JP2002317429A - Consolidation cascade type fishway - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fishway manufactured at a low cost, capable of assuring a water-friendly environment destroyed by the construction of a gate and a bank, and having an effectiveness on environmental protection. SOLUTION: In this fishway, at least one cascade timber having a consolidation gate and bank part, a slope part, a water cushion part, and a deflector part is disposed between an upstream protective floor timber and a downstream protective floor timber so that the lines connecting the head top parts of the consolidation gate and bank part and the deflector part are positioned below a planned river floor longitudinal line. At least one cutout having necessary depth and width is provided on the head top parts of the consolidation gate and bank and the deflector of the cascade timber at any position so that fishes can run to the upstream even if a river flow rate is below a normal flow rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fishway provided in a river, and more particularly to a cascade type fishway capable of sufficiently moving fish up even when the river flow is equal to or less than a normal water flow.

[0002]

2. Description of the Related Art Conventionally, rivers have been provided with various types of dams for water intake and the like. In this case, a fishway is provided at a considerable cost so that the fish can run upstream, but there are few cases where this fishway can be said to be functioning sufficiently effectively. In particular, in the case of large-scale weirs such as movable weirs, issues that should be solved from the viewpoint of river environmental conservation and the formation of a hydrophilic environment are high despite not only construction costs but also maintenance costs are high. Many occur.

Accordingly, the present inventors have conducted various studies on fishways that are low in construction cost, easy to maintain and maintain, and are also suitable from the viewpoint of environmental protection and formation of a hydrophilic environment. And at least one cascade having a deflector portion, and a part of the top of each of the dam and the deflector is provided with a cutout so that water flows even when the river flow rate is equal to or less than the normal flow rate, The present invention was found to be extremely effective as a fishway and found that the water cushion portion is useful for forming a hydrophilic environment.

[0004]

Accordingly, a first object of the present invention is to provide a fishway for rivers which is inexpensive and effective from the viewpoint of environmental protection. A second object of the present invention is to provide an inexpensive and effective fishway that can compensate for the hydrophilic environment destroyed by the construction of a dam.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide at least one cascade having a compaction dam, a slope, a water cushion, and a deflector. A fishway that is located between the upstream and downstream slabs so that the line connecting the crowns is below the planned riverbed vertical line. Characterized in that at least one notch having a required depth and width is provided at any position of each of the heads of the cascade work and the deflector so that the floor can be ascended. Achieved by a compact cascade fishway.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to examples.
It should be noted that the present invention is not limited thereby.
No. FIG. 1 shows a three-stage cascading fishway according to the present invention.
It is a section conceptual diagram of the example at the time of tying. Symbol 1 in the figure
Is the planned riverbed vertical line, 2 is the paragraph length, 3 is the bed embankment, 4
And 4 'are water cushion parts, 5 is deflector, 6 is paragraph
Height, 7 is water cushion depth (deflector height), 8
Is upstream protection, 9 is downstream protection, 10 is required
Water intake opening, 11 is a water pipe, θ₁Is paragraph slant
Surface tilt angle, θ ₂Is the deflector climbing slope inclination angle, L
Is the horizontal bottom length of the water cushion, B is the full width of the fishway, B 'is the missing fishway
Mouth width.

[0007] Each dam 3, fish has a slope of paragraph slope inclination angle theta ₁ to the downstream side is so easy to run up, water cushion unit 4 is deployed first (downstream side) of the slope. The water cushion portion 4 has a function of a waterfall basin of a population, and the water cushion portion 4 is not buried with the gravels, just like the waterfall basin is not buried with the gravels. The paragraph height 6 is determined depending on the number of stages of the cascading fishway of the present invention for the planned riverbed longitudinal section 1 and the paragraph length 2, and usually the paragraph height 6 is 1 m to 1.3 m. is there. Paragraph slope angle θ
₁ is preferably set to 40 ° to 65 ° so that fish expected to go up can easily go up.
Preferably between 5 ° and 60 °, generally about 50 °
It is most preferred that the

Water moss and the like grow on the water cushion portion 4 and can be used as a feed for fish that are stuck on the way up the river. The design flow rate for determining the hydraulic specifications of the water cushion is one of the planned high water volume.
In particular, the depth 7 (deflector height) is set at 0./5 from the viewpoint of functioning as a water playground for children.
It is preferably from 3 m to 0.5 m. In addition, if such a depth is secured, the inhabiting fish are less likely to be attacked by birds, which is suitable for forming a waterside environment. The water cushion horizontal bottom floor length L is 1.5 times or more the paragraph height 6 above.
Preferably it is 2.0 times.

