A method for determining a target water level of a lake-wetland in summer based on runoff prediction and multi-constraint coordination

Abstract

This invention discloses a method for determining summer target water levels in lake-wetland systems based on runoff prediction and multi-constraint coordination, relating to the fields of water resource management and eco-hydrological regulation. The invention includes acquiring data from the watershed containing the lake-wetland to construct a hydrological model, conducting watershed hydrological process simulations, and using machine learning methods to correct errors in the simulation results. With the goal of ensuring the safety and maintaining the ecological functions of the lake-wetland system, a multi-constraint system is constructed, including ecological constraints, water environment quality constraints, and engineering constraints, to determine the minimum allowable water levels for summer and winter. Based on the lake-wetland system water volume evolution model and combined with predicted runoff results, iterative calculations are used to determine the summer target water level that meets the requirements of multiple constraints and winter ecological water level protection. This invention enables proactive regulation of lake-wetland water levels, providing a basis for the efficient utilization of water resources and the enhancement of ecological functions in lake-wetland systems in arid and semi-arid regions.

Description

Technical Field

[0001] This invention relates to the field of water resources management and eco-hydrological regulation technology, and in particular to a method for determining the target water level of lakes and wetlands in summer based on runoff prediction and multi-constraint synergy. Background Technology

[0002] Lake-wetland systems are crucial units for surface water resource regulation and ecological control in arid and semi-arid regions. Their water level changes directly impact regional water resource utilization efficiency, water environment quality, and ecosystem security. Lakes and surrounding wetlands exhibit significant coupling relationships in water exchange, water level fluctuations, and ecological processes. The way lake water levels are regulated directly affects the habitat structure and ecological functions of wetlands. Under conditions of high summer temperatures and strong radiation, excessively high lake-wetland water levels and large water areas significantly increase evaporation losses, leading to ineffective water resource consumption and weakening the ecological replenishment capacity during non-irrigation periods. Therefore, rationally controlling summer lake-wetland water levels and reducing water area to minimize evaporation losses are important technical means to improve water resource utilization efficiency in arid regions.

[0003] Existing lake water level management focuses primarily on ensuring flood control safety or water supply needs. It typically employs fixed water level control or experience-based scheduling models based on historical runoff statistics. This lack of forward-looking judgment on future water inflow processes makes it difficult to address the challenges of increased runoff uncertainty under the background of climate change. Consequently, the determination of target water levels is delayed, and it is impossible to comprehensively consider evaporation loss control, water resource utilization efficiency improvement, and ecological needs protection during the decision-making stage.

[0004] Meanwhile, changes in lake-wetland water levels affect the distribution of aquatic vegetation, wetland habitat patterns, and water exchange processes, thereby altering the system's water capacity, hydraulic retention time, and pollutant concentration levels. Existing technologies often employ single water level thresholds or single-index constraints, where ecological constraints, water quality constraints, and engineering operational constraints are frequently considered separately. This lack of a unified, multi-constraint, collaborative water level decision-making framework makes it difficult to formulate control schemes that balance water resource utilization efficiency, ecological security, and the need for winter ecological water level return in multi-objective conflict scenarios. Therefore, providing a lake ecological target water level determination method based on runoff prediction and multi-constraint collaboration to overcome the difficulties of existing technologies is a problem urgently needing to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a method for determining the target water level of lakes and wetlands in summer based on runoff prediction and multi-constraint synergy, which can realize the forward regulation of lake and wetland water levels and provide a basis for the efficient utilization of water resources and the improvement of ecological functions of lake and wetland systems in arid and semi-arid regions.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for determining target water levels in lakes and wetlands during summer based on runoff prediction and multi-constraint synergy includes the following steps: Acquire data on the watershed where the lake-wetland is located, including meteorological and hydrological data, and underlying surface characteristic data; Hydrological models are built based on acquired data to simulate watershed hydrological processes. Machine learning methods are then used to correct the simulation results for errors, thereby improving the simulation effect of peak and low water levels. With the goal of ensuring the safety and maintaining the ecological function of the lake-wetland system, a multi-constraint system including ecological constraints, water quality constraints, and engineering constraints is constructed, and the minimum allowable water level in summer and winter is determined accordingly. Based on this, using a lake-wetland system water evolution model and combined with predicted runoff results, the target summer water level that meets multiple constraints and winter ecological water level protection requirements is determined through iterative calculation.

