A control method for improving the continuity of the hatching and feeding habitat of drifting fish eggs

Abstract

The present invention provides a control method for improving the continuity of the habitat for hatching and feeding of drifting fish eggs, including: collecting basic data on control working conditions; calculating the hydrodynamic conditions along the hatching channel; calculating the water temperature along the hatching channel, predicting the drift time required for the fish eggs to complete hatching; calculating the drift age of the fish eggs along the hatching channel, predicting the drift distance required for the fish eggs to complete hatching based on the drift age and the drift time, and then locating the position where the fish eggs have completed hatching; locating the fish egg hatching channel according to the drift distance required for the fish eggs to complete hatching and the position where the fish eggs have completed hatching, analyzing the habitat conditions of the fish egg hatching channel and the water area after hatching, judging whether the water area is suitable for feeding after the fish eggs have completed hatching, and using the current control working condition as a recommended control scheme for improving the continuity of the hatching and feeding of drifting fish eggs when it is judged to be suitable. The control method proposed by the present invention can ensure the continuity of key life history processes of fish eggs, which is beneficial to the protection of fish resources.

Description

Technical Field

[0001] The present invention relates to the field of water ecological protection, and in particular to a control method for improving the continuity of a habitat for hatching and feeding of drifting fish eggs. Background Art

[0002] Affected by the construction and operation of water projects, the water and heat distribution of natural rivers has changed. People have found that the reproduction of fish that lay drifting eggs has been affected. For example, the lag in water temperature has caused the spawning time of fish to be delayed, and the slowdown in hydrological processes has led to the decline in fish egg reproduction behavior.

[0003] Ecological regulation measures are currently widely used to promote the reproduction of drift-eating fish. However, improving habitat conditions during a single life cycle stage does not guarantee the smooth completion of subsequent life cycles. Existing regulation methods fail to consider fish's habitat requirements for hatching and feeding, lack consideration for habitat continuity during key life cycle stages, and are therefore unsuitable for national river ecological protection in the new era. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the background technology and provide a control method for improving the continuity of the hatching and feeding habitat of drifting fish eggs.

[0005] To achieve the above object, the present invention provides a method for improving the continuity of the habitat for hatching and feeding of drifting fish eggs, comprising the following steps:

[0006] A method for improving the continuity of a drifting fish egg hatching and feeding habitat comprises the following steps:

[0007] Step S1: Collect basic data of control conditions;

[0008] Step S2: Calculating the hydrodynamic conditions along the hatching channel based on the basic data of the control working conditions collected in step S1;

[0009] Step S3: Calculating the water temperature along the hatching channel based on the hydrodynamic conditions along the hatching channel calculated in step S2, and predicting the drifting time required for the fish eggs to complete hatching;

[0010] Step S4: calculating the floating age of the fish eggs along the hatching channel based on the hydrodynamic conditions along the hatching channel calculated in step S2, and predicting the floating distance required for the fish eggs to complete hatching according to the floating age of the fish eggs along the hatching channel and the floating time required for the fish eggs to complete hatching predicted in step S3, thereby locating the position where the fish eggs are to be hatched;

[0011] Step S5: Locate the egg hatching channel according to the drift distance required for the eggs to hatch and the hatching position of the eggs located according to the prediction in step S4, analyze the egg hatching channel and the habitat conditions of the water area after the eggs are hatched, and determine whether the water area after the eggs are hatched is suitable for feeding;

[0012] Step S6: When step S5 determines that the water area after the hatching of the fish eggs predicted and optimized in step S4 is suitable as a feeding habitat, the current control working conditions are used as a recommended control scheme to improve the continuity of hatching and feeding of drifting fish eggs.

[0013] Furthermore, the basic data of the control working conditions include hydrological data, meteorological data, underwater topography data, water project operation data and fish spawning ground data. The hydrological data include flow, water level, water temperature, etc. The meteorological data include temperature, cloud cover, radiation, wind speed and direction, etc. The water project operation data includes scheduling procedures, water level in front of the dam, and downstream flow; the fish spawning ground data includes the location and scale of the spawning ground.

