CN217352360U

CN217352360U - Spiral fishway suitable for small and medium-sized stepped barrage

Info

Publication number: CN217352360U
Application number: CN202220856116.5U
Authority: CN
Inventors: 徐海波; 王斌; 王月华; 尤爱菊; 杨烨; 王俊敏; 胡可可; 刘云
Original assignee: Zhejiang Institute of Hydraulics and Estuary
Current assignee: Zhejiang Institute of Hydraulics and Estuary
Priority date: 2022-04-14
Filing date: 2022-04-14
Publication date: 2022-09-02
Anticipated expiration: 2032-04-14

Abstract

The utility model relates to a river fishway. Aims to provide a spiral fishway suitable for small and medium stepped barrages; the fishway has the advantages of no extra increase of engineering quantity and improvement of fish tracing conditions. The technical scheme is as follows: a spiral fishway suitable for small and medium-sized stepped barrages comprises at least two drop basins positioned at the downstream of the barrages; the method is characterized in that: an upward tracing opening is formed in a tail sill of the water drop tank and located on one side, close to a bank slope of the river channel, of the tail sill, and a fishway outlet is formed in the weir dam.

Description

Spiral fishway suitable for small and medium-sized stepped barrage

Technical Field

The utility model relates to a river fishway, in particular to a spiral fishway suitable for a medium and small step-shaped weir dam.

Background

The medium and small-sized barrage is a common river barrage building, has the functions of intercepting water flow, regulating water quantity, storing water, irrigating, guiding water, generating electricity, adjusting stream slope and the like, and is one of important measures for small watershed management projects in mountainous areas. However, from an ecological perspective, the construction of the barrage destroys the connectivity of rivers, and especially, the barrage which is too dense, too high and too steep becomes an obstacle for the upstream and downstream migration of aquatic organisms such as fishes and the like, so that the migration behaviors such as propagation, bait-lifting, overwintering and the like are influenced, and meanwhile, the exchange of substances, energy and information on the upstream and downstream of the rivers is hindered, and the biological diversity and population quantity are reduced. For this reason, artificial fishways are usually constructed on barrages to compensate for the damage of development activities to fish migration channels.

General barrage fish way construction mode sets up the gentle slope groove of ramp type mainly for one side or both sides at the barrage, sets up hydraulic optimization measures such as baffling formula, vertical joint formula, step in the groove, because fishway and barrage are relatively independent, leads to when restoring river connectivity, also brings some drawbacks: firstly, the bottom slope of the fishway is relatively slow, according to the fishway design guide (SL 609-2013) of the hydraulic and hydro-power engineering, the bottom slope at the downstream side is generally required to be 1: 5-1: 10, namely a weir dam with the height difference of 2-3 m, the fishway length of the weir dam reaches 10-30 m, the longitudinal length of the common weir dam along the riverway is only 3-5 m, the weir dam is far shorter than the fishway length, and the landscape property is relatively poor; secondly, overflowing also exists at the top of the dam of a common medium-small weir dam, fishes are easy to gather at the bottom of the weir dam due to the characteristic of flow tendency, and the fish way inlet is difficult to find; thirdly, although the fishway bottom slope meets the standard requirements, most barrage fishways are simple and easy, the slope length is long, a rest room is not conventionally arranged, and the continuous upward tracing effect of the fishes is difficult to guarantee.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art and provide a spiral fishway suitable for a medium and small step-shaped barrage; the fishway has the characteristics of not additionally increasing engineering quantity and improving the fish up-tracking condition.

The utility model provides a technical scheme is:

a spiral fishway suitable for small and medium-sized stepped barrages comprises at least two drop basins positioned at the downstream of the barrages; the method is characterized in that: an upward tracing opening is formed in a tail sill of the water drop tank and located on one side, close to a bank slope of the river channel, of the tail sill, and a fishway outlet is formed in the weir dam.

Preferably, the upward tracking openings on the two adjacent stages of the falling water basin tail sills are staggered and respectively close to the bank slopes on the two sides of the river channel.

Preferably, in the water drop tank, a fishway inlet is formed in the last stage of water drop tank in the downstream direction, and the inlet is located in the main trough of the river channel so as to meet the requirement of tracing the fishes in the dry season.

Preferably, the fishway outlet is located at the main trough of the riverway upstream of the barrage.

Preferably, the height difference between the bottom end of the upward port and the water surface of the next-stage water drop pool is less than 10cm, and the pool depth of the water drop pool is more than 15 cm; so as to ensure the upstream tracing of the migratory fishes.

Preferably, in order to ensure a certain flow velocity along the water flow in the water dropping ponds, the bottom of each water dropping pond is inclined downwards along the direction of the water flow in the water dropping pond, and the gradient is less than or equal to 1%.

Preferably, the height difference of each drop basin tail sill is less than 20 cm.

Preferably, the width of the upstream opening, the fishway outlet and the fishway inlet is 10-15 cm.

