A water intake ecological regulation method based on early fish resource protection

Abstract

The application discloses a water taking ecological scheduling method based on fish early resource protection and belongs to the technical field of environmental protection of water crossing engineering. The method comprises the following steps: (1) monitoring fish early resources, and acquiring fish early resource biomass distribution data of a water taking section and each water layer of an upstream and a downstream; (2) obtaining fish early resource loss amount by using multi-dimensional space-time parameter coupling loss amount analysis; optimizing water taking head design to minimize fish early resource loss amount; and (3) establishing an ecological-hydraulic coupling multi-objective optimization decision model, calculating fish early resource loss amount in real time, and screening a scheduling scheme considering ecological protection and engineering efficiency. The application solves the problem that ecological protection and engineering efficiency are difficult to be considered in traditional technology by dynamic scheduling and engineering structure innovation, and provides a scientific and quantitative solution for sustainable utilization of water resources in a basin.

Description

Technical Field

[0001] This invention relates to the field of environmental protection technology for water-related engineering projects, and in particular to a water intake ecological scheduling method based on early fish resource protection. Background Technology

[0002] Water intake pumping stations, as key structures in water resource allocation, water diversion, and navigation projects, commonly experience water entrapment effects on aquatic organisms, especially early-stage fish populations, during operation. Studies have shown that early-stage fish populations with weak swimming abilities (such as fish eggs and larvae) are easily entrapped by the intake water flow, causing irreversible ecological damage. For example, loaches, which inhabit the slow-flowing bottom of rivers, are less affected by water entrapment, but their eggs during the breeding season may be lost due to water intake disturbance; gudgeon fish rely on the mid-to-lower layers of benthic organisms, but their drifting eggs may enter the intake area; while adults of the four major Chinese carp species can avoid debris barriers, their eggs and larvae, lacking the ability to avoid it, are easily entrapped by high-speed water flows.

[0003] In related fields, for example, Chinese invention patent CN117973706A discloses a reservoir ecological scheduling method that integrates the ecological flow and temperature process requirements of fish, including the following steps: constructing a target fish habitat model to deduce the ecological flow process of the target fish's life history; calculating the critical spawning water temperature and gonadal development accumulated temperature threshold of the target fish under the influence of the reservoir before dam construction and the current reservoir scheduling regulations; constructing a multi-objective reservoir scheduling model to obtain the flow process and water level after optimized reservoir scheduling; coupling a water temperature model to construct a multi-objective ecological scheduling model of the reservoir that integrates fish growth flow and water temperature processes, and calculating the reservoir outflow water temperature before and after optimized reservoir scheduling; calculating the improvement difference between the critical water temperature threshold and accumulated temperature threshold arrival date of the target fish after reservoir ecological scheduling and the date before optimized scheduling, and the difference between the critical water temperature threshold and accumulated temperature threshold of the target fish after reservoir ecological scheduling and the ideal state of the natural river before dam construction.

[0004] Chinese invention patent CN114223588A discloses a method for ecological regulation of reservoirs to ensure the hatching of eggs from fish that lay *Sphagnum moss* in a reservoir area. This method includes: obtaining information on the species composition and reproductive characteristics of fish that lay *Sphagnum moss* eggs in the reservoir area; determining the period of fastest water level decline in the reservoir; determining the species composition of fish that lay *Sphagnum moss* eggs during the period of fastest water level decline; determining the main species composition of fish that lay *Sphagnum moss* eggs affected by the reservoir water level during the stated period, thus obtaining the target fish species for regulation; determining the water temperature, water depth, weather, and time required from fertilization to hatching and the start of the lateral swimming stage for the target fish species during the period of fastest water level decline in the reservoir; determining the required ecological regulation time, water temperature, weather, and water level control parameters for the target fish species; determining the ecological regulation scheme; and regulating the reservoir water level according to the ecological regulation scheme. This invention can mitigate the adverse effects of continuous water level decline in reservoirs on the hatching of *Sphagnum moss* eggs.

[0005] Chinese invention patent CN119494483A discloses an optimization method for ecological scheduling of water conservancy and hydropower projects, relating to the field of ecological scheduling technology. This method includes: finely dividing the river channel into ecological zones, combining multiple factors to divide the river channel into multiple zones with clearly defined ecological functions. This invention, by real-time monitoring of the ecological water demand of different ecological zones within the river channel, accurately grasps the actual demand status of each ecological zone, enabling personalized ecological scheduling schemes tailored to the characteristics of different ecological zones, thus improving the accuracy of scheduling. The ecological model comprehensively considers multiple factors such as hydrology, water quality, ecology, and meteorology, and can predict the changing trends of ecological water demand in different ecological zones. By accurately meeting the ecological water demand of different ecological zones, a suitable living environment is provided for various aquatic organisms, which is conducive to the protection of rare and endangered species, promotes the stable development of biological communities, and improves the biodiversity level of the entire river ecosystem.

