JPH08218352A - Stepped fishway - Google Patents

Abstract

PURPOSE: To improve current conditions in a pool formed into a fishway and to enable fishes with low natatorial ability to ascend against a rushing stream. CONSTITUTION: Firshway blocks 11 forming a spiral stair fishway are constituted of a plane fan-shaped bottom slab 15 with a size dividing a disc forming the bottom of the fishway into approximately six parts, an interior wall 16 partitioning the inside of the fishway, an exterior wall 17 partitioning the outside thereof and a fan-shaped partition wall 18 formed in the direction of the radius between the interior wall 16 and exterior wall 17 so as to intersect with the down flowing direction of down flowing water from the fishway and, at the same time, the pivot section having a through-hole extended inward of the direction of the radius from the bottom slab 15 is provided to the inside of the interior wall 16. A pool in which the clown flowing water is settled is formed in the fishway by the partition wall 18, at the same time, since the partition wall 18 is constituted of an overflow section 22 and a non-overflow section 23, a resting space having quiet current conditions for fishes is provided to the rear of the non-overflow section 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stepped fishway,
In particular, it is installed close to a reservoir structure that dams rivers such as dams and weirs and forms a reservoir on the upstream side, and by connecting the river on the downstream side and the formed reservoir, fish can run upstream. About staircase-shaped fishway to do.

[0002]

2. Description of the Related Art A fishway is a dam structure that dams a river such as a dam or a weir to prevent a fish from running from the downstream side to the upstream side of the river by a reservoir structure that forms a reservoir on the upstream side. It is a water channel dedicated to fish that is provided for the purpose of connecting from the vicinity of the top of the water storage structure to the downstream river.

That is, according to this fish path, a flow path for river water is installed from the reservoir to the river on the downstream side at a slope that allows fish to go up close to the water storage structure. By moving fish through the reservoir, the sharp difference in water level between the water level in the reservoir and the water level of the river immediately below it is eliminated, which allows the downstream river to reach the reservoir and its upstream. It can allow fish to ascend to rivers.

[0004] In order to comfortably cause fish to ascend in such a fishway, the flow velocity of the effluent is 1.0 m or less, there is a resting place for the fish in the fishway, and air bubbles are present. It is desired to prepare for the flow conditions such as the occurrence of less.

Therefore, as a fishway that substantially satisfies the above conditions, a bottom plate portion that forms the bottom of the fishway, a side wall portion that divides the side of the fishway, and a partition wall portion that is provided so as to intersect in the flowing down direction of the flowing water. A staircase-shaped fishway is known in which fishway blocks each having a concave cross section are connected in a stepwise manner at a predetermined gradient to form a pool in the recesses of the fishway blocks while allowing the flow-down water to flow down.

Further, Japanese Patent Publication No. 60-25562 discloses an assembling type tubular fishway in which block members which are substantially fan-shaped in a plane are connected in a spiral staircase shape and are formed in a cylindrical shape as a whole.

[0007]

However, according to the above-mentioned conventional staircase-shaped fishway, the flow in the pool which is desirable as the above-mentioned fishway can be obtained by appropriately adjusting the connecting gradient of the fishway block and the height of the partition wall. However, it is difficult to maintain a suitable flow condition even for fish with low swimming ability such as sweetfish, and it is necessary to sufficiently attempt to run these fish with low swimming ability. There was a problem that I could not do it.

According to the conventional staircase-shaped fishway,
In order to enable the migration of bottom fish such as eels, the partition wall that divides the fishway has a through hole that communicates with each pool. There was a problem that the flow condition in the downstream pool would be disturbed due to the water being sprayed.

Therefore, the present invention has been made by paying attention to such a conventional problem, and further improves the flow condition in the pool in each fishway block so that the fish having a low swimming ability can easily be run up. The purpose is to provide a staircase-shaped fishway that can be

[0010]

The present invention has been made to achieve the above object, and its gist is to provide a water storage structure for damming a river such as a dam or weir to form a reservoir on the upstream side. It is a fishway that is provided in close proximity and that enables the upstream of fish by connecting the downstream river and the formed reservoir, and this fishway is a bottom plate part that constitutes the bottom of the fishway, A fishway block consisting of a side wall partitioning the side of the fishway and a partition wall section that is provided so as to intersect with the flowing-down direction of the flowing-down water to pool the flowing-down water, is connected stepwise at a predetermined gradient, and In the staircase-shaped fishway, the partition wall portion is composed of an overflow portion for allowing the overflow water to overflow, and a non-overflow portion protruding above the overflow portion.

