JP2604307B2 - Stair type fishway device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a river dam or a fixed weir without a water channel for upstream fish (hereinafter, for convenience, a fixed weir will be described as an example), and a water channel for upstream fish. The present invention relates to a staircase type fishway device that can be installed on a fixed weir that does not exhibit its function sufficiently even if it is provided.

[0002]

2. Description of the Related Art Conventionally, fixed weirs provided in rivers are used for storing water, preventing flood damage, and the like. In recent years, fixed weirs have been designed and built to maintain fish ecosystems.
In some cases, a fishway device is juxtaposed to a part of a fixed weir so as not to hinder fish run-up, thereby securing a run-up fish channel (hereinafter simply referred to as a water channel).

For example, a long concrete channel extending from the upstream side to the downstream side of the fixed weir is formed,
A plurality of concrete or steel dams were installed in this channel in steps, gradually increasing the height, and a gate corresponding to the upstream water level was mounted on the upper part of each dam so as to be able to move up and down. Some fishery devices are formed to secure a waterway.

[0004] The water channel provided with the stepwise weir body as described above is
Usually, the height of the gate is adjusted by operating a gate provided on the upper part of the weir in accordance with the fluctuation of the upstream water level.
In addition, a plurality of weirs are formed by cutting out a part of the top of the weir to increase the overflow water depth so that fish can easily run up.

[0005]

However, a fishway device having such a waterway is provided for a large river, and in a fixed weir provided for a small tributary river, a waterway is provided. If there is no waterway, or if a concrete waterway is installed, the location of the waterway is inappropriate, or there is a problem with the flow condition of the waterway, such as a narrow climbing fish entrance. In many cases, the function as a canal was not fully demonstrated.

[0006] In many cases, the fishway device is provided around the fixed weir, so that it is difficult to secure a sufficient place for the fishway device near the fixed weir. This is because it is difficult to construct an appropriate fishway device upstream. In addition, in order to finish the fishway device appropriately for upstream of the fish, a plurality of weirs are provided in a detoured flow path, and they are arranged in a stepwise manner with a height difference gradually, or a gate is provided. In some cases, the production of the fishway device was complicated. For this reason, it is conceivable to provide a fishway device on an existing fixed weir provided in a river, but it has been troublesome to adjust the height of the fishway device each time according to the height of a large number of fixed weirs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and it has been found that existing fixed weirs have a sufficient function even in a place where a water channel is not installed, or even when installed. By stacking fishway blocks downstream of a fixed weir in a river where it is not located, it does not form a diverted waterway as in the past, makes it easy to manufacture, and fully demonstrates its function It is an object of the present invention to provide a staircase type fishway device that can perform the operation.

[0008]

According to the present invention, as a means for solving the above-mentioned problems, a plurality of fishway blocks having notches formed in a wall downstream of an existing fixed weir provided in a river are shown in plan view. , The fishway blocks are stacked in a fan shape, and the stacked fishway blocks are connected in a stepwise manner from the upstream side to the downstream side, and the size of the cutout portion is reduced as going downward.

[0009]

According to the present invention, a plurality of fishway blocks having notches formed in the wall portion are connected in a stair-like manner on the downstream side of the existing fixed weir provided in the river. Can be used as a fishway device,
A waterway for fish is ensured.

Further, since the fishway device is formed by stacking a plurality of fishway blocks, the number of stages of the fishway block is adjusted to adjust the height of a large number of fixed weirs provided in the river. The height can be adjusted. Therefore, it is possible to connect to fixed weirs of various heights. In addition, since a plurality of fishway blocks are stacked and arranged in a fan shape in plan view, it is possible to widen a climbing port for fish going up. Further, since the notch formed in the wall is narrowed as it goes below the stacked fishway blocks, the flow rate of the fishway can be made constant.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. First, the river will be described with reference to FIG. A fixed weir 2 is installed in the river 1 over the entire width of the river 1, and a step-type fishway device 3 is provided at a substantially central position on the downstream side of the fixed weir 2. The flow rate flowing down the stepped fishway device 3 is the maintenance flow rate of the river 1. In FIG. 3, the right side is upstream of the river 1 and water flows as shown by the arrow.

