鯉、鯰等の魚類を、河川や湖等から排水路２に進入させ、前記隔壁５０の越流切欠部５２を遡上させて前記魚道６が存する場所に至らせることができる。その後、該魚道６を遡上させ得る。具体的には、水面が階段状である前記第５貯水３９Ｑ、第４貯水３９Ｐ、第３貯水３９Ｎ、第２貯水３９Ｍ、第１貯水３９Ｌを前記越流部２４で順に遡上させて、水田３ａに至らせ、水田で産卵させることができる。そして、各堰板２３を取り外すことによって、水田の水を円滑に排水できる。
【０１３５】
なお、前記堰板２３の越流切欠部３０の下流側を円弧面に形成し、又、堰板２３に魚類誘導用の紐状物６７を取り付ける構成は、前記実施の形態におけると同様である。そして、水路部材７の底部側に泥溜めを形成でき、これを、前記実施の形態におけると同様に機能させ得る。
【０１３６】
前記堰板２３は、排水路２の水位と水田３ａの水位との落差や、畦部の幅に応じた適切な越流部２４を形成できるようにするために、前記実施の形態におけると同様に構成するのがより好ましい。即ち、最上流側に位置する堰板２３として、所要高さの落とし込み調整板８６の所要枚数を装着溝９２に順次積み上げる構成の図２２に示す第１の堰板２３ａを採用し、それ以外の堰板２３として、図２３に示すような、スライド調整板９９を有する前記第２の堰板２３ｂを採用するのがよい。
【０１３７】
〔その他の実施の形態〕　　　　　　　　　　　　　　　　　　　　　　　　　本発明は、前記実施の形態で示したものに限定されるものでは決してなく、「特許請求の範囲」の記載内で種々の設計変更が可能であることはいうまでもない。その一例を挙げれば次のようである。
【０１３８】
（１）　本発明に係る魚類遡上構造は、前記した水田の他、休耕田を利用した養魚池、溜め池、親水公園の池等を含む、魚類の遡上を必要とする貯水池に対して応用できる。
【０１３９】
（２）　水路部材が前記したＵ字溝状に構成される場合、その水路内面の下流側部位に装着される堰板は、例えば図２に示すように下流端に装着されるとは限らず、それよりも稍上流側に装着される場合もある。
【０１４０】
（３）　図５９は、Ｕ字溝状をなす水路部材７の他の態様を示すものであり、くの字状に屈曲した構成を有する。そして前記と同様にして接合部１２と接合嵌合部１３が設けられており、該接合部１２が、下流側に設置された他の水路部材７Ａ１の接合嵌合部１３に嵌め入れられると共に、上流側に設置された他の水路部材７Ａ２の接合部１２が前記くの字状水路部材７の接合嵌合部１３に嵌め入れられる。かかる構成のくの字状水路部材７は、例えば、畦部幅が比較的小さいのに対して排水路と水田間の水位差が比較的大きい場合に好都合に用い得る。
【０１４１】
（４）　水路部材７が、上端開放で且つ周方向の壁部１８０で閉じられた有底の箱状に構成される場合、その箱状の形態は、図５１に示す直方体箱状や、図５５に示す円筒箱状に構成されるものには限られない。
【０１４２】
（５）　水路部材７がＵ字溝状に構成される場合、その上流側開口１０と下流側開口１１間を仕切るように、水路水を嵩上げする中間の堰板２３の一枚乃至複数枚が着脱可能に装着されることもある。
【０１４３】
（６）　水路部材７が、上端開放で且つ周方向の壁部で閉じられた有底の箱状を呈する場合、隣り合う貯水部の水位差を適正に設定するために、その水路に、上流側開口と下流側開口間を複数に仕切るように、水路水を嵩上げする中間の堰板の１枚乃至複数枚が着脱可能に装着されることもある。
例えば、水路部材７が図５１に示すような直方体箱状に構成される場合、上流側開口１０と下流側開口１１間を複数に仕切るように、水路水を嵩上げする中間の堰板２３の複数枚が着脱可能に装着されることもある。又、水路部材が図５５に示すような有底の円筒箱状に構成される場合、上流側開口１０と下流側開口１１間を複数に仕切るように、水路水を嵩上げする中間の堰板の１枚乃至複数枚が着脱可能に装着されることもある
【０１４４】
（７）　水路部材７が有底の箱状に構成される場合、貯水池と排水路の水位差が比較的小さい場合は、中間の堰板２３（例えば、図５１に示す直方体箱状を呈する水路部材における中間堰板）を省略することもある。
【０１４５】
（８）　上端開放で且つ周方向の壁部で閉じられた有底の箱状を呈する水路部材の上流側開口１０と下流側開口１１は、例えば図５５に示すように、該両開口１０，１１を通過する水の流れ方向が屈曲するように、前記壁部に設けるのが好ましいが、その屈曲状態は、畦部等の幅や、排水路と貯水池の水位差等を考慮して所要に設定され得る。
【０１４６】
（９）　水路部材７が有底の箱状に構成される場合、上流側開口１０と下流側開口１１の連通部分に、水路水を嵩上げする堰板を着脱可能に装着するとは、該上流側開口１０の内面や下流側開口１１の内面において装着される場合の他、上流側開口１０の近傍部位や下流側開口１１の近傍部位に装着される場合を含むものである。
【０１４７】
（１０）堰板を嵌め入れるためのガイド部は、前記のように溝状に形成されることの他、該堰板を対向側で挟むように、間隔を置いた突部間で形成されてもよい。
【０１４８】
（１１）最上流側に設置される水路部材における上流側部位に装着される堰板（例えば、図１に示す堰板２３１は省略されることもある
【０１４９】
（１２）貯水池３と排水路２間に存する畦部等の幅が比較的小さいのに対して排水路と貯水池間の水位が比較的大きい場合は、魚道６が、図３に一点鎖線で示すように斜めに設けられることもある。
【０１５０】
（１３）水路部材７がＵ字溝状に構成される場合、その上流側の水路底部１５に突設される支持台１７は、上流側に設置された水路部材の接合部の下面を下方から安定的に支持できるものであれば、該水路底部１５の全幅に亘って設けられることは必ずしも必要ではない
又該支持台１７は、図６０〜６１に示すように、水路部材７と別体に形成されて水路の底部１５に接着等の手段で固定されることもある。更に該支持台１７は、図６２に示すように、例えば単位高さの支持台片２０７の複数を積み上げて所定の高さに構成されることもある。又支持台１７が水路の底部１５に一体に形成される場合、該支持台１７の高さが低過ぎる場合は、図６３に示すように、別体の補助支持台２０９を該支持台１７に載せることにより、結果的に所要高さの支持台を構成することもある。
又図６４は、水路の底部１５に、水路長さ方向で見て前後に所要間隔を置いて複数の支持台１７を突設した構成を示すものである。同図においては２個の支持台１７ａ，１７ｂを突設している。この場合、上流側に位置する支持台１７ａの高さを、下流側に位置する支持台１７ｂの高さよりも低く設定する。このように構成すると、遡上する魚類の大きさに応じ、上流側に設置された水路部材の水位と下流側に設置された水路部材の水位との間に、魚類の遡上を可能とする所要水位差を設けることができる。遡上する魚類が大型であるときは、該水位差を大きく設定できるため、その場合は、高さのより高い支持台１７ｂを選択して魚類遡上構造を構成できる。これにより、魚道６を構成する水路部材の使用個数を減じ得る経済性がある。
【０１５１】
（１４）本発明に係る魚類遡上構造を構成する水路部材７は、前記した上端開放のものとして構成されることの他、例えば樹脂製等のパイプ状を呈するものとして構成されることもある。或いは、パイプ状を呈する水路部材と、上端が開放した水路部材との組み合わせで魚類遡上構造を構成することもある。
【０１５２】
（１５）水路部材に堰板を着脱可能に装着する構成は、前記したような嵌入溝に堰板を嵌め入れ可能に構成することの他、水路水を嵩上げできるように着脱可能な各種の構成を採用できる。
【０１５３】
（１６）又、前記堰板２３には、前記のような越流切欠部３０を設けない場合があるが、越流切欠部３０を設ける場合は、該越流欠切部を堰板の幅方向中央部に設けるものには限られない。例えば図６５に示すように、該越流切欠部３０を堰板２３の端に寄せ、上下方向で並設された堰板の有する越流切欠部が千鳥配置となるように設けることもある。このように構成するときは、魚道における水の流れを蛇行させて、魚類が遊泳できる淀み部分２１０を形成できることとなる。なお図６５においては、説明の便宜上、越流切欠部３０に斜線を付している。
【０１５４】
（１７）前記越流水深は、魚類の遡上状態に応じて設定されるものであり、３０〜５０ｍｍの越流水深を確保できるように構成すれば、各種魚類に応じた必要な越流水深を確保できる。
【０１５５】
（１８）前記水路部材に装着される堰板に設けた越流部の下流側を面取りする場合、前記した何れの実施の形態においても、該面取りは、傾斜面としての他、円弧面として形成できる。
このことは、該越流部を、前記堰板に設けた矩形状欠切部の下側部分を覆うように設けられるスライド調整板の上端として形成する場合も同様であり、このように構成する場合は、該欠切部の縁部分を、下流側に向けて拡大するように面取り（傾斜面や円弧面等の面取り）するのがよい。
【０１５６】
（１９）前記隔壁に設けた越流部の下流側を面取りする場合、前記した何れの実施の形態においても、該面取りは、傾斜面としての他、円弧面としても形成できる。
このことは、該越流部を、前記隔壁に設けた矩形状欠切部の下側部分を覆うように設けられるスライド式の調整板の上端として形成する場合も同様であり、このように構成する場合は、欠切部の縁部分を、下流側に向けて拡大するように面取り（傾斜面を円弧面等の面取り）するのがよい。
【０１５７】
（２０）前記堰板や隔壁に欠切部を設け、該欠切部にスライド調整板やスライド式の調整板を付設して所要の越流部を構成する場合、該欠切部は、前記した矩形状欠切部には限られず、台形状やＶ字状、円弧状等を呈する欠切部としても形成できる。
【０１５８】
（２１）前記堰板にスライド調整板を高さ調整可能に設けたり、前記隔壁に調整板を高さ調整可能に設ける手段は、前記のように、スライド調整板やスライド式の調整板の両側に設けた上下に長い調整孔にボルトを挿通させ、該ボルトをインサートに螺合して行う手段の他、公知の各種調整手段を用いて行うことができる。
【０１５９】
（２２）前記洗掘防止ブロックは、前記実施の形態においては、開放した両端を側板や土嚢で覆うように構成しているが、底板と一体に設けた側板で該両端を閉じるように構成してもよい。
【０１６０】
（２３）前記排水路は、前記コ字状枠を用いて組み立てるものの他、公知の各種構造のものを採用できる。
【０１６１】
（２４）Ｕ字溝状の水路部材を接合して構成した魚道本体の上下にパイプ状の水路部材を接合して構成する図２７に示す魚類遡上構造の考え方は、有底の箱状を呈する水路部材を用いて構成する前記第２、第３の実施の形態に係る魚類遡上構造にも応用できる。
【０１６２】
（２５）魚道本体１２１にパイプ状の水路部材７を接合して魚道６を構成する場合、該パイプ状の水路部材７の上端を地表に一部露出させる場合もある。図６６は、その一例を示すものであり、該パイプ状の水路部材７を、例えばＵ字溝状をなす上端開放の水路部材本体２２０と、その上端開放部２２１を着脱可能に閉蓋し得る蓋板２２２を以って構成し、該蓋板２２２の閉蓋によってパイプ状の水路部材７を形成している。この場合、図６６に示すように、前記水路部材本体２２０を地下埋設状態とし、前記蓋板２２２を地表に露出状態とすることにより、必要時に該蓋板２２２を取り外すことによって、パイプ状の水路部材７の内部を点検したり清掃することができる。
【０１６３】
（２６）前記隔壁５０は、図１に示すように、コ字状支持枠４１の内面に設けられた挿入溝４９に両端の縁部分を挿入して該コ字状支持枠４１に着脱可能に装着されることの他、該コ字状支持枠４１の上流側の側面にネジ止めされることもある。
【０１６４】
（２７）前記排水路２に、前記洗掘防止ブロック１５６を配設する場合、該洗掘防止ブロックの底板１５７は、越流部５４を通しての落水によって排水路の水路底の洗掘を防止できる限り、該越流部５４の下流側の近傍部分にのみ設けることがある。
【０１６５】
（２８）前記魚道６の上側を覆う防止ネット７７は、透明な塩化ビニルシート等の透明被覆材に変更されることもある。この透明被覆材は、魚道における魚類の遡上を可能とする限り、有色透明の被覆材であってもよい。
【０１６６】
【発明の効果】本発明は以下の如き優れた効果を奏する
（１）　本発明に係る魚類遡上構造は、排水路と、該排水路の水位よりも高い水位を有する貯水池に魚類を遡上させるための魚道を含んで構成されており、該魚道を、水路部材の複数を順次接合して構成することとし、各水路部材に堰板を着脱可能に装着する構成を採用し、又、該堰板の越流部を、下流側の水位に対して魚類が遡上可能な高さに設定する構成を採用している。
従って発明によるときは、貯水池と排水路との間の平面視で見た幅（畦部等の幅）と、排水路の水位と貯水池の水位との間の落差に応じて、必要個数の水路部材を直線状態や所要の屈曲状態で順次接合し、該水路部材に装着した堰板の越流部の高さと該越流部における越流水深を所要に設定して魚道を形成することにより、魚類を、前記排水路に必要に応じて設けた隔壁の越流部を順次遡上させて、前記魚道が存在する場所にまで至らせることができ、その後、排水路から貯水池に魚類を無理なく遡上させ得ることとなる
排水路と貯水池との間に魚道を形成する前記従来システムにあっては、夫々の施工現場に合わせて、現場打ち施工を主体に構成するものであったため、その施工に多くの手間を要して施工能率が悪く、施工コストの上昇を招く問題があった他、工期が長引く問題があった。特に、落差が大きい場合に該魚道を屈曲状態に形成せんとするときは、現場打ち施工が非常に複雑となって施工性が悪化し、又、施工コストの一層の上昇を招く等の問題を発生させた。又、排水路から貯水池に亘る長さを有する一体成形されたコンクリート製の魚道ブロックを用いて魚道を形成せんとするときは、該魚道ブロックを、施工現場に応じた長さに個別的に設計、製造しなければならず、施工コストが大幅に上昇する問題があった他、該コンクリート製の魚道ブロックは重量が大きくなり、施工現場への搬送が容易でなく、又施工性を悪化させる問題もあった。
これに対して、水路部材の複数を順次接合して、換言すれば、必要個数の水路部材を順次接合して魚道を構成する本発明によるときは、かかる問題点を一挙に解消できる。
又前記堰板は着脱可能であるため、堰板の全てを取り外すことによって、貯水池の水を排水路に円滑に排出させ得ると共に、魚道の掃除も容易である。
【０１６７】
（２）　水路部材に装着する前記堰板の上端部に、台形状やＵ字状、矩形状、Ｖ字状等を呈する越流切欠部を設ける場合は、魚道を流れる水の量が多くないときも、該越流切欠部において、魚類の遡上を可能とする所要水深を確保できることになる。
【０１６８】
（３）　水路部材に設けた上流側開口と下流側開口間を仕切るように、水路水を嵩上げする中間の堰板を水路部材に着脱可能に装着するときは、水路に、中間堰板によって水位差を形成することが可能となるため、排水路と貯水池との落差が大きい場合に、水路部材の使用個数を増すことなく、適切な水位差を有した魚道を経済的に形成できることになる。
該中間の堰板を、所要間隔を置いて複数装着するときは、水路部材の水路を更に区画でき、中間堰板間にも所要の水位差を形成できることになる。
【０１６９】
（４）　上端開放で且つ周方向の壁部で閉じられた有底の箱状を呈する水路部材を用いる場合において、その上流側開口と下流側開口を、該両開口を通過する水の流れ方向が屈曲するように前記壁部に設けるときは、該上流側開口及び下流側開口に他の水路部材の端部分を挿入状態とすることにより、畦部等の幅や、貯水池の水位と排水路の水位との間の落差に応じた適切な屈曲魚道を合理的に構成できることになる。例えば、畦部等の幅が小さくて落差が大きい場合、直線状の魚道では対処できなくても、魚道を屈曲させることにより対処できる利点がある。
【０１７０】
（５）　水路部材の複数を順次接合して構成した魚道本体の、最下流側に位置する水路部材に、排水路に連通され且つ地下埋設されたパイプ状の水路部材を接合する一方、最上流側に位置する水路部材に、水田に結果的に連通されるパイプ状の水路部材の端部を接合する構成を採用する場合は、畦の天端や、畦の法面下端と排水路との間をなす畦道に、一輪車等を障害なく走行させて、農作業の容易化を達成できる利点がある。
又このような構成は、畦部の幅が比較的小さく、排水路の水位と貯水池の水位との間の落差が大きい場合にも、該落差に応じて適切な越流部と越流水深を有する魚道を合理的に構成できる。更にかかるパイプ状の水路部材は、例えば昼間において、魚類の避難場所としても機能させ得る。
【０１７１】
（６）　上端開放で周方向の壁部で閉じられた有底の箱状をなす水路部材を、上端開放の有底の円筒箱状に構成する場合は、例えば直方体箱状を呈する場合とは異なり、壁部に上流側開口と下流側開口を設ける際の位置的制約が少ないため、両開口を通過する水の流れ方向が屈曲するようになすとき、上流側開口と下流側開口を、その屈曲角度に合わせて容易に形成できる利点がある。
【０１７２】
（７）　前記水路部材を、上端が開放したＵ字溝状に形成し、その上流側部分の水路幅を拡大して、水路部材の下流側部分をなす接合部を嵌め入れるための接合嵌合部とし、又、該水路部材の上流側部分の水路の底部に、前記接合部の下面を下方から支持する支持台を突設する構成を採用したときは、以下の如き特別の効果を奏する。即ち、
【０１７３】
▲１▼　前記支持台によって、水路の底部側に淀み場が形成されることになり、そこを、底生生物の生息場となし得る。
【０１７４】
▲２▼　又、前記支持台によって形成された水路の底部側が泥溜めとなり、魚道を流れる汚泥等の微粒土を堆積させ得る。これによって、肥料成分等の有機物を沈殿させることができる。又、堆積土から水草等が生えることによって、水路水中の有機物が捕捉され、水質浄化が図られることにもなる。かかることから、有機物による河川の汚染防止に寄与できる。
【０１７５】
▲３▼　前記接合嵌合部内に挿入された接合部の下側に空隙部を形成でき、この空隙部を、陰を好む底生生物の生息場所となし得、又、稚魚の避難場所ともなし得る。特に、この空隙部の表面側を自然石が露出した面とすることにより、藻類の繁殖を助けて底生生物の良好な餌場となし得る。
【０１７６】
▲４▼　前記支持台が接合部の下面を下方から支持できるため、支持台を定規にして、隣り合う水路部材相互を、所要段差で敷設することが容易となる。
【０１７７】
（８）　前記支持台を水路部材と別体に構成し、該支持台を水路部材に後付けする構成を採用したときは、所要高さの支持台を水路部材に固定することにより、隣り合う水路部材の敷設段差を所要に調節できる利点がある。又、支持台高さの異なる水路部材を一体に形成する場合よりも、水路部材の製造コストの低減を期し得る。
【０１７８】
（９）　支持台を水路部材と一体に形成した場合に、補助支持台を積重して所要高さの支持台を構成したり、水路部材とは別体の支持台を水路部材に後付けしたり、複数個の支持台片を積み重ねて支持台を形成するときは、次のような効果を奏し得る。即ち、魚道を遡上する魚類が大型であるときは、該補助支持台の積重等によって支持台の高さを結果的に高くすることにより、隣り合う水路部材の敷設段差を大きくでき、従って、水路部材の使用個数を減じて魚類遡上構造を経済的に構成できることとなる。
例えば、排水路と貯水池の落差が約６００ｍｍ程度ある場合、前記水路部材の下面と前記支持台の上面間の距離が１５０ｍｍであれば、水路部材を４段に設置して対処しなければならないのに対し、この距離が２００ｍｍであれば、３段の水路部材で対処できることとなる。
【０１７９】
（１０）更に、このように支持台を設ける場合、該支持台を、水路の長さ方向の前後に設け、上流側に位置する支持台を、下流側に位置する支持台よりも低く構成するときは、支持台の選択によって、隣り合う水路部材の敷設段差を変更できる利点がある。
【０１８０】
（１１）前記水路部材の底面部を、更には側面部を、自然石が露出した面に形成することにより、該自然石面に藻類を繁殖させることが可能になり、水路の内面部を、小魚類や底生生物の餌場ともなし得る。
【０１８１】
（１２）前記堰板を、欠切部が設けられた堰板本体と、該欠切部の下側部分を覆うように付設されたスライド調整板とにより構成する場合は、該スライド調整板の上下方向の高さ調節により、該スライド調整板の上端としての越流部の高さを、貯水池の水位と排水路の水位との間の落差に応じて、下流側の水位に対して魚類が遡上可能な適切な高さに設定することが容易である。
前記堰板として、例えば図４に示すように、欠切部が設けられた板体のみを以って形成する場合は、カッター等でカットして欠切部の深さを深くする等の現場調整が必要となるのであるが、スライド調整板を用いる場合は、このような面倒な調整を何ら要さず、越流部の高さ調整を簡易且つ確実に行い得る利点がある。
【０１８２】
（１３）水路部材をＵ字溝状に構成する場合において、下流側部位に着脱可能に装着される堰板を、その下流側の面が水路部材の下端面と面一に形成する場合は、魚道を遡上する魚類が水路部材の下端の角部分に引っ掛かって傷つくのを防止できる。
【０１８３】
（１４）排水路に着脱可能に装着する隔壁を、欠切部が設けられた隔壁本体と、該欠切部の下側部分を覆うように付設されるスライド式の調整板とにより構成する場合も、排水路の水嵩に応じて、魚類の遡上を可能とする越流部の高さを簡易且つ確実に調整できる利点がある。
【０１８４】
（１５）排水路に装着される堰板に、その越流部の下側に位置させて水抜き孔を設ける場合は、該水抜き孔を開放して水を放出させることにより、越流部における落水に加えて水抜き孔からの水の放出が加わるため、それらの流れを感じて魚類が越流部（越流欠切部）に向けて誘導されやすくなる効果を期待できる。
【０１８５】
（１６）排水路に設ける隔壁を、底板の前後に前板と後板を立設してなる洗掘防止ブロックの該前板を以って構成する場合は、越流部（越流欠切部）を通して落水しても、排水路の水路底が該底板で保護されていることから、水路底の洗掘を防止できる。又、越流欠切部の下流側に、水路底がより掘下げられた深み部が形成されるため、越流欠切部を魚類が遡上する際、その深みによって、勢いを付けて容易に遡上できる利点がある。更に、該洗掘防止ブロックの前板と後板との間をなす空所が泥溜めとなるため、魚道を通して水田から排水路に流入する等した、肥料成分等の有機物を含んだ微粒土を堆積させ、水質浄化を図り得ることとなる。この場合、前記空所に、藁や籾殻等の濾化材を収容することにより、排水路における水質浄化効果を向上させることができる。
【０１８６】
（１７）特に、魚道の下流側に洗掘防止ブロックを設置し、前記空所に濾過材を収容する構成を採用した場合は、前記魚道を通して水田から排水路に流入した肥料成分等の有機物を含んだ微粒土を、該濾過材で濾過でき、それだけ排水路の水質浄化を図り得る利点がある。
【０１８７】
（１８）魚道の上側を、図１６に示すように防止ネットや透明被覆材で覆う場合は、魚道を遡上する魚類が魚道の外に飛び出すのを防止できると共に、遡上中に魚類が鳥類に捕食されるのを防止できる。
【０１８８】
（１９）前記堰板の越流部の下流側を円弧面に形成し、或いは該下流側の部分を、１３〜６０度の角度で下方に傾斜する傾斜面に形成した場合は、該欠切部を遡上する魚類が該越流部の角部分に引っ掛かって傷つくのを防止できる。この場合、傾斜面の傾斜角度を３５〜４５度に設定することにより、このような引っ掛かりをより効果的に防止できる。
このことは、堰板に設けた欠切部をスライド調整板で覆う場合において、該欠切部の下流側の縁部分及びスライド調整板の上端としての越流部の下流側の部分を、前記と同様の円弧面や傾斜面に形成した場合も同様である。
更に、これらのことは、排水路に隔壁を設ける場合において、該隔壁の上端をなす越流部の下流側の部分を同様に形成し、又、該隔壁に欠切部を設け、該欠切部の下側部分をスライド式の調整板で覆う場合において、該調整板の上端をなす越流部の下流側の部分や欠切部の下流側の縁部分を、前記と同様に円弧面や傾斜面に形成した場合も同様である。
【０１８９】
（２０）前記堰板に、魚道を流れる水に漂う魚類誘導用の紐状物の上端側を取り付ける場合は、魚道を遡上する魚類を、越流欠切部に効果的に誘導できる利点がある。
【０１９０】
（２１）又、排水路の底部に、その幅方向に適宜間隔で水草状紐体を配置する場合は、排水路の底部分に水草が生えているような状態を形成でき、該水草状紐体を、魚類の産卵や育成の補助具として機能させ得る。
【図面の簡単な説明】
【図１】本発明に係る魚類遡上構造を示す全体斜視図である。
【図２】その断面図である。
【図３】その平面図である。
【図４】それに用いる水路部材を堰板と共に示す斜視図である。
【図５】その水路部材を示す斜視図である。
【図６】その水路部材を示す平面図である。
【図７】水路部材相互の接合状態を示す断面図である。
【図８】堰板の構成を越流状態と共に示す断面図である。
【図９】形成された魚道の作用を説明する斜視図である。
【図１０】形成された魚道の作用を説明する断面図である。
【図１１】排水路の構成を説明する部分斜視図である。
【図１２】排水路のその他の構成を説明する部分斜視図である。
【図１３】魚類誘導用の紐状物をその使用状態で示す断面図である。
【図１４】魚類誘導用の紐状物を示す斜視図である。
【図１５】魚道の堰板を取り外して水田の水を排水路に排水する状態を示す斜視図である。
【図１６】魚道を防止ネットで覆った状態を示す斜視図である。
【図１７】水路部材と、防止ネットを支持する支持枠を示す斜視図である。
【図１８】支持枠を水路部材に取り付けた状態を示す断面図である。
【図１９】本発明に係る魚類遡上構造の他の態様を作用と共に示す断面図である。
【図２０】最上流側の水路部材と中間の水路部材の接合状態を示す断面図である。
【図２１】水路部材と、これに装着される堰板を示す斜視図である。
【図２２】最上流側の水路部材の上流端側の堰板を示す分解斜視図である。
【図２３】水路部材の下流側に装着される堰板を示す分解斜視図である。
【図２４】水路部材の下流側に装着された堰板における、スライド調整板の高さ調整状態の一例を示す斜視図である。
【図２５】水路部材の下流側に装着された堰板における、スライド調整板の高さ調整状態の他の例を示す斜視図である。
【図２６】スライド調整板が取り外された堰板の装着状態を示す断面図である。
【図２７】本発明に係る魚類遡上構造の他の態様を示す平面図である。
【図２８】その断面図である。
【図２９】その魚類遡上構造における、最下流側の水路部材と排水路との接合状態を示す断面図である。
【図３０】その魚類遡上構造における最下流側の構成を説明する斜視図である。
【図３１】その魚類遡上構造における最上流側の構成を説明する断面図である。
【図３２】その魚類遡上構造における最上流側の構成その斜視図である。
【図３３】排水路に隔壁が装着された魚類遡上構造を示す平面図である。
【図３４】その魚類遡上構造における隔壁の越流部分を上流側から見た斜視図である。
【図３５】その魚類遡上構造における隔壁の越流部分を下流側から見た斜視図である。
【図３６】その魚類遡上構造における隔壁の越流部分を分解して示す斜視図である。
【図３７】排水路の底部に水草状の紐体を配置した状態を示す断面図である。
【図３８】排水路の隔壁に設けた水抜孔を閉じた状態を示す断面図である。
【図３９】洗掘防止ブロックを用いて排水路の隔壁を構成した状態を示す斜視図である。
【図４０】その断面図である。
【図４１】その正面図である。
【図４２】その平面図である。
【図４３】本発明に係る魚類遡上構造のその他の態様を説明する全体斜視図である。
【図４４】その断面図である。
【図４５】その平面図である。
【図４６】それに用いる水路部材を堰板と共に示す斜視図である。
【図４７】それに用いる水路部材を堰板と共に示す斜視図である。
【図４８】最下流側に設置された水路部材と排水路の連通状態を示す断面図である。
【図４９】中間の水路部材と最下流側の水路部材との接合状態を示す断面図である。
【図５０】最上流側の水路部材と中間の水路部材との接合状態を示す断面図である。
【図５１】形成された魚道を説明する斜視図である。
【図５２】形成された魚道の使用状態を示す断面図である。
【図５３】本発明に係る魚道遡上構造のその他の態様を示す全体斜視図である。
【図５４】その平面図である。
【図５５】形成された魚道を示す斜視図である。
【図５６】それを構成する水路部材を示す斜視図である。
【図５７】それを構成する水路部材を堰板と共に示す斜視図である。
【図５８】形成された魚道の使用状態を示す断面図である。
【図５９】コ字状水路部材をその使用状態で示す平面図である。
【図６０】水路部材のその他の態様を示す分解斜視図である。
【図６１】その部分断面図である。
【図６２】水路部材のその他の態様を示す部分断面図である。
【図６３】水路部材のその他の態様を示す部分断面図である。
【図６４】水路部材のその他の態様を示す部分断面図である。
【図６５】越流欠切部を千鳥状に配置した魚道を示す部分平面図である。
【図６６】パイプ状水路部材の他の態様を示す断面図である。
【図６７】従来の魚類遡上構造を示す斜視図である。
【符号の説明】
１　魚類遡上構造
２　用排水路
３　貯水池
５　畦部
６　魚道
７　水路部材
９　水路
１０　上流側開口
１１　下流側開口
１２　接合部
１３　接合嵌合部
１７　支持台
２３　堰板
２４　越流部
２５　嵌入溝
２９　嵌入溝
３０　越流欠切部
５０　隔壁
５２　越流欠切部
５４　越流部
６７　紐状物
７６　支持枠
７７　防止ネット
８５　堰板本体
８６　落とし込み調整板
８７　矩形状欠切部
９２　装着溝
９５　傾斜面
９７　堰板本体
９９　スライド調整板
１１１　インサート
１１２　ボルト
１１３　調整孔
１４３　インサート
１４４　調整孔
１４６　水抜き孔
１４７　水路底
１５０　紐状体
１５１　重り
１５２　浮き
１５３　紐片
１５４　毛片
１５６　洗掘防止ブロック
１５７　底板
１５９　前板
１６０　後板
１６９　矩形状欠切部
１７０　インサート
１７２　ボルト
１８０　壁部
１８７　嵌入溝
１９１　嵌入溝
２０１　嵌入溝
２０２　嵌入溝[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is provided between a drainage channel and a paddy field or a fallow rice field having a higher water level, a reservoir, a reservoir as a pond of a hydrophilic park, and the like, whereby fish can be easily moved upward from the drainage channel to the reservoir. The present invention relates to a fish run-up structure to a reservoir that is located in the water, and a waterway member constituting the fish run-up structure.
[0002]
[Prior art]
In recent years, it has become possible to achieve ecosystem conservation by using fish fields such as crucibles, carps, and catfishes to run up to reservoirs such as paddy fields and fallow fields, and using paddy fields as places for breeding and breeding fish. Attempts have been made to do so. One of the present applicants also proposed in Japanese Patent Application Laid-Open No. 2000-120052 a system for running fish up to a freshwater reservoir.
[0003]
As shown in FIG. 67, the fishway constituting the run-up system has a floor e where the freshwater reservoir side a is lower than the water level of the freshwater reservoir b and the waterway side c is lower than the water level of the waterway d. A space g formed by the side wall f rising upward from both sides of the floor portion e and forming a water passage connecting the freshwater reservoir b and the water channel d, and the floor portion e and both side walls f, f. And a partition j provided with an overflow section h for separating the upstream side and the downstream side and overflowing the water on the upstream side.
[0004]
As described in the application specification, the run-up system is designed so that the overflow section of each partition has a height at which fish can go up with respect to the water level on the downstream side, and adjusts the water level of the freshwater reservoir. Since the fishes were allowed to go up from the waterway side to the freshwater reservoir side while being maintained at a substantially predetermined level, the fishes could easily go up from the waterway side to the freshwater reservoir side. The biopreservation function was improved, and the biotope was able to inhabit a variety of living things.
[0005]
[Patent Document 1]
JP-A-2000-120052 (page 4-7, FIG. 3)
[0006]
[Non-patent document 1]
"Ecosystem-friendly construction method for agricultural drainage channel", Shiga Prefectural Agriculture, Forestry and Civil Engineering Concrete Products Association, December 21, 2001, p. 2-6
[0007]
[Problems to be solved by the invention]
However, when using the run-up system, the floor of the fishway and the side walls rising from both sides of this floor were formed in a series so as to connect the waterway and the freshwater reservoir, so the construction of the fishway requires the construction on site. Since it was mainly used, it took a lot of time and labor to individually perform construction according to the width of the ridges and the head, which not only increased the construction cost but also prolonged the construction period. Furthermore, when using the series of fishways, the bent fishway is difficult to construct, so if the head between the waterway and the freshwater reservoir is large, even if the bent fishway does not respond to this, the construction is not easy. There were also problems.
[0008]
Further, when the floor e and the side walls f, f rising from both sides thereof are formed as an integral U-shaped groove-shaped block, a block having a predetermined length according to the construction site must be individually designed and manufactured. In addition, the price of the mold rises, which causes a significant increase in the manufacturing cost. In addition, a long U-shaped groove-shaped block has a large weight, and is not easily transported to a construction site, and also causes problems that the workability is deteriorated.
[0009]
The present invention has been developed mainly in view of such a problem, and not only can the fish run up easily from a low-water drainage channel to a high-water reservoir, but also the water level of the drainage channel and the reservoir can be easily adjusted. It is an object of the present invention to provide a fish run-up structure to a reservoir, which can easily form an appropriate fishway according to the degree of head difference between the water levels and can improve construction efficiency and reduce construction costs.
[0010]
Another object of the present invention is to provide a fish run-up structure capable of appropriately adjusting the height of an overflow section that allows fish to run up in accordance with the construction site. It is an object to provide a fish run-up structure that is easy to induce. In addition, another object of the present invention is to provide a waterway member capable of rationally configuring such a fishway.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs the following means.
That is, the fish run-up structure according to the present invention includes a drainage channel, and a fishway for causing fish to run up to a reservoir having a water level higher than the water level of the drainage channel, and a plurality of waterway members are sequentially joined to the fishway. A fish run-up structure to a reservoir constructed as described above, wherein the waterway member has an upstream opening and a downstream opening at an upstream side and a downstream side of the waterway, and the waterway installed on the upstream side. The waterway members are joined to each other such that the downstream opening of the member communicates with the upstream opening of the waterway member installed on the downstream side, and the upstream opening of the waterway member installed on the most upstream side is the above-mentioned. A downstream opening of the waterway member, which is communicated with the reservoir and installed at the most downstream side, is communicated with the drainage passage. Further, a weir plate for raising channel water is detachably mounted at a downstream portion of the water channel of the water channel member, and the overflow portion of the weir plate is provided with a height at which fish can go up to the downstream water level. It is characterized by having been set to the above.
[0012]
In the fish run-up structure, the waterway member is formed in a U-shaped groove shape having a continuous waterway that is open at the upper end and extends from the upstream end to the downstream end, and increases the width of the waterway on the upstream side. A joining portion for fitting a joining portion that forms the downstream side of the member, and in a state where the joining portion is fitted into the joining portion, the joining portion of the joining portion with respect to the joining fitting portion of the waterway member A guide portion for detachably fitting the weir plate is provided at a downstream portion of the water channel of the water channel member so that the insertion amount as viewed in the length direction can be adjusted, and the water channel member installed at the upstream side It is preferable that the connecting portion is fitted into the connecting fitting portion of the waterway member installed on the downstream side, and the dam plate is fitted into the guide portion.
[0013]
In the fish run-up structure, it is preferable that a support pedestal that supports the lower surface of the joint of the waterway member installed on the upstream side from below is provided at the bottom of the waterway at the upstream side of the waterway member.
[0014]