[0014] Furthermore, step S2 includes: constructing a hydrodynamic mathematical model based on the hydrological data and underwater topographic data collected in step S1, and calculating the hydrodynamic conditions along the hatching channel according to the hydrodynamic mathematical model, wherein the hydrodynamic conditions along the hatching channel include flow velocity and water depth.

[0015] Furthermore, when the calculation speed is taken into account, a one-dimensional hydrodynamic mathematical model is constructed; when the lateral diffusion effect of fish eggs needs to be considered, a two-dimensional hydrodynamic mathematical model is constructed; when the vertical sedimentation of fish eggs needs to be considered, a three-dimensional hydrodynamic mathematical model is constructed.

[0016] Furthermore, step S3 specifically includes:

[0017] Step S31: Based on the hydrodynamic conditions along the hatching channel calculated in step S2, a water temperature mathematical model is constructed to calculate the water temperature along the hatching channel;

[0018] Step S32: establishing a mathematical relationship between water temperature and fish egg hatching time based on the hatching time data of fish eggs under different water temperature conditions;

[0019] Step S33: Based on the mathematical relationship between water temperature and the duration of fish egg incubation, the drifting time required for the fish eggs to complete hatching is predicted.

[0020] Furthermore, step S4 specifically includes:

[0021] Step S41: constructing a mathematical model of the floating age of fish eggs based on the hydrodynamic conditions along the hatching channel calculated in step S2, and calculating the floating age of fish eggs along the hatching channel;

[0022] Step S42: Calculate the fish egg floating age at the hatching location based on the calculated fish egg floating age at the spawning location and the floating time required for the fish eggs to complete hatching as predicted in step S3:

[0023] a e =a0+t f

[0024] Where ae is the floating age of the eggs at the hatching location; a0 is the floating age of the eggs at the spawning location. The spawning location is obtained from the basic data collected in step S1. Based on the floating age of the eggs along the hatching channel calculated in step S41, the floating age of the eggs at the spawning location is obtained. f ;

[0025] Step S43: Based on the floating age of the fish eggs along the hatching channel calculated in step S41 and the floating age of the fish eggs at the hatching completion position calculated in step S42, the floating distance required for the fish eggs to complete hatching is predicted, and the hatching completion position of the fish eggs is located.

[0026] Further, in step S43, the hatching position of the fish eggs is the fish egg floating age a e The corresponding spatial position, the drift distance required for the eggs to complete hatching is expressed as:

[0027] ΔS i =|S0-S e |

[0028] Where, ΔS i is the drift distance required for the eggs to hatch; S0 is the distance between the spawning site and the dam; S e The distance from the location where the eggs are hatched to the dam, corresponding to the egg floating age a e spatial distribution location.

[0029] Furthermore, step S5 specifically includes:

[0030] Step S51: Positioning the egg hatching channel according to the drift distance and specific hatching position required for the eggs to complete hatching predicted in step S4;

[0031] Step S52: Using data collection as the main method and field investigation as the supplement, the fish egg hatching channel and the habitat conditions of the water area after hatching are analyzed. The specific analysis indicators include: the satisfaction of the water flow conditions in the hatching channel, the abundance of bait resources such as plankton, the suitability of the water flow and temperature conditions, and the interference degree of human activities. Based on the analysis indicators, it is judged whether the water area after the fish eggs are hatched is suitable as a feeding habitat for fry.

[0032] Furthermore, when the water area predicted in step S4 is not suitable as a feeding habitat for fry after the eggs are hatched, an optimized control working condition is formulated in combination with the requirements of the habitat conditions. The formulation of the optimized control working condition takes into account the water and sediment control of the cascade reservoirs and the measures to restore the feeding habitat conditions, and steps S2 to S5 are re-executed.

[0033] Furthermore, it also includes: applying the reservoir water and sediment control and feeding habitat condition restoration measures taken to optimize the control conditions to the operation and management of water projects, and improving the continuity of drifting fish egg hatching and feeding.