[0006] Currently, none of the publicly available ecological scheduling methods address the entrainment effect of water intake heads on aquatic organisms. CN117973706A proposes integrating water temperature demand and fish ecological flow process demand, CN114223588A proposes a reservoir ecological scheduling method for hatching fish eggs from sticky grass, and CN119494483A proposes delineating ecological function zones for different areas. However, their research ideas, research objects, and research objectives are not applicable to pump station water intake scheduling.

[0007] The current pump station scheduling scheme primarily focuses on the safe operation of the project. The principles of project operation and scheduling are joint scheduling of the project's water source and the water source in the receiving area; prioritizing domestic and basic ecological water use; water volume scheduling subordinate to flood control scheduling; and strict adherence to total water consumption control targets. The water source pump station will cease operation when the design flood occurs at the intake section or when the sediment content of the inflow exceeds the design value during the flood season. However, with increasing emphasis on ecological environmental protection, the water intake of the water source pump station should also prioritize meeting the ecological discharge of the river at the intake section. Furthermore, the following design flaws exist: insufficient focus on ecological protection, failing to consider the fish spawning cycle and early resource spatial and temporal distribution characteristics, leading to increased ecological losses due to water intake behavior during sensitive periods; crude structural design, with traditional intake heads (such as right-angle inlets) prone to turbulence, amplifying the entrainment effect; and a lack of quantitative loss calculation, as existing technologies lack precise loss calculation models, making it difficult to provide a scientific basis for ecological scheduling. Summary of the Invention

[0008] In view of the above-mentioned deficiencies of the prior art, the present invention provides a water intake ecological scheduling method based on early fish resource protection, comprising the following steps:

[0009] (1) Monitor early fish resources and obtain data on the distribution of early fish biomass at the water intake section and in the upstream and downstream water layers;

[0010] (2) The early loss of fish resources was obtained by using the loss analysis of multidimensional spatiotemporal parameter coupling; the water intake design was optimized to minimize the early loss of fish resources.

[0011] (3) Establish an ecological-hydraulic coupling multi-objective optimization decision-making model, calculate the early resource loss of fish in real time, and screen scheduling schemes that take into account both ecological protection and engineering efficiency.

[0012] Preferably, in step (2), the formula for calculating the early loss of fish resources is as follows:

[0013] ;

[0014] In the formula:

[0015] W total Total early-stage losses of all fish species throughout the year (in fish).

[0016] i Early fish species composition ( i =1, 2, ..., n ,common n kind);

[0017] m Month (m=1, 2, ..., 12);

[0018] z Water layer numbering (surface, middle, bottom, etc., total) k layer);

[0019] D imz Biomass density, the first i Early resources of fish species in the first m month z Aquatic biomass (tails / m³) 3 );

[0020] Q m Total water withdrawal in month m (m 3 );

[0021] c z : z The water layer selection coefficient is determined based on the optimized location of the water intake head, and its value ranges from 0 to 1; middle and upper layers c z The value is 0.7~0.9, in the middle and lower layers. c z The value is 0.3~0.5, at the bottom layer. c z The value is 0.1~0.3;

[0022] K im : i Early resources of fish species in the first m The occurrence rate in a given month; that is, the occurrence rate of this species in the first month. m Number of days in a month / number of days m Total number of days in a month K im When the value is greater than 0.5, it is the peak period for fish spawning.

[0023] α z Flow rate amplification factor, i.e. z Water layer flow velocity influence coefficient, z The coefficient of water layer velocity on the early fish resource entrainment effect; the velocity distribution of each water layer was pre-calibrated based on computational fluid dynamics simulation, and the vertical velocity was monitored in real time by an acoustic Doppler velocity profiler for dynamic correction. α z value;

[0024] Tm : No. m Monthly operating days correction factor, i.e., the number of days the water intake pump station operates on the [number]th month. m Actual number of days in operation per month / number of days in operation m Total number of days in a month;

[0025] β: Intake head shape correction coefficient, with a value range of 0.5~1.5; determined based on engineering structural design optimization, the influence of the intake head structure is taken as a global coefficient, reflecting the regulatory role of engineering optimization on the overall loss and reflecting the control effect of different structural designs on water flow disturbance.

[0026] More preferably, the flow rate amplification factor ( α z This quantifies the difference in flow velocity as a direct impact on fish losses; α z When the value is greater than 1, it indicates that the water velocity in that layer is relatively high, the entrapment effect is amplified, and fish eggs and larvae are more easily entrapped (such as in the high-speed surface zone). α z When the value is less than 1, it indicates that the flow velocity of the water layer is low and the entrainment effect is weakened (such as the low-velocity zone at the bottom).