[0007] Optionally, the ecological constraint is that the effective habitat index of various key ecological habitats is higher than a predetermined minimum effective habitat index threshold. When satisfied At that time, the minimum allowable water level under ecological constraints was determined. ,in, For the first Similar ecological habitats at water level Effective habitat index under certain conditions.

[0008] Optional, The expression is: , In the formula, This represents the area of ​​the i-th habitat patch in the k-th type of ecological habitat that still meets the basic ecological function requirements under the water level H condition; This represents the ecological suitability coefficient of the corresponding habitat patch; This represents the spatial connectivity coefficient of the corresponding habitat patch.

[0009] Optional water quality constraints include: The water quality concentration met the pollutant concentration requirements throughout the simulation period. Water environment quality safety threshold The time proportion of each key water quality indicator is such that the time proportion of each key water quality indicator throughout the entire simulation period is not lower than a preset probability threshold. At that time, it is determined that the water quality constraints are met, and the minimum allowable water level under the water quality constraints is determined accordingly. .

[0010] Optionally, the expression for pollutant concentration is: , in, Let t be the water volume of the lake-wetland system corresponding to time period t. Let be the mass of the j-th pollutant in the lake-wetland system during time period t.

[0011] Optionally, determining the target water levels for the basin in summer and winter includes: Determining the winter ecological security baseline water level based on a multi-constraint system and the bottom line water level for summer ecological security The summer ecological security baseline water level will be used as the initial value for the target water level. Predicted runoff is obtained based on hydrological models, and daily inflow into the lake is determined by combining human water use index data. The lake-wetland water level process line is obtained by back-calculating the daily inflow of water into the lake based on the correspondence between lake-wetland water level and water body capacity. Determine the winter assessment period and detect the proportion of time during which the water level in the lake-wetland water level process line is not lower than the winter ecological safety baseline water level. When the statistical proportion is not lower than the preset threshold, the corresponding summer target water level scheme is deemed to meet the winter ecological return constraint; otherwise, the summer target water level is gradually increased according to the preset step size until the winter ecological return constraint is met, and the summer minimum water level is determined.

[0012] As can be seen from the above technical solution, compared with the prior art, the present invention provides a method for determining the target water level of lake ecology based on runoff prediction and multi-constraint synergy, which has the following beneficial effects: 1) Based on the future runoff prediction results, the present invention constructs the correspondence between lake-wetland water level, water surface area and water body capacity, and simulates and analyzes the evolution process of lake-wetland water volume under the premise of comprehensively considering constraints such as ecological security, water environment quality improvement and engineering operation safety, to determine the summer target water level that meets multiple constraints; 2) By implementing "summer discharge and winter storage", the present invention rationally controls the summer water level of lake-wetland, compresses the water area, reduces the evaporation loss of lake-wetland water surface, and uses the water saved by reducing evaporation for agricultural irrigation, thereby improving water resource utilization efficiency; 3) After agricultural water use stops in autumn and winter, the present invention allows river water to enter the lake, which on the one hand replenishes the lake-wetland and raises the water level, and on the other hand, increases the lake water circulation through "summer discharge and winter storage", improves the water environment and enhances the ecological function of the lake-wetland system. Furthermore, taking into account the need for winter ecological water level return, this approach enables forward-looking regulation of lake-wetland water levels, providing a technical pathway for the efficient utilization of water resources and the enhancement of ecological functions in lake-wetland systems in arid and semi-arid regions. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of a method for determining the target water level of a lake based on runoff prediction and multi-constraint synergy, as disclosed in this invention. Figure 2 This invention discloses a hydrological process line map of the Hotan River Basin based on the SWAT-Glacier-SRD model and combined with LSTM error correction. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Reference Figure 1 As shown, this invention discloses a method for determining the target water level of a lake's ecological ecosystem based on runoff prediction and multi-constraint synergy, comprising the following steps: Acquire data on the watershed where the lake-wetland is located, including meteorological and hydrological data, and underlying surface characteristic data; Hydrological models are built based on acquired data to simulate watershed hydrological processes. Machine learning methods are then used to correct the simulation results for errors, thereby improving the simulation effect of peak and low water levels. With the goal of ensuring the safety and maintaining the ecological function of the lake-wetland system, a multi-constraint system including ecological constraints, water quality constraints, and engineering constraints is constructed, and the minimum allowable water level in summer and winter is determined accordingly. Based on this, using a lake-wetland system water evolution model and combined with predicted runoff results, the target summer water level that meets multiple constraints and winter ecological water level protection requirements is determined through iterative calculation.

