Method for constructing fish spawning ground, feeding ground and hiding ground

Abstract

A method for constructing fish spawning, feeding, and hiding places comprises the following steps: S1, analyzing the terrain downstream of a dam to determine the centerline of an artificial spawning site suitable for constructing a cascade spawning site; S2, excavating along the centerline of the artificial spawning site determined in step S1 to form an artificial spawning site riverbed, and introducing water into the artificial spawning site riverbed to obtain an artificial spawning site; S3, creating an environment for fish spawning and hatching eggs in the artificial spawning site; S4, creating a habitat for juvenile fish in the artificial spawning site; and S5, regulating the water temperature and flow in the artificial spawning site. The spawning site provided by the present invention creates sufficient spawning and feeding sites for adult fish, provides stable and suitable water flow and temperature conditions for fish egg hatching, and provides a rich feeding, hiding, and growth environment for juvenile fish.

Description

Technical Field

[0001] The invention relates to the technical field of river aquatic life protection, in particular to a method for constructing fish spawning grounds, feeding grounds and hiding grounds. Background Art

[0002] Fish can only successfully spawn and hatch their eggs under suitable conditions, including water flow, temperature, riverbed sediment, and dissolved oxygen. During spawning season, fish in mountain rivers often migrate upstream from downstream to the main stream, or vice versa, to spawn in tributaries. Dams trap fish below the dams, preventing them from reaching suitable spawning streams above the dams. This can prevent them from spawning or cause migratory fish to gather in a limited spawning section below the dams. During this concentrated spawning, eggs laid earlier and already attached to the riverbed are dislodged by later spawning fish, causing them to be washed away or damaged, significantly reducing hatching rates. Although some dams have fishways designed for spawning and migrating fish, these cannot meet the spawning needs of fish in upstream river sections without suitable spawning habitats.

[0003] In addition to blocking fish spawning migrations, dams also reduce the probability of fish spawning or successful egg hatching by altering riverbed topography, hydrology, and water temperature. For example, hardening the riverbed below the dam or excavating gravel can alter the topography of the river below the dam, disrupting the riverbed suitable for spawning. For example, the discharge flow of reservoirs with regulating functions often experiences sudden fluctuations, causing fish eggs to become stranded and die due to sudden changes in water depth. Furthermore, high dams with temperature stratification in the reservoir area can divert cooler water from the reservoir bottom in spring and summer, altering the water temperature below the dam, causing the water temperature in the river below the dam to fall outside the suitable spawning range or shortening the period when suitable water temperatures occur.

[0004] To address the impact of dams on fish spawning, common mitigation measures currently include designating tributaries downstream of the dam as fish habitats for protection and safeguarding the spawning environment, including water flow, water temperature, and bottom soil of the tributaries. In situations where there are no suitable tributaries downstream of the dam for fish spawning, existing protection measures primarily involve creating spawning environments for fish within the existing main stream, such as through ecological regulation to stimulate spawning and by placing artificial fish nest structures in existing river sections to create spawning grounds. This approach, which unilaterally alters the hydrology or creates localized spawning grounds for fish, has the following drawbacks: it fails to provide an artificial habitat that is unaffected by water conservancy and hydropower projects and possesses suitable water flow, water depth, water temperature, bait organisms, and bottom soil conditions for successful fish spawning and egg hatching. Summary of the Invention

[0005] The main purpose of the present invention is to propose a method for constructing fish spawning grounds, feeding grounds and hiding grounds, create an artificial tributary downstream of the dam, and through precise control of the spawning matrix, water temperature and water flow of the tributary, as well as the creation of rich bait organisms, create sufficient spawning grounds and feeding grounds for adult fish, provide stable and suitable water flow and water temperature conditions for fish egg hatching, and provide a rich feeding and hiding growth environment for young fish, so as to solve the shortcomings of the existing technology.

[0006] To achieve the above-mentioned object, the present invention proposes a method for constructing fish spawning grounds, feeding grounds and hiding grounds, comprising the following steps:

[0007] S1. Analyze the terrain downstream of the dam and determine the centerline of the artificial spawning site suitable for the construction of cascade spawning sites;

[0008] S2, excavating along the center line of the artificial spawning ground determined in step S1 to form a riverbed for the artificial spawning ground, and introducing water into the riverbed for the artificial spawning ground to obtain an artificial spawning ground;

[0009] S3. Create a fish spawning environment in artificial spawning grounds;

[0010] S4. Create a habitat for juvenile fish in artificial spawning grounds;

[0011] S5. Regulate water temperature and water flow in artificial spawning grounds.

