JP2527694B2 - Fish path - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fishway which is provided at a step portion of a river or the like formed by a dam, a floor consolidation work or the like to facilitate the upstream passage of fish.

[0002]

2. Description of the Related Art In rivers and the like, weirs are provided to create reservoirs and floor consolidation work is performed to prevent damage to the river bottom due to water discharge from the reservoirs.
Steps may occur due to dams and floor hardening (see Fig. 9). Fish such as sweetfish have the habit of going upstream toward the flow, but if there is such a step, the fish's running is interrupted, the fish's ecosystem changes, and the natural environment is destroyed. To be done. For this reason, conventionally, a fishway 2 having a gentle gradient from the downstream side toward the stepped portion 1 is formed, and a large number of barriers 3 are erected in the fishway 2 in a zigzag manner to adjust the flow gently. Fish F can go up through the river.

[0003]

However, since the conventional fishway 2 is formed with a gentle slope, the length of the fishway 2 is increased, and the number of the barriers 3 is increased accordingly. Therefore, there is a problem that a large space is required and construction cost is high.

The present invention has been made in view of the above circumstances. An object of the present invention is to provide a fishway which has a small installation area, can reduce construction costs with a simple structure, and can easily go up fish. To provide.

[0005]

The invention according to claim 1 is a fishway provided at a stepped portion of a river or the like, which is erected from the riverbed from the downstream side to the upstream side so as to surround a part of the stepped portion. It is characterized in that it is composed of a water storage wall that is open on the upstream side and a water discharge port formed at the lower end of the water storage wall that is located on the downstream side of the step portion. The invention of claim 2 is characterized in that the water discharge port is provided on the front surface thereof with a gate for adjusting the opening area of the water discharge port so as to be vertically movable. The invention according to claim 3 is a fishway provided on a stepped portion of a river or the like, and a peripheral wall which is provided at an upper end portion so as to surround a part of the stepped portion and which is open to the upstream side and overflow water lower than the peripheral wall. A water storage chamber provided with a wall, which stores water from the upstream and flows a part of the water downward beyond the overflow wall, and in the step portion, in a plurality of steps between the water storage chamber and the lower end of the step portion. A run-up chamber which is provided with an inflow part for receiving water flowing down from above and an outflow part which is lower in height than the inflow part communicating with this inflow part at the bottom, and which overflows downward beyond the overflow wall of the outflow part; The water storage chamber has an overflow wall of the water storage chamber and an overflow wall of the run-up chamber, which is provided at an outer upper end of the overflow wall and has an inclined run-up upper surface portion for guiding water flowing from the overflow wall.

[0006]

According to the fishway of the invention of claim 1, the water flowing from the upstream side flows into the water storage wall through the opening, and the water level in the water storage wall is from the downstream side to the upstream side across the step. It will be almost the same. The water in the water storage wall is discharged downstream from the outlet. Since fishes have the property of proceeding against the flow, the fish circulating around the discharge mouth enters the water storage wall through the discharge mouth. Then, the upstream run is continued. When the amount of water on the upstream side changes, the water level in the reservoir wall can be kept almost the same by adjusting the opening area of the outlet by moving the gate up and down.

According to the fishway of the third aspect of the invention, the water flowing from the upstream is stored in the water storage chamber in substantially the same manner as on the upstream side,
Part of the water flows over the overflow wall downwards over the overflow wall. The overflowed water flows into the inflow part of the lower run-up chamber and flows along the bottom part to the outflow part. Then, it flows down over the upstream surface portion over the overflow wall of the outflow portion. The flow velocity at this time corresponds to the water level difference H1 between the inflow section and the outflow section. The water discharged downward flows into the inflow part of the lower run-up chamber, flows into the outflow part in the same manner as above, crosses over the overflow wall, and then sequentially flows into the inflow part of the lower run-up chamber. Runs down the river.