A more preferred embodiment of the fish run-up structure according to the present invention includes a drainage channel and a fishway for causing fish to run up to a reservoir having a water level higher than the water level of the drainage channel, wherein the fishway includes a plurality of waterway members. And a fish run-up structure to a reservoir constructed by sequentially joining the water passage members, wherein the water passage member is formed in a U-shaped groove shape having a continuous water passage open from the upper end and from the upstream end to the downstream end, The width of the water channel on the upstream side is enlarged, and the water channel member serves as a connection fitting portion for fitting a connection portion on the downstream side of the water channel member. Further, an insertion groove for detachably inserting a weir plate for raising channel water is provided on the opposite side surface and the bottom surface of the channel member on the downstream side of the channel, and the channel on the upstream side of the channel member is provided. A support pedestal for supporting the lower surface of the joint portion of the waterway member installed on the upstream side from below is protruded at the bottom of the waterway member. A fitting groove for detachably fitting a weir plate for raising water is provided. Also, the joint of the waterway member installed on the upstream side is fitted into the joint fitting portion of the waterway member installed on the downstream side while the joint is placed on the support table, and An upstream opening of the waterway member installed on the upstream side is communicated with the reservoir, and a downstream opening of the waterway member installed on the most downstream side is communicated with the drainage channel. Further, the overflow portion of the weir plate fitted in each of the fitting grooves is set to a height at which fish can go up with respect to the water level on the downstream side.
[0015]
In the fish run-up structure having a support, the support is protruded from a bottom portion of the waterway on an upstream portion of the waterway member at predetermined intervals before and after in a longitudinal direction of the waterway, and further upstream. Is preferably set at a lower height than the support table located downstream of the support table.
[0016]
In the fish run-up structure having a support, the support may be formed separately from the waterway member, and the support may be retrofitted to the waterway member. The post-installed support base may be configured by stacking support base pieces of a required height in a plurality of stages.
[0017]
When the waterway member is formed in a U-shaped groove shape, when the weir plate is removably fitted to a downstream portion of the waterway of the waterway member, a downstream end side of an outer peripheral surface of the weir plate is a downstream end of the waterway. And the downstream surface of the weir plate is preferably flush with the downstream end surface of the waterway member.
[0018]
Another embodiment of the fish run-up structure according to the present invention includes a drainage channel, and a fishway for causing fish to run up to a reservoir having a water level higher than the water level of the drainage channel, wherein the fishway includes a plurality of waterway members. Are sequentially connected to each other to form a fish run-up structure to a reservoir, wherein the waterway member is formed in a boxed shape with a bottom that is open at the upper end and closed by a circumferential wall. The required portion of the upstream side and the required portion of the downstream side are provided with an upstream opening and a downstream opening, and the downstream opening of the waterway member installed on the upstream side is installed on the downstream side. The waterway members are joined to each other so as to communicate with the upstream opening of the waterway member, and a weir plate for raising the water of the waterway is detachably attached to a communication portion between the two openings. Further, an upstream opening of the waterway member installed on the most upstream side is communicated with the reservoir, and a downstream opening of the waterway member installed on the most downstream side is communicated with the drainage channel. The overflow portion of the plate is set at a height at which fish can go up to the water level on the downstream side.
[0019]
In the fish run-up structure, at the upstream opening of the waterway member having a box shape with an open top and closed by a circumferential wall, a downstream portion of the waterway member installed upstream. And the insertion amount can be adjusted, and the upstream portion of the channel member installed on the downstream side is inserted into the downstream opening of the channel member so that the insertion amount can be adjusted. Is good.
[0020]
In the fish run-up structure including the waterway member having a box shape with a bottom that is open at the upper end and closed by a circumferential wall, the waterway of the waterway member includes a water passage between the upstream opening and the downstream opening. So that the middle weir plate that raises the channel water is detachably attached, and the overflow portion of the middle weir plate is set to a height at which fish can go up to the water level on the downstream side. Is good.
[0021]
In the fish run-up structure including the waterway member having a box shape with a bottom that is open at the upper end and closed by a circumferential wall, the waterway of the waterway member includes a water passage between the upstream opening and the downstream opening. A plurality of intermediate weir plates for raising the channel water are detachably attached so as to partition the water into a plurality, and the overflow portions of the respective intermediate weir plates can be fished upstream with respect to the water level on the downstream side. It is good to set to height.
[0022]
In each of the fish run-up structures provided with the waterway member having a box shape with a bottom that is open at the upper end and closed by a circumferential wall, the upstream opening and the downstream opening of the waterway member are the same. It is preferable to provide the wall portion so that the flow direction of water passing through the opening is bent.
[0023]
In each of the fish run-up structures, the downstream side of the overflow section may be formed in an arc surface. In each of the fish upstream structures, the downstream side of the overflow section is preferably formed as an inclined surface that is inclined downward at an angle of 13 to 60 degrees.
[0024]
Another embodiment of the fish run-up structure according to the present invention is a fish run-up structure including a drainage channel and a fishway for moving fish up to a paddy field having a water level higher than the water level of the drainage channel, The fishway is formed by sequentially joining a plurality of waterway members in the direction in which the ridges extending between the drainage channel and the paddy field extend to form a fishway main body, and installed at the most downstream side to form the fishway main body. The downstream end provided in the waterway member is connected to the upstream end of a pipe-shaped waterway member that is communicated with the drainage channel and buried underground, while being connected to the most upstream side that constitutes the fishway main body. A downstream end portion of the waterway member that is consequently connected to the paddy field is joined to an upstream opening of the installed waterway member, and a waterway water is provided for each of the waterway members constituting the fishway main body. A weir plate for raising the height is detachably mounted, and the overflow portion of the weir plate , It is characterized in that the fish has been set to allow height intrusion relative water level on the downstream side.
[0025]
Another embodiment of the fish run-up structure according to the present invention is a fish run-up structure including a drainage channel and a fishway for moving fish up to a paddy field having a water level higher than the water level of the drainage channel, The fishway is formed by sequentially joining a plurality of waterway members in the direction in which the ridges extending between the drainage channel and the paddy field extend to form a fishway main body, and installed at the most downstream side to form the fishway main body. The downstream end provided in the waterway member is connected to the upstream end of a pipe-shaped waterway member that is communicated with the drainage channel and buried underground, while being connected to the most upstream side that constitutes the fishway main body. An upstream opening of the installed waterway member is joined to a downstream end portion of a pipe-shaped waterway member that is consequently communicated with the paddy field and buried underground, and that constitutes the fishway main body. Weir plate for raising channel water is removable for each of the members Is mounted, the overflow portion of the weir plate, and is characterized in that the fish has been set to allow height intrusion relative water level on the downstream side.
[0026]
In these cases, the pipe-shaped waterway member is preferably formed, for example, in a circular pipe shape, and is disposed substantially horizontally.
[0027]
In each of the fish run-up structures, it is preferable that an upper end side of a string for guiding fish floating in water flowing through the fish passage is attached to the weir plate.
[0028]
In each of the fish upstream structures, the weir plate comprises a weir plate body detachably mounted on a waterway member and a slide adjusting plate attached to the weir plate body, and the weir plate body is open at the upper end. The slide adjusting plate is provided so as to be in contact with the weir plate main body and to be slidable in the up and down direction so as to cover a lower portion of the notch. The upper end of the plate is the overflowing portion, and the overflowing portion is capable of adjusting the vertical sliding state of the slide adjusting plate so that the fishes can reach a height at which the fish can go up to the downstream water level. It is preferable that the slide adjustment plate can be fixed to the weir plate main body in the adjustment state.
[0029]
In each of the fish run-up structures, the fish running up the fishway is prevented from jumping out of the fishway, and the fish running upstream is prevented from being preyed by birds. It is good to cover with a net or a transparent covering material. In this case, it is preferable that the prevention net or the transparent covering material is configured to cover the upper side of the fishway by covering a support frame provided upright on the waterway member.
[0030]
Further, in each of the fish upstream structures, a partition wall for raising water flowing through the drainage channel is detachably mounted on the drainage channel, and the partition wall is detachably mounted on the drainage channel. And an adjusting plate attached to the main body, wherein the partition main body is provided with a notch with an open upper end, and the adjusting plate is in contact with the partition main body so as to cover a lower portion of the notch. And the upper end of the adjusting plate is the overflow section, and the overflow section has a height at which fish can go up to the water level on the downstream side. As described above, it is preferable that the vertically slidable state of the adjusting plate can be adjusted, and the adjusting plate can be fixed to the partition main body in the adjusted state.
[0031]
In each of the fish upstream structures, the drainage channel is provided with a partition wall for raising water flowing through the drainage channel, and the partition wall extends in a flow direction of water in the drainage channel and has a width equal to the width of the drainage channel. A front plate is provided upright on an upstream end of a bottom plate having substantially the same width, and a scour prevention block is provided with the front plate provided with a rear plate provided on a downstream end of the bottom plate. It is preferable that a part of the front plate is formed as an overflow portion set to a height at which fish can go up with respect to the water level on the downstream side.
[0032]
In this case, the front plate serving as the partition wall includes a partition body that forms a part thereof and an adjustment plate attached to the partition body, and the partition body is provided with a cutout having an open upper end. The adjusting plate is attached to the partition main body so as to be slidable in the up and down direction so as to cover a lower portion of the cutout portion, and the upper end of the adjusting plate is the overflow portion, The vertical slide state of the adjusting plate can be adjusted so that the overflow portion has a height at which the fish can go up with respect to the water level on the downstream side, and the adjusting plate is fixed to the partition wall body in the adjusted state. It should be possible.
[0033]
In each of the fish run-up structures, a scour prevention block is disposed in the drainage channel at a position downstream of the fishway, and the scour prevention block extends in a flow direction of water in the drainage channel. At the upstream end of a bottom plate having a width substantially equal to the width of the drainage channel, a front plate that functions as a partition for raising water flowing through the drainage channel is erected, and a downstream end of the bottom plate is provided. A part of the front plate is an overflow part set to a height at which fish can go up with respect to the water level on the downstream side, and the front plate and the rear plate are provided. It is preferable that a filter medium is accommodated in a space between the filter material and the filter material.
[0034]
In the fish run-up structure in which the partition is detachably mounted, it is preferable that a downstream side of the overflow section is formed in an arc surface. Further, in the fish run-up structure, the downstream side of the overflow section may be formed as an inclined surface inclined downward at an angle of 13 to 60 degrees.
When the partition is constituted by a front plate of a scour prevention block, the front plate is attached to a drainage channel, and a partition main body provided with a cutout having an open upper end and a partition main body. In the case where the cutout portion is constituted by an adjusting plate, the edge portion on the downstream side of the cutout portion is preferably formed on an inclined surface inclined toward the downstream side so as to be enlarged at an angle of 13 to 60 degrees.
[0035]
When the weir plate is composed of a weir plate main body and a slide adjusting plate, it is preferable that an edge portion on the downstream side of the notch is formed in an arc surface. Alternatively, the downstream edge portion of the cutout portion may be formed on an inclined surface inclined toward the downstream side so as to be enlarged at an angle of 13 to 60 degrees.
[0036]
When the partition is composed of a partition main body and an adjusting plate, it is preferable that a downstream edge portion of the cutout portion is formed in an arc surface. Alternatively, the downstream edge portion of the cutout portion may be formed on an inclined surface inclined toward the downstream side so as to be enlarged at an angle of 13 to 60 degrees.
[0037]
In the fish run-up structure in which the drainage channel includes a partition wall, a drain hole may be provided below the overflow section.
[0038]
In each of the fish upstream structures, it is preferable that a waterweed-like string for spawning and breeding is arranged in the drainage channel at appropriate intervals in the width direction. In this case, the waterweed-like string body has a weight provided at one end of the string-like body and a float provided at the other end, and the string-like body has a length of about 50 to 100 mm on the peripheral surface of the string piece. It is assumed that a large number of bristle pieces are provided, and the weight is installed at the bottom of the drainage channel.
[0039]
A waterway member (hereinafter, referred to as a waterway member) used in the fish run-up structure according to the present invention is a waterway member that constitutes a fishway for moving fish upward to a reservoir having a water level higher than a water level of a drainage channel, It is formed in a U-shaped groove having an open and continuous water passage from the upstream end to the downstream end, and the width of the water passage on the upstream side is enlarged, and all or a part of the joint portion on the downstream side is fitted. A guide fitting portion for detachably fitting a weir plate for raising channel water is provided at a downstream portion of the channel, and a guide portion for detachably fitting a weir plate for raising channel water is provided on the downstream side of the channel. A support base protruding from the bottom of the water channel member installed on the upstream side for supporting the lower surface of the joint portion from below is provided.
[0040]
A more preferred embodiment of the waterway member according to the present invention is a waterway member constituting a fishway for running fish up to a reservoir having a water level higher than the water level of the drainage channel, the upper end being open and the upstream end being the downstream end. A U-shaped groove having a continuous water path toward the water passage, the width of the water path on the upstream side is enlarged, and a connection fitting part for fitting all or a part of the connection part on the downstream side is provided. In addition, a fitting groove for detachably fitting a weir plate that raises the channel water is provided on the opposite side surface and the bottom surface of the channel on the downstream side of the channel, and an upstream groove of the channel is provided. A support for projecting from below the lower surface of the joint portion of the water channel member installed on the upstream side is provided to project from the bottom.
[0041]
Another aspect of the waterway member according to the present invention is a waterway member that constitutes a fishway for causing fish to run up to a reservoir having a water level higher than the water level of the drainage channel, and has an upper end open and a circumferential wall portion. It is closed, and the inside thereof is formed in a box shape with a bottom as a water channel, and an upstream opening and a downstream opening are provided at a required portion on the upstream side and a required portion on the downstream side of the wall portion, A guide portion for detachably fitting a weir plate for raising channel water is provided on the inner surfaces of the upstream opening and the downstream opening, and the upstream opening and the downstream side are provided on the inner surface of the water channel. A guide portion for detachably fitting an intermediate weir plate that raises the channel water so as to partition between the openings is provided. Is set to a height at which it is possible to go up.
[0042]
In this case, a guide portion for detachably fitting a plurality of intermediate weir plates for raising channel water is provided on opposing side surfaces and a bottom surface so as to partition the upstream opening and the downstream opening into a plurality. It is preferable that the overflow portion of each of the weir plates is set to a height at which the fish can go up with respect to the water level on the downstream side.
[0043]
Another aspect of the waterway member according to the present invention is a waterway member that constitutes a fishway for causing fish to run up to a reservoir having a water level higher than the water level of the drainage channel, and has an upper end open and a circumferential wall portion. It is closed, and the inside thereof is formed in a box shape with a bottom as a water channel, and an upstream opening and a downstream opening are provided at a required portion on the upstream side and a required portion on the downstream side of the wall portion, On the opposite side and bottom of the upstream opening and the downstream opening, fitting grooves for detachably fitting a weir plate for raising channel water are provided, and on the opposite side and bottom of the channel. In order to partition between the upstream opening and the downstream opening, an insertion groove for detachably inserting an intermediate weir plate for raising channel water is provided, and an overflow portion of each of the weir plates is provided. Make sure that the fish is set at a height that allows fish to go upstream relative to the water level on the downstream side. It is an butterfly.