Next, the fishway device 3 attached to the fixed weir 2 of the river 1 will be described in detail with reference to FIGS. A plurality of fishway devices 3, three in this embodiment, steel fishway blocks 4, 5, and 6 are arranged in a three-tiered manner in a fan shape in plan view.
Furthermore, these stacked fishway blocks 4, 5, and 6 are connected to river 1
Are connected in a stepwise manner from the upstream to the downstream.

The lower fishway block 4 of the fishway blocks 4, 5, 6 is the widest in the flow direction of the river 1, and the uppermost fishway block 6 is the narrowest. It has become. And the lowest fishway block 4
Is fixed to the riverbed 7 by anchor bolts 8,
The middle fishway block 5 is fixed to the lower fishway block 4 via a packing 9 with mounting bolts 10. The uppermost fishway block 6 is fixed to the middle fishway block 5 via a packing 9 with mounting bolts 10.

Further, a watertight rubber 11 is attached between the uppermost fishway block 6 and the fixed weir 2 to prevent water leakage. In addition, each fishway block 4,
Notches 12 are formed on the front and left and right wall portions of 5, 6 as water channels. The width of the notch 12 is changed toward the bottom of the stacked fishway blocks 6, 5, and 4.
In other words, the width decreases as going downward. Thereby, the overflow water depth of the notch 12 becomes constant.

Next, the operation of this embodiment will be described. In this way, three fishway blocks 4, 5, 6 each having the cutout 12 formed in the wall are stacked and disposed on the downstream side of the existing fixed weir 2 provided in the river 1, and the fishway blocks 4, 5, 6 are provided. 6 are connected stepwise, it is possible to form the combined fishway blocks 4, 5, 6 into a stepped fishway apparatus 3 having a waterway.

Also, since the stairway type fishway device 3 is formed by stacking the fishway blocks 4, 5, and 6, the number of fishway blocks 4, 5, and 6 is adjusted, so that a large number of fixed fishway devices provided in the river 1 are provided. It is possible to adjust the height of the staircase type fishway device 3 in accordance with the height of the weir 2, and it is possible to connect to the fixed weir 2 of various heights. Also,
Since a plurality of fishway blocks are stacked and arranged in a fan shape in plan view, it is possible to widen a climbing port for fish going upstream.

Furthermore, the notches 12 formed in the front and right and left walls of the fishway blocks 4, 5, and 6 are narrowed as they go under the stacked fishway blocks 4, 5, and 6. Can be made constant, and the flow can be made the maintenance flow of the river 1 as described above.

[0018]

As described above, according to the present invention, a plurality of fishway blocks each having a cut-out portion formed in a wall portion on the downstream side of an existing fixed weir provided in a river are stacked and arranged. Are connected in a step-like manner, so that the interconnected fishway blocks can be used as a fishway device, and a waterway can be reliably secured. Thereby, the fishway device can be mounted downstream of the fixed weir in the river to exert its function sufficiently.

Further, since the fishway device is formed by stacking a plurality of fishway blocks, by adjusting the number of stages of the fishway block, the height of the staircase type fishway device can be adjusted to the height of the many fixed weirs provided in the river. Can be adjusted. Therefore, it can be connected to fixed weirs of various heights.

Thus, the fishway device can be easily attached to an existing fixed weir provided in a river, and a plurality of weirs are gradually arranged in a flow path in a stepwise manner in a flow path as in the prior art. There is no need to provide a gate or a gate, and it is possible to avoid troublesome installation. In addition, since a plurality of fishway blocks are stacked and arranged in a fan shape in a plan view, it is possible to widen a climbing port for fish going upstream. Thereby, the condition of the flow in the channel can be improved. Furthermore, since the notch formed in the wall is narrowed as it goes below the stacked fishway blocks, the flow rate of the fishway can be made constant.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing an embodiment of the present invention, taken along line AA of FIG. 2;

FIG. 2 is a plan view of the stepped fishway device of the present invention.

FIG. 3 is a plan view of a fixed weir and a river to which the stepped fishway device of the present invention is attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 River 2 Fixed weir 3 Stair-type fishway device 4 Fishway block 5 Fishway block 6 Fishway block

Claims (1)

(57) [Claims] 1. A plurality of fishway blocks each having a cutout formed in a wall thereof are arranged in a fan shape on a downstream side of an existing fixed weir provided in a river, and the stacked fishway blocks are arranged from an upstream side. A stepped fishway device, characterized in that the cutout portion is connected to the downstream side in a stepwise manner, and the size of the cutout portion is reduced as going downward.