In the staircase-shaped fishway according to the present invention, the fishway blocks are formed in a substantially fan-shaped plane, and the fishway blocks are sequentially arranged in concentric circles centering on a main part to form a spiral. It is preferable to form a stepped fish path.

Further, in the staircase-shaped fishway according to the present invention, a latent hole formed in the partition wall for communicating between the upstream pool and the downstream pool is opened toward the bottom surface of the downstream pool. It is preferable to form it.

[0013]

According to the staircase-shaped fishway of the present invention having the above-mentioned structure, the partition wall forming the fishway block has the overflow portion for overflowing the overflow water and the non-overflow portion protruding above the overflow portion. Since it is composed of two parts, it provides a resting place for fish with less disturbance in the flow area behind the non-overflow part in the pool where the spilled water has accumulated, which allows fish with low swimming ability to run upstream. A fish path that is easy to form is formed.

Further, in the spiral staircase-shaped fishway which reduces the installation area of the fishway, by adopting the above configuration,
A fishway that allows fish with low swimming ability to easily run up is formed, and a submerged hole that connects the upstream pool and the downstream pool is formed in the partition wall toward the bottom of the downstream pool. If formed so as to open, the flow condition in the pool,
Furthermore, it can be made quiet with less disturbance.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Fishway 10 according to this embodiment
As shown in FIG. 1 and FIG. 2, a cylindrical structure as a whole is formed by sequentially arranging a fish path block 11 having a substantially fan-shaped plane described later in a concentric pattern centered on a main part 12 thereof with a predetermined gradient. A spiral staircase-shaped fishway 10 forming 20 is configured. That is, the spiral staircase-shaped fishway 10
According to the above, after the fishway blocks 11 manufactured in advance in a factory or the like are carried in to the installation site, the main parts of each fishway block 11 are mounted on the foundation blocks 12 and on the columns 13 standing upright in the center of the foundation blocks 19. By inserting the through holes 14 formed in 12 and sequentially stacking them, the fishway 10 can be easily and quickly constructed and formed, and the fishway 10 can be provided with a small installation area.

The fishway block 11 constituting this embodiment is formed as a block member made of reinforced concrete, for example, and as shown in FIGS. 3 to 6, the disk forming the bottom surface of the fishway is approximately six. A flat fan-shaped bottom plate 15 of equal size, an inner wall 16 that partitions the inner surface of the fishway, an outer wall 17 that partitions the outer surface of the fishway, and an inner wall that intersects the downflow direction of the downflow water that flows down the fishway. The partition wall 18 is formed in the fan-shaped radial direction between the outer wall 16 and the outer wall 17, and a through hole 14 is provided inside the inner wall 16 to extend radially inward from the bottom plate 15. The unit 12 is provided.

Here, the outer wall 17 is formed higher than the inner wall 16, and the outer wall 17 is provided with a notch 21, and the notch 21 is connected to the fishway block 11 to form a cylindrical structure 20. At this time, a lighting window is formed on the outer peripheral portion of the cylindrical structure 20. In addition, the top end portion of the inner wall 16 has an inclination that becomes lower toward the downstream side.

Further, the bottom slab 15 is formed with a step so that the bottom surface on the upstream side is higher than the bottom surface on the downstream side with the part where the partition wall 18 is provided as a boundary, whereby each fishway block 11 is formed. When the fish are arranged in series, a staircase-shaped fishway 10 is formed.

Further, the partition wall 18 is composed of an overflow portion 22 having a low crown height located on both sides thereof, and a non-overflow portion 23 having a high crown height projecting upward in the central portion, and Both ends of the non-overflow portion 23 project to the upper side in the downflow direction of the downflow water to form a recess facing the downflow direction. Further, the partition wall 18 is close to the inner wall 16 and the outer wall 17, and has a pool 26 on the upstream side and a pool 2 on the downstream side at the bottom thereof.
6 (see FIG. 7) are formed to form a pair of latent holes 24. That is, the latent hole 24 has a bottom plate 1 having a step.
5 is formed in an oblique direction from the upstream side bottom surface to the downstream side bottom surface, and is formed so as to open toward the downstream side bottom surface.

As described above, the fishway block 11 having such a structure is carried in to the installation site of the fishway 10 and then, on the foundation block 12 formed in advance at this installation site, in the circumferential direction. The through-holes 14 formed in the main portion 12 are inserted into the support columns 13 while the angle is shifted by 60 degrees, and the fish paths 10 are spirally stepped with a predetermined gradient by sequentially stacking them.