[0044]
In this case, in order to partition the upstream opening and the downstream opening into a plurality, a fitting groove for detachably fitting a plurality of intermediate weir plates for raising channel water is provided on the opposite side surface and the bottom surface. It is preferable that the overflow portion of each of the weir plates is set to a height at which the fish can go up with respect to the water level on the downstream side.
[0045]
In each of the waterway members, the upstream opening and the downstream opening are preferably provided on the wall so that the flow direction of water passing through both openings is bent.
[0046]
In each of the waterway members, the downstream side of the overflow section of the weir plate is preferably formed in an arc surface. Alternatively, the downstream side of the overflow portion of the weir plate may be formed as an inclined surface that is inclined downward at an angle of 13 to 60 degrees.
[0047]
In each of the waterway members, the weir plate is composed of a weir plate body detachably mounted on the waterway member and a slide adjusting plate attached to the weir plate body, and the weir plate body has an upper end open. A notch is provided, and the slide adjusting plate is attached to the weir plate main body so as to be slidable in the up and down direction so as to cover a lower portion of the notch. The upper end of the slide adjusting plate can adjust the vertical sliding state of the slide adjusting plate so that the overflow portion has a height at which the fish can run up to the water level on the downstream side. It is preferable that the slide adjusting plate can be fixed to the dam body in this state.
[0048]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
In FIG. 1, a fish run-up structure 1 according to the present invention is for moving fish to a drain 3 connected to a river or a lake and a reservoir 3 as a paddy field 3a having a water level higher than the water level of the drain 2. The fishway 6 is included. The fishway 6 is configured by joining a plurality of waterway members 7 linearly and stepwise to a ridge portion 5 between the paddy field 3a and the drainage channel 2 in a stepwise manner. When the head between the water levels of the reservoir 3 as the paddy field 3a is relatively small, it can be conveniently handled. Now, it is assumed that the width of the ridge 5 (indicated by L1 in FIG. 3) is about 1900 mm, and the head (indicated by L2 in FIG. 2) between the water level of the drainage channel 2 and the paddy field 3a is about 650 mm. I do.
[0049]
In the present embodiment, as shown in FIGS. 4 and 5, the water channel member 7 is formed in a U-shaped groove having an open upper end and a continuous water channel 9 from the upstream end to the downstream end. The upstream end of the water channel 9 is an upstream opening 10 and the downstream end is a downstream opening 11. The upstream portion of the waterway member 7 has a widened waterway width, and serves as a connection fitting portion 13 for fitting the bonding portion 12 forming the downstream portion of the waterway member 7 substantially closely. . To illustrate the dimensions of the main part of the waterway member 7, its total length is set to about 600 mm, its waterway depth is set to about 500 mm, and the waterway width of the upstream portion is set to about 610 mm, The channel width of the downstream portion is set to about 500 mm.
[0050]
As shown in FIGS. 5 and 7, the bottom 15 of the upstream portion of the waterway member 7 has a lower surface 16 of the joint 12 of the waterway member 7 installed on the upstream side over the entire width thereof. A support 17 is provided to support from below. The support 17 has an upper surface 19 formed in a horizontal plane and a height of about 100 mm. The distance L3 (FIG. 7) between the upper surface 19 of the support 17 and the lower surface 18 of the waterway member is set to about 150 mm, which is substantially equal to the water level at which fish can run up.
[0051]
As shown in FIGS. 4 to 7, the channel water is raised on the opposing side surfaces 21, 21 and the bottom surface 22 of the channel member 7 on the downstream side of the channel 9, and its overflow portion 24 (FIGS. 4 and 9). ), A fitting groove 25 for fitting the weir plate 23 for allowing water to overflow toward the downstream side is provided continuously. In the upstream portion of the water channel 9, the water of the reservoir 3 is raised on the opposing side surfaces 26, 26 and the bottom surface 27 of the upstream portion in a state close to the support table 17, and the overflow portion is provided. At 24 (FIGS. 4 and 9), a fitting groove 29 for fitting the weir plate 23 for allowing water to overflow toward the downstream side is provided continuously.
[0052]
As shown in FIG. 4, the weir plate 23 has a trapezoidal shape, an arc shape, a rectangular shape, a V-shape, or the like, and an overflow notch portion whose lower end is the overflow portion 24, in the center of the upper end. 30 are provided. The shape, width, and depth of the overflow notch 30 can be obtained in consideration of the size of the fish that runs up the fishway 6, the amount of water flowing through the fishway 6, and the like. It is set as follows. For example, when the overflow width is small and the overflow depth is shallow, small fish can be moved up, but large fish cannot be moved up, and only limited fish can be moved up. . Therefore, in the present embodiment, the overflow cutout portion 30 is formed in a trapezoidal shape having an upper end width L4 of about 150 mm and a depth L5 of about 100 mm so that large fishes can also run up. The downstream side of the upper end of the overflow cutout portion 30 is formed in an arcuate surface 28 as shown in an enlarged view in FIG. 8, so that fish running upstream does not easily get caught.
[0053]
However, in order to configure the fish run-up structure 1 using the waterway member 7 having such a configuration, as shown in FIGS. 1 to 3, the ridge portion 5 between the drainage channel 2 and the paddy field 3 a is formed. Excavation is performed in a linearly inclined state substantially orthogonal to the flow direction of the drainage channel 2, and the four waterway members 7, 7, 7, 7 are sequentially joined to the excavation portion 31 linearly and stepwise. At this time, as shown in FIG. 7, the joining portion 12 of the waterway member 7b installed on the upstream side is fitted into the joining fitting portion 13 of the waterway member 7a installed on the downstream side, 12 is placed on the support 17 of the downstream waterway member 7a, and each waterway member is placed in a substantially horizontal state. As a result, the lower surface 16 of the joint 12 comes into contact with the upper surface 19 of the support base 17, and the joint 12 is fitted into the joint fitting portion 13. When the waterway members 7, 7 are joined together in this way, the fishway 6 is formed. In addition, in order to adopt a configuration in which the joint of the waterway member 7b installed on the upstream side is fitted into the joint fitting portion 13 of the waterway member 7a installed on the downstream side, the joint portion 32 between the waterway members 7 (FIG. ) Does not require any special measures against water leakage. FIG. 9 is an enlarged perspective view of the fishway 6, and FIG. 10 is an enlarged sectional view of the fishway.
[0054]
At the time of the joining, the insertion length of the joining portion 12 into the joining fitting portion 13 is set as necessary in consideration of the width of the ridge portion 5 and the number of waterway members 7 used, and the total length of the fishway is determined by the ridge. Adjust appropriately according to the width of the part. 2 and 7, the end 33 of the joint 12 protrudes downstream from the support table 17, has an overlap margin of, for example, about 7 cm, and has a lower surface 36 of the projecting portion 35 of the joint. An air gap 37 is formed between the joint fitting portion 13 and the bottom surface 15.
[0055]
As shown in FIG. 2, the upstream opening 10 of the waterway member 7c installed on the most upstream side communicates with the paddy field 3a, and the downstream opening 11 of the waterway member 7d installed on the most downstream side. Are connected to the drainage channel 2. The weir plate 23 is provided in the fitting grooves 25, 25, 25, 25 on the downstream side provided in each of the waterway members 7 and the fitting grooves 29 on the upstream side of the waterway member 7 c installed on the most upstream side. Each is detachably fitted.
[0056]
9 and 10, the four waterway members are referred to as a first waterway member 7A, a second waterway member 7B, a third waterway member 7C, and a fourth waterway member 7D in FIGS. The five dams fitted into the fitting grooves are referred to as a first dam 23A, a second dam 23B, a third dam 23C, a fourth dam 23D, and a fifth dam 23E in order from the top. Further, the water stored in each channel member raised by the weir plate is referred to as a first water storage 39A, a second water storage 39B, a third water storage 39C, and a fourth water storage 39D in order from the top, and a portion storing the water is a first water storage 39A. It is referred to as a reservoir 40A, a second reservoir 40B, a third reservoir 40C, and a fourth reservoir 40D.
[0057]
In the present embodiment, as shown in FIGS. 1 and 2 and FIGS. 11 to 12, the drainage channel 2 has U-shaped support frames 41 arranged side by side at a required interval, and has the length of the drainage channel 2. The side plates 43 are supported in a plurality of stages between the rising pieces 42 adjacent to each other in the direction, and a waterway wall 44 is formed by the side plates 43 supported in the plurality of stages. And the water level of the drainage channel 2 is raised as required by the partition 50 (FIGS. 1-3, 11-12).
[0058]
The partition walls 50 are installed at required intervals according to the gradient of the drainage channel 2 and the amount of water flowing through the drainage channel 2 so that fish can go up the drainage channel 2. For example, as shown in Figs. The water level of the drainage channel 2 is raised as required by the partition wall 50, and water overflows to the downstream side at the overflow notch portion 52 provided at the upper end of the partition wall. Is set to a height (for example, 50 to 150 mm) at which the fish can go up with respect to the water level on the downstream side. The overflow cutouts 52 may be arranged in a straight line as viewed in the length direction of the drainage channel 2 or may be provided in a staggered arrangement as shown in FIGS. In FIG. 11, a swimming place for fish is formed in the corner portion 53 between the partition walls.
[0059]
In addition, the downstream opening 11 of the most downstream water passage member 7D communicates with the opening 38 formed by cutting off the water passage wall 44. At this time, as shown in FIG. 10, the bottom surface 38a of the opening 38 and the bottom surface 48 of the downstream opening 11 are substantially flush.
[0060]
The drainage channel 2 is partially, for example, as shown in FIG. 12, a part of one of the channel walls 44a is expanded to the ridge side, and the bottom is dug down as necessary, so that spawning, habitat, and evacuation of fish and shellfish can be performed. Suitable stagnation and depth sections are provided. Further, from the bottom to the upper end of the enlarged portion 45, a slope member 46 having a step-like or slope-like shape and provided with an appropriate unevenness is provided, and insects, amphibians, and reptiles make the slope member 46. It is designed to be able to go up and down to move between the drainage channel 2 and the ridge surface 47 or the paddy field 3a. The enlarged portion may be provided on both of the channel walls 44.
[0061]
Next, the operation of the fish run-up structure 1 configured as described above will be described with reference to FIGS. That is, when the freshwater is supplied to the paddy field via a pump (not shown) in the above-described fishway 6, the water level is raised by the first dam plate 23A of the waterway member 7A installed on the most upstream side. The fresh water overflows the overflow portion 24 as the lower end of the overflow cutout portion 30 and flows into the first reservoir 40A. The channel water flowing into the first reservoir 40A is raised by the second weir plate 23B, and flows through the overflow unit 24 as a lower end of the overflow notch 30 provided in the second weir plate 23B. Water flows into the second reservoir 40B. The channel water that has flowed into the second reservoir 40B is raised by the third weir plate 23C, overflows the overflow unit 24 as the lower end of the overflow notch 30 of the weir plate, and becomes the third weir. It flows into the reservoir 40C. The channel water that has flowed into the third reservoir 40C is raised by the fourth weir plate 23D, and overflows the overflow unit 24 as the lower end of the overflow cutout 30 of the weir plate to form the fourth reservoir. Flow into 40D. The channel water that has flowed into the fourth reservoir 40D is raised by the fifth weir plate 23E, and overflows the overflow unit 24 as the lower end of the overflow notch 30 of the weir plate to form the drainage channel. Flow out into 2.
[0062]
And, between the water level 56 of the drainage channel and the water level 57 of the fourth water storage 39D, between the water level 57 of the fourth water storage 39D and the water level 59 of the third water storage 39C, the water level 59 of the third water storage 39C and the second water storage 39B Between the water level 60 of the second water storage 39B and the water level 61 of the first water storage 39A, there is a water level difference of about 50 to 150 mm, for example, about 100 mm, at which fish can go up. Is provided. Also, a water level difference of about 70 mm is provided between the water level 62 of the paddy field and the water level 61 of the water channel member 7A on the most upstream side. Then, the fishes can go upstream in each of the overflow sections (overflow water depth is about 30 to 50 mm) 24.
[0063]
Therefore, when using the fish upstream structure 1 according to the present invention, fish such as crucian carp, carp, and catfish enter the drainage channel 2 from a river or a lake, and are moved upstream through the overflow notch 52 of the bulkhead 50. It is possible to reach the place where the fishway 6 exists. Thereafter, the fishway 6 can be moved up. Specifically, the fourth water storage 39D, the third water storage 39C, the second water storage 39B, and the first water storage 39A, each of which has a step-like water surface, are sequentially moved up to the paddy field 3a and spawned in the paddy field. . As a result, the paddy field 3a can be used as a place for spawning, breeding, and breeding fish, and rice cultivation in harmony with nature can be developed.
[0064]
As shown in FIGS. 9 and 13, one end 68 of a string 67 for guiding fish is fixed to, for example, the upper end 66 of the weir plate 23 by means such as screws. It is preferable to attach it by hanging it on a hooked portion provided on the weir plate 23 or the like. The upper end side 66 is set as the lower side of the overflow cutout portion 30 or the periphery of the overflow cutout portion 30 (side portion, etc.) as long as the attached string-like material 67 can have a function of guiding fish. it can.
[0065]
The string 67 is formed using an organic material, for example, using a rough rope (having a diameter of about 5 to 20 mm) or a cotton material in consideration of the final disposal at the end of use of the fishway 6. It is preferable to use a resin, but it may be made of resin. FIG. 14 shows a specific example of the string 67, in which a bristle 67b having a length of about 50 to 100 mm is radially formed on a peripheral surface of a string 67a having a thickness of about 1 to 3 mm. It is provided in large numbers.
[0066]
As described above, the string-shaped object 67 has a relatively small length of about 30 to 50 cm, for example, such that the one end 68 is attached to each of the weir plates 23 and the other end 69 reaches the waterway member installed on the downstream side. In addition to being set to a short length, one end 68 is attached to the uppermost dam plate 23A as shown by a broken line in FIG. May be set. Alternatively, the length may be set so as to be dripped over a plurality of waterway members.
[0067]
The string-like object 67 attached in this manner swings in a state of flowing downstream, like a water plant in a river in nature, and can induce fish to run up.
[0068]
In the case where the reservoir 3 is a paddy field, the timing of spawning of fish into the paddy field substantially coincides with the time of planting the rice. Therefore, when the weir plate 23 is attached at this time, a certain amount of drainage in the fishway 6 is performed. The water level in the paddy field can be kept constant. Conversely, when it is necessary to lower the water level before middle drying or rice harvesting (the fishway is not necessary at this time), as shown in FIG. Drain to drain channel 2. Further, by removing the weir plate in this way, the fish passage 6 can be easily cleaned.
[0069]
Further, in the present embodiment, the lower surface 16 of the joining portion 12 of the waterway member installed on the upstream side is supported from below by the support base 17 of the waterway member installed on the downstream side, and Since the weir plate 23 is mounted on the downstream side of each channel member, a mud reservoir 72 is formed at the bottom of each channel member as shown in FIGS. Accordingly, in the mud reservoir 72, organic substances contained in the water flowing down the fishway from the paddy field can be precipitated, and the outflow of the organic substances into the drainage channel 2 can be prevented accordingly. Further, aquatic plants and the like grow from the soil accumulated in the mud reservoir 72, which can be expected to capture organic matter in the channel water and purify the water quality. This can contribute to prevention of river pollution. Also, as shown in FIG. 7, by forming the bottom surface portion 73 and further the side surface portion 75 of the waterway member 7 on a surface where natural stone is exposed, it is possible to propagate algae on the natural stone surface. In other words, the bottom of the waterway can be used as a feeding ground for small fish and benthic organisms, and a habitat can be provided.
[0070]
When joining the waterway members to each other, as shown in FIGS. 2 and 7, between the lower surface 36 of the projecting portion of the joint portion 12 projecting into the joint fitting portion 13 and the bottom surface 15 of the joint fitting portion 13. Since the gap 37 is formed, algae can be grown in this place, and the gap 37 can be a habitat for benthic organisms who prefer shade, and can also be a place for refuge for fry.
[0071]
In the present embodiment, as shown in FIG. 16, in order to prevent fishes going up the fishway 6 from jumping out of the fishway, and to prevent fishes going upstream from being eaten by birds. A protection net 77 made of, for example, resin is attached via a support frame 76 so as to cover the upper side of the fishway 6. The mesh of the prevention net 77 is formed in, for example, a rhombus having a side length of about 30 mm.
[0072]
The support frame 76 is attached to, for example, each of the four waterway members 7, 7, 7, 7, which are joined in the vertical direction. As shown in FIGS. Equally inverted U-shaped three frame pieces 79a, 79b, 79c are arranged at intervals, and the upper horizontal portions 80, 80, 80 of the three frame pieces are separated by two on both sides of the lower surface thereof. The frame piece 79a which is integrally connected by the linear connection pieces 81, 81 and is located on the upstream end side of the waterway member 7 is formed to be slightly wider than the remaining frame pieces 79b, 79c. These frame pieces are formed by, for example, cutting a hollow pipe or a solid bar (made of metal or resin) having a diameter of about 10 mm into a predetermined length, and bending this into an inverted U shape. The maximum height from the upper end of the water channel member 7 is set to, for example, about 300 to 400 mm.
[0073]
