JP3927904B2 - Fishway equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fishway facility constructed in a dam.
[0002]
[Prior art]
Fishes (including crustaceans) go up in favor of fishways that have a stable amount of water, but the amount of water in the fishway tends to fluctuate depending on the level of the dam lake that is the source of intake. 2. Description of the Related Art Conventionally, a technique has been proposed in which a fishway waterway intake or a partition wall whose height can be adjusted is provided in the middle of a fishway to stabilize the amount of fishway water. In Patent Document 1 (see paragraph 0013), a water intake is provided in a movable water channel that can be raised and lowered, and the movable water channel is floated against the urging force of a spring cylinder, and the height of the water intake is adjusted to the level of the dam lake. A technique for tracking changes is described.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-115243
[Problems to be solved by the invention]
However, according to the conventional fishway equipment, the amount of fishway water is adjusted by the movable part, so that the structure of the fishway is complicated and the equipment cost is high. In addition, the intake of the fishway canal also functions as an outlet for fish (fishway exit), so the intake had to be provided facing the dam lake. For this reason, when the water intake is submerged at the time of water increase, there is a problem that driftwood and boulders in the muddy flow flow into the fishway or damage the water intake. Measures have been taken to attach a protective fence to the water intake, but there was the inconvenience that trash tends to collect and maintenance is troublesome.
[0005]
An object of the present invention is to solve the above-mentioned problems, and to provide a fishway facility that can obtain a stable amount of fishway water with a simple configuration and is easy to maintain.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the fishway equipment of the present invention comprises a fishway waterway attached to a dam, a fishway inlet is provided at the downstream end of the fishway waterway, a water intake is provided at the upstream end of the fishway waterway, A water supply channel is connected, an overflow wall is erected downstream from the intake in the fishway channel, a fishway exit is provided at the falling point of the flowing water over the overflow channel in the fishway channel, and fish is sent to the dam lake at the fishway exit. It is characterized by connecting a guiding channel to guide.
[0007]
Here, the fishway waterway is not limited to a specific structure, and for example, a waterway having a stepped slope structure, a waterway having a track spiral structure, a waterway having a bridge type switchback structure, and the like can be employed. The material of the fishway channel is not particularly limited, and examples thereof include concrete, resin, and wood. In the case of concrete, it is possible to construct the fishway canal by an on-site construction method, but it is preferable to use a precast concrete fishway block for at least a part of the canal because the construction period can be shortened and the equipment cost can be reduced. .
[0008]
According to the present invention, the intake part of the fishway channel is provided separately from the fishway outlet (fish outlet), and a stable amount of water is always supplied to the intake part from the water supply channel. For this reason, it is not necessary to let the intake section face the dam lake. For example, install the intake section at a position higher than the dam's full water level (dam design upper limit water level) to avoid driftwood and rocks at the time of flooding. Can do. For water supply to the intake section, a water supply channel may be laid from the upstream water area of the dam, but it is preferable to connect the water supply channel to a pump for pumping river water from the viewpoint of reducing the equipment cost.
[0009]
It is desirable to provide a means for efficiently guiding fish to the fishway exit on the overflow wall. For example, it is preferable to incline the overflow wall to the downstream side, to form a notch at the upper end of the overflow wall, and to provide a fishway outlet at the location where the flowing water falls beyond the notch. In this way, since the separated flow is formed by the overflow wall, the fish is prevented from going up by the separated flow, and is led to the notch where there is abundant water flow, and is washed away into the overflow water with a rapid flow velocity beyond the notch. , Fall into the fishway exit. In addition, since fish prefers rectifying water, it is preferable to provide a rectifying member such as a perforated plate or a wire net in the intake portion and rectify the turbulent flow in advance in the intake portion.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the fishway facility of this embodiment includes a concrete fishway channel 2 attached to the dam 1 on the downstream side of the dam 1. A water intake portion 3 for taking in river water is provided at the upstream end of the fishway waterway 2, and a slow flow portion 4 with a gentle gradient (about 1/20 to 1/30) is provided downstream of the water intake portion 3 in the fishway waterway 2. Is provided. A relatively steep slope (about 1/3 to 1/15, most preferably around 1/10) of a rapid flow portion 5 is provided on the downstream side of the slow flow portion 4 in the fishway channel 2. A fishway entrance 6 serving as an entrance for fish is provided so as to open to the river bed downstream from the dam 1.
[0011]
The intake section 3 is installed on the upper surface of the dam 1 so as to be positioned higher than the full water level of the dam 1. Connected to the intake section 3 are a pumping pipe 9 for pumping the water from the dam lake 8 to the water intake section 3, and a surplus water discharge pipe 10 for returning surplus water from the intake section 3 to the dam lake 8. The pumping pipe 9 functions as a water supply channel to the intake section 3, and the lower end thereof is connected to a pump 11 that pumps up the water of the dam lake 8. The pump 11 is installed in a state of being floated on the water surface of the dam lake 8 by the float 12. The pumping pipe 9 and the residual water discharge pipe 10 are respectively provided with valves 13 and 14 for flow rate adjustment.