[0012] Preferably, in step S1, the method for determining the center line of the artificial spawning site includes:

[0013] S101. Measure the terrain below the dam and draw a topographic map, identifying valleys close to the dam and riverbank terraces close to the main river channel below the dam and with elevations higher than the water level of the main river channel below the dam;

[0014] S102, drawing topographic profiles including riverbank terraces and valleys at equal plane projection intervals, finding the lowest elevation point of each profile of the riverbank terraces and valleys, and drawing the corresponding position of the lowest point of each profile on the topographic map;

[0015] S103, on the drawn topographic map, sequentially connect the lowest elevation points of each section of the river terrace and the valley and extend to the centerline of the river below the dam, so that the line connecting the lowest elevation points of each section of the river terrace is the centerline of the first tier spawning ground, and the line connecting the lowest elevation points of each section of the valley is the centerline of the second tier spawning ground;

[0016] S104. Extract line segments whose elevations are lower than the dead water level of the dam reservoir from the center lines of the first and second tier spawning grounds, respectively; compare the lengths and gradients i of the extracted line segments, and the vegetation conditions around the line segments, and select the line segments that meet the conditions as the center lines of the artificial spawning grounds.

[0017] Preferably, in step S104, among the extracted line segments, a line segment with a length of not less than 100 m, a gradient i of not more than 1:5, and lush vegetation on both sides is selected as the center line of the artificial spawning ground.

[0018] Preferably, in step S2, the width b1 of the excavated riverbed of the artificial spawning ground is 1 to 5 m, and the slope i is between 1:5 and 1:100; the method of introducing water into the riverbed of the artificial spawning ground includes adopting the method of gravity, water pumping, and siphon water diversion, and introducing water from the water resources around the riverbed of the artificial spawning ground. The water resources around the riverbed of the artificial spawning ground include reservoir water of the dam, water seeping from the dam, hillside runoff, spring water below the dam and groundwater.

[0019] Preferably, in step S2, the method of introducing water flow is: by setting water diversion pipes at different elevations of the dam, the water in the reservoir area of ​​the dam is diverted to the riverbed of the artificial spawning ground by gravity.

[0020] Preferably, the water diversion pipe includes at least an upper water diversion pipe, a middle water diversion pipe and a lower water diversion pipe; the upper water diversion pipe is used to divert surface water of the reservoir to the riverbed of the artificial spawning ground; the middle water diversion pipe is used to divert middle water of the reservoir to the riverbed of the artificial spawning ground; the lower water diversion pipe is used to divert bottom water of the reservoir to the riverbed of the artificial spawning ground; gate valves for controlling flow rate are respectively provided on the upper water diversion pipe, the middle water diversion pipe and the lower water diversion pipe.

[0021] Preferably, in step S3, the step of creating a fish spawning environment includes:

[0022] S301, sequentially and spaced apart, a plurality of flow-blocking structures are arranged on the artificial spawning ground, and the top elevations of the flow-blocking structures are gradually lowered along the water flow direction of the artificial spawning ground;

[0023] S302. Dig a pit in the riverbed on the upstream side of each flow-blocking structure; lay a spawning cushion layer with a thickness of D1 in the pit, and lay a fish egg attachment layer with a thickness of D2 on the surface of the spawning cushion layer to provide an environment for fish eggs to attach; form a single-stage spawning ground between two adjacent flow-blocking structures.

[0024] Preferably, in step S302, the spawning cushion is paved with gravel with a diameter of 3 to 10 cm, and the fish egg attachment layer is paved with pebbles with a diameter of 1 to 3 cm; the thickness D1 of the spawning cushion and the thickness D2 of the fish egg attachment layer are both 5 to 10 cm.

[0025] Preferably, in step S301, the method for setting up the flow-blocking structure is: along the water flow direction of the artificial spawning ground, a plurality of pairs of limiting grooves are dug out in sequence on both sides of the artificial spawning ground, and a plurality of logs are placed in each pair of limiting grooves, with the axial direction of the logs perpendicular to the water flow direction; and pebbles are filled in the gap formed by the ends of the logs and the limiting grooves; blocks of stone are set on the top of both ends of the logs to apply downward pressing force to the logs; the spacing between two adjacent flow-blocking structures is b2, and b2=3~6m.

[0026] Preferably, the interior of the log is configured as a hollow structure and forms hiding holes; each log is provided with one or more fish inlet troughs connected to the hiding holes inside the log; and the hiding holes between two adjacent logs are connected to each other.

[0027] Preferably, in step S4, the method for creating a habitat for juvenile fish is: placing a pile of stones made of pebbles and gravel, branches, stumps, and prefabricated ecological concrete blocks in the artificial spawning ground to create a microhabitat that is conducive to hiding juvenile fish and can increase the fish's chance of foraging; and providing a space for fish hiding in the prefabricated ecological concrete blocks.