[0027] More preferably, the flow rate amplification factor ( α z The coefficient values ​​are obtained through computational fluid dynamics simulation calibration, and the steps are as follows:

[0028] S1. Establish a three-dimensional fluid model of the water intake pumping station head: Import the water intake head, pump house and other structures into computational fluid dynamics analysis software to simulate the velocity distribution; divide the grid (the denser the grid, the higher the accuracy, but the greater the computational load).

[0029] S2. Set fluid boundary conditions: Set the inflow velocity based on actual hydrological data; Select the k-ε or k-ω model to simulate water flow turbulence and establish a turbulence model;

[0030] S3. Simulate vertical velocity field: Run calculations to obtain different water layers ( z =Velocity distribution in the surface / middle / bottom layers;

[0031] S4, Calibration α z Nonlinear relationship with flow velocity; dynamic control, real-time monitoring of actual flow velocity, and dynamic correction. α z Automatic adjustment z Water layer selectivity ( c z coefficient).

[0032] Furthermore, in S4, calibration α z The fitting formulas for the nonlinear relationship between experimental data and flow velocity include:

[0033] ;

[0034] in, v 基准For reference flow velocity (e.g., 0.5 m / s in the middle layer). v z for z Water flow velocity.

[0035] In the fluid dynamics simulation, a three-dimensional fluid model of the intake pump station head is established to simulate the velocity distribution; then, parameter calibration is performed, and the results of each water layer are output based on the simulation results. α z Value, will α z The data is written into the database of the ecological scheduling algorithm; combined with dynamic regulation, the actual flow rate is monitored in real time and dynamically corrected. α z Automatic adjustment of water intake level ( c z (Coefficient); based on the assessment of the impact of water intake on the early resources of rare and endemic protected fish species, the water intake head can be switched to the middle and lower layers, avoiding the upper and middle layers. α z To reduce losses in the area.

[0036] More preferably, the water intake head shape correction coefficient ( β ) represents the engineering correction coefficient for the degree of influence of the intake head structure design on the entrainment effect, quantifying the optimization of the engineering structure as a direct control over ecological losses; among which, β When <1, it means that the shape of the water intake head is an optimized structure (such as a streamlined design, which reduces water flow disturbance and reduces the entrainment effect). β A value greater than 1 indicates a poor structural design (such as right-angle bends, which exacerbate water flow turbulence and amplify the entrainment effect).

[0037] Furthermore, the optimized water intake design is adjusted based on data such as early fish biomass distribution and real-time flow velocity monitoring. β The system is equipped with a replaceable water intake head module and a hydraulic drive device for rapid switching, with switching time controlled within 2 hours, achieved by actively reducing the water intake head. β The goal is to minimize early-stage fish resource losses.

[0038] Furthermore, the aforementioned β The relationship between value adjustment and water intake head module adjustment includes the following aspects:

[0039] (I) During non-fish spawning seasons and when fish biomass is low in the early stages, the water intake should be switched to a right-angle intake, with water entering at a 90° angle. In areas of strong turbulence, water should be taken from the middle to upper layers. c z =0.7~0.9, β The value adjustment range is 1.3~1.5, which makes the high-speed water flow beneficial to water intake operation;

[0040] (II) During the early development stage of fish resources, the water intake head is switched to a funnel-shaped diffuser with a gradually expanding cross section, resulting in uniform flow velocity and dynamic stratification. c z =0.5~0.7, β The value adjustment range is 0.9~1.1, which stabilizes the water flow, reduces disturbance to early resources, and takes into account water intake operations;

[0041] (III) During the fish spawning season (off-peak period), the water intake head is switched to a grid-guided type, with a porous grid to divert the flow, suppress eddies, and select the middle and lower layers of water for intake. c z =0.3~0.5, β The value adjustment range is 0.7~0.9, low speed protects fish eggs;

[0042] (IV) During the peak spawning season for fish and when the early biomass of fish resources is relatively high, the water intake head is switched to a biomimetic streamlined shape for laminar flow control, restricting bottom water intake. c z =0.1~0.3, β The value is adjusted within the range of 0.5 to 0.7 to minimize the impact of water flow turbulence.

[0043] Water intake head shape correction factor ( β The coefficient () is an engineering correction factor reflecting the degree of influence of the intake head structure design on the entrainment effect. Its core significance lies in quantifying the optimization of the engineering structure as a direct control over ecological losses. Different head shapes alter the flow regime (e.g., generating eddies, turbulence), thus affecting the probability of early fish resource entrainment. In the formula for early fish resource loss, β As a global multiplier, it directly scales the ecological loss of the entire system proportionally. For example, if the head structure is optimized to make... β Reducing the voltage from 1.2 to 0.8 will decrease the total loss by 33%. Therefore, by optimizing the intake head design, the loss can be proactively reduced. β This value minimizes ecological loss.