[0034] The present invention has the following beneficial effects:

[0035] 1. The prediction of the hatching location of fish eggs does not rely on on-site surveys of early fish resources, and has the advantages of low cost and high accuracy;

[0036] 2. Comprehensive consideration of the spatial and temporal matching of key life history stages ensures the continuity of the hatching and feeding habitats, which is conducive to improving the survival rate of fish resources;

[0037] 3. It is easy to preset multiple control scenarios and compare the control effects at low cost, which can ensure that the final control method is more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flow chart of a control method for improving the continuity of a drifting fish egg hatching and feeding habitat according to one embodiment of the present invention;

[0039] Figure 2 A mathematical relationship between water temperature and fish egg incubation duration established for one embodiment of the present invention;

[0040] Figure 3 A schematic diagram of a regulation method for improving the suitability of a feeding habitat according to one embodiment of the present invention;

[0041] Figure 4 This is the flow rate condition of the fish egg hatching channel in one embodiment of the present invention;

[0042] Figure 5 This is one of the embodiments of the present invention for improving the optimization and control conditions for the continuity of the fish egg hatching and feeding habitat. DETAILED DESCRIPTION

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0044] like Figure 1 The embodiment of the present invention provides a method for improving the continuity of the habitat for hatching and feeding of drifting fish eggs, comprising the following steps:

[0045] Step S1: Collect basic data of control conditions;

[0046] The basic data for control working conditions include hydrological data, meteorological data, underwater topographic data, water project operation data and fish spawning ground data.

[0047] Hydrological data include flow, water level, water temperature, etc.; meteorological data include temperature, cloud cover, radiation, wind speed and direction, etc.; water project operation data include scheduling procedures, water level in front of the dam, downstream flow, etc.; fish spawning ground data include spawning ground location and scale, etc.

[0048] Step S2: Calculating the hydrodynamic conditions along the hatching channel based on the basic data of the control working conditions collected in step S1;

[0049] Specifically, based on the basic information such as the hydrological data and underwater topographic data collected in step S1, a hydrodynamic mathematical model is constructed to calculate the hydrodynamic conditions along the hatching channel, including flow velocity, water depth, etc.

[0050] When taking the calculation speed into consideration, a one-dimensional hydrodynamic mathematical model should be constructed; when the lateral diffusion effect of fish eggs needs to be considered, a two-dimensional hydrodynamic mathematical model should be constructed; when the vertical sedimentation of fish eggs needs to be considered, a three-dimensional hydrodynamic mathematical model should be constructed.

[0051] This embodiment adopts a one-dimensional hydrodynamic mathematical model:

[0052]

[0053] Where Q is the flow rate (m 3 / s); A is the cross-sectional area of ​​the flow (m 2 ); x is the longitudinal coordinate (m); t is the time (s); q is the lateral inflow or outflow (m 2 / s); α is the momentum distribution coefficient; g is the acceleration due to gravity (m / s 2 ); h is the water depth (m); C is the coefficient of 1 / 2 / s); R is the hydraulic radius (m)

[0054] Step S3: Calculating the water temperature along the hatching channel based on the hydrodynamic conditions along the hatching channel calculated in step S2, and predicting the drifting time required for the fish eggs to complete hatching;

[0055] Step S3 specifically includes:

[0056] Step S31: Based on the basic data such as the hydrodynamic conditions along the hatching channel calculated in step S2, a water temperature mathematical model is constructed to calculate the water temperature along the hatching channel. The dimension used by the water temperature mathematical model is consistent with the dimension of the hydrodynamic mathematical model in step S2.

[0057] This embodiment adopts a one-dimensional water temperature mathematical model:

[0058]

[0059] Where, T is the water temperature (℃); D is the diffusion coefficient (m 2 / s); T2 is the source / sink water temperature (℃); is the heat exchange flux (J / (m 2 ·s)); ρ is the water density (kg / m 3 ); ρ is the specific heat of water (J / (kg·℃).

[0060] Step S32: Based on the hatching time data of fish eggs under different water temperature conditions, a mathematical relationship between water temperature and hatching time of fish eggs is established.