[0028] Preferably, the ecological concrete prefabricated block is a polyhedron structure with a hollow interior, and fish holes are provided on one or more sides of the ecological concrete prefabricated block to connect to its inner cavity; when creating a habitat for young fish in step S4, multiple ecological concrete prefabricated blocks are used to form a stacking structure, and the inner cavities of adjacent ecological concrete prefabricated blocks in each stacking structure are connected to each other.

[0029] Preferably, the ecological concrete prefabricated block is a prefabricated part, and its preparation method is: adding 1% to 15% of amino acid powder by weight of concrete into a container filled with conventional concrete, and stirring it thoroughly, and injecting the stirred concrete containing amino acids into the prefabricated part template to prepare it; the amino acid powder is one or more of arginine, glycine, alanine, proline, tyrosine, tryptophan and histidine.

[0030] Preferably, in step S5, the method for regulating water temperature and water flow is: first, respectively grasp the time, water temperature, water depth and flow rate conditions of fish spawning, fish egg hatching and juvenile growth, and then regulate the water supply source and water supply flow of the artificial spawning ground according to the water temperature and water flow conditions required for fish spawning, fish egg hatching and juvenile growth at different times, until the water temperature, water depth and flow rate of the artificial spawning ground are suitable for fish spawning, fish egg hatching and juvenile growth; the water supply source regulation is to select one or more of the upper water diversion pipe, middle water diversion pipe and lower water diversion pipe for operation according to the water temperature requirement, take surface water, middle water or bottom water of the reservoir, or take water from different water layers and then mix them to lead to the artificial spawning ground; the water supply flow is regulated by the gate valves on each water diversion pipe.

[0031] Preferably, in step S5, when regulating the water flow, the following requirements are met: the water depth h2 of the spawning ground is 10 cm to 60 cm; the water depth h3 at the upper end of the flow blocking structure is not less than 10 cm;

[0032] The water level difference between two adjacent spawning grounds is ΔH, which satisfies:

[0033]

[0034] Among them, L P is the body length of spawning fish; U max is the initial jumping velocity of spawning fish; β is the incident angle of fish jumping, and g is the acceleration due to gravity.

[0035] Preferably, the method further includes the following steps: S6, evaluating the effectiveness of the artificial spawning ground; evaluating from four aspects, namely, spawning of adult fish, hatching of eggs, growth of juvenile fish, and bait organisms, through investigation and sampling results at different periods; counting the number and species of adult fish entering the artificial spawning ground, the number and species of fry in the artificial spawning ground, the number and species of fish bait organisms such as phytoplankton, attached algae, and benthic animals, and the distribution of leaves and dead branches that have fallen from the woods on both sides into the artificial spawning ground.

[0036] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0037] In the present invention, by analyzing the terrain downstream of the dam, the center line of an artificial spawning ground suitable for building a cascade spawning ground is determined, and an artificial spawning ground that is not adversely affected by the dam is created along the center line of the artificial spawning ground. By creating a fish spawning environment and a habitat for juvenile fish in the artificial spawning ground, and by regulating the water temperature and water flow in the artificial spawning ground, sufficient spawning grounds and feeding grounds are created for adult fish, stable and suitable water flow and water temperature conditions are provided for fish egg hatching, and a rich feeding, hiding and growth environment is provided for juvenile fish. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0039] Figure 1 The topographic map below the dam and the schematic diagram of the center lines of the first and second tier spawning grounds drawn in the present invention;

[0040] Figure 2This is a schematic diagram of the artificial spawning site constructed along the center line of the artificial spawning site;

[0041] Figure 3 This is a schematic diagram of the longitudinal section of the artificial spawning site;

[0042] Figure 4 This is a schematic diagram of the flow-blocking structure in the artificial spawning ground;

[0043] Figure 5 This is a schematic diagram of the longitudinal section of the artificial spawning site with a flow-blocking structure;

[0044] Figure 6 Schematic diagram of longitudinal section for creating environment for spawning of adult fish and hatching of eggs;

[0045] Figure 7 Create a plan diagram for the habitat of young fish;

[0046] Figure 8 This is a schematic diagram of the transverse section of the spawning ground;

[0047] Figure 9 This is a structural diagram of an eco-concrete prefabricated block;

[0048] Figure 10 Schematic diagram of the structure when multiple eco-concrete prefabricated blocks are stacked

[0049] Figure 11 A schematic diagram of the structure for setting hiding holes in logs;

[0050] Figure 12 A three-dimensional diagram for setting up hidden holes in logs;

[0051] Figure 13 A cross-section of a spawning site with hiding space.

