Fish passing structure suitable for upstream variable water level

Abstract

The invention discloses a fish passing structure suitable for an upstream variable water level, belongs to the technical field of fishway structures, and can solve the problem that an existing pool weir type fishway cannot adapt to upstream reservoir water level changes. The fish passing structure comprises a vertical seam type fishway; the regulating reservoir is connected to the downstream end of the vertical seam type fishway; the bottom plate elevation of the adjusting tank is the same as the bottom elevation of the downstream end of the vertical seam type fishway; an overflow port is formed in the side wall of the adjusting tank; a protective fishing net is mounted on the overflow port; the pond weir type fishway is connected to the downstream end of the adjusting pond; the bottom elevation of the upstream end of the pool weir type fishway is higher than that of a bottom plate of the adjusting pool; the bottom elevation of the overflow port is higher than the top elevation of a weir plate in the pool weir type fishway; the water discarding channel is connected to the outer side of the side wall, provided with the overflow port, of the adjusting tank, and water higher than the bottom elevation of the overflow port in the adjusting tank is discharged through the water discarding channel. The invention is used for the pool weir type fishway.

Description

Technical Field

[0001] The present invention relates to a fish passage structure suitable for variable water levels in the upper reaches, belonging to the technical field of fishway structures. Background Art

[0002] Some water conservancy projects such as river-blocking sluice dams block the migration channels of fish during the breeding period. In order to restore the migration channels of fish, fishways are generally built on the sluice dams to help fish overcome the obstacles of hydraulic structures such as dams.

[0003] There are mainly four existing types of fishways: vertical-slot fishways, Daniel fishways, pool-and-weir fishways, and combined fishways. Among them, the pool-and-weir fishway has a stable water flow passing through, is suitable for fish that like to live on the water surface or like to jump, and is widely used.

[0004] However, the pool-and-weir fishway also has its own disadvantages, mainly manifested in that the water head above the weir of the pool-and-weir fishway cannot be too high. Generally, when the water head above the weir exceeds 20 cm - 30 cm, the flow velocity above the weir increases sharply, exceeding the maximum limit swimming ability of fish (generally requiring the flow velocity to be less than 1.2 m / s), forming a flow velocity barrier, which is not conducive to fish crossing the weir plate; the water head above the weir should not be too low either, generally not less than 10 cm. Too low a water head will cause the flow velocity in the pool to be too small, which is not conducive to fish using the flow-tending characteristics to swim upstream. Therefore, due to the inability to adapt to large water level changes in the upstream reservoir, the traditional pool-and-weir fishway is only suitable for construction on sluice dams with small water level changes in the upstream reservoir, restricting its application range. Summary of the Invention

[0005] The present invention provides a fish passage structure suitable for variable water levels in the upper reaches, which can solve the problem that the existing pool-and-weir fishway cannot adapt to the water level changes in the upstream reservoir.

[0006] The present invention provides a fish passage structure suitable for variable water levels in the upper reaches, comprising: A vertical-slot fishway; A regulating pool, connected to the downstream end of the vertical-slot fishway; the bottom elevation of the regulating pool is the same as the bottom elevation of the downstream end of the vertical-slot fishway; an overflow opening is provided on the side wall of the regulating pool; a protective fishing net is installed on the overflow opening; A pool-and-weir fishway, connected to the downstream end of the regulating pool; the bottom elevation of the upstream end of the pool-and-weir fishway is higher than the bottom elevation of the regulating pool; the bottom elevation of the overflow opening is higher than the top elevation of the inner weir plate in the pool-and-weir fishway; A water discharge channel, connected to the outside of the side wall of the regulating pool where the overflow opening is provided, and the water in the regulating pool above the bottom elevation of the overflow opening is discharged through the water discharge channel.

[0007] Optionally, the vertical-slot fishway comprises: A first water flow channel, with the regulating pool connected to the downstream end of the first water flow channel; A plurality of vertical slit partition units, which are arranged at intervals along the water flow direction in the first water flow channel, and a first pool chamber is formed between two adjacent vertical slit partition units.

[0008] Optionally, the vertical slit partition unit includes: A partition plate, fixed in the middle of the bottom plate of the first water flow channel; Two baffle plates, located on both sides of the partition plate and respectively fixed on the two side walls of the first water flow channel; the partition plate and the two baffle plates are both perpendicular to the water flow direction in the first water flow channel; a fish passage vertical slit is formed between each of the two baffle plates and the partition plate.