[0061] like Figure 2 As shown in the figure, this example uses domestic fish as the research object to establish an exponential response relationship (R 2 =0.9271):

[0062] t f =270.5175e -0.0875T (4)

[0063] Where, t f is the incubation time of fish eggs (h); T is the water temperature (℃).

[0064] Step S33: Based on the mathematical relationship between water temperature and the duration of fish egg incubation, the drifting time required for the fish eggs to complete hatching is predicted.

[0065] Step S4: calculating the floating age of the fish eggs along the hatching channel based on the hydrodynamic conditions along the hatching channel calculated in step S2, and predicting the floating distance required for the fish eggs to complete hatching according to the floating age of the fish eggs along the hatching channel and the floating time required for the fish eggs to complete hatching predicted in step S3, thereby locating the position where the fish eggs are to be hatched;

[0066] Step S4 specifically includes:

[0067] Step S41: Based on the hydrodynamic conditions along the hatching channel calculated in step S2, a mathematical model of the floating age of the fish eggs is constructed to calculate the floating age of the fish eggs along the hatching channel. The dimension used in the mathematical model of the floating age of the fish eggs is consistent with the dimension of the hydrodynamic mathematical model in step S2.

[0068] This embodiment adopts a one-dimensional fish egg floating age mathematical model:

[0069]

[0070] Where C is the tracer egg concentration (ind / m 3 ); D is the diffusion coefficient of tracer eggs (m 2 / s); α is the concentration of tracer fish eggs at floating age ((ind·s) / m 3 ); a is the roe buoyancy age (s).

[0071] Step S42: Calculate the fish egg floating age at the hatching location based on the calculated fish egg floating age at the spawning location and the floating time required for the fish eggs to complete hatching as predicted in step S3:

[0072] a e =a0+t f (8)

[0073] Where a e is the floating age of the eggs at the hatching location (h); a0 is the floating age of the eggs at the spawning location (h). The spawning location can be obtained from the basic data collected in step S1. Based on the floating age of the eggs along the hatching channel calculated in step S41, the floating age of the eggs at the spawning location t is obtained. f .

[0074] Step S43: Based on the floating age of the fish eggs along the hatching channel calculated in step S41 and the floating age of the fish eggs at the hatching completion position calculated in step S42, the floating distance required for the fish eggs to complete hatching is predicted, and the hatching completion position of the fish eggs is located.

[0075] The position where the eggs are hatched is the egg buoyancy age a e The corresponding spatial position, the drift distance required for the eggs to complete hatching can be expressed as:

[0076] ΔS i =|S0-S e | (9)

[0077] Where, ΔS i is the drift distance required for the eggs to hatch (km); S0 is the distance from the spawning site to the dam (km); S e is the distance from the dam to the location where the eggs are hatched (km), corresponding to the egg floating age a e spatial distribution location.

[0078] This example uses the Three Gorges Reservoir as the research area. Based on steps 3 and 4, the fish drifting age and hatching completion position are calculated, as shown in Table 1.

[0079] Table 1 Calculation table of rafting age and completed hatching position

[0080]

[0081] Step S5: Locate the egg hatching channel according to the drift distance required for the eggs to hatch and the hatching position of the eggs located according to the prediction in step S4, analyze the egg hatching channel and the habitat conditions of the water area after the eggs are hatched, and determine whether the water area after the eggs are hatched is suitable for feeding;

[0082] Step S5 specifically includes:

[0083] Step S51: Locate the fish egg hatching channel according to the drift distance required for the fish eggs to complete hatching and the specific hatching completion position predicted in step S4.

[0084] Step S52: Using data collection as the main method and field investigation as the supplement, the fish egg hatching channel and the habitat conditions of the water area after hatching are analyzed. The specific analysis indicators include: the satisfaction of the water flow conditions in the hatching channel, the abundance of bait resources such as plankton, the suitability of the water flow and temperature conditions, the interference degree of human activities, etc. Based on the analysis indicators, it is judged whether the water area after the fish eggs are hatched is suitable as a feeding habitat for fry.

[0085] Furthermore, when the water area predicted in step S4 is not suitable as a feeding habitat for fry after the eggs are hatched, an optimized control working condition is formulated in combination with the requirements of the habitat conditions, and steps S2 to S5 are re-executed.