When the fish ascending from the downstream side reaches the lower end of the step portion, it encounters the flow of the upper surface of the lower descending chamber. Then, guided by this flow, it goes up the runway upper surface part and enters the outflow part of the rundown chamber in the lower stage again. Then, the inflow portion rises up against the water flowing at the bottom of the run-up chamber to reach the run-up surface of the upper run-up chamber. Here again, water from the upper run-up chamber flows down the run-up surface, so that the fish is further guided by the flowing water to run up the run-up surface and enters the outflow part of the upper run-up chamber. When this is repeated to run up multiple run-up chambers, the water reaches the water storage chamber at the end. The water level in this reservoir is kept almost the same as the upstream side, so fish go upstream in the river.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to claim 1 will be described below with reference to FIGS. First, in FIG. 1 and FIG. 2, the floor hardener 11 is installed to fill the width of the river so as to cross the river bottom, and a step portion 14 is formed between the upstream river bottom 12 and the downstream river bottom 13. . The water storage wall 15
It is erected from the river bottom by concrete so as to surround a part 14a of the step portion 14. The water storage wall 15 is composed of wall portions 15a, 15a that are substantially parallel to the water flows 16a, 16b from the downstream side to the upstream side, and a wall portion 15b that connects the downstream end portions of the wall portions 15a, 15a. Part 15a,
The upstream end of 15a is open. Also, the wall 15
The heights of a and 15b are preferably higher than the water level 12a so that the fish F do not jump over.

The water discharge port 17 is formed at the lower end of the water storage wall 15 located downstream of the stepped portion 14. The position and the number of the water discharge ports 17 are appropriately determined, and in the present embodiment, they are provided on the wall portions 15a, 15a and the wall portion 15b, respectively. The walls 15a and 15b have
Guide frames 18 are formed on both sides of the water discharge port 17, and a gate 19 is inserted into the guide frames 18 so as to be vertically movable. The gate 19 closes the front surface of the water outlet 17 to adjust the opening area, and the upper end portion (lower end portion of the gate 19) of the water outlet 17 is at substantially the same height as the water level 13a on the downstream side. It is preferably lower than this.
The height of the gate 19 is automatically adjusted by a detection device (not shown) that detects the upstream water level 12a and the downstream water level 13a with a float or the like. A rectifying wall 30 having the same height is provided on both sides of the water storage wall 15.

Next, the operation of the above configuration will be described. 1, water flow 1 that flows through the area where the water storage wall 15 is not provided
As shown in FIG. 3, 6a has a water level of 12a upstream.
And then falls from the step portion 14 at a position away from the water discharge port 17 by bypassing the flow regulating wall 30 and flows downstream at the water level 13a. The fish F that has gone up is hit against the step portion 14 and stopped going up. Then, while swimming laterally along the stepped portion 14, this time, the water hits the water storage wall 15, and the outlet 1
Orbiting around 7. Bubbles and the like due to the fall of water do not occur around the water discharge port 17.

2, the water flow 16b flowing through the portion where the water storage wall 15 is provided is introduced into the water storage wall 15 and discharged from the water discharge port 17 as described above at the downstream side of the water discharge port 17 as shown in FIG. Joins the water stream 16a. The opening area of the water discharge port 17 is adjusted by a detection device (not shown) so that the amount of inflow into the water storage wall 15 and the amount of discharge from the water discharge port 17 are the same. It is almost level with the water level 12a on the side. 3. The fish F circulating around the water discharge port 17 advances toward the flow so as to be attracted by the water discharge flow from the water discharge port 17 and enters the water storage wall 15. 4. The fish F that has entered the water storage wall 15 floats up, crosses the stepped portion 14, and continues to run upstream.

When the water level on the upstream side decreases and the amount of inflow to the water storage wall 15 decreases, the opening area of the water discharge port 17 is lowered to decrease the amount of discharge from the water discharge port 17. When the water level on the upstream side rises and the amount of inflow to the water storage wall 15 increases, the gate 19 may be raised to increase the amount of discharge from the water discharge port 17. It is preferable that the water continuously flows in the water storage wall 15, and it is better that the vortex or the like does not occur beyond the step portion 14.