[0044] Comparison of typical water intake head structures under the above preferred conditions with β The design concept for the value range is shown in Table 1.

[0045] Table 1: Comparison of Typical Water Intake Head Structures β Value range

[0046]

[0047] β The value ranges from 0.5 to 1.5. Lower limit. β= 0.5, corresponding to the idealized optimal structure (such as bionic streamline combined with active flow control), and this value is verified by the inventor through computational fluid dynamics simulation and experiments. The upper limit β = 1.5, corresponding to the worst structure (such as right-angle elbow combined with no grid), in actual engineering β Structures with > 1.5 are usually eliminated due to too low efficiency. During the design process of this solution, through empirical verification of the value range, it is obtained by statistical analysis of the hydraulic engineering database (including 127 pump station cases):

[0048] (1) Traditional structure β Mean value: 1.05 (standard deviation 0.25);

[0049] (2) Optimized structure β Mean value: 0.82 (advanced engineering can reach 0.6);

[0050] (3) Extremely poor structure β Measured value: 1.48 (a certain agricultural pump station).

[0051] When β <0.5, it means that breakthrough technologies are required (such as magnetohydrodynamic drag reduction, intelligent deformable structure). β > 1.5 represents being eliminated in actual engineering. Considering actual engineering applications, this invention confirms β The value is within the above range.

[0052] By incorporating β the coefficient into the dynamic scheduling system, "structure - operation" collaborative optimization can be achieved. During the sensitive period of dynamic adjustment β , during the peak spawning period of fish (such as May - June), it automatically switches to a low β value structure module. The formula is as follows:

[0053] ;

[0054] Thus, in the overall operation, multi - structure linkage control is achieved, and a deformable water intake head is configured to adjust the β value according to real - time monitoring data (such as fish egg density, flow velocity, etc.).

[0055] Furthermore, the design parameters of the optimized water intake head design include the curvature radius of the water inlet, the porosity of the grid, and the angle of the guide plate; the relationship between each parameter and the β value is as follows:

[0056] 1) Curvature radius of the water inlet: The larger the curvature (such as arc transition), β the lower the value (β ∝ 1 / curvature radius);

[0057] 2) Porosity of the grid: When the porosity is 30% - 50%, β the value is the lowest (at this time, both flow diversion and anti - clogging are considered);

[0058] 3) Deflector angle: 15°~30° tilt angle, reducing... β Value: 20%~40%.

[0059] In terms of specific engineering implementation, the design of the water intake structure can be optimized through modular structural design, digital twin systems, and intelligent control algorithms to achieve the goal of protecting early-stage fish resources. Examples of feasibility include, but are not limited to, the following:

[0060] (1) Modular structural design: prefabricated replaceable head modules (horn mouth / grid / bionic type, etc.); hydraulic drive device is installed to achieve rapid switching, and the switching time is controlled within 2 hours;

[0061] (2) Digital twin system: Establishment β Value-structure parameter mapping database; predicting different combinations through computational fluid dynamics simulations. β value;

[0062] (3) Objective function: min W total = f ( β,γz ,Q m The constraints are: water intake guarantee rate ≥ 95% and pump station efficiency ≥ 85%.

[0063] Preferably, in step (3), the ecological-hydraulic coupled multi-objective optimization decision model is as follows:

[0064] ;

[0065] Where, min W total This represents the minimum early-stage fish resource loss; st Q 取水 ≥0.95 Q 设计 η≥85% Q 河道 ≥0.3 Q 多年平均 To ensure safe operation of the project, under the premise that the water intake guarantee rate is ≥95%, the pumping station efficiency is ≥85%, and the ecological flow of the downstream river channel of the water intake section is not less than 30% of the multi-year average flow of the section, an ecological water intake scheduling method based on early fish resource protection should be established.

[0066] In the model design, referring to the "Code for Calculation and Design of Ecological Flow Discharge for Water Conservancy and Hydropower Projects" (SL / T 820-2023), the ecological flow index of the downstream river channel at the water intake section is 0.3. Q 多年平均That is, 30% of the multi-year average flow of the cross section.

[0067] A pump station efficiency of ≥85% is an industry standard or empirical value. It refers to the overall operating efficiency of the pump station, that is, the efficiency of energy conversion.

[0068] Pump station efficiency (η) = effective output power / input power × 100%;

[0069] Effective output power: The actual work done by the water pump on the water flow, calculated using the following formula:

[0070] P 输出 = ρgQH

[0071] in, r The density of water (approximately 1000 kg / m³) 3 ); g Gravitational acceleration (9.8 m / s²) 2 ); Q Flow rate (m 3 / s); H : Head (the total height the pump lifts the water body, unit: m); Input power: the electrical power consumed by the motor driving the pump (unit: kW).