[0009] Optionally, the pool weir type fishway includes: A second water flow channel, connected to the downstream end of the regulating pool; A plurality of weir plates, which are arranged at intervals along the water flow direction in the second water flow channel, and a second pool chamber is formed between two adjacent weir plates.

[0010] Optionally, the plurality of weir plates are divided into a plurality of concave plates and a plurality of convex plates; the plurality of concave plates and the plurality of convex plates are arranged alternately.

[0011] Optionally, the protruding height of the convex plate is 0.1 m to 0.2 m higher than the groove height of the concave plate.

[0012] Optionally, the length of the first pool chamber is the same as the length of the second pool chamber.

[0013] Optionally, the length of the overflow opening is less than the length of the regulating pool.

[0014] Optionally, the longitudinal slope of the bottom plate of the first water flow channel is 1% to 5%. The beneficial effects that can be produced by the present invention include: The fish passage structure applicable to variable upstream water levels provided by the present invention, by arranging a vertical slit type fishway and a regulating pool upstream of the pool weir type fishway, and arranging an overflow opening and a waste water channel on one side of the regulating pool, the water flow enters the pool weir type fishway gently after being rectified by the regulating pool after flowing out of the vertical slit. The present invention controls the waste water flow by adjusting the bottom elevation and width of the overflow opening, so that the water level and flow rate in the regulating pool meet the water level and flow rate required for the normal operation of the pool weir type fishway, to smoothly connect the water level and flow rate required by the pool weir type fishway, that is, it can automatically adjust the weir head of the pool weir type fishway, avoid the weir head being too high or too low, and ensure the smooth upstream migration of fish. This enables the pool weir type fishway to be applied to reservoirs or sluice dams with large water level changes.

[0015] The fish - passing structure applicable to variable water levels in the upper reaches provided by the present invention designs the weir plates of the pool - weir fishway into the form of a concave plate with "high on both sides and low in the middle" and a convex plate with "low on both sides and high in the middle". The structure of the concave plate with "high on both sides and low in the middle": The water flow mainly discharges concentratedly from the low - lying middle part, forming a high - speed main flow area. However, due to the relatively high elevation on both sides, the flow velocity is relatively slow, and a slow - flow zone can be formed. The structure of the convex plate with "low on both sides and high in the middle": After the water flow is blocked by the high weir in the middle, it disperses to both sides, and relatively high - velocity lateral flows are formed on both sides, while the flow velocity in the middle area decreases due to the increase in water depth. By arranging the two kinds of weir plates alternately, the water flow is repeatedly contracted - diffused - turned longitudinally (up - and - down stream direction) and transversely (left - and - right bank direction), breaking the single high - speed flow, making the overall flow velocity more uniform, and avoiding the local flow velocity exceeding the limit flow velocity of fish. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. is a three - dimensional structure schematic diagram of the fish - passing structure provided by an embodiment of the present invention; Figure 2 FIG. is a top - view schematic diagram of the fish - passing structure provided by an embodiment of the present invention Figure 1 ; Figure 3 FIG. is a top - view schematic diagram of the fish - passing structure provided by an embodiment of the present invention Figure 2 ; Figure 4 is Figure 1 a cross - sectional view taken along the AA direction in REFERENCE NUMERALS: 1, first side wall; 2, second side wall; 3, first bottom plate; 4, partition board; 5, baffle; 6, regulating pool; 7, overflow opening; 8, protective fishing net; 9, waste - water channel; 10, weir plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The present invention will be described in detail below with reference to the embodiments, but the present invention is not limited to these embodiments.

[0018] An embodiment of the present invention provides a fish - passing structure applicable to variable water levels in the upper reaches, as Figures 1 to 4 shown, including: Vertical - slot fishway.

[0019] A regulating pool 6 is connected to the downstream end of the vertical - slot fishway; the bottom elevation of the regulating pool 6 is the same as the bottom elevation of the downstream end of the vertical - slot fishway; an overflow opening 7 is arranged on the side wall of the regulating pool 6; a protective fishing net 8 is installed on the overflow opening 7.

[0020] A pool - weir fishway is connected to the downstream end of the regulating pool 6; the bottom elevation of the upstream end of the pool - weir fishway is higher than the bottom elevation of the regulating pool 6; the bottom elevation of the overflow opening 7 is higher than the top elevation of the inner weir plate 10 in the pool - weir fishway.

[0021] The water discharge channel 9 is connected to the outer side of the side wall of the regulating pond 6 provided with an overflow outlet 7, and the water in the regulating pond 6 above the bottom elevation of the overflow outlet 7 is discharged through the water discharge channel 9.