According to the above embodiment, the following effects can be obtained. 1. Since the water storage wall 15 is provided so as to surround a part 14a of the step portion 14, the fish F that has entered through the water outlet 17 can float vertically and cross the step portion 14. Therefore, the installation area of the fishway can be made significantly smaller than that of the conventional fishway 2 having a gentle slope. 2. Since the water in the water storage wall 15 only needs to be in a laminar flow state,
The construction cost for installation can be remarkably reduced as compared with the conventional fishway that requires a large number of barriers 3 to reduce the flow velocity. 3. Compact and simple in construction. 4. Since the opening area of the water outlet 17 can be adjusted by the gate 19, it is possible to cope with the increase or decrease of the water amount.

FIGS. 4 and 5 show a second embodiment of the present invention, which is applied to a dam 20 as a step portion having a large height. The difference from the above embodiment is that the water storage wall 15
A plurality of stages, for example, three stages of water storage portions 21, 22, 23 forming a part of the water storage wall are provided outside the. Upper water reservoir 2
The side surface of No. 1 is open to the upstream side, and the discharge port 24 at the lower end is opened into the water storage section 22 in the middle stage. In addition, the discharge port 25 at the lower end of the water storage unit 22 opens into the water storage unit 23 at the lower stage, and the discharge port 26 at the lower end of the water storage unit 22 is opened to the downstream side of a river or the like.

Further, the respective discharge ports 24, 25, 26
The maximum opening area of the discharge port 24 is
The order is set to be smaller. In addition, the water storage unit 22,
The upper surface of 23 is open so that light can be transmitted therethrough, and a spillage port 27 to which a strainer is attached is provided at the upper end. The spillage outlet 27 discharges the water overflowing from the water storage sections 22 and 23 to the downstream side, and at this time, the fish F is prevented from jumping out by the strainer. According to this embodiment, in addition to the effects of the above-described embodiment, there is an effect that it can be applied even when the height of the step portion is large.

It should be noted that the present invention relates to the first aspect of the invention described above and shown in the drawings.
However, the shape of the water storage wall 15 is not limited to the U shape, and may be set appropriately. The water level in the water storage wall 15 is the same as the upstream water level. It does not have to be, and the point is that various modifications can be made without departing from the spirit, such as being higher than the step and allowing fish to easily go up.

6 and 7 show a third embodiment according to the third aspect. The water storage chamber 40 is formed at the upper end so as to surround the part 14 a of the step portion 14. The water storage chamber 40 has one wall portion 15a provided on the upstream side.
(See FIG. 2), a peripheral wall 40a formed continuously, a peripheral wall 40b parallel to the step portion 14, and an overflow wall 40c located on an extension line of the other wall portion 15a and connecting the peripheral wall 40b and the step portion 14 to each other. And the surrounding wall 4 at a position lower than the upstream river bottom 12.
0a, the peripheral wall 40b, the lower end of the overflow wall 40c and the step 1
4 and a bottom wall portion 40d that connects the four. The height of this overflow wall 40c is the same as the other peripheral walls 40a and 40b.
It is set lower than the above, and an inclined back surface 41 is formed at the outer upper end thereof.

The first run-up chamber 42 has a box shape and is continuously provided below the water storage chamber 40. This run-up room 42
Is partitioned into an inflow section 44 and an outflow section 45 by a partition wall 43 extending obliquely downward from the overflow wall 40c of the water storage chamber 40, and the inflow section 44 and the outflow section 45 communicate with each other at their bottoms. There is. The side wall 44a of the inflow portion 44 is set at the same height as the peripheral wall 40b of the water storage chamber 40, and the height of the overflow wall 45a of the outflow portion 45 is lower than that of the side wall 44a and is almost the same as the lower end portion of the partition wall 43. They are set to the same height. In addition, an inclined back surface 46 is formed on the outer upper end of the overflow wall 45a.

The second upstream chamber 47 and the third upstream chamber 48 are
The first run-up chamber 42 is alternately stacked in a plurality of stages below the first run-up chamber 42. These second run-up chamber 47 and third run-up chamber 4
8 is configured symmetrically. Second run-up room 47
Is the inflow part 49 on the left side and the outflow part 50 on the right side, as shown in FIG.
There is a slanted partition wall 5 that divides these in the center.
1 is provided. The partition wall 51 is provided in the upper run chamber 4
It is integrally extended below the second overflow wall 45a. An inclined back surface 52 is formed at the outer upper end of the overflow wall 50a of the outflow part 50.