In order to attach the support frame 76 having such a configuration to the waterway member 7, the lower end portions 82 of the wide frame piece 79 a are substantially fixed in the length direction of the upper surface of the joint fitting portion 13 of the waterway member 7. While being inserted closely into the support holes 83 provided in the center, the lower end portions 82 of the intermediate frame piece 79b are positioned substantially at the center of the upper surface of the water channel member 7 in the longitudinal direction (the joint fitting portion). 13 and the joint portion 12), the lower end portions 82, 82 of the frame piece 79c located on the downstream end side of the waterway member 7, This is performed by closely inserting into the support holes 83 provided on the upper surface on the downstream end side of the water channel member 7. After the support frames 76 are attached to the respective waterway members in an upright state in this manner, the prevention net 77 is covered with the support frames 76, 76, 76, 76 so as to cover the upper surface and both side portions thereof. When the waterway members 7, 7, 7, 7 are covered so as to cover the upper side portions thereof, as shown in FIG. 16, the upper side of the fishway 6 is covered with a prevention net 77 in a semicircular tub shape projecting upward. State. The support frame 76 and the prevention net 77 can be removed when the fishway is not in use. The support hole 83 provided in the waterway member 7 is shown only in FIGS. 16 to 18 for convenience.
[0074]
FIGS. 19 and 20 show a fishway 6 in which the waterway members 7 shown in FIG. 21 formed in a U-shaped groove shape are sequentially joined in the up-down direction. The configuration of a weir plate (hereinafter, referred to as a first weir plate) 23a for raising the water in the reservoir 3 as a damper and a weir plate (hereinafter, referred to as a second weir plate) 23b for raising the channel water is different. Further, the groove width of the fitting groove 29 provided at the upstream side portion of the water channel member 7 is formed slightly wider.
[0075]
As shown in FIGS. 20 to 22, the first weir plate 23 a for raising the water in the reservoir 3 has a weir plate main body 85 that is fitted into the fitting groove 29 and a drop adjustment that is attached to the weir plate main body 85. The weir plate main body 85 is provided with a vertically elongated rectangular notch 87 (FIG. 22) extending from the upper end to the vicinity of the bottom surface of the water channel member 7. The upper end width L6 of the rectangular cutout 87 is set to about 150 mm, and the drop adjusting plate 86 for raising the water in the reservoir 3 is fitted into the opposing side surfaces 89, 90 and the bottom surface 91 of the rectangular cutout. Mounting grooves 92 are provided continuously.
[0076]
The lower end portion of the upstream surface of the first weir plate 23a is formed as an inclined surface 95 that can abut on the downstream inclined surface 93 of the support base 17, and the upper end of the inclined surface 95 The surface 96 extending at right angles intersects the upper surface 19 of the support 17 at right angles. Further, in the present embodiment, two drop-down adjusting plates 86 having different vertical heights are used in the mounting groove 92. Then, a rectangular overflow cutout portion 30 as shown in FIG. 21 is formed above the upper end of the upper drop adjusting plate, and the overflow portion 24 serves as the upper end, and the fishes run backward to the water level on the downstream side. The height is set to an ascending height (for example, 50 to 150 mm), and the overflow water depth in the overflow section 24 is set to, for example, about 30 to 50 mm.
[0077]
In the present embodiment, the second dam plate 23b is, as shown in FIGS. 20 to 21 and FIG. 23, a dam plate main body which is fitted into the fitting groove 25 provided at a downstream portion of the waterway member 7. 97, and a slide adjusting plate 99 attached to the weir plate main body 97 in a contact state, and the weir plate main body 97 is provided on the upstream end side of the outer peripheral surface 100 with a projection fitted into the fitting groove 25. A ridge 101 is provided. Then, in a state where the ridge portion 101 is fitted into the fitting groove 25, as shown in FIG. 20, the downstream end side 102 of the outer peripheral surface 100 contacts the inner peripheral surface 103 at the downstream end of the water channel, In this state, as shown in FIGS. 20 and 24, the downstream surface 105 of the second dam plate 23b is configured to be flush with the downstream end surface 106 of the waterway member 7.
[0078]
Further, a rectangular notch 107 having an upper end width L7 of about 150 mm and a depth of about 270 mm is provided slightly closer to the same side as the first dam plate 23a. In the present embodiment, the peripheral edge portion 109 of the rectangular notch 107 is chamfered so as to expand toward the downstream side. The chamfer is provided to make it difficult for catching fish to catch on the peripheral portion, and the inclination angle is about 13 to 60 degrees, preferably about 35 to 45 degrees, and more preferably about 45 degrees. Is set to Inserts 111, 111, 111, 111, 111, 111 for fixing the slide adjustment plate 99 with bolts are embedded in both sides of the surface 110 on the downstream side of the rectangular notch 107 in three steps. I have.
[0079]
The slide adjusting plate 99 covers the rectangular cutout 107 on the upstream side or the downstream side (covers on the downstream side in FIGS. 19 to 20), so that the upper side of the upper end of the slide adjusting plate 99 is covered. Next, this is used to form a rectangular overflow notch 30 as shown in FIG. The overflow section 24 as the upper end is set to a height (for example, 50 to 150 mm) at which the fish can go up to the water level on the downstream side, and the overflow water depth in the overflow section 24 is 30. It is set to about 50 mm.
[0080]
Further, as shown in FIG. 23, the downstream side 108 of the upper end 112 of the slide adjusting plate 99 is, for example, on an inclined surface inclined at about 13 to 60 degrees, preferably about 35 to 45 degrees, more preferably at 45 degrees. It is formed on an inclined surface that is inclined to the extent that it makes it difficult for fish that go upstream to be caught. On both sides of the slide adjusting plate 99, vertically long adjusting holes 113 for inserting a bolt 112 screwed into the insert 111 are provided.
[0081]
FIG. 24 shows a state in which the slide adjusting plate 99 is fixed to the weir plate main body 97 using the lower two-stage inserts 111, 111, 111, 111, and the overflow portion 24 is at the downstream water level. On the other hand, it is set to about 50 to 150 mm, and the overflow water depth in the overflow section 24 is set to about 30 to 50 mm. FIG. 25 shows a state in which the slide adjusting plate 99 is fixed to the weir plate main body 97 using the upper two-stage inserts 111, 111, 111, 111. The height of the overflow portion 24 and the overflow water depth are as follows. The settings are the same as above.
[0082]
In addition, as shown in FIG. 26, the lower end of the rectangular notch 107 may be used as the overflow portion 24 without attaching the slide adjusting plate 99.
[0083]
The first and second dam plates 23a and 23b are made of heavy concrete such as concrete, and the drop adjusting plate 86 and the slide adjusting plate 99 are made of wood, resin, metal or the like. Is done.
[0084]
FIG. 19 shows the fish run-up structure 1 configured by using the waterway member 7 to which the first and second weir plates 23a and 23b having the above-mentioned configuration are attached, and the waterway members 7 and 7 are mutually connected. The procedure for joining and forming the fishway 6 is the same as described above. That is, the fishway 6 excavates the ridge portion 5 between the drainage channel 2 and the paddy field 3 a in a linearly inclined state substantially perpendicular to the flow direction of the drainage channel 2. The water channel members 7, 7, 7 are sequentially joined in a straight line at different levels. At this time, as in the above embodiment, the joint 12 of the waterway member installed on the upstream side is fitted into the joint fitting portion 13 of the waterway member installed on the downstream side, and the joint 12 Is placed on the support 17 of the downstream channel member 7, and the respective channel members are set substantially horizontally. As a result, the lower surface 16 of the joint 12 comes into contact with the upper surface 19 of the support base 17, and the joint 12 is fitted into the joint fitting portion 13. The waterway members 7, 7 are thus joined to each other to form the fishway 6.
[0085]
As shown in FIG. 19, the upstream opening 10 of the waterway member 7g installed on the most upstream side communicates with the paddy field 3a, and the downstream opening 11 of the waterway member 7e installed on the most downstream side. The overflow notch 30 communicates with the drainage channel 2. Further, the second dam plate 23b is removably fitted into the downstream fitting grooves 25, 25, 25 provided in each of the waterway members 7, and the waterway member 7g installed at the most upstream side is detachably fitted. The first weir plate 23a is removably fitted in the fitting groove 29 on the upstream side.
[0086]
For each of the first dam plate 23a and the second dam plates 23b, 23b, 23b, the height of the overflow section 24 and the overflow water depth at the rectangular cutouts 87, 107 are determined by the drainage channel 2 According to the drop L2 between the water levels of the paddy fields 3a and the width L1 of the ridges 5, the drop adjustment plate 86 and the slide adjustment plate 99 are adjusted so as to enable fish to run up. Is what is done. The setting procedure is as described above.
[0087]
In the present embodiment, the first weir plate 23a also functions as an earth retaining member for preventing the soil of the paddy field from moving to the fishway side. In addition, the space 115 formed between the upper and lower second dam plates 23b and 23b and the space 116 between the first and second dam plates 23a and 23b in the uppermost stream side water passage member 7g. As shown in FIG. 19 with dotted lines, the filter medium 117 can be accommodated. By placing the filter medium 117 in this way, it is possible to filter fine particles such as sludge contained in the water flowing from the paddy field and purify the water quality of the wastewater flowing into the drainage channel 2. In addition, it is preferable to use what consists of organic materials, such as a straw and a rice husk, considering the final disposal as the filter medium 117. In the same manner as described above, as shown in FIG. 19, it is preferable to mount a support frame 76 on each water channel member 7 and cover the prevention net 77. Also, it is preferable to attach a waterweed-like string 67 to the first and second dam plates 23a and 23b in the same manner as shown in FIGS. FIG. 19 shows a case where a long string-like object 67 that is dripped down from the paddy field 3a side to the drainage channel 2 side is attached.
[0088]
FIG. 27 shows another embodiment of the fishway 6 configured by using the waterway member 7 having a U-shaped groove. This is provided when it is desired to allow a unicycle or the like to run on the formed ridgeway 119 without obstacles.
[0089]
As shown in FIGS. 27 to 28, the fishway 6 sequentially joins four waterway members 7, 7, 7, 7 in the longitudinal direction of the ridge at the boundary between the ridgeway 6 and the slope 120 of the ridge. To form the fishway main body 121. For this purpose, the joining part 12 of the waterway member 7k installed on the upstream side is fitted into the joining fitting part 13 of the waterway member 7j installed on the downstream side, and the joining part 12 is connected to the waterway on the downstream side. Each of the waterway members is placed in a substantially horizontal state by being placed on the support base 17 of the member 7j. 27, 30, and 32 in the fitting groove 29 on the upstream end side of the waterway member 7m installed on the most upstream side and the fitting groove 25 on the downstream end side of the waterway member 7j installed on the most downstream side. As shown, end plates 122 and 123 having no rectangular cutouts 87 and 107 as described above are fitted. Except for the most downstream waterway member, a weir plate 23, 23, 23 having the same configuration as the second weir plate 23b is fitted into the fitting groove 25, 25, 25 on the downstream side of each waterway member. The overflow notch 30 of each weir plate is set, for example, in the same manner as shown in FIG. 20 so that the overflow section 24 of the required height and the overflow water depth can be obtained by sliding the slide adjusting plate 99. You.
[0090]
Further, as shown in FIGS. 27 to 30, the fishway 6 has a downstream opening as a circular hole, for example, at the lower end of the side surface portion 125 of the waterway member 7j located at the most downstream side facing the drainage channel 2. The downstream opening 11 is formed as a PVC pipe having an inner diameter of, for example, about 150 to 200 mm and a length of about 60 to 200 cm, which is in communication with the drainage channel 2. The upstream end portion 127 of the water channel member 7n which is buried underground substantially horizontally is joined in an inserted state.
[0091]
In addition, as shown in FIGS. 27 and 31 to 32, an upstream opening 10, for example, as a circular hole is provided at the lower end of the side surface portion 129 facing the paddy field 3 a of the waterway member 7 m located on the most upstream side. For example, a water channel formed as a vinyl chloride pipe having an inner diameter of about 150 to 200 mm and buried substantially horizontally underground, communicating with a water channel member 7p as a basin member provided at a portion of the ridge on the paddy field side. The downstream end portion 130 of the member 7q is joined in an inserted state.
[0092]
The waterway member 7p as the measure member is one component of the fishway 6, and is configured in a rectangular tube shape as shown in FIGS. 31 to 32, for example, and is a pipe-shaped waterway member 7q located at the most upstream side. A downstream opening 11 for joining an upstream end portion 131 of the fish passage in an inserted state is provided at a lower end side of a side surface portion 132 facing the fishway main body 121. The paddy side of the basin member (water channel member) 7p is entirely open, and a weir plate 137 that raises the water of the paddy field 3a is fitted into the opposing side surfaces 135 and 135 and the bottom surface 136 of the opening 133. Fitting grooves 139 are provided continuously. The dam plate 137 is configured by mounting the required number of drop adjusting plates 138c in fitting grooves 138b of a rectangular cutout 138a provided in the dam plate main body 138 in the same manner as in the dam plate shown in FIG. ing.
[0093]
In the case of the fish run-up structure 1, the fish that has entered the lower pipe-shaped channel member 7n from the drainage channel 2 passes through the U-shaped groove-shaped channel member 7 through the weir plates 23, 23, 23. Through the overflow notch 30, and reaches the U-shaped groove-shaped channel member 7m located on the most upstream side. After that, the water enters the pipe-shaped waterway member 7q located above, reaches the basin member (waterway member) 7p, and enters the paddy field 3a through the overflow notch 140 of the weir plate 137 provided in the basin member 7p. Can be reached.
[0094]
The laying height of the pipe-shaped waterway member 7n located below is set so that the inside of the waterway member is always full in order to facilitate the entry of fish into the waterway member 7n. Is good. The upper and lower pipe-shaped waterway members 7n and 7q can function as evacuation places for fish, for example, in the daytime, in addition to functioning as a way for fish to enter.
[0095]
Note that the support frame 76, the prevention net 77, the string 67, and the filtering material 117 provided in the same manner as described above can be removed when the fishway is not needed.
[0096]
In addition, the U-shaped groove-shaped waterway member is joined so as to cross the ridge to form a fishway main body, and a pipe-shaped waterway member is provided only on the downstream end side or only on the upstream end side of the fishway main body. In some cases, they join to form a fishway.
[0097]
FIGS. 19 and 33 to 37 show another embodiment of the drainage channel 2 constituting the fish upstream structure 1 according to the present invention. The U-shaped support frame 41 having the same configuration as above is provided at a required interval. The side plates 43 are supported in a plurality of stages between the rising pieces 42 adjacent to each other in the length direction of the drainage channel 2, and the channel walls 44 are formed by the side plates 43 supported in the plurality of stages. I have. Then, by inserting the edge portions 50a, 50a at both ends of the concrete partition wall 50 into the insertion groove 49 provided on the inner surface of the selected U-shaped support frame 41, the water level of the drainage channel 2 becomes necessary. Raised. As shown in FIGS. 34 and 35, a rectangular notch 140 having an open upper end is provided on one end side of the partition wall 50, and the adjusting plate 141 is connected to, for example, an upstream surface of the rectangular notch 140. In this embodiment, an overflow notch 52 is formed above the adjustment plate 141 so as to be slidable in the vertical direction. The peripheral edge portion 142 of the overflow notch 52 is chamfered so as to expand toward the downstream side. The opening width of the overflow notch 52 is set to, for example, 150 mm, and the depth is set to, for example, 180 mm.
[0098]
Also, as shown in FIG. 36, inserts 143, 143 and 143 for fixing the adjustment plate 141 in the upper and lower three stages are located on both sides of the rectangular cutout 140 on the upstream surface of the partition wall 50. 143, 143, 143, 143 are embedded.
[0099]
The adjusting plate 141 is made of wood, resin, metal, or the like, has a horizontally long rectangular plate shape, and has vertically long adjusting holes 144 and 144 on both sides thereof. 19, 34, and 37 show a state in which the adjusting plate 141 is fixed to the partition wall 50 using bolts 145 screwed into the upper two-stage inserts 143, 143, 143, and 143. FIG. This shows a state in which the adjusting plate 141 is fixed to the partition wall 50 using bolts 145 screwed into the two-stage inserts 143, 143, 143, 143. In these, depending on the amount of water flowing in the drainage channel 2, the overflow portion 54 as the upper end of the adjusting plate 141 has a height at which fish can go up to the downstream water level (for example, a height of about 50 to 150 mm). The overflow water depth in the overflow section 54 is set to, for example, about 30 to 50 mm.Depending on the amount of flowing water, the lower end of the rectangular cutout 140 may be removed by removing the adjustment plate. Sometimes.
[0100]
Also, in the present embodiment, at the lower end side of the partition 50, water is provided below the rectangular notch 140 (for example, substantially at the center in the width direction of the rectangular notch 140) and at the other end of the partition. Holes 146 and 146 are provided. The drain hole 146 is formed, for example, as a circular hole having a diameter of 50 to 100 mm (a circular hole having a diameter of about 50 mm in FIGS. 19 and 34), and a water channel bottom 147 of the drainage channel 2 (FIG. 37). From about 30 to 50 mm. As shown in FIG. 38, the drain hole 146 can be closed by a plug 148 by means such as fitting or screwing.
[0101]
The drainage holes 146a (FIGS. 19, 34, and 37) provided below the rectangular cutouts 140 are opened to release water, so that the overflow cutouts 52 are formed. In addition to the water drop F1 (FIG. 37) from the water, the water discharge F2 (FIG. 37) from the drain hole 146a is added, so that the fish feels the flow and is easily guided toward the overflow notch 52. The effect can be expected.
[0102]
When the drain hole 146b (FIG. 19) on the other end side is also opened, the flow action due to the discharge of water from the drain hole 146b causes the water to flow around the drain hole 146b. It can form a relatively slow flowing part and a relatively fast flowing part underneath, so that it is possible to mix a place with stagnation and a place with flow, and to create a habitat suitable for the ecological environment of fish. It can be formed.