[0052] Explanation of the numbers in the figures: 1. Centerline of the artificial spawning ground; 11. Centerline of the first cascade spawning ground; 12. Centerline of the second cascade spawning ground; 21. Topographic contour line; 22. Valley; 23. Riverbank terrace; 31. Dam; 32. Main river channel below the dam; 33. Reservoir area; 4. Water diversion pipe; 41. Upper water diversion pipe; 42. Middle water diversion pipe; 43. Lower water diversion pipe; 5. Artificial spawning ground; 51. Flow blocking structure; 511 , limiting grooves; 512, logs; 512a, hiding holes; 512b, fish inlet troughs; 513, stone blocks; 514, gravel; 52, pits; 521, spawning cushion; 522, fish egg attachment layer; 53, precast ecological concrete blocks; 54, dead branches; 55, tree stumps; 56, stone piles made of gravel; 61, benthic animals; 62, fallen leaves and other organic matter; 63, attached algae; 70, single-stage spawning ground. In addition: b1 is the width of the riverbed of the artificial spawning ground; b2 is the distance between two adjacent flow-blocking structures; b3 is the net length of the spawning ground; h1 is the water depth of the pit; h2 is the water depth of the spawning ground; h3 is the water depth at the top of the flow-blocking structure 51; B is the rock and soil at the bottom of the riverbed; T is the vegetation; i is the slope of the artificial spawning ground; D1 is the thickness of the spawning cushion layer; D2 is the thickness of the fish egg attachment layer; F1 is the adult fish; F2 is the juvenile fish. DETAILED DESCRIPTION

[0053] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0054] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0055] In addition, the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0056] As shown in the accompanying drawings, this embodiment provides a method for creating fish spawning grounds, feeding grounds, and hiding grounds, and the specific steps include:

[0057] S1. Analyze the terrain downstream of the dam 31 and determine the centerline 1 of the artificial spawning site suitable for constructing a cascade spawning site;

[0058] S2, excavating along the center line 1 of the artificial spawning ground determined in step S1 to form a riverbed for the artificial spawning ground, and introducing water into the riverbed for the artificial spawning ground to obtain an artificial spawning ground 5;

[0059] S3, creating a fish spawning environment in the artificial spawning ground 5;

[0060] S4, creating a habitat for juvenile fish in the artificial spawning ground 5;

[0061] S5. Regulating the water temperature and water flow in the artificial spawning ground 5.

[0062] Combine Figure 1 As shown, in the step S1, the method for determining the center line 1 of the artificial spawning site includes:

[0063] S101. Measure the terrain below the dam and draw a topographic map. The accuracy of the topographic map must be no less than 1:1000. The topographic map must include topographic contour lines 21, valleys 22, the dam 31, the main river channel 32 below the dam, and the reservoir area 33 formed upstream of the dam 31. Based on the drawn topographic map, identify the valley 22 near the dam 31 and the riverbank terraces 23 near the main river channel 32 below the dam and at a higher elevation than the water surface of the main river channel 32 below the dam.

[0064] S102, drawing topographic profiles including the riverbank terrace 23 and the valley 22 at equal plane projection intervals, finding the lowest elevation point of each profile of the riverbank terrace 23 and the valley 22, and drawing the corresponding position of the lowest point of each profile on the topographic map;

[0065] S103, on the drawn topographic map, sequentially connect the lowest elevation points of each cross-section of the river terrace 23 and the valley 22 and extend to the centerline of the river below the dam, so that the line connecting the lowest elevation points of each cross-section of the river terrace 23 is the centerline 11 of the first tier spawning ground, and the line connecting the lowest elevation points of each cross-section of the valley 22 is the centerline 12 of the second tier spawning ground;

[0066] S104: Extract line segments from the centerline 11 of the first tier spawning ground and the centerline 12 of the second tier spawning ground that are lower than the dead water level of the reservoir area of ​​dam 31. Compare the lengths, gradients i, and surrounding vegetation of the extracted line segments, and select the line segments that meet the requirements as the centerline 1 of the artificial spawning ground. Specifically, select the line segments with a length of at least 100 meters, a gradient i of no greater than 1:5, and lush vegetation on both sides as the centerline 1 of the artificial spawning ground.

[0067] Combine Figure 2 and Figure 3 As shown, in step S2, the width b1 of the excavated artificial spawning site riverbed is 1 to 5 meters. This is to ensure the width of the artificial spawning site 5 and facilitate the subsequent creation of a fish spawning environment and a habitat for juvenile fish. The slope i of the excavated artificial spawning site riverbed is between 1:5 and 1:100 to facilitate water flow. Methods for introducing water into the artificial spawning site riverbed include gravity flow, water pumping, siphon water diversion, and water resources surrounding the artificial spawning site riverbed. Water resources surrounding the artificial spawning site riverbed include reservoir water from dam 31, water seepage from dam 31, hillside runoff, spring water below the dam, and groundwater.