[0009] Deflector crawling up slope angle θ ₂
Is preferably about 20 ° to 25 °. Further, at the lower end of the fishway of the present invention, in order to prevent scouring and to form a migration area for upstream fish, a water cushion portion 4 ′ having a block, a jaw basket, a futon basket, etc. arranged at the bottom is provided. Preferably, it is provided. On the other hand, it is preferable to provide a water conduit 11 for taking in the riverbed stored water in the uppermost bed consolidation dam, and to drain water from the back of the dam together with water intake.

The fishway of the present invention is generally made of a concrete structure. However, in an area where a suitable stone material can be obtained, it is adapted to the natural environment by lining the stone or making a masonry structure to prevent abrasion. The structure can be made easy. When the fishway of the present invention is constructed on a permeable ground (river bed), it is necessary to set the paragraph length to a length that can secure a sufficient permeation path length.

The most significant feature of the fishway of the present invention is that each dam and deflector is provided with a depth and width required for fish to run up so that fish running up is not hindered even if the river flow is low. The point is that the mouth 12 is provided. The depth of the missing hole is more than the assumed height of the upstream fish plus the height of the back fin,
The width of the missing hole shall be １ ／ or more of the assumed upstream fish length. In addition, the location of the opening may be on one side or both sides of the river, or may be at the center of the river, and the number thereof is also particularly limited, depending on the topography and flow condition of the river. Not that.

In the cascade on the most upstream side, an intake port (opening) 10 can be provided in the side wall of the water cushion according to the amount of intake, if necessary. In addition, it is preferable that a water control gate be provided at the water intake to enable opening and closing of the water intake and adjustment of the water intake. As described above, the fishway according to the present invention is characterized in that the fishway is mainly designed in consideration of the river environment and the flow condition, and the water intake facility is provided as an accessory.

[0013]

According to the present invention, the floor cascading fishway of the present invention
The fishway is mainly designed in consideration of the river environment and the flow condition, so that the environmental protection of the river and the formation of a hydrophilic environment can be sufficiently achieved.
If the water flow rate of the river is equal to or higher than the normal flow rate, the entire width of the cascade works as a fishway, as well as the open section. As a result, the fish will not always be blocked from going up.

[Brief description of the drawings]

FIG. 1 is a conceptual sectional view of an embodiment in which three-stage cascading fishways of the present invention are connected in three stages.

FIG. 2 is a plan view of the embodiment of FIG.

FIG. 3 is a sectional view taken along line AA and a sectional view taken along line BB of the embodiment of FIG. 1;

[Brief description of reference numerals]

1. Planned riverbed vertical line 2. Paragraph length 3. Floor consolidation dam 4. Water cushion 4 '. Water cushion 5. Deflector 6 Paragraph height 7. 7. Water cushion depth (deflector height) 8. Upstream protection 9 Downstream protection work 10. 10. Water intake opening Water pipe 12. Missing θ ₁ . Paragraph slope angle θ ₂ . Deflector crawling up slope inclination angle Water cushion horizontal bottom length B. Fishway full width B '. Fishway opening width

Claims (10)

[Claims] 1. A method of connecting at least one cascade having a compaction dam, a slope, a water cushion, and a deflector, wherein a line connecting each top of the compaction dam and a deflector is equal to or less than a planned riverbed vertical line. Indeed, it is a fishway arranged between the upstream protection work and the downstream protection work, so that the fish can go up even if the river flow is less than the normal water flow,
A floor consolidation cascade type fishway, wherein at least one cutout having a required depth and width is provided at any one of the tops of the cascade floor consolidation dam and the deflector. 2. The cascade type fishway according to claim 1, wherein the cascades are connected in two or more stages. 3. The cascading floor-type fishway according to claim 2, wherein the cascade on the most upstream side has an intake port on one side wall of the water cushion portion. 4. The cascading fishway according to claim 3, wherein a water control gate is provided at the water intake. 5. The floor-packed cascade fishway according to claim 1, wherein a difference between a top height of the bed-consolidating weir and a deflector top height is 0.4 to 0.8 m. 6. The depth of the gap is equal to or greater than the height of the assumed upstream body height plus the dorsal fin height.
The cascade-type fishway according to any one of Items 1 to 5, wherein 7. The inclination angle θ _{1 of the} slope portion is approximately 40 ° to 6 °.
The cascade type fishway according to any one of claims 1 to 6, wherein the angle is 5 °. 8. The horizontal floor length L of the water cushion portion is approximately 1.5 to 2.0 times the height of the embankment embankment.
The cascade-type fishway according to any one of Items 1 to 7, wherein: 9. inclination angle theta ₂ of the deflector portion creeping up the inclined surface is about 20 ° to 25 °, have been floor compaction cascade method fishway according to any one of claims 1 to 8. 10. A water pipe for taking in riverbed stored water is arranged at the most upstream bed consolidation dam.
A cascaded fishway according to any one of the preceding claims.