The fishway 10 is drained from the downstream river by flowing down the spilled water taken from the reservoir via the intake channel 25 toward the outlet 27 at the lower end of the fishway 10. A passage for fish that enters the fishway 10 through the outlet 26 and goes up to the reservoir is secured.

Here, in this fishway 10, as shown in FIG. 7, the partition walls 18 of each fishway block 11 form a pool 26 in which the spilled water is accumulated, and the partition walls 18 are formed.
However, the overflow section 22 that overflows the sewage and this overflow section 22
Since the non-overflow portion 23 having a concave cross-section protruding upward is provided, a resting place for fish with very little disturbance of the flow condition is provided behind the non-overflow portion 23. In addition, the pool 2 on the upstream side is provided through a latent hole 24 formed obliquely downward.
The runoff water sprayed from 6 to the downstream pool 26 collides with the bottom surface of the downstream pool 26 to reduce its momentum, thereby keeping the flow condition in the pool 26 quiet.

The gradient of the fishway 10 is the fishway block 11
And the size of the step between the bottom plate 15 on the upstream side and the downstream side of each fishway block 11 can be appropriately designed, and the planar fan-shaped fishway block 11 divides the disk shape into six equal parts. It is not limited to what was done.

Further, in the above embodiment, the case where the present invention is applied to the spiral staircase-shaped fishway 10 has been described, but the present invention is not limited to such an embodiment, and for example, the fishway block 11 is used. It can be applied to any staircase-shaped fishway in which fishway blocks including a bottom plate portion, a side wall portion, and a partition wall portion are connected in a staircase shape, such as those connected in a straight line.

Furthermore, when it is not necessary to consider the run-up of bottom fish such as eel, the pool 2 on the upstream side
It is not always necessary to provide the latent hole 24 that connects 6 and the pool 26 on the downstream side.

[0026]

As described above in detail, according to the staircase-shaped fishway of the present invention, the partition wall portion constituting the fishway block is located at the overflow portion for overflowing the overflow water and above the overflow portion. Since it consists of a projecting non-overflow part, a resting place for fish with less disturbance in the flow condition is provided behind the non-overflow part in the pool where the spillage is accumulated, so fish with low swimming ability are provided. It is also possible to easily run up to.

Further, even in a spiral staircase-shaped fishway in which the installation area of the fishway is reduced, it is possible to form a fishway in which fish having low swimming ability can easily go up.

Further, if a latent hole for communicating between the upstream pool and the downstream pool formed in the partition wall is formed so as to open toward the bottom surface of the downstream pool, the flow condition in the pool will be improved. Can be made quieter with less disturbance.

[Brief description of drawings]

FIG. 1 is a plan view of a spiral staircase-shaped fishway according to an embodiment of the present invention viewed from above.

FIG. 2 is a side view showing a cylindrical structure in which a spiral staircase-shaped fishway is formed.

FIG. 3 is a perspective view showing a fishway block constituting a spiral staircase-shaped fishway according to an embodiment of the present invention.

FIG. 4 is a plan view of the fishway block of FIG. 3 seen from above.

5 is a cross-sectional view taken along the line AA of FIG.

6 is a cross-sectional view taken along the line BB of FIG.

FIG. 7 is a vertical cross-sectional view showing the flow-down state of the flow-down water along the fishway.

[Explanation of symbols]

 10 Fishway (spiral stepped fishway) 11 Fishway block 15 Bottom plate 16 Inner wall (sidewall) 17 Outer wall (sidewall) 18 Partition wall 22 Overflow part 23 Non-overflow part 24 Submerged hole 26 Pool

Claims (3)

[Claims] 1. A fish run-up is provided in the vicinity of a water storage structure that forms a reservoir on the upstream side by damming a river such as a dam or weir, and connects the downstream river to the formed reservoir. A fishway for enabling the fishway, the fishway is provided by intersecting the bottom plate portion forming the bottom surface of the fishway, the side wall partitioning the side of the fishway, and the flowing-down direction of the flowing water. A fishway block consisting of a partition wall for pooling is connected in a stepwise manner at a predetermined gradient, and the partition wall part overflows the overflow water and a non-overflow portion protruding above the overflow part. A staircase-shaped fishway characterized by consisting of an overflow section. 2. The fishway block has a substantially fan-shaped plane and is sequentially arranged in concentric circles centering on a main part to form a spiral staircase-shaped fishway. The listed staircase fishway. 3. The partition wall is provided with a latent hole that connects an upstream pool and a downstream pool that are adjacent to each other with the partition wall interposed therebetween.
The stepped fishway according to claim 1 or 2, which is formed so as to open toward the bottom surface of the pool on the downstream side.