[0072] As an example, a certain pumping station has a head H = 20m and a flow rate of... Q =1 m 3 / s, input power P 输入 =250 kW, then:

[0073] P 输出 =1000×9.8×1×20=196,000 W=196 kW; η=196 / 250×100%=78.4%;

[0074] If an efficiency of ≥85% is required, the design needs to be optimized to reduce the input power to below 230 kW.

[0075] The primary function of a pumping station is to pump water from a lower elevation to a higher elevation or to a distant location, a process that consumes electricity or other energy sources. High efficiency means less energy waste and lower operating costs. In ecological scheduling optimization, it is essential not only to reduce losses to fish resources but also to ensure that the basic functions of the pumping station are not significantly affected. Otherwise, even if the ecological protection effect is good, the solution is not feasible if the operating cost of the pumping station is too high or cannot meet the water supply demand. 85% is currently the efficiency threshold for advanced pumping stations; a value below this indicates a flaw in the design or equipment selection. This indicator is selected based on the specific design objectives mentioned above and is not a conventional choice in this field. The constraint of "pumping station efficiency ≥ 85%" reflects the following core design concepts:

[0076] (1) Economic requirements

[0077] Inefficiency leads to energy waste and increased operating costs. For example: 78% efficiency → 1.28 kWh of electricity is consumed per ton of water pumped; 85% efficiency → 1.18 kWh of electricity is consumed per ton of water pumped; annual operating costs can be reduced by 7% to 10%.

[0078] (2) Functional protection

[0079] Ecological scheduling needs to protect early fish resources while ensuring that pumping stations meet water supply / irrigation needs; if efficiency is too low, water intake may be forced to be reduced due to energy consumption limitations, leading to functional failure.

[0080] (3) Technical feasibility assessment

[0081] 85% is the current efficiency threshold for advanced pumping stations; a value below this indicates a flaw in the design or equipment selection.

[0082] Table 2 lists the factors that directly affect the efficiency of the pumping station, serving as a reference for comprehensive optimization in the design.

[0083] Table 2: Factors Affecting Pump Station Efficiency and Optimization Measures

[0084]

[0085] Thus, a balance can be struck between efficiency and early fish resource conservation, achieving synergistic optimization:

[0086] (1) Dual optimization of water intake head structure

[0087] Early conservation of fish resources: by reducing β A coefficient (e.g., from 1.2 to 0.8) reduces the entrainment effect;

[0088] Efficiency improvement: Optimize flow channel design (such as increasing the radius of curvature) to reduce hydraulic losses.

[0089] (2) Dynamic scheduling algorithm

[0090] During the sensitive period of fish (high) D imz Time period):

[0091] Prioritize water intake from the middle and lower layers (lowering) W total );

[0092] Synchronously adjust the pump speed to maintain the total water intake Q → ensure that efficiency does not decrease;

[0093] (3) Multi-objective optimization model

[0094] By solving the Pareto optimal solution set through algorithms, a balance between ecology and efficiency can be achieved.

[0095] A water intake guarantee rate of ≥95% is required, meaning a design guarantee rate of ≥95%. The design guarantee rate is stipulated by relevant industry design specifications and national or local policies. For example, the design guarantee rate for industrial projects is generally higher than 90%, for agricultural projects it is generally 50%~90%, and for urban domestic water supply projects it is generally as high as 95% or more. When applying for water intake, water-intake units or individuals should state the project's design guarantee rate requirements in the submitted project water resources assessment report and demonstrate whether the water source meets the project's water intake and guarantee rate requirements. If the project design requirements cannot be met, the water intake plan or project design plan should be adjusted.

[0096] The water intake guarantee rate refers to the probability or percentage of time that a pumping station can fulfill its water supply task according to the planned water intake within its design life. Its calculation formula is:

[0097] Water intake guarantee rate = (Actual number of days with water intake meeting standards / Total number of operating days) × 100%.

[0098] Table 3 lists the factors that directly affect the water intake guarantee rate, serving as a reference for comprehensive optimization in the design.

[0099] Table 3: Factors Affecting Water Intake Guarantee Rate and Optimization Measures

[0100]

[0101] The dual objectives of "high guarantee rate + low ecological loss" can be achieved through time-space co-optimization methods:

[0102] (1) Time dimension: During the non-sensitive period (low K im Excess water withdrawal during the month should be stored in the regulating reservoir; during sensitive periods (high water intake) K im (Month) Reduce water withdrawal, consuming stored water;

[0103] (2) Spatial dimension: stratified water intake, prioritizing extraction from water layers with sparse fish populations (through adjustment) c z Distributed water intake involves setting up multiple small water intakes to disperse the flow rate and reduce local flow velocity (reduce flow rate). α z ).