[0022] Since the pool-and-weir fishway cannot bear a relatively high water head above the weir, nor is it advisable to make the water head above the weir too low. Generally, it is required to be within a certain range, that is, the flow rate required for the pool-and-weir fishway is within a certain range. However, the working water level at the fishway outlet section upstream of the pool-and-weir fishway often changes due to the change of the reservoir water level. Therefore, in this application, a vertical-slot fishway, a regulating pond 6, and a water discharge channel 9 are provided at the fishway outlet section. When the upstream reservoir water level is relatively high and the fishway outlet section operates at a high water level, through the water discharge function of the overflow outlet 7 on the regulating pond 6, the water level at the regulating pond 6 is maintained at a certain height, so that the water surface line at the fishway outlet section gradually decreases in a stepped shape, connecting with the water surface line of the downstream pool-and-weir fishway. When the upstream water level is relatively low, due to the regulating pond 6 itself having a certain depth, the water depth at the fishway outlet section can also be maintained at a certain depth.

[0023] The function of the fishway outlet section is that when the reservoir water level changes between the low water level and the high water level, through the regulation of this outlet section, the flow rate of the water flowing into the pool-and-weir fishway will not exceed the maximum limit flow rate that the pool-and-weir fishway can bear.

[0024] The present invention applies a vertical-slot fishway upstream of the pool-and-weir fishway. By adapting to the variable range of the upstream reservoir water level, the pool-and-weir fishway can be applied to reservoirs or sluice dams with large water level changes, breaking through the application limitations of traditional pool-and-weir fishways.

[0025] The present invention can make the water flow smoothly enter the pool-and-weir fishway after being rectified by the regulating pond 6 after flowing out of the vertical slot by arranging the regulating pond 6 at the fishway outlet section. And by controlling the bottom elevation and width of the overflow outlet 7 to control the water discharge flow rate, the water level and flow rate in the regulating pond 6 can meet the water level and flow rate required for the normal operation of the pool-and-weir fishway, so as to smoothly connect the water level and flow rate required by the pool-and-weir fishway, that is, it can automatically adjust the water head above the weir of the pool-and-weir fishway, avoid the water head above the weir being too high or too low, and ensure the smooth upstream migration of fish.

[0026] The present invention can adjust the minimum water depth in the vertical-slot fishway at the fishway outlet section by changing the bottom elevation of the regulating pond 6, so that the fishway outlet section can also maintain a certain water depth when operating at a low water level, meeting the upstream migration requirements of bottom-loving fish.

[0027] In practical applications, generally, the length L3 of the overflow outlet 7 is set to be less than the length L2 of the regulating pond 6.

[0028] Further, referring to Figure 1 and Figure 2 as shown, the vertical-slot fishway includes: A first water flow channel, and the regulating pond 6 is connected to the downstream end of the first water flow channel; A plurality of vertical slit partition units are arranged at intervals along the water flow direction in the first water flow channel within the first water flow channel, and a first pool chamber is formed between two adjacent vertical slit partition units.

[0029] Among them, the vertical slit partition unit includes: A partition plate 4, fixed in the middle of the bottom plate of the first water flow channel; Two baffle plates 5, located on both sides of the partition plate 4 and respectively fixed on the two side walls of the first water flow channel; the partition plate 4 and the two baffle plates 5 are both perpendicular to the water flow direction in the first water flow channel; a fish passage vertical slit is formed between each of the two baffle plates 5 and the partition plate 4 respectively.

[0030] By arranging two fish passage vertical slit channels at the fishway outlet section in the present invention, the fish passage area at the fishway outlet section can be increased compared with a single fish passage vertical slit channel.

[0031] In practical applications, the first water flow channel includes: A first bottom plate 3; A first side wall 1 and a second side wall 2, vertically arranged on opposite sides of the first bottom plate 3, and the first side wall 1, the second side wall 2 and the first bottom plate 3 form the first water flow channel.

[0032] The longitudinal slope of the bottom plate of the first water flow channel (i.e., the first bottom plate 3) is generally 1% - 5%. For example, the longitudinal slope of the bottom plate of the first water flow channel can be 1%, 2% or 5%.

[0033] In the embodiment of the present invention, the pool - weir type fishway includes: A second water flow channel, connected to the downstream end of the regulating pool 6; A plurality of weir plates 10, arranged at intervals along the water flow direction in the second water flow channel within the second water flow channel, and a second pool chamber is formed between two adjacent weir plates 10. In practical applications, generally, the length L1 of the first pool chamber is the same as the length L4 of the second pool chamber.