[0086] like Figure 3 As shown, the hatching location in this embodiment is located in Wanxian. There are not enough slow-flowing waters such as tributaries and estuaries nearby. The abundance of zooplankton is low, and there is a lack of food for fry. It is necessary to further increase the floating distance of the eggs to ensure that the hatching location of the eggs is moved down to the waters near Yunyang. There are many tributaries and estuaries such as Xiaojiang River and Modao Creek at this location, which have habitat conditions that meet the feeding needs of fry.

[0087] Furthermore, the formulation of optimized control conditions can consider measures such as water and sediment control in cascade reservoirs and restoration of feeding habitat conditions.

[0088] This embodiment is analyzed, as shown in FIG. Figure 4 As shown in the figure, the water flow rate in the hatching channel is too low to maintain the drifting hatching of fish eggs. The operation mode of the upstream reservoir needs to be optimized and the following Figure 5 The optimized control scheme shown.

[0089] Step S6: When step S5 determines that the water area after the hatching of the fish eggs predicted and optimized in step S4 is suitable as a feeding habitat, the current control working conditions are used as a recommended control scheme to improve the continuity of hatching and feeding of drifting fish eggs.

[0090] Furthermore, measures such as reservoir water and sediment control and restoration of feeding habitat conditions taken to optimize the control conditions will be applied to water project operation and management according to local conditions to improve the continuity of hatching and feeding of drifting fish eggs.

[0091] This embodiment adopts Figure 5 After the operation mode of the upstream reservoir is optimized, the drift distance required for the eggs to complete hatching is predicted in steps S3 and S4, the hatching channel and the hatching position are determined, and it is judged in step S5 that the flow rate of the hatching channel of the control scheme can meet the drifting hatching requirements of the eggs ( Figure 4 ), and the hatching location has a tributary estuary slow-flow habitat ( Figure 3 ), can meet the feeding needs of fry, and better improve the continuity of the hatching-feeding habitat. Compared with the traditional method, the present invention has higher practical application value.

[0092] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by technicians in this technical field within the technical scope disclosed in the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for improving the continuity of the habitat for hatching and feeding of drifting fish eggs, characterized in that: The following steps are involved: Step S1: Collect basic data on control conditions; the basic data on control conditions include hydrological data, meteorological data, underwater topography data, water project operation data, and fish spawning ground data. The hydrological data includes flow, water level, and water temperature; the meteorological data includes temperature, cloud cover, radiation, wind speed, and wind direction; the water project operation data includes scheduling procedures, dam front water level, and downstream flow; and the fish spawning ground data includes spawning ground location and size. Step S2: Calculating the hydrodynamic conditions along the hatching channel based on the basic data of the control working conditions collected in step S1; Step S3: Calculating the water temperature along the hatching channel based on the hydrodynamic conditions along the hatching channel calculated in step S2, and predicting the drifting time required for the eggs to complete hatching; Step S4: Calculating the drifting age of the fish eggs along the hatching channel based on the hydrodynamic conditions along the hatching channel calculated in step S2, and predicting the drifting distance required for the fish eggs to complete hatching according to the drifting age of the fish eggs along the hatching channel and the drifting time required for the fish eggs to complete hatching predicted in step S3, thereby locating the position where the fish eggs are to complete hatching; Step S5: Locate the egg hatching channel according to the drift distance required for the eggs to hatch and the hatching position of the eggs located according to the prediction in step S4, analyze the egg hatching channel and the habitat conditions of the water area after the eggs are hatched, and determine whether the water area after the eggs are hatched is suitable for feeding; Step S6: When step S5 determines that the water area after the hatching of the fish eggs predicted and optimized in step S4 is suitable as a feeding habitat, the current control working condition is used as a recommended control scheme for improving the continuity of hatching and feeding of drifting fish eggs; When the water area predicted in step S4 is not suitable as a feeding habitat for fry after the eggs are hatched, an optimized control working condition is formulated in combination with the requirements of the habitat conditions. The formulation of the optimized control working condition takes into account the water and sediment control of the cascade reservoirs and the measures to repair the feeding habitat conditions, and steps S2 to S5 are re-executed.