[0104] As a feasibility example, at a pumping station in the Chu River basin, the design flow rate Qdesign = 10 m2 3 / s, and the guarantee rate must be ≥95%. The scheduling strategy is shown in Table 4.

[0105] Table 4: Dispatch Strategy for a Pumping Station in the Chu River Basin under a 95% Guarantee Rate Scenario

[0106]

[0107] This solution, through dynamic scheduling, reduces fish egg loss by 65% ​​and energy consumption by 4.7% while the guarantee rate decreases by only 2.2%.

[0108] Based on the above technical solutions, the design concept and principle of this invention are as follows:

[0109] Based on the distribution of early fish resources (fish eggs, larvae and juveniles), this invention sets the location of the water intake head of the water intake pumping station, optimizes the structural design of the water intake head, considers the ecological flow of the downstream river channel of the water intake section, and carries out ecological scheduling of water intake to minimize the impact of water intake operation on the loss of early fish resources.

[0110] This method investigates the species composition and biomass distribution of early-stage fish resources at the water intake section and upstream and downstream areas during each month (January to December). It determines the location of the water intake head at the pumping station and optimizes the structural design of the intake head to minimize the impact of water intake operations on early-stage fish resource losses. Loss analysis using multi-dimensional spatiotemporal parameter coupling achieves full species coverage of early-stage fish resources. The accumulated losses of different early-stage fish species comprehensively reflect the overall impact of water intake on early-stage resources. The spatiotemporal refinement of the loss impact assessment is achieved through triple summation (species × month × water layer), with water intake divided by month in the time dimension (…). Q m ) and biomass ( D imz ), spatial layer calculation for water layer selection ( c z ) and the effect of flow velocity ( α z And will affect the structure of the water intake head (). β As a global coefficient, it reflects the regulatory effect of engineering optimization on the overall loss. By establishing an ecological-hydraulic coupled multi-objective optimization decision model, the total early-stage fish resource loss is calculated in real time, based on... α z and D imz Distribution, dynamic adjustment of water layer selectivity c z Water withdrawal volume allocated monthly Q m ; Best Match β The value is then switched to the corresponding module to filter scheduling schemes that balance ecological protection and engineering efficiency.

[0111] This invention can significantly reduce ecological losses; through dynamic scheduling (activating a biomimetic streamlined head during sensitive periods and restricting bottom water intake), the loss of fish eggs is reduced; combined with stratified water intake ( c z Regulation) and flow rate control α z (Revised), improving the efficiency of fish egg and larval protection. Balancing engineering efficiency and safety, meeting the needs of emergency response and routine operation. Quantitative evaluation and dynamic optimization were completed; a system was established. W total The formula for calculating the loss amount, which integrates the spatiotemporal distribution ( D imz , Q m ), hydraulic parameters ( α z ), engineering structure ( β Multi-dimensional data, such as simulation data and real-time monitoring data, improves calculation accuracy; dynamic correction is achieved through the fusion of simulation and real-time monitoring data. α z Coefficients are used to ensure the reliability of the model.

[0112] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0113] This invention provides a water intake ecological scheduling method based on early fish resource protection. Through dynamic scheduling and engineering structure innovation, it overcomes the problem of balancing ecological protection and engineering efficiency in traditional technologies, and provides a scientific and quantitative solution for the sustainable use of watershed water resources. Attached Figure Description

[0114] Figure 1 This diagram illustrates the relationship between the elevation of the water intake head and the water level during the fish breeding season. Detailed Implementation

[0115] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0116] The implementation method selected a water intake pumping station on the Yangtze River. This pumping station is located within an aquatic life protection area. According to data analysis, the entrainment effect during the operation of this pumping station resulted in an annual loss of 4 × 10⁻⁶ eggs and larvae of drifting fish. 6 These particles accounted for 0.3% of the total amount generated in the upstream section of the river. To reduce early resource losses, a dynamic ecological scheduling scheme was designed and implemented based on research:

[0117] (1) Conduct early resource monitoring, using planktonic nets and eDNA technology to monitor the density of fish eggs (surface, middle and bottom layers) at the water intake section and upstream and downstream on a monthly basis, and obtain data on the distribution of early fish resource biomass at the water intake section and upstream and downstream water layers;

[0118] (2) The early-stage fish resource loss was obtained by using the following multidimensional spatiotemporal parameter coupling loss analysis:

[0119] ;

[0120] A schematic diagram showing the relationship between the elevation of the water intake head and the water level during the fish breeding season is shown below. Figure 1 As shown, a three-dimensional model of the water intake head was established. The structure of the water intake head, pump house, etc., was imported into computational fluid dynamics analysis software to simulate the velocity distribution, set fluid boundary strips, simulate the vertical velocity field, and calibrate. α z :

[0121] ;

[0122] The results showed that the surface flow rate was high ( α z =1.3~1.5), low bottom layer flow velocity ( α z =0.7~0.9).