[0103]
The drain hole 146 is provided so that the slide-type adjusting plate 141 is not covered with the adjusting plate 141 even at the lowest position.
[0104]
In addition, when the water volume in the drainage channel 2 abnormally increases due to an unexpected rainfall, the water level of the drainage channel 2 is adjusted without opening the drainage hole 146 without releasing the partition wall 50. May be possible. For this purpose, the number of drain holes provided may be increased or the diameter of the drain holes may be increased.
[0105]
In addition, there is an effect that fish and shellfish can move to the opposite side of the partition wall 50 through the drain holes 146a and 146b.
[0106]
In this embodiment, as shown in FIG. 37, a waterweed-like string 149 for breeding and laying eggs is arranged at appropriate intervals in the drainage channel 2. As shown in FIG. 37, the waterweed-like string 149 is provided with a weight 151 such as a stone or a concrete mass at one end of a resin string-like body 150, and a float 152 such as styrene foam or a bladder at the other end. Provided. The string-like object 149 has a configuration in which a large number of hair pieces 154 having a length of about 50 to 100 mm are radially provided on the peripheral surface of a string piece 153 having a diameter of about 1 to 3 mm, The length is set to, for example, about 100 to 130 cm in accordance with the water depth of the drainage channel 2. In the waterweed-like string body 149 having such a configuration, the weight 151 is placed on the waterway bottom 147 of the drainage channel 2, and is disposed at appropriate intervals in the waterway width direction. It forms a state and functions as an aid for spawning and growing fish.
[0107]
For example, as shown in FIG. 37, when water falls on the downstream side through the overflow cutout portion 52 provided in the partition wall 50, the waterfall may scour the channel bottom. 39 to 42, the partition wall 50 is formed by using a scouring prevention block 156 having a function of preventing such scouring.
[0108]
The scour prevention block 156 is made of, for example, precast concrete and has a width substantially equal to the width of the drainage channel 2 as shown in FIGS. A front plate 159 functioning as the partition wall 50 is erected at the upstream end of the extended bottom plate 157, and a rear plate 160 is erected at the downstream end of the bottom plate 157. It has an open configuration, and the height of the rear plate 160 is set such that its upper end 161 is substantially flush with the water channel bottom 147. The length of the bottom plate 157 of the scouring prevention block 156 in the front-rear direction is set to, for example, 820 mm, the height of the front plate 159 is set to, for example, 440 mm, and the height of the rear plate 160 is set to, for example, 190 mm. A space 163 having a width of about 700 mm is formed between the front plate 159 and the rear plate 160.
[0109]
The scouring prevention block 156 having such a configuration is configured such that the front portion 159 serving as the partition wall 50 comes into contact with the downstream surface 164 of the U-shaped support frame 41 constituting the drainage channel 2 and the lower portion 165 drains. The open ends 166, 166 of the scouring prevention block 156, which are buried and installed at the bottom of the road 2, are closed with, for example, side plates 167, 167 as shown in FIG. A rectangular notch (having an opening width of about 150 mm) 169 having an open upper end is provided in the front plate 159 serving as the partition wall 50, and inserts 170 are provided on both sides of the rectangular notch 169 in three vertical steps. Is buried. Then, a bolt 172 that passes through adjustment holes 171 and 171 provided on both sides of the slide-type adjustment plate 141 configured in the same manner as above is screwed into a required insert 170 to thereby adjust the adjustment plate 141. Can be fixed to the front plate 159. Thus, the overflow cutout portion 52 can be formed above the adjustment plate 141, and the overflow portion 54 that allows fish to run up is formed in the same manner as described above.
[0110]
In the case of such a configuration, since the bottom plate 157 exists on the downstream side of the partition (front plate 159) 50, the water channel bottom is protected by the bottom plate 157 even if water is dropped through the overflow notch 52. Therefore, scouring of the water channel bottom can be prevented. Further, since a deep portion 172 (FIG. 40) in which the channel bottom is further dug down is formed on the downstream side of the overflow notch portion 52, when fish go up the overflow notch portion 52, depending on the depth, There is an advantage that it is easy to run up with momentum.
[0111]
In addition, since the empty space 163 between the front plate 159 and the rear plate 160 of the scour prevention block 156 serves as a mud pool, the fertilizer component flows into the drainage channel 2 from the paddy field through the fishway 6 and the like. In this case, fine soil containing organic matter such as is deposited to purify water.
[0112]
In addition, by containing the filtering material 173 such as straw or chaff in the empty space 163 of the scour prevention block 156, the water purification effect in the drainage channel 2 can be improved. Also in the present embodiment, drain holes 146 having the same function as above are provided on, for example, both sides of rectangular cutout 169. In the same manner as above, a string 67 for guiding fish can be attached around the adjustment plate 141 or the rectangular cutout 169.
[0113]
[Second embodiment]
43 to 45 show another embodiment of the fish run-up structure 1 according to the present invention, in which the ridge 5 between the water level of the drainage channel 2 and the water level of the reservoir 3 as the paddy field 3a is provided. It forms a fishway 6 for fish to go up from the drainage channel 2 toward the reservoir 3, and can conveniently cope with a large drop between the water level of the drainage channel 2 and the water level of the reservoir 3 as the paddy field 3 a. . Now, the width of the ridge 5 (indicated by L1 in FIG. 45) is about 1900 mm, and the head (indicated by L2 in FIG. 44) between the water level of the drainage channel 2 and the water level of the reservoir 3 as the paddy field 3a is about 900 mm. Assume the case.
[0114]
As shown in FIGS. 46 to 47, the waterway member 7 is open at the upper end and closed by a circumferential wall portion 180, and is formed in a bottomed rectangular parallelepiped box shape having a waterway 9 therein. The long side length is set to about 1100 mm, the short side length is set to about 600 mm, and the vertical height is set to about 860 mm. As shown in FIG. 47, a rectangular downstream side having a length of approximately 300 mm, a width of approximately 300 mm, and a depth of approximately 600 mm, which is vertically longer from the upper end to the lower end side, is provided at a portion near one short side of one long side wall portion 180 a. As shown in FIG. 46, a square having the same width as the downstream opening 11 and having a depth of about half of that of the downstream opening 11 is provided in the portion near the other short side of the other long side wall portion 180b. An upstream opening 10 is provided.
[0115]
A fitting groove 183 for fitting the weir plate 23 for raising the channel water is continuously provided on the inner side surfaces 181 and 181 and the bottom surface 182 of the downstream opening 11 facing each other. On the inner side surfaces 185 and 185 and the bottom surface 186, fitting grooves 187 for fitting the weir plate 23 for raising the channel water are continuously provided. In the center of both long side walls 180a, 180b, an intermediate fitting groove 191 for fitting the weir plate 23 for raising channel water into the opposing inner side surfaces 189, 189 and the bottom surface 190 of the channel member. It is provided continuously. Each of the weir plates 23 is provided with an overflow notch 30 similar to the above at the center of the upper end.
[0116]
Then, as shown in FIG. 45, the waterway members 7, 10 are connected such that the downstream opening 11 of the waterway member 7 installed on the upstream side communicates with the upstream opening 10 of the waterway member 7 installed on the downstream side. 7 are joined to each other, and at the communicating portion between the upstream opening 10 and the downstream opening 11, a weir plate 23 is fitted into a fitting groove provided at one of the openings, and a water passage on the upstream side of the weir plate is provided. Water is being raised.
[0117]
However, in order to configure the fish run-up structure 1 using the waterway member 7 having the above-described configuration, as shown in FIGS. 43 to 45, the ridge portion 5 between the drainage channel 2 and the paddy field 3 a is excavated, and At the excavation part, the three waterway members 7E, 7F, and 7G are arranged in a substantially horizontal state in order from the top, and are sequentially joined stepwise. In this case, as shown in FIG. The 7G downstream opening 11 is communicated with an opening 38 provided in a water channel wall 43 of the drainage channel 2 having the same configuration as described above. Then, as shown in FIG. 48, the bottom surface 38a of the opening 38 and the bottom surface 48 of the downstream opening 11 are substantially flush.
[0118]
Further, as shown in FIG. 49, the bottom surface 48 of the downstream opening 11 of the waterway member 7F located at the middle stage is substantially flush with the bottom surface 192 of the upstream opening 10 of the waterway member 7G installed at the most downstream side. To
[0119]
As shown in FIG. 50, the bottom surface 48 of the downstream opening 11 of the channel member 7E located at the most upstream side is substantially flush with the bottom surface 192 of the upstream opening 10 of the channel member 7F located at the middle stage. . Then, the upstream opening 10 of the water channel member 7E installed on the most upstream side is communicated with the paddy field 3a. The upper and lower waterway members 7, 7 are connected to each other using, for example, an angle member 193 shown in FIG. FIG. 51 is an enlarged perspective view of the fishway 6.
[0120]
As shown in FIG. 45, the fitting groove 183 and the middle fitting groove 191 provided in the downstream opening 11 of the most downstream waterway member 7G, and the fitting groove provided in the downstream opening 11 of the middle waterway member 7F. The fitting groove 191 between the groove 183 and the waterway member, and the fitting groove 183 of the downstream opening 11 of the waterway member 7E installed at the most upstream side and the middle fitting groove 191 in the waterway member, The weir plate 23 is fitted into each of the fitting grooves 187 of the upstream opening 10. The weir plate 23 is provided with an overflow notch 30 having the same configuration as described above.
[0121]
For convenience of explanation, FIGS. 52 and 51 showing cross-sectional views taken along the line AA of FIG. 45 and FIG. 45 show the seven damping plates fitted as described above in order from the top, the first damping plate 23E, The second dam 23F, the third dam 23G, the fourth dam 23H, the fifth dam 23I, the sixth dam 23J, and the seventh dam 23K. In addition, the stored water raised by the second to seventh dam plates is arranged in order from the top, a first water storage 39E, a second water storage 39F, a third water storage 39G, a fourth water storage 39H, a fifth water storage 39I, and a sixth water storage 39J. That is, the portions storing the water are referred to as a first reservoir 40E, a second reservoir 40F, a third reservoir 40G, a fourth reservoir 40H, a fifth reservoir 40I, and a sixth reservoir 40J.
[0122]
However, when the fish upstream structure 1 is used, the water level of the water supplied to the paddy field 3a is raised by the first weir plate 23E, and flows into the first reservoir 40E from the overflow cutout portion 30. The water that has flowed into the first reservoir 40E is raised by the second weir plate 23F and flows into the second reservoir 40F from the overflow notch 30. Similarly, the water that has flowed into the second reservoir 40F is raised by the third weir plate 23G, flows into the third reservoir 40G from the overflow notch 30, and flows into the third reservoir 40G. The water is raised by the fourth weir plate 23H and flows into the fourth reservoir 40H from the overflow notch 30. The water that has flowed into the fourth reservoir 40H is raised by the fifth weir plate 23I. The water flowing from the overflow notch 30 into the fifth reservoir 40I, the water flowing into the fifth reservoir 40I is raised by the sixth weir plate 23J, and flows into the sixth reservoir 40J from the overflow notch 30J. Then, the water that has flowed into the sixth reservoir 40J is raised by the seventh weir plate 23K and flows out of the overflow notch 30 into the drainage channel 2. In FIG. 52, a water level difference of about 50 to 150 mm, for example, about 100 mm, at which fish can run up, is provided between adjacent water levels, and the water level of the paddy field 3a and the first water storage 39E are different. There is a similar difference between the water level and the water level. In the overflow section (overflow water depth is, for example, about 30 to 50 mm) 24 as a lower end of each overflow cutout section 30, fish can go up.
[0123]
Therefore, when using the fish upstream structure 1 according to the present invention, fish such as crucian carp, carp, and catfish enter the drainage channel 2 from a river or a lake, and are moved upstream through the overflow notch 52 of the bulkhead 50. It is possible to reach the place where the fishway 6 exists. Thereafter, the fishway 6 can be moved up. Specifically, the sixth water storage 39J, the fifth water storage 39I, the fourth water storage 39H, the third water storage 39G, the second water storage 39F, and the first water storage 39E having a stepped water surface are sequentially passed through the overflow section 24. It is possible to go up to the paddy field 3a and lay eggs in the paddy field. Then, by removing each weir plate 23, the water in the paddy field can be smoothly drained to the drainage channel 2.
[0124]
The downstream side of the overflow notch 30 of the weir plate 23 is formed in an arcuate surface, and the configuration in which the string 67 for guiding fish is attached to the weir plate 23 is the same as in the above-described embodiment. . Then, a mud reservoir can be formed on the bottom side of the water channel member 7, and this can be made to function in the same manner as in the above embodiment.
[0125]
The weir plate 23 is formed in the same manner as in the above-described embodiment in order to form a suitable overflow portion 24 according to the difference between the water level of the drainage channel 2 and the water level of the paddy field 3a and the width of the ridge. It is more preferred to configure That is, as the weir plate 23 located on the most upstream side, the first weir plate 23a shown in FIG. 22 having a configuration in which the required number of the drop adjusting plates 86 of the required height are sequentially stacked in the mounting groove 92 is adopted. As the dam plate 23, the second dam plate 23b having a slide adjusting plate 99 as shown in FIG. 23 is preferably used.
[0126]
[Third Embodiment]
53 to 54 show that the width (shown by L1 in FIG. 54) of the ridge portion 5 between the paddy field 3a and the drainage channel 2 of the fish run-up structure 1 according to the present invention is relatively small. And the water level of the reservoir 3 as the paddy field 3a (shown by L2 in FIG. 58) is relatively large. The bent fishway 6 is formed by using two kinds of waterway members, a first waterway member 7H having a cylindrical shape and a second waterway member 7I having a U-shaped groove shape, and joining these waterway members as required. Is what you do. Now, it is assumed that the width of the ridge portion 5 is about 1700 mm and the head between the water level of the drainage channel 2 and the water level of the paddy field 3a is about 580 mm.
[0127]
As shown in FIGS. 55 to 56, the first water channel member 7H is formed in a bottomed cylindrical box shape that is open at the upper end and closed by a circumferential wall portion 180, and has an inner diameter of about 900 mm in plan view. The upper and lower portions are formed to have a height of about 720 mm, and an upstream opening 10 and a downstream opening 11 are provided at required portions of an upstream portion and a downstream portion of the wall portion 180. In the present embodiment, the upstream opening 10 and the downstream opening 11 are formed as a rectangular opening having an open upper end whose upper end is slightly larger than the lower end, and the flow of water passing through both openings 10 and 11 is restricted. It is provided so as to be bent at a substantially right angle. And the upper end width of the upstream opening 10 and the downstream opening 11 is formed to be about 610 mm, the depth of the upstream opening 10 is formed to be about 360 mm, and the depth of the downstream opening 11 is larger than that. It is formed slightly deep, about 560 mm.
[0128]
As shown in FIGS. 55 and 57, the second water channel member 7I is formed in a U-shaped groove shape, the upstream end of the water channel being the upstream opening 10 and the downstream end being downstream. It is a side opening 11. Further, fitting grooves 201 and 202 for fitting the weir plate 23 for raising the channel water are provided continuously on the opposing side surfaces 197 and 197 and the bottom surface 199 at the upstream portion and the downstream portion of the inner surface of the channel. I have. In the present embodiment, the total length is set to about 600 mm, and the channel depth is set to about 500 mm.
[0129]
However, in order to configure the fish upstream structure 1 using the first and second waterway members 7H and 7I, as shown in FIGS. The first water channel member 7H is disposed on the upstream side and the downstream side along the extension direction of No. 2. Then, the upstream portion 203 of the second channel member 7I installed in a substantially horizontal state on the downstream side is fitted to the downstream opening 11 of the first channel member 7H with an elastic water blocking material interposed. At the same time, the downstream side opening 11 of the second channel member 7I is communicated with the opening 38 provided in the channel wall 44 of the drainage channel 2.
[0130]
Further, the adjacent first water passage members 7H, 7H are connected by the second water passage member 7I as a U-shaped groove. At this time, the downstream portion 206 of the second water passage member 7I is At the upstream opening 10 of the first water channel member 7H installed on the downstream side, while being inserted in a fitted state with an elastic water blocking material interposed, the upstream portion 203 of the second water channel member 7I is An elastic water blocking material is inserted into the downstream opening 11 of the first water channel member 7H installed on the upstream side in a fitted state. The downstream portion 206 of the second water channel member 7I is similarly inserted into the upstream opening 10 of the first water channel member 7H installed on the upstream side in a fitted state. Then, the upstream opening 10 of the second water channel member 7I is communicated with the paddy field 3a.
[0131]
Also, in each of the second water channel members 7I, the dam plates 23, 23 are detachably fitted in the upstream fitting groove 201 and the downstream fitting groove 202, respectively. These weir plates 23 are provided with overflow notches 30.
[0132]
For convenience of explanation, FIGS. 58 and 55 showing BB cross-sectional views of FIGS. 54 and 54 show the six dams fitted as described above in order from the top, the first dam 23L and the first dam 23L. The second dam 23M, the third dam 23N, the fourth dam 23P, the fifth dam 23Q, and the sixth dam 23R. Further, the water storage portions raised by the second to fifth dam plates are referred to as a first water storage 39L, a second water storage 39M, a third water storage 39N, a fourth water storage 39P, and a fifth water storage 39Q in order from the top. Are stored as a first reservoir 40K, a second reservoir 40L, a third reservoir 40M, a fourth reservoir 40N, and a fifth reservoir 40P.