[0034] Preferably, the plurality of weir plates 10 are divided into a plurality of concave plates and a plurality of convex plates; the plurality of concave plates and the plurality of convex plates are arranged alternately.

[0035] The weir plate 10 of the pool weir type fishway is designed in the form of a concave plate with "high on both sides and low in the middle" and a convex plate with "low on both sides and high in the middle". The structure of the concave plate with "high on both sides and low in the middle": The water flow mainly discharges concentratedly from the middle low-lying area, forming a high-speed main flow area. However, due to the relatively high elevation on both sides, the flow velocity is relatively slow, and a slow flow zone can be formed. The structure of the convex plate with "low on both sides and high in the middle": After the water flow is blocked by the high weir in the middle, it disperses to both sides, and relatively high-speed lateral flows are formed on both sides, while the flow velocity in the middle area decreases due to the increase in water depth. By arranging the two types of weir plates 10 alternately in the present invention, the water flow is repeatedly contracted - diffused - turned longitudinally (up and down stream direction) and transversely (left and right bank direction), breaking the single high-speed flow, making the overall flow velocity more uniform, and avoiding the local flow velocity exceeding the limit flow velocity of fish (>1.2 m / s).

[0036] Under the alternating action of the structures of the two types of weir plates 10, complex turbulence (such as transverse vortices and hydraulic jumps) is generated, consuming the kinetic energy of the water flow and reducing the overall flow velocity. The enhancement of water flow turbulence promotes gas exchange, increases the dissolved oxygen concentration in the water body, alleviates the hypoxia problem caused by low flow velocity, and is more conducive to the survival environment of fish.

[0037] The concave plate with "high on both sides and low in the middle": Fish can ascend through the middle low-lying area (with relatively large water depth) or the slow flow zones on both sides. The convex plate with "low on both sides and high in the middle": Fish can pass through along the low troughs on both sides or bypass the slow flow zone of the middle high weir. By setting these two types of weir plates 10, multiple low-flow velocity paths are provided for fish with different swimming abilities (such as juvenile fish, adult fish, strong / weak swimming type fish species), realizing a multi-path migration channel and significantly improving the passing rate.

[0038] In addition, at low water levels: The low troughs on both sides of the convex plate with "low on both sides and high in the middle" can still maintain a certain water depth and flow velocity, avoiding the flow velocity in the pool being too small due to insufficient water head (<0.1 m). And at high water levels: The middle low-lying area of the concave plate with "high on both sides and low in the middle" can divert most of the water flow, preventing the flow velocity at the weir crest from increasing sharply (>1.2 m / s). In this way, the flexibility of adapting to water level fluctuations is achieved.

[0039] In summary, through the structural complementarity of the concave plate and the convex plate, the flow velocity in the pool is maintained within an appropriate range (0.2 m / s - 1.2 m / s) under a wide water level variation. This helps to create different water heads above the weir and fish passageways, adapting to fish with different swimming abilities to cross the weir plate 10.

[0040] In practical applications, the protruding height of the convex plate is 0.1 m - 0.2 m higher than the groove height of the concave plate.

[0041] In a specific embodiment of the present invention, the maximum water head above the weir required for the pool weir type fishway is 0.3 m, the minimum water head is 0.1 m, and the maximum required flow rate is 1.33 m3 At / s, the minimum flow rate is 0.36 m 3 / s, which can ensure that the flow velocity in the second chamber of the pool-and-weir fishway remains between 0.2 m / s and 1.2 m / s, suitable for fish passage.

[0042] In this embodiment, the width B of the first chamber of the fishway outlet section is 4.0 m, the longitudinal slope of the bottom plate of the first water flow channel is 2%, and the total length of the fishway outlet section is 100 m; the length L1 of the first chamber of the fishway outlet section is 2.5 m; the length L4 of the second chamber of the pool-and-weir fishway is 2.5 m; the height H4 of the convex plate in the weir plate 10 (i.e., the protruding height of the convex plate) is 0.6 m, and the height H3 of the concave plate in the weir plate 10 (i.e., the groove height of the concave plate) is 0.5 m; the height H2 of the bottom plate of the regulating pool 6 from the bottom plate of the upstream end of the pool-and-weir fishway is 1.4 m; the bottom height H1 of the overflow port 7 is 2.25 m, the height H of the partition plate 4 is greater than the bottom height H1 of the overflow port 7, and the length L2 of the regulating pool 6 is 5 m; the length L3 of the overflow port 7 is 4.5 m, the width B1 of the waste water channel 9 is 1.2 m. It is required that when the water depth at the fishway outlet section varies from 1 m to 3 m, the maximum flow velocity at the fishway outlet section does not exceed 1.2 m / s.