The utility model has the advantages that:

(1) the utility model adopts the fishway reconstructed from the weir dam drop basin, and compared with the common fishway, the fish tracing condition is more favorable; firstly, the fishway inlet is convenient to find; secondly, the hydraulic conditions in the fishway are better, and the fishway has the effect of a rest pool; thirdly, the downward discharge flow is limited, and the overflow landscape of the barrage cannot be obviously influenced.

(2) The fishway can be integrated with a weir dam, the abrupt visual sensation of the conventional narrow and long fishway is eliminated, and the additional increase of the construction cost is not needed.

(3) Is easy to reconstruct, and can partially reconstruct the prior stepped fish-scale type fishway.

Drawings

Fig. 1 is a schematic plan view of the present invention.

Fig. 2 is a cross-sectional view (a cross-section parallel to the length direction of the river) of the present invention.

Fig. 3 is a perspective view of the present invention.

Reference numbers:

1. a fishway outlet; 2. a fishway inlet; 3. tracing to the mouth; 4. tracing a path; 5. river course bank slope; 6. a barrage; 7. a drop pool; 8. and (4) dropping a pool tail sill.

Detailed Description

The spiral fishway suitable for the small and medium-sized stepped barrage as shown in the figure is sequentially arranged along the water flow direction of a river channel: the fishway system comprises a fishway outlet 1 arranged on a weir dam, a drop pool 7, an upward tracing port 3 positioned on a drop pool tail sill 8 (the amount of the upward tracing port is determined according to the amount of the drop pool), and a fishway inlet 2 (an upward tracing path 4 is indicated by a dotted line) close to the downstream first-stage drop pool tail sill. The fishway arrangement is mainly suitable for small and medium-sized fishes in mountainous areas; in order to ensure that the transverse water flow in the drop basin has a certain flow velocity, the bottom of the drop basin is inclined downwards along the flow direction of the drop basin, and the gradient is not more than 1% (preferably, the gradient is 0.5-1.0%). In order to ensure the upward tracing of the migratory fishes, the height difference between the bottom end of an upward tracing port formed on the tail sill of the drop pool and the water surface of the next drop pool is less than 10cm, the pool depth of the drop pool is more than 15cm, and the height difference of the tail sill of each drop pool is not more than 20 cm. In addition, the silted sediment in the drop chutes needs to be cleaned regularly, because the silted sediment can be taken away by the water flow in case of a large flood, but the flow of the river channel is not enough to take away the silt in the dry season. Considering that the water depth on both sides of the river may not meet the requirement of the fishes for going up during the dry season, the inlet and outlet of the downstream and upstream of the fishway are preferably located at the main channel of the river.

The utility model discloses under the condition that does not increase the engineering volume hardly, can guarantee the demand of tracing to on of fish. A notch with the width of 10-15cm is newly opened at the main channel part of the river channel close to the downstream first-stage ladder (drop basin) to be used as a fishway inlet, and the velocity of the fishway inlet are required to be ensured not to be less than the minimum induction velocity of the migratory fish. Based on the above, the upstream mouths of each stage are staggered at the edge parts of the later stages (water drop tanks), and the transverse length (the size parallel to the width direction of a river) of each stage is used as a fish migration path, so that the upstream fishes can be upstream step by step until the upstream fishes reach the upstream water area of the weir dam. As each stage of step part of the barrage, the migratory fishes can have a good rest area in the upward tracing process, continuous multi-stage jumping of the fishes is avoided, and the migratory fishes have good endurance for upward tracing.

Claims

1. A spiral fishway suitable for small and medium-sized stepped barrages comprises at least two drop basins (7) positioned at the downstream of the barrages; the method is characterized in that: an upward tracing opening (3) is formed in a tail sill (8) of the water drop pool and is located on one side, close to a bank slope of a river channel, of the tail sill, and a fishway outlet (1) is formed in the weir dam.

2. The spiral fishway suitable for small and medium stepped barrages of claim 1, wherein: the upward tracking openings on the two adjacent stages of the falling water tank tail sills are staggered with each other and are respectively close to bank slopes on two sides of the river channel.

3. The spiral fishway suitable for small and medium stepped barrages of claim 2, wherein: among the drop pond, be located the last level drop pond of downstream direction and seted up fishway import (2), this import is located river course owner groove position to satisfy the demand of tracing to on of dry season fish.

4. The spiral fishway suitable for small and medium stepped barrages of claim 3, wherein: the fishway outlet is positioned at the main groove part of the river channel where the barrage is positioned.

5. The spiral fishway suitable for small and medium stepped weirs of claim 4, wherein: the height difference between the bottom end of the upper tracing port and the water surface of the next-stage water drop pool is less than 10cm, and the pool depth of the water drop pool is more than 15 cm; so as to ensure the upstream tracing of the migratory fishes.

6. The spiral fishway suitable for small and medium stepped weirs of claim 5, wherein: the bottom of each water drop pool inclines downwards along the water flow direction in the water drop pool, and the gradient is less than or equal to 1%.

7. The spiral fishway suitable for small and medium stepped barrages of claim 5, wherein: the height difference of each drop basin tail sill is less than 20 cm.

8. The spiral fishway suitable for small and medium stepped barrages of claim 7, wherein: the width of the upstream opening, the fishway outlet and the fishway inlet is 10-15 cm.