[0133]
However, in the case of the fish upstream structure 1, the level of the water supplied to the paddy field 3a is raised by the first weir plate 23L, and flows into the first reservoir 40K from the overflow cutout 30. The water that has flowed into the first reservoir 40K is raised by the second weir plate 23M and flows into the second reservoir 40L from the overflow notch 30. Similarly, the water that has flowed into the second reservoir 40L is raised by the third weir plate 23N, flows into the third reservoir 40M from the overflow notch 30, and flows into the third reservoir 40M. The water is raised by the fourth weir plate 23P and flows into the fourth reservoir 40N from the overflow notch 30. The water that has flowed into the fourth reservoir 40N is raised by the fifth weir plate 23Q and overflows. It flows into the fifth reservoir 40P from the flow notch 30, and finally flows out into the drainage channel 2 from the fifth reservoir 40P. In FIG. 58, a water level difference of about 50 to 150 mm, for example, a water level difference of about 100 mm is provided between adjacent water levels so that fish can go up. Then, in the overflow section (the overflow water depth is, for example, about 30 to 50 mm) as the lower end of each of the overflow cutouts 30, the fish can go up.
[0134]
Therefore, when using the fish upstream structure 1 according to the present invention, fish such as crucian carp, carp, and catfish enter the drainage channel 2 from a river or a lake, and are moved upstream through the overflow notch 52 of the bulkhead 50. It is possible to reach the place where the fishway 6 exists. Thereafter, the fishway 6 can be moved up. Specifically, the fifth water storage 39Q, the fourth water storage 39P, the third water storage 39N, the second water storage 39M, and the first water storage 39L having a stepped water surface are moved up in the overflow section 24 in this order, and 3a, and can be spawned in paddy fields. Then, by removing the weir plates 23, the water in the paddy fields can be drained smoothly.
[0135]
The downstream side of the overflow notch 30 of the weir plate 23 is formed in an arcuate surface, and the configuration in which the string 67 for guiding fish is attached to the weir plate 23 is the same as in the above-described embodiment. . Then, a mud reservoir can be formed on the bottom side of the water channel member 7, and this can be made to function in the same manner as in the above embodiment.
[0136]
The weir plate 23 is formed in the same manner as in the above-described embodiment in order to form a suitable overflow portion 24 according to the difference between the water level of the drainage channel 2 and the water level of the paddy field 3a and the width of the ridge. It is more preferred to configure That is, the first dam plate 23a shown in FIG. 22 having a configuration in which the required number of the drop adjusting plates 86 of the required height are sequentially stacked in the mounting groove 92 is adopted as the dam plate 23 located on the most upstream side, As the weir plate 23, it is preferable to employ the second weir plate 23b having a slide adjusting plate 99 as shown in FIG.
[0137]
[Other Embodiments] The present invention is not limited to the embodiment described above, and various design changes are possible within the scope of the claims. Nor. An example is as follows.
[0138]
(1) The fish run-up structure according to the present invention is applied to reservoirs that require fish run-up, including fish ponds, reservoir ponds, and water park ponds using fallow fields, in addition to the paddy fields described above. it can.
[0139]
(2) When the channel member is configured in the above-described U-shaped groove shape, the weir plate mounted on the downstream portion of the inner surface of the channel is not necessarily mounted at the downstream end as shown in FIG. 2, for example. , May be mounted slightly upstream.
[0140]
(3) FIG. 59 shows another mode of the water channel member 7 having a U-shaped groove shape, and has a configuration bent in a U shape. The joint 12 and the joint 13 are provided in the same manner as described above, and the joint 12 is fitted into the joint 13 of the other channel member 7A1 installed on the downstream side, The joint 12 of the other channel member 7A2 installed on the upstream side is fitted into the joint fitting portion 13 of the U-shaped channel member 7. The V-shaped channel member 7 having such a configuration can be advantageously used, for example, when the ridge width is relatively small while the water level difference between the drainage channel and the paddy field is relatively large.
[0141]
(4) When the waterway member 7 is configured as a box with a bottom that is open at the upper end and closed by a wall 180 in the circumferential direction, the box shape may be a rectangular parallelepiped box shape shown in FIG. The configuration shown in FIG.
[0142]
(5) When the channel member 7 is configured in the shape of a U-shaped groove, one or a plurality of intermediate dam plates 23 for raising channel water are provided so as to partition between the upstream opening 10 and the downstream opening 11. It may be detachably mounted.
[0143]
(6) When the waterway member 7 has a box shape with a bottom that is open at the upper end and closed by a wall in the circumferential direction, the waterway is located upstream of the waterway in order to properly set the water level difference between adjacent water storage portions. One or more intermediate weir plates for raising the channel water may be detachably mounted so as to partition the side opening and the downstream opening into a plurality.
For example, when the channel member 7 is configured in a rectangular parallelepiped box shape as shown in FIG. 51, a plurality of intermediate weir plates 23 for raising channel water so as to partition the upstream opening 10 and the downstream opening 11 into a plurality. The sheets may be detachably mounted. When the channel member is formed in a cylindrical box shape with a bottom as shown in FIG. 55, an intermediate weir plate for raising channel water so as to partition the upstream opening 10 and the downstream opening 11 into a plurality of sections. One or more pieces may be detachably mounted
[0144]
(7) When the waterway member 7 is configured in a box shape with a bottom, and when the water level difference between the reservoir and the drainage channel is relatively small, the middle weir plate 23 (for example, a water channel having a rectangular parallelepiped box shape shown in FIG. 51). The intermediate weir plate of the member may be omitted.
[0145]
(8) As shown in FIG. 55, for example, as shown in FIG. 55, the upstream opening 10 and the downstream opening 11 of the waterway member having a bottomed box shape that is open at the upper end and closed by a circumferential wall portion. It is preferable to provide the wall portion so that the flow direction of the water passing through 11 is bent. Can be set.
[0146]
(9) When the waterway member 7 is configured as a box with a bottom, a weir plate that raises waterway water is detachably attached to a communicating portion between the upstream opening 10 and the downstream opening 11 on the upstream side. In addition to the case where it is mounted on the inner surface of the opening 10 and the inner surface of the downstream opening 11, it includes the case where it is mounted on a part near the upstream opening 10 and a part near the downstream opening 11.
[0147]
(10) The guide portion for fitting the weir plate is not only formed in a groove shape as described above, but also formed between spaced projections so as to sandwich the weir plate on the opposite side. Is also good.
[0148]
(11) A weir plate (for example, the weir plate 231 shown in FIG. 1 may be omitted) mounted on an upstream portion of a waterway member installed on the most upstream side.
[0149]
(12) When the width of the ridge existing between the reservoir 3 and the drainage channel 2 is relatively small while the water level between the drainage channel and the reservoir is relatively large, the fishway 6 is indicated by a dashed line in FIG. It may be provided diagonally like this.
[0150]
(13) When the channel member 7 is formed in a U-shaped groove shape, the support 17 projecting from the channel bottom portion 15 on the upstream side faces the lower surface of the joint of the channel member installed on the upstream side from below. It is not always necessary to be provided over the entire width of the water channel bottom 15 as long as it can be stably supported.
Further, as shown in FIGS. 60 to 61, the support base 17 may be formed separately from the water channel member 7 and fixed to the bottom 15 of the water channel by bonding or the like. Further, as shown in FIG. 62, the support base 17 may be configured to have a predetermined height by stacking a plurality of support base pieces 207 each having a unit height, for example. When the support 17 is formed integrally with the bottom 15 of the water channel, and when the height of the support 17 is too low, a separate auxiliary support 209 is attached to the support 17 as shown in FIG. The mounting may result in the formation of a support having a required height.
FIG. 64 shows a configuration in which a plurality of support bases 17 are protruded from the bottom part 15 of the waterway at required intervals in the front and rear as viewed in the length direction of the waterway. In the figure, two support bases 17a and 17b are protruded. In this case, the height of the support 17a located on the upstream side is set lower than the height of the support 17b located on the downstream side. According to this structure, the fish can run up between the water level of the waterway member installed on the upstream side and the water level of the waterway member installed on the downstream side according to the size of the fish going upstream. The required water level difference can be provided. When the fish going upstream is large, the water level difference can be set large. In this case, the support 17b having a higher height can be selected to configure the fish upstream structure. Thereby, there is economical efficiency that the number of waterway members constituting the fishway 6 can be reduced.
[0151]
(14) The waterway member 7 constituting the fish run-up structure according to the present invention may be configured to have a pipe shape made of, for example, resin, in addition to being configured to have the above-described open top. . Alternatively, a fish run-up structure may be configured by a combination of a waterway member having a pipe shape and a waterway member having an open upper end.
[0152]
(15) The configuration in which the weir plate is detachably attached to the waterway member is not only configured such that the weir plate can be fitted into the fitting groove as described above, but also various configurations that are detachable so that the waterway water can be raised. Can be adopted.
[0153]
(16) Although the overflow notch 30 as described above may not be provided in the weir plate 23, when the overflow notch 30 is provided, the overflow notch 30 is formed by the width of the weir plate. It is not limited to the one provided at the center in the direction. For example, as shown in FIG. 65, the overflow notch 30 may be moved to the end of the weir plate 23, and the overflow notches of the weir plates arranged vertically may be provided in a staggered arrangement. With such a configuration, the flow of water in the fishway is meandered, and the stagnation portion 210 where fish can swim can be formed. In FIG. 65, the overflow notch 30 is hatched for convenience of explanation.
[0154]
(17) The overflow depth is set according to the run-up state of the fish, and if the overflow depth of 30 to 50 mm is ensured, the required overflow depth according to various fishes is provided. Can be secured.
[0155]
(18) In the case of chamfering the downstream side of the overflow section provided on the weir plate attached to the waterway member, in any of the above-described embodiments, the chamfer is formed not only as an inclined surface but also as an arc surface. it can.
The same applies to the case where the overflow portion is formed as the upper end of a slide adjustment plate provided so as to cover the lower portion of the rectangular cutout provided in the weir plate, and is configured in this manner. In this case, it is preferable to chamfer the edge portion of the notch so as to expand toward the downstream side (chamfer such as an inclined surface or an arc surface).
[0156]
(19) In the case of chamfering the downstream side of the overflow section provided in the partition wall, in any of the above-described embodiments, the chamfer can be formed not only as an inclined surface but also as an arc surface.
The same applies to the case where the overflow portion is formed as the upper end of a slide-type adjusting plate provided so as to cover the lower portion of the rectangular cutout provided in the partition. In such a case, it is preferable to chamfer the edge portion of the notch so as to expand toward the downstream side (chamfering an inclined surface such as an arc surface).
[0157]
(20) When a notch is provided in the weir plate or the partition wall, and a slide adjusting plate or a slide-type adjusting plate is attached to the notch to form a required overflow portion, the notch is The cutout is not limited to the rectangular cutout, and may be formed as a trapezoidal, V-shaped, or arcuate cutout.
[0158]
(21) The means for providing a slide adjusting plate on the weir plate so that the height can be adjusted or the means for providing an adjusting plate on the partition wall so that the height can be adjusted is, as described above, provided on both sides of the slide adjusting plate or the slide type adjusting plate. A bolt can be inserted through the vertically long adjustment hole provided in the above, and the bolt can be screwed into the insert, or other known adjustment means can be used.
[0159]
(22) In the above embodiment, the scour prevention block is configured so that both open ends are covered with side plates or sandbags, but is configured such that both ends are closed by side plates provided integrally with the bottom plate. You may.
[0160]
(23) The drainage channel may be of various known structures in addition to the one assembled using the U-shaped frame.
[0161]
(24) The idea of the fish run-up structure shown in FIG. 27 in which a pipe-shaped waterway member is joined to the upper and lower sides of a fishway main body formed by joining U-shaped grooved waterway members is a bottomed box shape. The present invention can also be applied to the fish run-up structure according to the second and third embodiments, which is configured using the waterway member presented.
[0162]
(25) When the pipe-like waterway member 7 is joined to the fishway main body 121 to form the fishway 6, the upper end of the pipe-like waterway member 7 may be partially exposed on the ground. FIG. 66 shows an example of this. The pipe-shaped waterway member 7 can be removably closed, for example, with a U-shaped groove-opening waterway member body 220 and an upper end opening 221 thereof. The cover plate 222 is formed, and the pipe-shaped waterway member 7 is formed by closing the cover plate 222. In this case, as shown in FIG. 66, the waterway member main body 220 is buried underground and the cover plate 222 is exposed to the surface of the ground, and the cover plate 222 is removed when necessary, thereby forming a pipe-shaped waterway. The inside of the member 7 can be inspected and cleaned.
[0163]
(26) As shown in FIG. 1, the partition 50 can be detachably attached to the U-shaped support frame 41 by inserting edges of both ends into insertion grooves 49 provided on the inner surface of the U-shaped support frame 41. In addition to being attached, it may be screwed to the upstream side surface of the U-shaped support frame 41.
[0164]
(27) When the scour prevention block 156 is provided in the drainage channel 2, the bottom plate 157 of the scour prevention block can prevent scouring of the channel bottom of the drainage channel by falling water through the overflow portion 54. As long as it is provided, it may be provided only in the vicinity of the downstream side of the overflow section 54.
[0165]
(28) The prevention net 77 covering the upper side of the fishway 6 may be changed to a transparent covering material such as a transparent vinyl chloride sheet. This transparent covering material may be a colored and transparent covering material as long as fish can go up in the fishway.
[0166]
The present invention has the following excellent effects.
(1) The fish run-up structure according to the present invention is configured to include a drainage channel and a fishway for causing fish to run up to a reservoir having a water level higher than the water level of the drainage channel. A plurality of waterway members are sequentially joined, and a configuration is adopted in which a weir plate is detachably attached to each of the waterway members. Has a configuration in which the height is set so that it can go up.
Therefore, according to the invention, the required number of waterways is determined according to the width between the reservoir and the drainage channel in plan view (the width of the ridges and the like) and the difference between the water level of the drainage channel and the water level of the reservoir. By sequentially joining the members in a straight state or a required bending state, by setting the height of the overflow section of the weir plate attached to the waterway member and the overflow water depth in the overflow section as required, a fishway is formed. The fish can be sequentially moved up the overflow section of the partition wall provided as necessary in the drainage channel to reach the place where the fishway is present, and thereafter, the fish is easily sent from the drainage channel to the reservoir. Will be able to go upstream
In the above-mentioned conventional system in which a fishway is formed between the drainage channel and the reservoir, since the construction mainly consists of cast-in-place construction in accordance with each construction site, the construction requires much labor. In addition, there was a problem that construction efficiency was poor and the construction cost was increased, and there was a problem that the construction period was prolonged. In particular, when the fishway is to be formed in a bent state when the head is large, there is a problem that the on-site construction is extremely complicated, the workability is deteriorated, and the construction cost is further increased. Raised. When a fishway is formed by using an integrally formed concrete fishway block having a length extending from the drainage channel to the reservoir, the fishway block is individually designed to have a length according to the construction site. In addition to the above, there is a problem that the construction cost is greatly increased, and the fishway block made of concrete is heavy, which makes it difficult to transport to the construction site and deteriorates the workability. There was also.
In contrast, according to the present invention in which a plurality of waterway members are sequentially joined, in other words, a required number of waterway members are sequentially joined to form a fishway, such a problem can be solved at once.
Further, since the weir plate is detachable, by removing all of the weir plate, the water in the reservoir can be smoothly discharged to the drainage passage, and the fish passage can be easily cleaned.
[0167]
(2) When an overflow cutout having a trapezoidal shape, a U shape, a rectangular shape, a V shape, or the like is provided at the upper end of the weir plate attached to the waterway member, the amount of water flowing through the fishway is not large. At this time, the required water depth that enables the fish to run up can be secured in the overflow notch.
[0168]
(3) When an intermediate weir plate for raising channel water is detachably attached to the water channel member so as to partition between the upstream opening and the downstream opening provided in the water channel member, the water level is set in the water channel by the intermediate weir plate. Since the difference can be formed, when the head between the drainage channel and the reservoir is large, a fishway having an appropriate water level difference can be economically formed without increasing the number of used waterway members.