[0068] Combine Figure 1 As shown, in this embodiment, water is introduced by installing water diversion pipes 4 at different elevations of the dam 31, allowing water from the reservoir 31 to flow into the riverbed of the artificial spawning ground by gravity. Due to the stratified water temperature of the reservoir 33, in winter, the surface water temperature is low and the lower water temperature is high; in summer, the surface water temperature is high and the lower water temperature is low. In this embodiment, the water diversion pipes 4 include at least an upper diversion pipe 41, a middle diversion pipe 42, and a lower diversion pipe 43. The upper diversion pipe 41 is used to divert surface water from the reservoir to the riverbed of the artificial spawning ground; the middle diversion pipe 42 is used to divert middle water from the reservoir to the riverbed of the artificial spawning ground; and the lower diversion pipe 43 is used to divert bottom water from the reservoir to the riverbed of the artificial spawning ground. Gate valves are installed on each of the upper, middle, and lower diversion pipes 41, 42, and 43 to control flow rates. By controlling the flow rate, the flow rate in the artificial spawning site 5 is guaranteed to be no less than 0.02m 3 / s.

[0069] In addition to the above-mentioned water introduction method, water seeping from the dam 31 can also be introduced into the artificial spawning ground 5, such as Figure 1 K represents the water seeping out of the diversion dam 31. It is also possible to use the surrounding ditch water, spring water, hillside runoff or groundwater to collect and lead to the artificial spawning ground 5, such as Figure 1 The arrow A in the middle indicates that the water of the main river channel 32 below the dam can also be pumped into the artificial spawning ground 5 by a water pump (this method is not shown in the figure).

[0070] According to the water introduction method determined by the artificial spawning ground 5, the artificial spawning ground 5 is flushed with water until the sludge on the surface of the artificial spawning ground 5 is washed away and the topography of the riverbed of the artificial spawning ground is basically stable.

[0071] Combine Figures 4 to 6 As shown, in step S3, the steps of creating a fish spawning environment include:

[0072] S301, sequentially and spaced apart, a plurality of flow-blocking structures 51 are arranged on the artificial spawning ground 5, and the top elevation of the flow-blocking structures 51 gradually decreases along the water flow direction of the artificial spawning ground 5;

[0073] S302: dig a pit 52 in the riverbed upstream of each flow blocking structure 51. The area of ​​the pit 52 is not less than 1m 2 The water depth h1 of the pit 52 is 30 cm to 100 cm. A spawning cushion layer 521 with a thickness of D1 is laid in the pit 52, and a fish egg attachment layer 522 with a thickness of D2 is laid on the surface of the spawning cushion layer 521 to provide an environment for fish eggs to attach. A single-stage spawning ground 70 is formed between two adjacent flow-blocking structures 51. Specifically, the spawning cushion layer 521 is paved with gravel with a diameter of 3 to 10 cm, and the fish egg attachment layer 522 is paved with pebbles with a diameter of 1 to 3 cm. The thickness D1 of the spawning cushion layer 521 and the thickness D2 of the fish egg attachment layer 522 are both 5 to 10 cm.

[0074] In this embodiment, the method for setting up the flow-blocking structure 51 is as follows: along the water flow direction of the artificial spawning ground 5, multiple pairs of limiting grooves 511 are dug in sequence on both sides of the artificial spawning ground 5, and multiple logs 512 are placed in each pair of limiting grooves 511, with the axial direction of the logs 512 perpendicular to the water flow direction; and pebbles 514 are filled in the gap formed by the ends of the logs 512 and the limiting grooves 511; blocks 513 are set on the top of both ends of the logs 512 to apply downward pressing force to the logs 512; the distance between two adjacent flow-blocking structures 51 is b2, and b2=3~6m.

[0075] Combine Figures 11 to 13 As shown, the interior of the logs 512 is hollow and has hiding holes 512a formed therein. Each log 512 is provided with one or more fish entry slots 512b connected to the hiding holes 512a therein. The hiding holes 512a between two adjacent logs 512 are interconnected. Juvenile fish F2 can enter and hide in the hiding holes 512a within the logs 512.

[0076] Combine Figure 7 、 Figure 8As shown, in step S4, the method for creating a juvenile fish habitat is to place a pile of gravel 56, branches 54, tree stumps 55, and prefabricated eco-concrete blocks 53 within the artificial spawning ground 5 to create a micro-habitat that is conducive to hiding juvenile fish and increases their feeding opportunities. Spaces for fish to hide are provided within the prefabricated eco-concrete blocks 53. By utilizing the gaps within the pile of gravel 56, branches 54, and tree stumps 55, a hiding place for juvenile fish and feeding is formed.