[0043] Numerical simulation studies show that when the water depth at the fishway outlet section is 3 m, the flow rate at the fishway outlet section is 1.45 m 3 / s, the overflow flow rate of the overflow port 7 is 0.12 m 3 / s, and the flow rate flowing into the pool-and-weir fishway is 1.33 m 3 / s. The main flow in the second chamber is obvious. The vertical slot flow velocity in the vertical slot fishway at the fishway outlet section is between 1.0 m / s and 1.1 m / s, and the water depth of the regulating pool 6 is 2.3 m, that is, the water depth along the fishway outlet section is between 2.3 m and 3 m; when the water depth at the fishway outlet section is 1 m, the flow rate at the fishway outlet section is 0.36 m 3 / s, the overflow port 7 does not overflow, the main flow is clear, and the flow velocity in the vertical slot and the regulating pool 6 is between 0.3 m / s and 1.1 m / s. The water depth of the regulating pool 6 is 2.1 m, that is, the water depth along the fishway outlet section is between 1 m and 2.1 m, and there is a channel for fish to ascend. This simulation shows that the structure of the fishway outlet section can ensure that when the working water depth at the outlet varies from 1 m to 3 m, the flow rate at the outlet section can always be less than the maximum flow rate that the pool-and-weir fishway can withstand by adjusting the waste water discharge method of the overflow port 7 on the regulating pool 6, and the flow velocity of the fishway chambers at the outlet section is always less than the maximum fish passage flow velocity of 1.2 m / s.

[0044] The above are only several embodiments of the present application, and do not impose any form of limitation on the present application. Although the present application is disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, makes some changes or modifications using the technical content disclosed above, which are equivalent to equivalent implementation cases and all belong to the scope of the technical solution.

Claims

1. A fish - passing structure applicable to variable water levels in the upstream, characterized in that, Comprising: Vertical-slot fishway; Regulating pond, connected to the downstream end of the vertical-slot fishway; the bottom elevation of the regulating pond is the same as the bottom elevation of the downstream end of the vertical-slot fishway; an overflow opening is provided on the side wall of the regulating pond; a protective fishing net is installed on the overflow opening; Pool-and-weir fishway, connected to the downstream end of the regulating pond; the bottom elevation of the upstream end of the pool-and-weir fishway is higher than the bottom elevation of the regulating pond; the bottom elevation of the overflow opening is higher than the top elevation of the inner weir plate in the pool-and-weir fishway; Wastewater channel, connected to the outside of the side wall of the regulating pond where the overflow opening is provided, and the water in the regulating pond above the bottom elevation of the overflow opening is discharged through the wastewater channel.

2. The fish-passage structure according to claim 1, characterized in that, The vertical-slot fishway includes: First water flow channel, with the regulating pond connected to the downstream end of the first water flow channel; Multiple vertical-slot partition units, arranged at intervals along the water flow direction in the first water flow channel, and a first pool chamber is formed between two adjacent vertical-slot partition units.

3. The fish passage structure according to claim 2, wherein, The vertical-slot partition unit includes: Partition board, fixed in the middle of the bottom plate of the first water flow channel; Two baffle plates, located on both sides of the partition board and respectively fixed on the two side walls of the first water flow channel; the partition board and the two baffle plates are perpendicular to the water flow direction in the first water flow channel; fish-passing vertical slots are respectively formed between the two baffle plates and the partition board.

4. The fish - passing structure according to claim 2, characterized in that, The pool-and-weir fishway includes: Second water flow channel, connected to the downstream end of the regulating pond; Multiple weir plates, arranged at intervals along the water flow direction in the second water flow channel, and a second pool chamber is formed between two adjacent weir plates.

5. The fish passage structure according to claim 4, wherein, The multiple weir plates are divided into multiple concave plates and multiple convex plates; the multiple concave plates and the multiple convex plates are arranged alternately.

6. The fish passage structure according to claim 5, characterized in that, The raised height of the convex plate is 0.1 m to 0.2 m higher than the groove height of the concave plate.

7. The fish passage structure according to claim 4, characterized in that, The length of the first pool chamber is the same as the length of the second pool chamber.

8. The fish passage structure according to claim 1, characterized in that, The length of the overflow opening is less than the length of the regulating pond.

9. The fish passage structure according to claim 2, wherein The longitudinal slope of the bottom plate of the first water flow channel is 1% to 5%.

Images