[0017] Furthermore, the watershed data includes: meteorological and hydrological data; topographic mapping data and historical depth data of lakes and their associated wetland areas; spatial distribution data of key ecological habitats such as lake aquatic vegetation, fish habitats and wetland habitats; water quality monitoring data and pollutant load characteristic parameters of the lake-wetland system; and constraints on lake engineering operations, including legally controlled water levels, flood control limits and minimum operating water levels at water intakes.

[0018] In one specific embodiment, topographic data is acquired through existing surveying and mapping results, water resources department data, UAV aerial survey data, sonar depth sounding data, and other means. Based on this topographic data, inundation analysis is used to determine the water surface area function corresponding to the lake-wetland under different water level conditions. and library capacity function Establish a reversible relationship between water level and reservoir capacity. .

[0019] Furthermore, spatial distribution data of key lake-wetland ecological habitats were obtained, including aquatic vegetation habitats, fish habitats or breeding habitats, benthic organism habitats, and wetland or shallow water habitats. These ecological habitat data were used to characterize the spatial distribution features of ecological habitats under different water level conditions, and were obtained through remote sensing image interpretation, UAV image analysis, field ecological surveys, and existing ecological survey data.

[0020] Data on human water use indicators related to the lake-wetland system are obtained, including water consumption for agriculture, industry, urban domestic use, and ecological replenishment. The total water consumption of each type is then used as a deduction in the calculation of lake-wetland inflow, where the inflow is the result of subtracting the corresponding human water consumption from the model-predicted runoff.

[0021] Acquire lake-wetland water quality monitoring data and pollutant load characteristic data. The water quality indicators include at least total nitrogen, total phosphorus and chemical oxygen demand, and if necessary, also indicators such as ammonia nitrogen, dissolved oxygen and chlorophyll a. The pollutant load data includes exogenous pollution load and endogenous pollution release parameters. The endogenous pollution release parameters are determined through sediment surveys, experimental tests or empirical parameters of similar lakes.

[0022] Obtaining management and control conditions and engineering operation parameters related to lake water level regulation includes: statutory control water level, flood control limit water level, minimum operating water level at water intake, discharge capacity of hydraulic structures, and structural safety limits.

[0023] Acquire historical and future hydrological and meteorological data of the lake-wetland watershed, as well as relevant data for watershed hydrological modeling.

[0024] Furthermore, obtaining runoff simulation results involves using future meteorological forecast data products and downscaling and bias correction of the meteorological data; based on this, the processed meteorological data is used to drive the hydrological model to obtain future runoff prediction results, and the runoff prediction results are further rolled over by combining measured meteorological and hydrological data.

[0025] In one specific embodiment, runoff simulation of the Hotan River Basin is performed based on the SWAT-Glacier-SRD model. The SWAT-Glacier-SRD model is constructed by introducing a glacier dynamics module and a snow redistribution module on the basis of the SWAT model. It can characterize the glacier ablation and snow redistribution process in the watershed of high-altitude cold mountainous areas. This model has been proven to reliably simulate the runoff process in the watershed of high-altitude cold mountainous areas.