The third run-up chamber 48 has an inflow portion 49 on the right side,
An outflow section 50 is provided on the left side, and an oblique partition wall 51 for partitioning the outflow section 50 is provided in the center of the overflow wall 50a of the upper run-up chamber 47.
It is provided by extending. Further, an inclined upper surface 52 is formed at the outer upper end of the overflow wall 50a of the outflow portion 50. The height of the inflow portion 49 of each run-up chamber 47, 48 is set to a height that does not allow the water flowing down from the upper run-up chamber to overflow, and sunlight is projected above each run-up chamber. Space is provided. Further, a net 53 for preventing the fish from jumping is attached to the upper end of the inflow portion 49 so as to close the space.

Next, the operation of the third embodiment will be described. The water flowing from the upstream is stored in the water storage chamber 40 at substantially the same water level as the upstream side, and a part of the water flows over the overflow wall 40c and flows through the upstream surface portion 41 to the inflow portion 44 of the first upstream chamber 42. Inflow. This water flows along the bottom to the outflow 45,
It flows over the overflow wall 45a of the outflow portion 45, flows through the upstream surface portion 46, and flows into the inflow portion 49 of the second upstream upstream chamber 47. In this way, after sequentially starting to flow from the upper run chambers 48 and 47 into the lower run chambers, finally to the third lower run chamber 4 in the lower stage again.
The water that has flowed through the upstream surface portion 52 of No. 8 flows out to the downstream side.

By the way, the water flowing through the upstream surface portions 46 and 52 has a water level difference H between the inflow portions 44 and 49 and the outflow portions 45 and 50.
Although it has a flow velocity corresponding to 1, in this embodiment, since the height of the step portion 14 is divided into a plurality of stages of upstream chambers, the difference H1 between these water levels is small and therefore the flow velocity is small. Further, the height H2 at which the fish run up, that is, the difference H2 between the water levels of the inflow portions 44 and 49 and the height of the overflow wall 45a is preferably within a range where the fish can go up, for example, 70 cm or less. Therefore, the inflow part 44,
H2 is kept at 70 cm or less by appropriately selecting the volumes of 49 and the outflow portions 45, 50, the flow passage areas, and the distance H3 between the bottom surface of the upstream chamber and the partition walls 43, 51.

When the fish F, which has run up from the downstream side, reaches the lower end of the step portion 14, the run-up surface portion 5 of the run-up chamber 48 in the lower stage again.
Encounter a flow down 2. Then, the fish F is guided by this flow to go up the runway upper surface part 52 and enter the outflow part 50, and further goes up the inflow part 49 against the water flowing at the bottom part of the runup chamber 48. Again, since the water from the upper runway chamber 47 flows down the runway upper surface portion 52, the fish F is further guided by the water flowing through the runway upper surface portion 52 and goes up the runway upper surface portion 52 and goes up the upper runway. Entering the outflow section 50 of the chamber 47. When this is repeated and the plurality of stages of the upstream chambers 47, 48, 42 are upstream, the water reaches the water storage chamber 42 at the end. Since the water level in the water storage chamber 40 is kept almost the same as the upstream side, the fish move to the river and go upstream to the upstream side.

According to the third embodiment, the following effect is obtained in addition to the effect of the first embodiment. That is, since the step portion 14 is provided with a plurality of stages of the upstream chambers 47, 48, 42, even when the step portion 14 is high, the upstream surface portions 41, 46,
The flow velocity of the water flowing through 52 can be kept low, and the height H2 of the run-up can be set to a height suitable for the run-up of the fish F, so that the fish F can easily be run even when the step 14 is high. It has the effect of being able to go back up. In addition, if concave groove portions are provided in the run-up surface portions 41, 46, 52, water flows concentratedly in the groove portions even when the amount of water is small, so that the fish F can easily go up.

FIG. 8 shows a fourth embodiment according to the third aspect of the present invention. The difference from the third embodiment is that the run-up chambers 47 and 4 are different from each other.
The front end of an oblique partition wall 60 that divides the ports 8, 42 into the inflow portions 49, 44 and the outflow portions 50, 45 is connected to the bottom portion, and the partition wall 60 is provided with an opening 61. According to the fourth embodiment, in addition to the effect of the third embodiment, the run-up height H2 can be adjusted by adjusting the area of the opening 61, and further along the partition wall 60. As a result, the fish F rises, which makes it easier to go up.