[0077] Combine Figure 9 As shown, in this embodiment, the eco-concrete prefabricated block 53 is a polyhedron structure with a hollow interior. Fish holes are provided on one or more sides of the eco-concrete prefabricated block 53 to connect to its inner cavity. Common polyhedron structures include trihedrons, tetrahedrons, hexahedrons, etc. Figure 9 The cube structure used in the Figure 10 As shown, when creating a habitat for young fish in step S4, multiple ecological concrete prefabricated blocks 53 are used to form a stacking structure. The stacking structure can be a multi-layer structure. The inner cavities of adjacent ecological concrete prefabricated blocks 53 are interconnected to form a hiding place for attracting fish.

[0078] In this embodiment, the prefabricated eco-concrete blocks 53 are prefabricated components. The prefabricated eco-concrete blocks 53 are prepared by adding 1% to 15% amino acid powder, representing 1% to 15% of the concrete's weight, to a container containing conventional concrete, stirring thoroughly, and then injecting the stirred amino acid-containing concrete into the prefabricated formwork. The amino acid powder is one or more of arginine, glycine, alanine, proline, tyrosine, tryptophan, and histidine. The incorporation of amino acids into concrete imparts environmental benefits. The amino acid-containing concrete promotes the growth of algae, including cyanobacteria, green algae, and diatoms, 63, which attach to and grow on the surface of the prefabricated eco-concrete blocks 53, providing a rich source of fish food.

[0079] In this embodiment, the method for regulating water temperature and flow in step S5 is as follows: first, the time, water temperature, water depth, and flow rate of fish spawning, egg hatching, and juvenile growth are determined. Then, the water supply source and flow rate of artificial spawning ground 5 are regulated according to the water temperature and flow conditions required for fish spawning, egg hatching, and juvenile growth at different times until the water temperature, water depth, and flow rate of artificial spawning ground 5 are suitable for fish spawning, egg hatching, and juvenile growth. For example, Qinling trout spawn in February and March each year, with an optimal water temperature of 5-10°C. Egg hatching requires a water temperature below 15°C, a water temperature above 2°C in winter, and a water temperature not exceeding 20°C in summer.

[0080] The water supply source is regulated based on water temperature requirements by selecting one or more of the upper water diversion pipes 41, middle water diversion pipes 42, and lower water diversion pipes 43 for operation, drawing water from the surface, middle, or bottom layers of the reservoir, or drawing a mixture of water from different layers and directing it to the artificial spawning ground 5, thereby achieving the purpose of regulating water temperature. The water supply flow rate is regulated by gate valves on each water diversion pipe. For example, for Qinling smelt salmon, during the spawning season from February to March, the water intake depth is preferentially selected based on the temperature differences between different water layers in the reservoir, and the water temperature in the artificial spawning ground 5 is controlled between 5 and 10°C. During the egg incubation period, the water temperature is controlled below 15°C. In winter, high-temperature water from the bottom layer of the reservoir is preferred to ensure that the water temperature in the artificial spawning ground 5 is above 2°C. In summer, high-temperature water from the surface layer of the reservoir is avoided to ensure that the water temperature in the artificial spawning ground 5 does not exceed 20°C.

[0081] In step S5, when regulating the water flow, the following requirements are met: the water depth h2 of the spawning ground 70 is 10 cm to 60 cm; the water depth h3 at the upper end of the flow blocking structure 51 is not less than 10 cm; the water level difference between two adjacent spawning grounds 70 is ΔH, which satisfies:

[0082]

[0083] Among them, L P is the body length of spawning fish; U max is the initial jumping velocity of spawning fish; β is the incident angle of fish jumping, and g is the acceleration due to gravity.

[0084] In this embodiment, a method for creating fish spawning grounds, feeding grounds and hiding places also includes step S6, evaluating the effectiveness of the artificial spawning ground 5; through survey sampling results at different periods, evaluating from four aspects: spawning of adult fish F1, hatching of fish eggs, growth of fry F2 and bait organisms; counting the number and type of adult fish F1 entering the artificial spawning ground 5, the number and type of fish eggs in the artificial spawning ground 5, the number and type of fish fry F2 in the artificial spawning ground 5, counting the number and type of fish bait organisms such as phytoplankton, attached algae 63 and benthic animals 61, and counting the distribution of leaves and dead branches that fell from the woods on both sides into the artificial spawning ground 5.

[0085] Combine Figure 8 As shown, it is a schematic diagram of the transverse section of the spawning ground 70. The spawning ground 70 that is finally formed is covered with vegetation T on both sides. Benthic animals 61 and the like are attached to the gravel inside the spawning ground 70, and organic matter such as fallen leaves 62 will fall into the spawning ground 70.