[0026] Based on this, the Long Short-Term Memory (LSTM) neural network technology is used to correct errors in the model's simulated runoff results, thereby improving the accuracy of runoff simulation. Figure 2 The runoff simulation results were presented. During the validation period, the model's Nash efficiency coefficient (NSE) reached 0.84, indicating that the constructed runoff simulation method can accurately reflect the characteristics of watershed runoff changes. Furthermore, the model can reasonably reproduce the watershed runoff hydrograph and has a good ability to characterize peak flow and baseflow changes, providing reliable runoff input conditions for subsequent water level regulation of the lake-wetland system based on runoff prediction results. Subsequently, high-timeliness meteorological forecast data products suitable for short-term prediction were used to obtain meteorological element information for the study area in the future short term (approximately one year), and the meteorological data underwent spatial downscaling. Based on this, the quantile mapping method was used to correct the bias of the downscaled meteorological elements. Then, the downscaled and bias-corrected meteorological data was used to drive the above runoff simulation model to obtain runoff prediction results for future periods. Further, during actual operation, measured meteorological observation data were continuously introduced to continuously correct the simulated runoff results.

[0027] Furthermore, the ecological constraint is that the effective habitat index of various key ecological habitats must be higher than a predetermined minimum effective habitat index threshold. When satisfied At that time, the minimum allowable water level under ecological constraints was determined. ,in, For the first Similar ecological habitats at water level Effective habitat index under certain conditions

[0028] Furthermore, The expression is: , In the formula, This represents the area of ​​the i-th habitat patch in the k-th type of ecological habitat that still meets the basic ecological function requirements under the water level H condition; This represents the ecological suitability coefficient of the corresponding habitat patch; This represents the spatial connectivity coefficient of the corresponding habitat patch.

[0029] In one specific embodiment, key ecological habitats include: aquatic vegetation habitats distributed along the lake shore and in shallow water areas (wetland vegetation zones mainly composed of reeds and sedges), fish habitats and breeding habitats formed by shallow waters and vegetation edges, and benthic invertebrate habitats distributed on the surface of lake bottom sediments that provide a food base for aquatic organisms.

[0030] Under given water level conditions, habitat patches that still meet the basic ecological function requirements of the above-mentioned ecological habitats are identified, and their corresponding effective areas are calculated. At the same time, considering the differences in adaptability of different habitats to water depth conditions, vegetation cover characteristics and water connectivity, corresponding ecological suitability coefficients and spatial connectivity evaluation indicators are assigned to each habitat patch, thereby comprehensively calculating the effective habitat index of aquatic vegetation habitats, fish habitats and benthic organism habitats under the given water level conditions.

[0031] For the ecological operation needs of summer and winter, ecological safety thresholds for the aforementioned key ecological habitats are pre-set under corresponding seasonal conditions. These include the minimum effective coverage of aquatic vegetation, the minimum continuous area of ​​key fish habitat patches, and the minimum area requirement for suitable habitats for benthic organisms. When the effective habitat index of the aforementioned key ecological habitats is not lower than the corresponding seasonal ecological safety threshold under a certain water level, the water level condition is deemed to meet the hard constraints of ecological safety, and the minimum allowable water levels corresponding to the ecological constraints under summer and winter conditions are determined accordingly.

[0032] Furthermore, water quality constraints include: The water quality concentration met the pollutant concentration requirements throughout the simulation period. Water environment quality safety threshold The time proportion of each key water quality indicator is such that the time proportion of each key water quality indicator throughout the entire simulation period is not lower than a preset probability threshold. At that time, it is determined that the water quality constraints are met, and the minimum allowable water level under the water quality constraints is determined accordingly. .

[0033] Furthermore, the expression for pollutant concentration is: , in, Let t be the water volume of the lake-wetland system corresponding to time period t. Let be the mass of the j-th pollutant in the lake-wetland system during time period t.

[0034] In one specific embodiment, water quality constraints focus on the safety of the lake's aquatic environment and the risk of eutrophication, selecting total nitrogen, total phosphorus, and chemical oxygen demand as the main water quality control indicators, while simultaneously considering auxiliary indicators such as ammonia nitrogen and dissolved oxygen as needed. Regarding pollutant data acquisition, exogenous pollution load data mainly comes from water quality monitoring data of inflow river sections within the lake-wetland system, statistical data of watershed pollution sources, and historical water quality survey results. Combined with future runoff forecasts, the input process of pollutants entering the lake-wetland system with the inflow of water is calculated. Endogenous pollution release parameters are determined based on the distribution characteristics of lake sediments, combined with existing sediment survey data, experimental test results, or empirical parameters from similar lakes, taking into account the impact of water level changes on the sediment exposure range and endogenous release intensity. Through the above data processing, the mass change process of major pollutants in the lake-wetland system under different water level conditions is constructed.