[0027]

The invention according to claim 1 is a fishway provided on a stepped portion of a river or the like, which is erected from the river bottom from the downstream side to the upstream side so as to surround a part of the stepped portion and the upstream side is open. The water storage wall and the water discharge port formed at the lower end of the water storage wall located on the downstream side of the stepped portion make it possible to significantly reduce construction costs with a small installation area and a simple structure. It is possible to adapt to the increase and decrease of the water amount, and it has an excellent effect that fishes can easily go up. The invention according to claim 3 is a fishway provided on a stepped portion of a river or the like, and a peripheral wall which is provided on an upper end portion so as to surround a part of the stepped portion, and which is open to the upstream side and lower than the peripheral wall. A water storage chamber provided with an overflow wall, which stores water from the upstream and flows a part of the water downwardly beyond the overflow wall, and a plurality of stages between the water storage chamber and the lower end of the stepped portion in the step portion. A run-up chamber that has an inflow part that is provided at the bottom and that receives water that flows down from above, and an outflow part that is lower in height than the inflow part that communicates with this inflow part at the bottom, and that overflows downward beyond the overflow wall of the outflow part. And the inclined upper surface portion which is provided on the outer upper end portion of the overflow wall of the water storage chamber and the overflow wall of the upstream chamber and guides the water flowing from the overflow wall, the installation area is small and simple. Construction can significantly reduce construction costs and increase / decrease water volume Also it can be adapted, even when the height of the step portion is high, in which excellent effects that fish can be easily run-up.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a river or the like in a first embodiment.

FIG. 2 is a plan view of a river or the like in the first embodiment.

FIG. 3 is a vertical sectional front view of a river or the like having a step portion.

FIG. 4 is a perspective view of a second embodiment.

5 is a cross-sectional view taken along the line VV in FIG.

FIG. 6 is an external perspective view of the third embodiment.

7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is an external perspective view of a fourth embodiment.

FIG. 9 is a vertical sectional front view of a river or the like showing a conventional fishway.

[Explanation of symbols]

 11 Floor consolidation 12 River bottom 13 River bottom 14 Step 15 Reservoir 17 Water outlet 17 Gate 20 Gate 20 Dam (step) 21 Reservoir 22 Reservoir 23 Reservoir 24 Outlet 25 Outlet 26 Outlet 40 40 Reservoir 40a Surrounding wall 40b 40c overflow wall 41 upstream surface part 42 first upstream chamber 44 inflow portion 45 outflow portion 45a overflow wall 46 upstream surface portion 47 second upstream chamber 48 third upstream chamber 49 inflow portion 50 outflow portion 52 upstream surface Department

Claims (3)

(57) [Claims] 1. A fishway provided at a stepped portion of a river or the like, wherein a water storage wall is provided upright from the river bottom from the downstream side to the upstream side so as to surround a part of the stepped portion, and the upstream side is open, and the stepped portion. A fishway comprising a water discharge port formed at a lower end portion of a water storage wall located downstream of the portion. 2. The fishway according to claim 1, wherein a gate for adjusting an opening area of the water outlet is provided on the front surface of the water outlet so as to be vertically movable. 3. A fishway provided at a stepped portion of a river or the like, which is provided at an upper end portion so as to surround a part of the stepped portion,
A water storage chamber that has a peripheral wall that is open on the upstream side and an overflow wall that is lower than this peripheral wall, stores water from the upstream and flows a part of the water downwardly beyond the overflow wall, and the water storage chamber at the step portion. The inflow section is provided between the lower end of the step section and receives water flowing down from above, and an outflow section having a height lower than that of the inflow section communicating with the inflow section at the bottom. A run-up chamber that overflows downwards across the wall, and a sloped run-up upper surface portion that is provided at an outer upper end of the overflow wall of the water storage chamber and the overflow wall of the run-up chamber and guides water flowing from the overflow wall. A fish road that is characterized by that.