When a plurality of the intermediate weirs are mounted at a required interval, the water channel of the waterway member can be further partitioned, and a required water level difference can be formed between the intermediate weirs.
[0169]
(4) In the case of using a box-shaped waterway member that is open at the upper end and closed by a circumferential wall, the flow direction of water passing through the upstream opening and the downstream opening is set to the upstream opening and the downstream opening. When it is provided on the wall portion so that it is bent, the width of the ridge portion and the like, the water level of the reservoir and the drainage channel are set by inserting the end portions of other water channel members into the upstream opening and the downstream opening. Therefore, it is possible to rationally configure an appropriate bent fishway according to the head between the water level and the water level. For example, when the width of a ridge or the like is small and the head is large, there is an advantage that it can be dealt with by bending the fishway, even if the straight fishway cannot be dealt with.
[0170]
(5) A pipe-shaped waterway member that is communicated with the drainage channel and buried underground is connected to the waterway member located at the most downstream side of the fishway main body formed by sequentially joining a plurality of waterway members, while being the most upstream. When adopting a configuration that joins the end of a pipe-shaped channel member that is consequently connected to the paddy field to the channel member located on the side, the top of the ridge or the lower end of the slope of the ridge and the drainage channel There is an advantage that a unicycle or the like can be run without obstacles on the interstitial ridges to facilitate the agricultural work.
In addition, even when the width of the ridge is relatively small and the head between the water level of the drainage channel and the water level of the reservoir is large, such a configuration can provide an appropriate overflow part and overflow depth in accordance with the head. The fishway which has can be constituted rationally. Further, such a pipe-shaped waterway member can also function as a shelter for fish in the daytime, for example.
[0171]
(6) When the channel member having a box shape with a bottom closed at the upper end and closed by a circumferential wall portion is configured as a cylindrical box with a bottom at the upper end, for example, the case of presenting a rectangular parallelepiped box shape Differently, since there are few positional restrictions when providing the upstream opening and the downstream opening in the wall portion, when the flow direction of water passing through both openings is bent, the upstream opening and the downstream opening are There is an advantage that it can be easily formed according to the bending angle.
[0172]
(7) The waterway member is formed in a U-shaped groove shape whose upper end is open, and the width of the waterway at the upstream side thereof is enlarged to join the connection portion forming the downstream side portion of the waterway member. When a configuration is adopted in which a support base that supports the lower surface of the joint from below is provided at the bottom of the water channel at the upstream portion of the water channel member, the following special effects are obtained. That is,
[0173]
{Circle around (1)} The support base forms a stagnation area on the bottom side of the waterway, which can be used as a habitat for benthic organisms.
[0174]
{Circle around (2)} Further, the bottom side of the water channel formed by the support stand serves as a mud pool, and fine soil such as sludge flowing through the fishway can be deposited. Thereby, organic substances such as fertilizer components can be precipitated. In addition, when water plants and the like grow from the sedimentary soil, organic matter in the channel water is captured, thereby purifying the water quality. Thus, it is possible to contribute to the prevention of river pollution by organic matter.
[0175]
{Circle around (3)} A gap can be formed below the joint inserted into the joint fitting section, and this gap can be used as a habitat for benthic organisms preferring shade, and also as an evacuation place for fry. obtain. In particular, by making the surface side of the void portion a surface on which natural stones are exposed, it is possible to promote the growth of algae and provide a good feeding ground for benthic organisms.
[0176]
{Circle around (4)} Since the support can support the lower surface of the joint from below, it becomes easy to lay adjacent water channel members at required steps using the support as a ruler.
[0177]
(8) When the support stand is formed separately from the waterway member and the support stand is retrofitted to the waterway member, the support stand having a required height is fixed to the waterway member so that the adjacent waterway can be used. There is an advantage that the step of laying the members can be adjusted as required. Further, the manufacturing cost of the waterway member can be reduced as compared with the case where the waterway members having different support pedestals are integrally formed.
[0178]
(9) When the support stand is formed integrally with the waterway member, the auxiliary support stand is stacked to form a support stand having a required height, or a support stand separate from the waterway member is attached to the waterway member. In addition, when a plurality of support base pieces are stacked to form a support base, the following effects can be obtained. That is, when the fish that run up the fishway is large, by increasing the height of the support base as a result of stacking of the auxiliary support, etc., it is possible to increase the step of laying adjacent waterway members, and therefore Thus, the number of used waterway members can be reduced to economically configure the fish run-up structure.
For example, when the head of a drainage channel and a reservoir is about 600 mm, if the distance between the lower surface of the waterway member and the upper surface of the support stand is 150 mm, the waterway member must be installed in four steps to deal with it. On the other hand, if this distance is 200 mm, it can be dealt with by three-stage waterway members.
[0179]
(10) Further, when the support base is provided in this way, the support base is provided before and after in the longitudinal direction of the water channel, and the support base located on the upstream side is configured lower than the support base located on the downstream side. In some cases, there is an advantage that the step of laying adjacent waterway members can be changed by selecting the support base.
[0180]
(11) By forming the bottom surface and the side surface of the waterway member on the surface where the natural stone is exposed, algae can be propagated on the natural stone surface, and the inner surface of the waterway is It can also serve as a feeding ground for small fish and benthic organisms.
[0181]
(12) When the weir plate is constituted by a weir plate main body provided with a notch and a slide adjustment plate provided so as to cover a lower portion of the notch, the weir plate is provided with a slide adjustment plate. By adjusting the height in the vertical direction, the height of the overflow section as the upper end of the slide adjusting plate is adjusted by the fish relative to the water level on the downstream side according to the drop between the water level of the reservoir and the water level of the drainage channel. It is easy to set to an appropriate height that allows going up.
For example, as shown in FIG. 4, when the weir plate is formed of only a plate provided with a notch, the cut-off portion may be cut with a cutter or the like to increase the depth of the notch. Adjustment is required, but when a slide adjustment plate is used, there is an advantage that such troublesome adjustment is not required at all and the height adjustment of the overflow section can be performed simply and reliably.
[0182]
(13) In the case where the waterway member is formed in a U-shaped groove shape, when the weir plate detachably attached to the downstream portion is formed such that the downstream surface thereof is flush with the lower end surface of the waterway member, It is possible to prevent fishes going up the fishway from being caught and damaged by corners at the lower end of the waterway member.
[0183]
(14) When the partition wall detachably attached to the drainage channel is composed of a partition wall main body provided with a notch, and a slide-type adjustment plate provided so as to cover a lower portion of the notch. In addition, there is an advantage that the height of the overflow portion enabling the fish to run up can be easily and reliably adjusted according to the water volume of the drainage channel.
[0184]
(15) In the case where the weir plate attached to the drainage channel is provided with a drain hole located below the overflow portion, the drain hole is opened to release water, and the overflow portion is released. In addition to the falling water in the above, the release of water from the drain hole is added, so that an effect that the fishes are easily guided toward the overflow portion (overflow cutout portion) by feeling the flow can be expected.
[0185]
(16) In the case where the partition provided in the drainage channel is constituted by the front plate of the scour prevention block having the front plate and the rear plate standing up and down before and after the bottom plate, the overflow portion (overflow notch ), The bottom of the drainage channel is protected by the bottom plate, so that scouring of the channel bottom can be prevented. In addition, since a deeper part where the channel bottom is dug down is formed on the downstream side of the overflow cut-off part, when the fish goes up the overflow cut-off part, it is easy to apply momentum by the depth. There is an advantage that can be run up. Furthermore, since the void between the front and rear plates of the scour prevention block serves as a mud pool, the fine soil containing organic matter such as fertilizer components, which flows into the drainage channel from the paddy field through the fishway, etc. It can be deposited to purify water. In this case, a water purification effect in the drainage channel can be improved by storing a filtering material such as straw or chaff in the empty space.
[0186]
(17) In particular, in the case where a scour prevention block is installed on the downstream side of the fishway and a configuration is adopted in which the filtering material is accommodated in the empty space, organic matter such as fertilizer components flowing from the paddy field to the drainage channel through the fishway is removed. There is an advantage that the fine soil containing can be filtered by the filter medium, and the water quality of the drainage channel can be improved accordingly.
[0187]
(18) When the upper side of the fishway is covered with a prevention net or a transparent covering material as shown in FIG. 16, it is possible to prevent fishes going up the fishway from jumping out of the fishway and to prevent birds from moving up the fishway. Predation can be prevented.
[0188]
(19) In the case where the downstream side of the overflow portion of the weir plate is formed in an arc surface or the downstream portion is formed in an inclined surface inclined downward at an angle of 13 to 60 degrees, the notch is formed. It is possible to prevent fish that run upstream from being caught and damaged by the corners of the overflow section. In this case, such catching can be more effectively prevented by setting the inclination angle of the inclined surface to 35 to 45 degrees.
This means that, when the notch provided in the weir plate is covered with the slide adjustment plate, the downstream edge portion of the notch and the downstream portion of the overflow section as the upper end of the slide adjustment plate are described above. The same applies to the case of forming on the same arc surface or inclined surface.
Further, when a partition wall is provided in the drainage channel, the same applies to the downstream portion of the overflow section that forms the upper end of the partition wall. In the case where the lower portion of the portion is covered with a slide-type adjusting plate, the downstream portion of the overflow portion and the downstream edge portion of the notch, which form the upper end of the adjusting plate, have an arc-shaped surface as described above. The same applies to the case of forming on an inclined surface.
[0189]
(20) When the upper end side of the string for guiding fish floating in the water flowing through the fishway is attached to the weir plate, there is an advantage that the fish upstream in the fishway can be effectively guided to the overflow cutout. is there.
[0190]
(21) Further, in the case where the weed-like cords are arranged at the bottom of the drainage channel at appropriate intervals in the width direction thereof, it is possible to form a state in which waterweeds grow at the bottom of the drainage passage, The body can function as an aid for spawning and growing fish.
[Brief description of the drawings]
FIG. 1 is an overall perspective view showing a fish run-up structure according to the present invention.
FIG. 2 is a sectional view of the same.
FIG. 3 is a plan view thereof.
FIG. 4 is a perspective view showing a water channel member used together with a weir plate.
FIG. 5 is a perspective view showing the water channel member.
FIG. 6 is a plan view showing the water channel member.
FIG. 7 is a cross-sectional view showing a joined state of water channel members.
FIG. 8 is a cross-sectional view showing a configuration of a weir plate together with an overflow state.
FIG. 9 is a perspective view illustrating the operation of the formed fishway.
FIG. 10 is a cross-sectional view illustrating the operation of the formed fishway.
FIG. 11 is a partial perspective view illustrating a configuration of a drainage channel.
FIG. 12 is a partial perspective view illustrating another configuration of the drainage channel.
FIG. 13 is a cross-sectional view showing a string for guiding fish in a used state.
FIG. 14 is a perspective view showing a string for guiding fish.
FIG. 15 is a perspective view showing a state in which a weir plate of a fishway is removed and water in a paddy field is drained to a drainage channel.
FIG. 16 is a perspective view showing a state in which the fishway is covered with a prevention net.
FIG. 17 is a perspective view showing a water channel member and a support frame for supporting the prevention net.
FIG. 18 is a cross-sectional view showing a state where the support frame is attached to the waterway member.
FIG. 19 is a cross-sectional view showing another embodiment of the fish run-up structure according to the present invention together with the operation.
FIG. 20 is a cross-sectional view showing a joined state of the most upstream waterway member and an intermediate waterway member.
FIG. 21 is a perspective view showing a water channel member and a weir plate attached to the water channel member.
FIG. 22 is an exploded perspective view showing a weir plate on the upstream end side of the most upstream waterway member.
FIG. 23 is an exploded perspective view showing a weir plate mounted on the downstream side of the water channel member.
FIG. 24 is a perspective view showing an example of a height adjustment state of a slide adjustment plate in a weir plate mounted downstream of a water channel member.
FIG. 25 is a perspective view showing another example of the height adjustment state of the slide adjustment plate in the weir plate attached downstream of the water channel member.
FIG. 26 is a cross-sectional view showing a mounted state of the weir plate from which the slide adjustment plate has been removed.
FIG. 27 is a plan view showing another embodiment of the fish upstream structure according to the present invention.
FIG. 28 is a sectional view of the same.
FIG. 29 is a cross-sectional view showing a joint state between a waterway member on the most downstream side and a drainage channel in the fish run-up structure.
FIG. 30 is a perspective view illustrating the configuration of the lowermost stream in the fish run-up structure.
FIG. 31 is a cross-sectional view illustrating the configuration of the fish upstream structure on the most upstream side.
FIG. 32 is a perspective view of the configuration of the uppermost stream side in the fish run-up structure.
FIG. 33 is a plan view showing a fish run-up structure in which a partition is attached to a drainage channel.
FIG. 34 is a perspective view of the overflow portion of the partition wall in the fish run-up structure as viewed from the upstream side.
FIG. 35 is a perspective view of the overflow portion of the partition wall in the fish run-up structure as viewed from the downstream side.
FIG. 36 is an exploded perspective view showing an overflow portion of a partition wall in the fish run-up structure.
FIG. 37 is a cross-sectional view showing a state in which a weed-like cord is disposed at the bottom of the drainage channel.
FIG. 38 is a cross-sectional view showing a state in which a drain hole provided in a partition wall of a drainage channel is closed.
FIG. 39 is a perspective view showing a state where a partition wall of a drainage channel is formed by using a scour prevention block.
FIG. 40 is a sectional view of the same.
FIG. 41 is a front view thereof.
FIG. 42 is a plan view thereof.
FIG. 43 is an overall perspective view illustrating another embodiment of the fish run-up structure according to the present invention.
FIG. 44 is a sectional view of the same.
FIG. 45 is a plan view thereof.
FIG. 46 is a perspective view showing a water channel member used together with a weir plate.
FIG. 47 is a perspective view showing a water channel member used together with a weir plate.
FIG. 48 is a cross-sectional view showing a state of communication between a water channel member installed at the most downstream side and a drainage channel.
FIG. 49 is a cross-sectional view showing a joint state between an intermediate waterway member and a most downstream waterway member.
FIG. 50 is a cross-sectional view showing a joined state of the most upstream waterway member and an intermediate waterway member.
FIG. 51 is a perspective view illustrating a formed fishway.
FIG. 52 is a cross-sectional view showing a used state of the formed fishway.
FIG. 53 is an overall perspective view showing another embodiment of the fishway running-up structure according to the present invention.
FIG. 54 is a plan view thereof.
FIG. 55 is a perspective view showing a formed fishway.
FIG. 56 is a perspective view showing a water channel member constituting the water channel member.
FIG. 57 is a perspective view showing a water channel member constituting the same together with a weir plate.
FIG. 58 is a cross-sectional view showing a used state of the formed fishway.
FIG. 59 is a plan view showing a U-shaped channel member in a used state.
FIG. 60 is an exploded perspective view showing another embodiment of the water channel member.
FIG. 61 is a partial sectional view of the same.
FIG. 62 is a partial cross-sectional view showing another embodiment of the water channel member.
FIG. 63 is a partial cross-sectional view showing another embodiment of the water channel member.
FIG. 64 is a partial cross-sectional view showing another embodiment of the water channel member.
FIG. 65 is a partial plan view showing a fishway in which overflow cutouts are arranged in a staggered manner.
FIG. 66 is a cross-sectional view showing another embodiment of the pipe-shaped waterway member.
FIG. 67 is a perspective view showing a conventional fish run-up structure.
[Explanation of symbols]
1 Fish run-up structure
2 drainage channel
3 reservoir
5 ridges
6 Fishway
7 Waterway components
9 Waterway
10 Upstream opening
11 Downstream opening
12 Joint
13 Joint fitting part
17 Support
23 dam
24 Overflow
25 Fitting groove
29 Fitting groove
30 Overflow notch
50 partition
52 Overflow Notch
54 Overflow
67 String
76 Support frame
77 Prevention net
85 Weir plate body
86 Drop adjustment plate
87 rectangular notch
92 Mounting groove
95 slope
97 Weir plate body
99 Slide adjustment plate
111 insert
112 volts
113 Adjustment hole
143 insert
144 adjustment hole
146 drain hole
147 Waterway bottom
150 String
151 weight
152 float
153 string piece
154 hair pieces
156 scour prevention block
157 bottom plate
159 Front plate
160 rear plate
169 rectangular notch
170 Insert
172 volts
180 wall
187 fitting groove
191 Fitting groove
201 Fitting groove
202 Fitting groove