[0035] For both summer and winter operating conditions, the concentration change sequences of each water quality indicator were calculated based on the pollutant quality change process during the simulated period. The proportion of time during which the concentrations of each key water quality indicator met the water quality safety threshold was also statistically analyzed for each corresponding season. When the proportion of time during which key water quality indicators such as total nitrogen, total phosphorus, and chemical oxygen demand met the standards in the corresponding season was not lower than a preset probability threshold, the water level condition was deemed to meet the hard constraints for water environmental quality safety. Based on this, the minimum allowable water level corresponding to the water quality constraints under summer and winter conditions was determined respectively.

[0036] Furthermore, the mass change of the j-th pollutant in the lake-wetland system between time period t and t+1 can be expressed as: , in, Let be the mass of the j-th pollutant in the lake-wetland system during time period t; Water level The area of ​​sediment that may be subject to endogenous release under certain conditions; The outflow of water from the lake after regulation Furthermore, engineering constraints include: determining the minimum safe operating water level for the project based on the operating conditions of the engineering facilities. And require: When there is a flood control limit water level At that time, further requirements were made:

[0037] Specifically, engineering constraints are mainly used to ensure the safety, stability and compliance of relevant hydraulic structures and water intake facilities in the lake-wetland system during operation. Their constraint boundaries are not aimed at optimization, but serve as hard restrictions on lake-wetland water level regulation.

[0038] In one specific embodiment, the minimum safe operating water level for the project is determined by comprehensively considering factors such as the minimum operating water level at the water intake, the minimum submerged water depth at the pumping station, the minimum opening and closing water level at the gate, and the structural safety water level of the dam or sluice gate. Specifically, the minimum operating water level at the water intake and the minimum submerged water depth at the pumping station are used to ensure the normal operation of the water intake and pumping facilities under low water level conditions; the minimum opening and closing water level at the gate is used to ensure that the discharge and control facilities have the necessary opening and closing conditions; and the structural safety water level of the dam or sluice gate is used to meet the requirements for the structural stability and safe operation of the hydraulic structures. These engineering parameters are typically determined based on engineering design documents, operation and management procedures, and relevant technical specifications, and serve as inviolable lower limits during lake-wetland water level regulation.

[0039] Meanwhile, to meet flood control safety requirements, based on the basin flood control plan, flood control scheduling scheme, and historical operation and management regulations, the flood control limit water level or flood season limit water level of lakes is determined as the upper limit constraint for lake-wetland water level regulation. When the lake-wetland water level is higher than the flood control limit water level, further raising of the water level is not allowed; when the lake-wetland water level is lower than the minimum safe operating water level of the project, further lowering of the water level is not allowed. During the water level determination process, when the water level simultaneously meets the conditions of not being lower than the minimum safe operating water level of the project and not being higher than the flood control limit water level, the water level condition is considered to meet the hard constraint of project safety, and based on this, the allowable water level range corresponding to the project constraint under summer and winter operating conditions is determined respectively, providing the project safety boundary for the subsequent determination of lake-wetland water level regulation schemes.

[0040] Furthermore, determining the target water levels for the basin in summer and winter includes: Determining the winter ecological security baseline water level based on a multi-constraint system and the bottom line water level for summer ecological security The summer ecological security baseline water level will be used as the initial value for the target water level. in, , ; Predicted runoff is obtained based on hydrological models, and daily inflow into the lake is determined by combining human water use index data. The lake-wetland water level process line is obtained by back-calculating the daily inflow of water into the lake based on the correspondence between lake-wetland water level and water body capacity. Determine the winter assessment period and detect the proportion of time during which the water level in the lake-wetland water level process line is not lower than the winter ecological safety baseline water level. When the statistical proportion is not lower than the preset threshold, the corresponding summer target water level scheme is deemed to meet the winter ecological return constraint; otherwise, the summer target water level is gradually increased according to the preset step size until the winter ecological return constraint is met, and the summer minimum water level is determined.