[0086] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A method for constructing a fish spawning ground, feeding ground and hiding ground, characterized in that the steps include: S1. Analyze the terrain downstream of the dam (31) and determine the centerline of the artificial spawning site suitable for constructing a cascade spawning site (1); S2, excavating along the center line (1) of the artificial spawning ground determined in step S1 to form a riverbed of the artificial spawning ground, and introducing water into the riverbed of the artificial spawning ground to obtain an artificial spawning ground (5); S3, creating an environment for fish spawning and egg hatching in the artificial spawning ground (5); S4. Create a habitat for juvenile fish in the artificial spawning ground (5); S5, regulating the water temperature and water flow in the artificial spawning ground (5); In step S1, the method for determining the center line (1) of the artificial spawning site includes: S101, measuring the terrain below the dam and drawing a topographic map, finding the valley (22) close to the dam (31) and the riverbank terrace (23) close to the main river channel (32) below the dam and having an elevation higher than the water surface elevation of the main river channel (32) below the dam; S102, drawing topographic profiles including the riverbank terrace (23) and the valley (22) at equal plane projection intervals, finding the lowest elevation point of each profile of the riverbank terrace (23) and the valley (22), and drawing the corresponding position of the lowest point of each profile on the topographic map; S103, on the drawn topographic map, sequentially connect the lowest elevation points of each section of the river terrace (23) and the valley (22) and extend them to the center line of the river below the dam, so that the line connecting the lowest elevation points of each section of the river terrace (23) is the center line (11) of the first tier spawning ground, and the line connecting the lowest elevation points of each section of the valley (22) is the center line (12) of the second tier spawning ground; S104, respectively extracting line segments whose elevations are lower than the dead water level elevation of the dam (31) reservoir area from the center line (11) of the first cascade spawning ground and the center line (12) of the second cascade spawning ground; and comparing the lengths, gradients i, and vegetation conditions around the extracted line segments, and selecting the line segment that meets the conditions as the center line (1) of the artificial spawning ground.

2. A method for constructing fish spawning grounds, feeding grounds and hiding grounds according to claim 1, characterized in that: In step S104, among the extracted line segments, a line segment with a length of not less than 100 m, a gradient i of not more than 1:5, and lush vegetation on both sides is selected as the center line (1) of the artificial spawning site.

3. The method for constructing a fish spawning ground, feeding ground and hiding ground according to claim 1, characterized in that: In step S2, the width b1 of the excavated artificial spawning site riverbed is 1 to 5 m, and the slope i is between 1:5 and 1:100; the method of introducing water flow into the artificial spawning site riverbed includes adopting the method of water flow gravity, water pumping, and siphon water diversion, and introducing water flow from the water resources around the artificial spawning site riverbed. The water resources around the artificial spawning site riverbed include reservoir water of the dam (31), water seeping from the dam (31), hillside runoff, spring water below the dam, and groundwater.

4. The method for constructing a fish spawning ground, feeding ground and hiding ground according to claim 1, wherein: In step S2, the method of introducing water flow is: by setting water diversion pipes (4) at different elevation positions of the dam (31), the water in the reservoir area of ​​the dam (31) is diverted to the riverbed of the artificial spawning ground by gravity.

5. A method for constructing fish spawning grounds, feeding grounds and hiding places according to claim 4, characterized in that: The water diversion pipe (4) at least comprises an upper water diversion pipe (41), a middle water diversion pipe (42) and a lower water diversion pipe (43); the upper water diversion pipe (41) is used to divert surface water of the reservoir to the riverbed of the artificial spawning ground; the middle water diversion pipe (42) is used to divert middle water of the reservoir to the riverbed of the artificial spawning ground; the lower water diversion pipe (43) is used to divert bottom water of the reservoir to the riverbed of the artificial spawning ground; gate valves for controlling flow rate are respectively provided on the upper water diversion pipe (41), the middle water diversion pipe (42) and the lower water diversion pipe (43).

6. The method for constructing a fish spawning ground, feeding ground and hiding ground according to claim 1, characterized in that: In step S3, the steps of creating a fish spawning environment include: S301, sequentially and spaced apart, a plurality of flow-blocking structures (51) are arranged on the artificial spawning ground (5), and the top elevation of the flow-blocking structures (51) gradually decreases along the direction of water flow in the artificial spawning ground (5); S302, digging a pit (52) in the riverbed on the upstream side of each flow blocking structure (51); laying a spawning cushion layer (521) with a thickness of D1 in the pit (52), and laying a fish egg attachment layer (522) with a thickness of D2 on the surface of the spawning cushion layer (521) to provide an environment for fish egg attachment; forming a single-stage spawning ground (70) between two adjacent levels of flow blocking structures (51).