[0123] In terms of time stratification, based on the peak fish breeding season (May 20th to July 10th), sensitive and non-sensitive periods are divided; during the sensitive period, water intake is reduced to 75% of the design value. Q m =0.75 Q 设计 );

[0124] In terms of spatial layering, adopt c z The coefficient dynamically adjusts the water intake level; during sensitive periods, the water intake head is raised to the middle and lower layers (bottom layer). c z <0.7), avoid upper floors. α z district( α z >1.3); During non-sensitive periods, water intake from the upper layers is permitted ( α z >0.7);

[0125] Structural optimization, as shown in Table 5, involves configuring modular water intake heads that can be switched as needed to minimize early fish resource losses.

[0126] Table 5: Optimization of the Water Intake Head Structure of Jiang's Water Intake Pumping Station

[0127]

[0128] Optimize the intake head design to minimize early fish resource loss;

[0129] (3) Establish an ecological-hydraulic coupled multi-objective optimization decision-making model, with the objective function as follows:

[0130] ;

[0131] The NSGA-II genetic algorithm was used to generate the Pareto optimal solution set, and the following scheme, which balances efficiency and ecological protection, was selected:

[0132] 1) During sensitive periods, water intake is reduced by 30%. c z =0.8, β =0.6;

[0133] 2) During non-sensitive periods, water intake is restored to 100%. c z =0.5, β =0.8.

[0134] This method can be extended to similar water intake pumping stations, providing a standardized solution for the coordinated development of water resources and ecological protection in watersheds.

[0135] In summary, this invention achieves dynamic adaptation to the fish reproductive cycle. Under the premise of meeting engineering safety and ecological flow requirements, it dynamically adjusts the water intake strategy based on the fish spawning period and early resource distribution patterns to reduce entrainment losses during sensitive periods. It reduces water flow disturbance through engineering structural innovation and quantifies the impact of structural parameters on ecological losses. It establishes a spatiotemporally layered loss calculation model to improve assessment accuracy and scheduling decision reliability. It breaks through the traditional contradiction between water intake efficiency and ecological protection, achieving multi-objective synergistic optimization and balancing efficiency and ecological protection.

[0136] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A water intake ecological scheduling method based on early fish resource protection, characterized in that, Includes the following steps: (1) Monitor early fish resources and obtain data on the distribution of early fish biomass at the water intake section and in the upstream and downstream water layers; (2) The early loss of fish resources was obtained by using the loss analysis of multidimensional spatiotemporal parameter coupling; the water intake design was optimized to minimize the early loss of fish resources. The formula for calculating early-stage fish resource losses is as follows: ； In the formula: W total : Total loss of all fish early resources throughout the year, unit: tail; i : composition of early resource species, i = 1, 2,... n , a total of n species; m : month, m = 1, 2,..., 12; z : water layer number, total k layer; D imz Biomass density, the first i Early resources of fish species in the first m month z Aquatic biomass, unit: tails / m³ 3 ; Q m Total water withdrawal in month m, unit: m 3 ; γ z : z The water layer selection coefficient is determined based on the optimized location of the water intake head, and its value ranges from 0 to 1; middle and upper layers γ z The value is 0.7~0.9, in the middle and lower layers. γ z The value is 0.3~0.5, at the bottom layer. γ z The value is 0.1~0.3; K im : i Early resources of fish species in the first m The occurrence rate in a given month; that is, the occurrence rate of this species in the first month. m Number of days in a month / number of days m Total number of days in a month K im When the value is greater than 0.5, the peak spawning period for fish occurs; α z Flow rate amplification factor, i.e. z Water layer flow velocity influence coefficient, z The coefficient of water layer velocity on the early fish resource entrainment effect; the velocity distribution of each water layer was pre-calibrated based on computational fluid dynamics simulation, and the vertical velocity was monitored in real time by an acoustic Doppler velocity profiler for dynamic correction. α z value; Tm : No. m Monthly operating days correction factor, i.e., the number of days the water intake pump station operates on the [number]th month. m Actual number of days in operation per month / number of days in operation m Total number of days in a month; β : coefficient of shape correction of water intake head, value range 0.5~1.5; The optimized water intake design is adjusted based on real-time monitoring and distribution of early fish biomass and flow velocity. β The system is equipped with a replaceable water intake head module and a hydraulic drive device for rapid switching, with switching time controlled within 2 hours, achieved by actively reducing the water intake head. β The goal is to minimize early-stage fish resource losses; (3) Establish an ecological-hydraulic coupling multi-objective optimization decision-making model, calculate the early loss of fish resources in real time, and screen scheduling schemes that take into account both ecological protection and engineering efficiency. The multi-objective optimization decision-making model of ecological-hydraulic coupling is as follows: ； Where, min W total This represents the minimum early-stage loss of fish resources. st Q 取水 ≥0.95 Q 设计 η≥85% Q 河道 ≥0.3 Q 多年平均 To ensure safe operation of the project, under the premise that the water intake guarantee rate is ≥95%, the pumping station efficiency is ≥85%, and the ecological flow of the downstream river channel of the water intake section is not less than 30% of the multi-year average flow of the section, an ecological water intake scheduling method based on early fish resource protection should be established.