[0012]
As shown in FIGS. 2 to 5, a rectifying member 16 made of a perforated plate is provided inside the water intake unit 3, and turbulent water immediately after being pumped by the water intake unit 3 is rectified by the rectifier member 16. On the downstream side of the rectifying member 16 in the fishway channel 2, an overflow wall 17 is erected on the boundary between the intake portion 3 and the slow flow portion 4 with the upper side inclined to the downstream side. 17, flows into the slow flow portion 4 as a separated flow (water flow separated from the downstream side wall surface of the overflow wall 17). A cutout 18 is formed on one side of the upper end of the overflow wall 17, and a fishway outlet 19 is provided at the floor corner of the slow flow portion 4 at the location where the flowing water falls beyond the cutout 18. Then, the fish that has run up to the vicinity of the overflow wall 17 falls into the fishway exit 19 together with the rapid water from the notch 18.
[0013]
In consideration of the upstream environment preferred by fish, the amount of water in the intake section 3 is set to the valve of the pumping pipe 9 and the remaining water discharge pipe 10 so that a separated flow having a depth of about 2 cm is formed above the overflow wall 17. It is preferable to adjust at 13 and 14. It is desirable to form the notch 18 at a depth of about 2 cm so that a separation flow having a depth of about 4 cm is formed at the notch 18. Further, the width of the notch 18 is set slightly larger than the opening width of the fishway outlet 19 so that most of the overflow from the notch 18 falls to the fishway outlet 19 and the remaining part falls on the floor of the slow flow portion 4. Good.
[0014]
A guide water channel 22 (see FIG. 1) is connected to the fishway outlet 19 via a guide pipe 21. The guide water channel 22 is provided in a gentle oblique shape on the dam 1, and guides the fish that has fallen from the fishway outlet 19 to the dam lake 8 from the upstream side of the dam 1. The downstream end of the guide water channel 22 may be higher or lower than the water surface of the dam lake 8, but the lower end is preferable in that it is difficult to clog up dust. When the drop between the fishway exit 19 and the water surface of the dam lake 8 is large, the guide water channel 22 may be formed in a step shape, or a pond in which fish rest may be provided in the middle of the guide water channel 22. It is also possible to provide the guide water channel 22 so as to bypass the dam 1 from the fishway exit 19 and extend to the dam lake 8 through the river bank.
[0015]
The slow flow portion 4 is divided in the width direction by a partition wall 23 extending in the flowing water direction, and includes a narrow water passing area 4a that allows the overflow water to pass through the rapid flow part 5, and a water storage area 4b that temporarily stores the overflow water. ing. In the water storage area 4b, the floor surface of the portion corresponding to the partition wall 23 is formed horizontally (see FIG. 5), and a fish resting pool with a slow flow is formed in this portion. A drain hole 24 is provided in the floor corner of the water storage area 4b, and a drainage adjustment valve 26 (see FIG. 3) is provided on a drain pipe 25 connected thereto. By adjusting the amount of drainage, the amount of water flowing out from the upstream end of the partition wall 23 toward the water flow area 4a can be adjusted, and a substantially constant amount of slow flow water can be stored in the water storage area 4b. Coarse stones 27 are sparsely laid on the floor surfaces of the slow flow portion 4 and the rapid flow portion 5.
[0016]
In the fishway facility configured as described above, fish enters the fishway waterway 2 from the fishway entrance 6, goes up the rapid flow part 5, and reaches the slow flow part 4. Since the slow flow part 4 is provided with a water storage area 4b having a slow flow velocity, the fish rest here for a while and then resumes going up toward the overflow wall 17. However, since the overflow wall 17 is inclined downstream and forms a separated flow having a hollow behind, the fish is prevented from going up by the separated flow, and a notch 18 is searched for an upstream route with abundant flow. To the side. Then, it tries to run up the overflow of the notch 18, but is swept into the overflow water with a rapid flow velocity and falls into the fishway outlet 19. Thereafter, the fish reaches the dam lake 8 through the guide pipe 21 and the guide water channel 22.
[0017]
Therefore, the fishway facility of this embodiment can efficiently raise fish from the downstream side of the dam 1 to the upstream side with a simple water channel structure in which the intake section 3 and the fishway outlet 19 are separated. In addition, by separating the water intake unit 3 from the fishway outlet 19, the water intake unit 3 can be installed at a position higher than the full water level of the dam 1. For this reason, the amount of fishway water can be constantly stabilized by the water supply from the pump 11 without being affected by the water level change of the dam lake 8. In addition, since the intake section 3 is not submerged even when the water is increased, there is no risk of driftwood or boulders flowing into the fishway channel 2 or damaging the intake section 3, eliminating the need for a protective fence and eliminating the need to remove dust. It can be omitted.