7. A method for constructing fish spawning grounds, feeding grounds and hiding grounds according to claim 6, characterized in that: In step S302, the spawning cushion layer (521) is paved with gravels having a diameter of 3 to 10 cm, and the fish egg attachment layer (522) is paved with pebbles having a diameter of 1 to 3 cm; the thickness D1 of the spawning cushion layer (521) and the thickness D2 of the fish egg attachment layer (522) are both 5 to 10 cm.

8. The method for constructing a fish spawning ground, feeding ground and hiding ground according to claim 6, characterized in that: In step S301, the method for setting the flow blocking structure (51) is as follows: along the water flow direction of the artificial spawning ground (5), a plurality of pairs of limiting grooves (511) are dug out in sequence on both sides of the artificial spawning ground (5), and a plurality of logs (512) are placed in each pair of limiting grooves (511), with the axial direction of the logs (512) being perpendicular to the water flow direction; and pebbles (514) are filled in the gaps formed between the ends of the logs (512) and the limiting grooves (511); blocks (513) are provided on the tops of both ends of the logs (512) for applying a downward pressing force to the logs (512); and the spacing between two adjacent flow blocking structures (51) is b2, and b2=3-6m.

9. A method for constructing fish spawning grounds, feeding grounds and hiding places according to claim 8, characterized in that: The interior of the log (512) is configured as a hollow structure and forms a hiding hole (512a); one or more fish inlet troughs (512b) are provided on each log (512) and are connected to the hiding hole (512a) inside the log; and the hiding holes (512a) between two adjacent logs (512) are connected to each other.

10. The method for constructing a fish spawning ground, feeding ground and hiding ground according to claim 1, characterized in that: In step S4, the method for creating a habitat for young fish is as follows: a pile of stones (56) made of pebbles and gravels, branches (54), stumps (55), and prefabricated eco-concrete blocks (53) are placed in the artificial spawning ground (5) to create a micro-habitat that is conducive to hiding young fish and can increase the fish's chance of foraging; and a space for fish hiding is provided in the prefabricated eco-concrete blocks (53).

11. A method for constructing fish spawning grounds, feeding grounds and hiding grounds according to claim 10, characterized in that: The ecological concrete prefabricated block (53) is a polyhedral structure with a hollow interior. Fish holes are provided on one or more surfaces of the ecological concrete prefabricated block (53) to communicate with the inner cavity thereof. When creating a habitat for young fish in step S4, a plurality of ecological concrete prefabricated blocks (53) are used to form a stacking structure, and the inner cavities of adjacent ecological concrete prefabricated blocks (53) in each stacking structure are connected to each other.

12. The method for constructing a fish spawning ground, feeding ground and hiding ground according to claim 10, characterized in that: The ecological concrete prefabricated block (53) is a prefabricated part, and its preparation method is: adding amino acid powder accounting for 1% to 15% of the weight of the concrete into a container filled with conventional concrete, and fully stirring it, and injecting the stirred concrete containing amino acids into the prefabricated part template to prepare it; the amino acid powder is one or more of arginine, glycine, alanine, proline, tyrosine, tryptophan and histidine.

13. The method for constructing a fish spawning ground, feeding ground and hiding ground according to claim 5, characterized in that: In step S5, the method for regulating water temperature and water flow is as follows: first, respectively mastering the time, water temperature, water depth and flow rate conditions for fish spawning, fish egg hatching and juvenile fish growth, and then regulating the water supply source and water supply flow rate of the artificial spawning ground (5) according to the water temperature and water flow conditions required for fish spawning, fish egg hatching and juvenile fish growth at different periods, until the water temperature, water depth and flow rate of the artificial spawning ground (5) are suitable for fish spawning, fish egg hatching and juvenile fish growth; regulating the water supply source is to select one or more of the upper water diversion pipe (41), the middle water diversion pipe (42) and the lower water diversion pipe (43) to operate according to the water temperature requirement, and take the surface water, the middle water or the bottom water of the reservoir, or take the water of different water layers and mix them to lead to the artificial spawning ground (5); the water supply flow rate is regulated by the gate valves on each water diversion pipe.

14. A method for constructing fish spawning grounds, feeding grounds and hiding places according to claim 6, characterized in that: In step S5, when regulating the water flow, the following requirements are met: the water depth h2 of the spawning ground (70) is 10 cm to 60 cm; the water depth h3 of the upper end of the flow blocking structure (51) is not less than 10 cm; The water level difference between two adjacent spawning grounds (70) is ΔH, which satisfies: Among them, L P is the body length of spawning fish; U max is the initial jumping velocity of spawning fish; β is the incident angle of fish jumping, and g is the acceleration due to gravity.

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