Claims

A drainage channel, and a fishway for moving fish up to a reservoir having a water level higher than the water level of the drainage channel, wherein the fishway runs up to a reservoir formed by sequentially joining a plurality of waterway members. And
The waterway member has an upstream opening and a downstream opening at an upstream side and a downstream side of the waterway, and the downstream opening of the waterway member installed at the upstream side is installed at the downstream side. The waterway members are joined to each other so as to communicate with the upstream opening of the member, and the upstream opening of the waterway member installed on the most upstream side is communicated with the reservoir, and the waterway installed on the most downstream side A downstream opening of the member is communicated with the drainage channel, and a weir plate for raising channel water is detachably attached to a downstream portion of the water channel of the water channel member, and an overflow portion of the weir plate is provided. A fish run-up structure characterized in that the height is set such that the fish can go up with respect to the water level on the downstream side.

The waterway member is formed in a U-shaped groove shape having an open upper end and a continuous waterway from the upstream end to the downstream end, and the width of the upstream waterway is enlarged, forming a downstream side of the waterway member. In the state where the joining portion is fitted into the joining fitting portion, the length direction of the water channel member with respect to the joining fitting portion of the joining portion is set as a joining fitting portion for fitting the joining portion. A guide portion for detachably fitting the weir plate is provided at a downstream portion of the water channel of the water channel member, and a water channel member installed on the upstream side. 2. The fish according to claim 1, wherein the joining portion is fitted into the joining fitting portion of the waterway member installed on the downstream side, and the dam plate is fitted into the guide portion. 3. Run-up structure.

3. A support pedestal for supporting a lower surface of the joint portion of the waterway member installed on the upstream side from below at a bottom of the waterway at an upstream portion of the waterway member. 4. Fish run-up structure.

A drainage channel, and a fishway for moving fish up to a reservoir having a water level higher than the water level of the drainage channel, wherein the fishway runs up to a reservoir formed by sequentially joining a plurality of waterway members. And
The waterway member is formed in a U-shaped groove shape having an open upper end and a continuous waterway from the upstream end to the downstream end, and the width of the upstream waterway is enlarged, forming a downstream side of the waterway member. A fitting groove for fitting a joining portion, and a detachable fitting groove for detachably fitting a weir plate for raising channel water on opposite side surfaces and a bottom surface of a downstream portion of the channel of the channel member. Is provided at a bottom portion of the channel in an upstream portion of the channel member, and a support base for supporting a lower surface of the joining portion of the channel member installed on the upstream side from below is protruded, and further, the channel is further provided. On the opposite side surface and the bottom surface of the upstream portion of the water channel of the member, an insertion groove for detachably inserting a weir plate for raising the water of the reservoir is provided,
The joint portion of the waterway member installed on the upstream side is fitted into the joint fitting portion of the waterway member installed on the downstream side while the joint portion is placed on the support table, and the most upstream side The upstream opening of the waterway member installed in the reservoir is connected to the reservoir, and the downstream opening of the waterway member installed in the most downstream side is connected to the drainage channel,
Further, the overflowing portion of the weir plate fitted into each of the fitting grooves is set to a height at which the fish can go up with respect to the water level on the downstream side.

The support stand is provided at the bottom of the waterway on the upstream side of the waterway member at a required interval before and after in the longitudinal direction of the waterway, and the support stand located further upstream is located downstream of the support stand. The fish run-up structure according to claim 3 or 4, wherein the height of the fish is set lower than the height of the support stand located on the side.

6. The fish run-up structure according to claim 3, wherein the support is formed separately from the waterway member, and the support is retrofitted to the waterway member.

7. The fish run-up structure according to claim 6, wherein the support base to be retrofitted is formed by stacking support base pieces of a required height in a plurality of stages.

When the weir plate is detachably fitted to the downstream portion of the water channel of the water channel member, the downstream end side of the outer peripheral surface of the weir plate abuts on the inner peripheral surface of the downstream end of the water channel, and the downstream of the weir plate. The fish run-up structure according to claim 2 or 4, wherein a side surface is configured to be flush with a downstream end surface of the waterway member.

A drainage channel, and a fishway for moving fish up to a reservoir having a water level higher than the water level of the drainage channel, wherein the fishway runs up to a reservoir formed by sequentially joining a plurality of waterway members. And
The waterway member is formed in a box shape with a bottom that is open at the upper end and closed by a circumferential wall, and has a required portion on the upstream side and a required portion on the downstream side of the wall. An opening and a downstream opening are provided, and the waterway members are joined so that the downstream opening of the waterway member installed on the upstream side communicates with the upstream opening of the waterway member installed on the downstream side. In the communicating portion of the two openings, a weir plate for raising the channel water is detachably mounted,
Further, an upstream opening of the waterway member installed on the most upstream side is communicated with the reservoir, and a downstream opening of the waterway member installed on the most downstream side is communicated with the drainage channel. A fish run-up structure in which the overflow portion of the plate is set at a height at which the fish can go up with respect to the water level on the downstream side.

The downstream portion of the waterway member installed on the upstream side is inserted into the upstream opening of the waterway member having a box shape with a bottom that is open at the upper end and closed by a circumferential wall portion, and the insertion amount thereof Is adjustable, and the upstream portion of the waterway member installed on the downstream side is inserted into the downstream opening of the waterway member, and the insertion amount is adjustable. The fish run-up structure according to claim 9.

An intermediate weir that raises channel water so as to partition between the upstream opening and the downstream opening in a water channel of the water channel member having a box shape with a bottom that is open at the upper end and closed by a circumferential wall. The fish according to claim 9 or 10, wherein the board is detachably mounted, and the overflow portion of the intermediate weir plate is set to a height at which the fish can go up with respect to the water level on the downstream side. Run-up structure.

An intermediate part for raising channel water so as to partition the upstream-side opening and the downstream-side opening into a plurality of channels in the water channel of the water channel member having a box shape with a bottom and closed at a top end and closed by a circumferential wall portion. 10. A plurality of weir plates are detachably mounted, and the overflow portion of each intermediate weir plate is set to a height at which fish can go up to the water level on the downstream side. Or the fish run-up structure according to 10.

The upstream opening and the downstream opening of the waterway member exhibiting a box shape with a bottom that is open at the upper end and closed by a circumferential wall portion are formed such that a flow direction of water passing through both openings is bent. The fish upstream structure according to claim 9, 10, 11, or 12, wherein the structure is provided on a wall.

The fish upstream structure according to any one of claims 1 to 13, wherein a downstream side of the overflow section of the weir plate is formed in an arc surface.

The fish upstream structure according to any one of claims 1 to 13, wherein a downstream side of the overflow section of the weir plate is formed on an inclined surface inclined downward at an angle of 13 to 60 degrees. .

Drainage channel, a fish run-up structure including a fishway for fish to run up to a paddy field having a water level higher than the water level of the drainage channel,
The fishway is formed by sequentially joining a plurality of waterway members in an extending direction of a ridge portion between the drainage channel and the paddy field to form a fishway main body, and at the most downstream side to form the fishway main body. A downstream opening provided in the installed waterway member is connected to an upstream end portion of a pipe-shaped waterway member connected to the drainage channel and buried underground, while the most upstream side constituting the fishway main body. A downstream end portion of the waterway member that is consequently communicated with the paddy field is joined to an upstream opening of the waterway member installed in the waterway member. A fish run-up structure, wherein a weir plate for raising water is detachably mounted, and an overflow portion of the weir plate is set to a height at which fish can go up with respect to a downstream water level.

Drainage channel, a fish run-up structure including a fishway for fish to run up to a paddy field having a water level higher than the water level of the drainage channel,
The fishway is formed by sequentially joining a plurality of waterway members in the extension direction of the ridge portion between the drainage channel and the paddy field to form a fishway main body, and at the most downstream side to constitute the fishway main body. A downstream opening provided in the installed waterway member is connected to an upstream end portion of a pipe-shaped waterway member connected to the drainage channel and buried underground, while the most upstream side constituting the fishway main body. An upstream opening of a waterway member installed at the downstream end portion of a pipe-shaped waterway member that is consequently communicated with the paddy field and buried underground is joined, and the fishway main body is formed. In each of the waterway members, a weir plate for raising the water in the waterway is detachably mounted, and the overflow portion of the weir plate is set to a height at which fish can go up to the water level on the downstream side. A fish run-up structure characterized by:

18. The fish run-up structure according to claim 16, wherein the pipe-shaped waterway member is disposed substantially horizontally.

The fish upstream structure according to any one of claims 1 to 18, wherein an upper end side of a string for guiding fish floating in water flowing through the fish passage is attached to the weir plate.

The weir plate is composed of a weir plate main body removably attached to a waterway member and a slide adjustment plate attached to the weir plate main body, and the weir plate main body is provided with a cutout with an open upper end. The slide adjusting plate is attached to the weir plate main body so as to cover the lower portion of the notch so as to be slidable in the up and down direction, and the upper end of the slide adjusting plate is provided with the overflow portion. The vertical position of the slide adjusting plate can be adjusted so that the overflow portion has a height at which fish can go up to the downstream water level, and the slide adjusting plate can be adjusted in the adjusted state. 18. The fish run-up structure according to claim 1,2,4,9,16, or 17, wherein the fish can be fixed to the weir plate main body.

In order to prevent fish that run up the fishway from jumping out of the fishway, and to prevent fish that are going upstream from being eaten by birds, cover the upper side of the fishway with a prevention net or transparent covering material. 18. The fish run-up structure according to claim 1, 2, 4, 9, 16, or 17, wherein

The fish run-up structure according to claim 21, wherein the prevention net or the transparent covering material is covered by a support frame provided in an upright state on the waterway member, and covers an upper side of the fishway.

In the drainage channel, a partition wall for raising water flowing through the drainage channel is detachably mounted, the partition wall is a partition main body detachably mounted in the drainage channel, and an adjustment plate attached to the partition main body. The partition main body is provided with a notch with an open upper end, and the adjustment plate is slidable in the up-and-down direction in a contact state with the partition main body so as to cover a lower portion of the notch. The upper end of the adjusting plate is the overflow portion, and the overflow portion is vertically positioned above and below the adjusting plate so that the fish can go up to the water level on the downstream side. 18. The fish run-up structure according to claim 1, wherein the adjustment state of the direction can be adjusted and the adjustment plate can be fixed to the partition wall body in the adjustment state.

The drainage channel is provided with a partition wall for raising water flowing through the drainage channel, and the partition wall extends in a flow direction of water in the drainage channel and has a bottom plate having a width substantially equal to the width of the drainage channel. A front plate is erected at an upstream end, and a scour prevention block is formed with the front plate of a scour prevention block having a rear plate erected at a downstream end of the bottom plate. 18. A part of the front plate is an overflow portion set to a height at which fish can go up to the water level on the downstream side, wherein the overflow portion is set. Fish run-up structure described.

The front plate serving as the partition wall includes a partition main body that forms a part thereof, and an adjustment plate attached to the partition main body.The partition main body is provided with a cutout having an open upper end, and the adjustment plate includes: The adjusting plate is provided so as to be slidable in the up-down direction while being in contact with the partition body so as to cover a lower portion of the notch. However, the vertical slide state of the adjustment plate can be adjusted and the adjustment plate can be fixed to the partition wall body in the adjustment state so that the fishes can reach a height at which the fish can go up to the downstream water level. The fish run-up structure according to claim 24, wherein:

In the drainage channel, a scour prevention block is disposed downstream of the fishway, and the scour prevention block extends in a flow direction of water in the drainage channel and is substantially equal to a width of the drainage channel. At the upstream end of the bottom plate having a width, a front plate that functions as a partition for raising the water flowing through the drainage channel is provided upright, and a rear plate is provided at the downstream end of the bottom plate. A part of the front plate is an overflow section set to a height at which fish can go up to the water level on the downstream side, and is filtered into a space formed between the front plate and the rear plate. The fish upstream structure according to claim 1, 2, 4, 9, 16, or 17, wherein a material is accommodated.

27. The fish run-up structure according to claim 23, 24, 25 or 26, wherein a downstream side of the overflow section is formed in an arc surface.

The fish upstream structure according to claim 23, 24, 25 or 26, wherein a downstream side of the overflow section is formed on an inclined surface which is inclined downward at an angle of 13 to 60 degrees.

21. The fish run-up structure according to claim 20, wherein a downstream edge portion of the notch is formed in an arc surface.

21. The fish run-up as claimed in claim 20, wherein the downstream edge portion of the cutout portion is formed on a slope inclined toward the downstream side so as to expand at an angle of 13 to 60 degrees. Construction.

The fish upstream structure according to claim 23 or 25, wherein a downstream edge portion of the notch is formed in an arc surface.

The fish according to claim 23 or 25, wherein a downstream edge portion of the cutout portion is formed on an inclined surface inclined toward the downstream side so as to expand at an angle of 13 to 60 degrees. Run-up structure.

26. The fish upstream structure according to claim 23, 24 or 25, wherein a drain hole is provided below the overflow section of the partition wall.

A partition wall for raising water flowing through the drainage channel is detachably attached to the drainage channel, and a part of the partition wall is set to a height at which fish can go up to the downstream water level. The fish upstream structure according to claim 1, 2, 4, 9, 16, or 17, wherein the drainage hole is provided below the overflow portion, the drainage hole being provided as a flow portion.

In the drainage channel, a waterweed-like string for laying eggs is arranged at appropriate intervals in the width direction, and the waterweed-like string has a weight provided at one end of the string and floats at the other end. Is provided, a large number of hair pieces having a length of about 50 to 100 mm are provided on the peripheral surface of the string piece, and the weight is installed at the bottom of the drainage channel. 18. The fish run-up structure according to claim 1, 2, 4, 9, 16, or 17.

A waterway member that constitutes a fishway for fish to run up to a reservoir having a water level higher than the water level of the drainage channel,
The upper end is open and formed in a U-shaped groove having a continuous water passage from the upstream end to the downstream end, and the width of the upstream water passage is enlarged, and all or a part of the joining portion forming the downstream side is formed. A joining fitting portion for fitting is formed, and a guide portion for detachably fitting a weir plate for raising channel water is provided at a downstream portion of the channel, and an upstream portion of the channel. A waterway member used for a fish run-up structure, characterized in that a support base for supporting a lower surface of the joint portion of a waterway member installed on an upstream side from below is protruded from a bottom portion of the waterway member.

A waterway member that constitutes a fishway for fish to run up to a reservoir having a water level higher than the water level of the drainage channel,
The upper end is opened and formed in a U-shaped groove having a continuous water passage from the upstream end to the downstream end, and the width of the upstream water passage is enlarged, and all or a part of the joint portion forming the downstream side is formed. A joint fitting portion for fitting is formed, and a fitting groove for detachably fitting a weir plate for raising channel water is provided on a downstream side portion of the water channel on an opposing side surface and a bottom surface thereof. Further, a support for supporting a lower surface of the joint portion of the waterway member installed on the upstream side from below is protrudingly provided at a bottom portion on the upstream side of the waterway, and is used for a fish run-up structure, characterized in that: Waterway members.

A waterway member that constitutes a fishway for fish to run up to a reservoir having a water level higher than the water level of the drainage channel,
The upper end is open and closed by a circumferential wall portion, the inside of which is formed in a box shape with a bottom as a water channel, and a required portion on the upstream side and a required portion on the downstream side of the wall portion have an upstream side. An opening and a downstream opening are provided, and guide portions for detachably fitting a weir plate for raising channel water are provided on inner surfaces of the upstream opening and the downstream opening, and an inner surface of the water channel. In order to partition between the upstream opening and the downstream opening, a guide portion for detachably fitting an intermediate weir plate for raising channel water is provided, and an overflow portion of each of the weir plates is provided. A water channel member used for a fish run-up structure, wherein the height is set such that the fish can go upstream with respect to the water level on the downstream side.

A waterway member that constitutes a fishway for fish to run up to a reservoir having a water level higher than the water level of the drainage channel,
The upper end is closed and closed by a circumferential wall, the inside of which is formed in a box shape with a bottom as a water channel, and a required portion on the upstream side and a required portion on the downstream side of the wall portion have an upstream side. An opening and a downstream opening are provided, and an insertion groove for detachably inserting a weir plate that raises the channel water is provided on opposing side surfaces and a bottom surface of the upstream opening and the downstream opening, An insertion groove for detachably inserting an intermediate weir plate for raising channel water is provided on the opposed side surface and the bottom surface of the water channel so as to partition between the upstream opening and the downstream opening. A waterway member used in a fish run-up structure, wherein an overflow portion of each weir plate is set at a height at which fish can run up with respect to a water level on a downstream side.

In order to partition the upstream opening and the downstream opening into a plurality, a guide portion for detachably fitting a plurality of intermediate weir plates for raising channel water is provided on opposing side surfaces and a bottom surface. 39. The waterway member according to claim 38, wherein the overflow portion of each of the weir plates is set to a height at which the fish can go up with respect to the water level on the downstream side.

In order to partition between the upstream opening and the downstream opening into a plurality, fitting grooves for detachably fitting a plurality of intermediate weir plates for raising channel water are provided on opposing side surfaces and a bottom surface. 40. The waterway member according to claim 39, wherein the overflow portion of each of the weir plates is set to a height at which the fish can go up with respect to the water level on the downstream side.

The said upstream opening and the downstream opening of the said waterway member are provided in the said wall part so that the flow direction of the water which passes through both said opening may be bent. A waterway member used for the fish run-up structure described in the above.

41. The waterway member according to claim 36, 37, 38, 39 or 40, wherein a downstream side of the overflow section of the weir plate is formed in an arc surface.

41. The fish run-up according to claim 36, 37, 38, 39 or 40, wherein a downstream side of the overflow section of the weir plate is formed on an inclined surface which is inclined downward at an angle of 13 to 60 degrees. Waterway member used for construction.

The weir plate is composed of a weir plate main body removably attached to a waterway member and a slide adjustment plate attached to the weir plate main body, and the weir plate main body is provided with a cutout with an open upper end. The slide adjusting plate is attached to the weir plate main body so as to cover the lower portion of the notch so as to be slidable in the up and down direction, and the upper end of the slide adjusting plate is provided with the overflow portion. The vertical position of the slide adjusting plate can be adjusted so that the overflow portion has a height at which fish can go up to the downstream water level, and the slide adjusting plate can be adjusted in the adjusted state. 41. The waterway member for use in a fish run-up structure according to claim 36, wherein the waterway member can be fixed to the weir plate main body.