[0018]
FIGS. 6-8 shows the example of a change of a fishway waterway. The fishway channel 31 includes a water intake part 32, a slow flow part 33, a horizontal part 34, and a stair part 35, and a fishway inlet (not shown) is provided at the downstream end of the stair part 35. A drain pipe 36 is erected on the bottom wall of the water intake 32 on the upstream side of the rectifying member 16 so that the height can be adjusted. A partition wall 37 is erected at the boundary between the slow flow portion 33 and the horizontal portion 34, and a notch 38 is formed on one side of the upper end thereof. The roadbed of the slow flow portion 33 forms the lowest inclined surface in the vicinity of the notch 38, and the flowing water over the overflow wall 17 flows toward the notch 38. In addition, stones or bricks 39 having a flat surface are laid on the roadbed near the fishway exit 19 so that fish can easily approach.
[0019]
The horizontal portion 34 forms a fish resting pool, and stones 41 that rectify turbulent flow are deposited on the roadbed. The staircase portion 35 is configured by connecting a number of precast concrete fishway blocks 42 in a staircase pattern, rectifying stones 41 are laid on the bottom of each block 42, and a notch 44 is formed on the upper end side of the partition wall 43. ing. The overflow water depth of the partition wall 43 is about 4 to 5 cm, the flow velocity is about 0.4 to 0.6 m / s, the overflow water depth of the notch 44 is about 8 to 9 cm, and the flow velocity is about 0.8 to 1.2 m / s. preferable. Since the drain pipe 36 is provided in the intake section 32 so that the height can be adjusted, the flow rate of each part of the fishway channel 31 can be adjusted by adjusting the amount of water in the intake section 32 in combination with the drain pipe 36 and the valves 13 and 14. The flow rate can be easily fine-tuned. Corresponding to the decrease in the flow rate from the fishway outlet 19, the width of the staircase portion 35 is set narrower than the horizontal portion 34 or the like. Other configurations and operational effects are the same as those of the fishway channel 2.
[0020]
In addition, this invention is not limited to the said embodiment, For example, it can also be suitably changed and embodied as follows, for example in the range which does not deviate from the meaning of invention.
(1) Separate the intake part of the fishway from the dam and install it on the riverbank downstream or upstream from the dam.
(2) Pumping river water downstream from the dam with a pump and supplying it to the intake section.
(3) A submersible pump is submerged in a dam lake or a river downstream from the dam and pumped to the intake.
(4) Install the pump fixed on the dam.
[0021]
【The invention's effect】
As described above in detail, according to the fishway equipment according to the present invention, since the intake part is provided separately from the fishway outlet, a simple structure can provide a stable amount of fishway water and facilitate maintenance. There is an effect.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of a fishway facility according to the present invention.
FIG. 2 is a perspective view showing a fishway channel of the same equipment.
FIG. 3 is a plan view of the water channel.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3;
5 is a cross-sectional view taken along line VV in FIG.
FIG. 6 is a perspective view showing a modification example of a fishway waterway.
FIG. 7 is a plan view of the water channel.
FIG. 8 is a sectional view of the water channel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Dam 2 Fishway channel 3 Intake part 4 Slow flow part 5 Rapid part 6 Fishway entrance 8 Dam lake 9 Pumping pipe 11 Pump 16 Rectification member 17 Overflow wall 18 Notch 19 Fishway exit 22 Guidance channel 31 Fishway channel 32 Intake part 33 Slow flow Part 34 Horizontal part 35 Stair part 42 Fishway block

Claims (5)

There is a fishway waterway attached to the dam, a fishway entrance is provided at the downstream end of the fishway waterway, a water intake is provided at the upstream end of the fishway waterway, a water supply channel is connected to the water intake, and the fishway waterway goes downstream from the water intake. A fishway facility characterized by standing a flow wall, providing a fishway outlet at the falling point of the flowing water over the overflow wall in the fishway channel, and connecting a guide waterway that guides fish to the dam lake. The fishway facility according to claim 1, wherein the intake section is installed at a position higher than the full water level of the dam. The fishway facility according to claim 1 or 2, wherein the water supply channel is connected to a pump for pumping up river water. The upper wall of the overflow wall is inclined to the downstream side, a notch is formed at the upper end of the overflow wall, and a fishway outlet is provided at a falling point of the flowing water beyond the notch. The described fishway equipment. The fishway facility according to any one of claims 1 to 4, wherein a rectifying member is provided in the intake portion.

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