2. The method for improving the continuity of the habitat for hatching and feeding drifting fish eggs according to claim 1, wherein: Step S2 includes: constructing a hydrodynamic mathematical model based on the hydrological data and underwater topographic data collected in step S1, and calculating the hydrodynamic conditions along the hatching channel according to the hydrodynamic mathematical model, wherein the hydrodynamic conditions along the hatching channel include flow velocity and water depth.

3. The method for improving the continuity of the habitat for hatching and feeding of drifting fish eggs as claimed in claim 2, wherein: When the calculation speed is taken into account, a one-dimensional hydrodynamic mathematical model is constructed; when the lateral diffusion effect of fish eggs needs to be considered, a two-dimensional hydrodynamic mathematical model is constructed; when the vertical sedimentation of fish eggs needs to be considered, a three-dimensional hydrodynamic mathematical model is constructed.

4. The method for improving the continuity of the habitat for hatching and feeding drifting fish eggs according to claim 1, wherein: Step S3 specifically includes: Step S31: Based on the hydrodynamic conditions along the hatching channel calculated in step S2, a water temperature mathematical model is constructed to calculate the water temperature along the hatching channel; Step S32: establishing a mathematical relationship between water temperature and fish egg hatching time based on the hatching time data of fish eggs under different water temperature conditions; Step S33: Based on the mathematical relationship between water temperature and the duration of fish egg hatching, the drifting time required for the fish eggs to complete hatching is predicted.

5. The method for improving the continuity of the habitat for hatching and feeding drifting fish eggs according to claim 1, wherein: Step S4 specifically includes: Step S41: constructing a mathematical model of the floating age of fish eggs based on the hydrodynamic conditions along the hatching channel calculated in step S2, and calculating the floating age of fish eggs along the hatching channel; Step S42: Calculate the egg drifting age at the hatching location based on the calculated egg drifting age at the spawning site and the drifting time required for the eggs to complete hatching as predicted in step S3: ； Where, The age of the fish eggs at the hatching position; The floating age of the fish eggs at the spawning site is obtained based on the basic data collected in step S1. The floating age of the fish eggs along the hatching channel calculated in step S41 is used to obtain the floating age of the fish eggs at the spawning site. ; Step S43: Based on the floating age of the fish eggs along the hatching channel calculated in step S41 and the floating age of the fish eggs at the hatching completion position calculated in step S42, the floating distance required for the fish eggs to complete hatching is predicted, and the hatching completion position of the fish eggs is located.

6. The method for improving the continuity of the habitat for hatching and feeding drifting fish eggs according to claim 5, wherein: In step S43, the hatching position of the fish eggs is the fish egg floating age The corresponding spatial position, the drift distance required for the eggs to complete hatching is expressed as: ； Where, The drift distance required for the eggs to complete hatching; The distance between the spawning site and the dam; The distance from the dam to the hatching location of the fish eggs, corresponding to the floating age of the fish eggs spatial distribution location.

7. The method for improving the continuity of the habitat for hatching and feeding drifting fish eggs according to claim 1, wherein: Step S5 specifically includes: Step S51: Positioning the egg hatching channel according to the drift distance and specific hatching position required for the eggs to complete hatching predicted in step S4; Step S52: Using data collection as the main method and field investigation as the supplement, the fish egg hatching channel and the habitat conditions of the water area after hatching are analyzed. The specific analysis indicators include: the satisfaction of the water flow conditions in the hatching channel, the abundance of plankton bait resources, the suitability of the water flow and temperature conditions, and the interference degree of human activities. Based on the analysis indicators, it is judged whether the water area after the fish eggs are hatched is suitable as a feeding habitat for fry.

8. The method for improving the continuity of the habitat for hatching and feeding drifting fish eggs according to claim 1, wherein: Also includes: The reservoir water and sediment control and feeding habitat condition restoration measures taken to optimize the control conditions will be applied to the operation and management of water projects to improve the continuity of hatching and feeding of drifting fish eggs.

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