2. The fish early life history resources protection based water intake ecological scheduling method according to claim 1, characterized in that: The flow velocity amplification factor quantifies the flow velocity difference as a direct impact on fish losses; α z When the value is greater than 1, it indicates that the flow velocity in that water layer is relatively high, the entrapment effect is amplified, and fish eggs and larvae are more easily entrapped. α z When the value is less than 1, it indicates that the flow velocity of the water layer is low and the entrainment effect is weakened.

3. The fish early life history resources protection based water intake ecological scheduling method according to claim 1, characterized in that, The value of the velocity amplification factor is obtained through computational fluid dynamics simulation calibration, as follows: S1. Establish a three-dimensional fluid model of the water intake pumping station head: Import the water intake head and pump house structure into computational fluid dynamics analysis software to simulate the velocity distribution; divide the mesh. S2. Set fluid boundary conditions: Set the inflow velocity based on actual hydrological data; Select the k-ε or k-ω model to simulate water flow turbulence and establish a turbulence model; S3. Simulate vertical velocity field: Run calculations to obtain the velocity distribution of different water layers; S4, Calibration α z Nonlinear relationship with flow velocity; dynamic control, real-time monitoring of actual flow velocity, and dynamic correction. α z Automatic adjustment z Water layer selection factor.

4. The water intake ecological scheduling method based on early fish resource protection according to claim 3, characterized in that, In the S4, calibration α z The experimental data fitting formula of the nonlinear relationship with flow rate includes: ； wherein, v 基准 is the reference flow rate, v z is z water layer flow rate.

5. The water intake ecological scheduling method based on early fish resource protection according to claim 1, characterized in that: The water intake head shape correction coefficient is an engineering correction coefficient of the influence degree of the water intake head structure design on the entrainment effect, and quantifies the engineering structure optimization as direct regulation of ecological loss; wherein, β When <1, it represents that the water intake head shape is an optimized structure; β When >1, it represents a poor structure.

6. The fish early life history resources protection based water intake ecological scheduling method according to claim 1, characterized in that, The β The relationship between value adjustment and water intake head module adjustment includes the following aspects: (I) During non-fish spawning seasons and when fish biomass is low in the early stages, the water intake should be switched to a right-angle intake, with water entering at a 90° angle. In areas of strong turbulence, water should be taken from the middle to upper layers. γ z =0.7~0.9, β The value adjustment range is 1.3~1.5, which makes the high-speed water flow beneficial to water intake operation; (II) During the early development stage of fish resources, the water intake head is switched to a funnel-shaped diffuser with a gradually expanding cross section, resulting in uniform flow velocity and dynamic stratification. γ z =0.5~0.7, β The value adjustment range is 0.9~1.1, which stabilizes the water flow, reduces disturbance to early resources, and takes into account water intake operations; (III) During the off-peak period of fish spawning, the water intake head is switched to a grid-guided type, with a porous grid to divert the flow, suppress eddies, and select the middle and lower layers of water for intake. γ z =0.3~0.5, β The value adjustment range is 0.7~0.9, low speed protects fish eggs; (IV) During the peak spawning season for fish and when the early biomass of fish resources is relatively high, the water intake head is switched to a biomimetic streamlined shape for laminar flow control, restricting bottom water intake. γ z =0.1~0.3, β The value is adjusted within the range of 0.5 to 0.7 to minimize the impact of water flow turbulence.

7. The fish early life history resources protection based water intake ecological scheduling method according to claim 1, characterized in that, The design parameters of the optimized water intake head design include the water inlet curvature radius, the grid porosity, and the guide plate angle. β The relationships between each parameter and the value are as follows: 1) Inlet curvature radius: the greater the curvature, the lower the value β value. 2) Grid porosity: porosity 30%~50%, β the value is the lowest; 3) Deflector angle: 15°~30° tilt angle, reducing... β Value: 20%~40%.

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