[0041] The evolution of water storage capacity in the lake-wetland system can be represented as follows: , in, and These represent the water volumes of the lake-wetland system corresponding to time periods t and t+1, respectively. The amount of water entering the lake-wetland system during a given period is obtained by subtracting the predicted runoff from the water consumption indicators for agriculture, industry, and urban life within the watershed. Indicates the volume of water discharged from the lake; This represents the amount of precipitation predicted based on future climate conditions. This represents the evaporation rate predicted and calculated based on future climate conditions. Indicates the lake-wetland system at the water level The corresponding water surface area under these conditions is determined based on the relationship between water level and water surface area in the lake-wetland system. The expression for the lake-wetland water level is: ; Determine the outflow volume of the lake Used for dynamic regulation of water levels in lake-wetland systems during the summer operation phase, described as follows:

[0042] The lake-wetland water levels are compared with the summer target water levels. When the lake-wetland water levels are not higher than the summer target water levels, only the minimum outflow required to meet ecological and engineering operation requirements is maintained to avoid excessive water discharge that could lower water levels and damage ecological security. When the lake-wetland water levels are higher than the summer target water levels, the outflow is gradually increased according to the degree of excess to prevent the water levels from rising continuously and thus avoid increased evaporation losses. During non-summer operation periods, the lake outflow is no longer controlled by the summer target water levels, but is regulated based on ecological baseflow requirements and routine engineering operation rules. The rationality of the lake-wetland summer water level regulation plan is verified by determining whether the lake-wetland water levels are not lower than the ecological safety baseline water level during the winter period.

[0043] During the winter determination period Internally, based on simulation results, the statistical lake-wetland water levels meet the requirements. The time ratio, when the ratio is not lower than the preset threshold At that time, it was determined that the corresponding summer target water level scheme met the winter ecological regression constraints.

[0044] When the winter ecological regression constraint is not met, proceed according to the preset step size. Gradually raise the target water level for summer:

[0045] Repeat the above water evolution simulation and winter regression determination process until the minimum summer target water level that meets the winter ecological regression constraint is obtained.

[0046] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining target water levels in lakes and wetlands during summer based on runoff prediction and multi-constraint synergy, characterized in that, Includes the following steps: Acquire data on the watershed where the lake-wetland is located, including meteorological and hydrological data and underlying surface characteristic data; Hydrological models are built based on acquired data to simulate watershed hydrological processes. Machine learning methods are then used to correct the simulation results for errors, thereby improving the simulation effect of peak and low water levels. With the goal of ensuring the safety and maintaining the ecological function of the lake-wetland system, a multi-constraint system including ecological constraints, water quality constraints, and engineering constraints is constructed, and the minimum allowable water level in summer and winter is determined accordingly. Based on this, using a lake-wetland system water evolution model and combined with predicted runoff results, the target summer water level that meets multiple constraints and winter ecological water level protection requirements is determined through iterative calculation.

2. The method for determining the summer target water level of lakes and wetlands based on runoff prediction and multi-constraint synergy, as described in claim 1, is characterized in that... The ecological constraint is that the effective habitat index of various key ecological habitats is higher than the predetermined minimum effective habitat index threshold. When satisfied At that time, the minimum allowable water level under ecological constraints was determined. ,in, For the first Similar ecological habitats at water level Effective habitat index under certain conditions.

3. The method for determining the summer target water level of lakes and wetlands based on runoff prediction and multi-constraint synergy, as described in claim 2, is characterized in that... The expression is: ， In the formula, This represents the area of ​​the i-th habitat patch in the k-th type of ecological habitat that still meets the basic ecological function requirements under the water level H condition; This represents the ecological suitability coefficient of the corresponding habitat patch; This represents the spatial connectivity coefficient of the corresponding habitat patch.

4. The method for determining the target water level of lakes and wetlands in summer based on runoff prediction and multi-constraint synergy, as described in claim 1, is characterized in that... Water quality constraints include: The water quality concentration met the pollutant concentration requirements throughout the entire simulation period. Water environment quality safety threshold The time proportion of each key water quality indicator is such that the time proportion of each key water quality indicator throughout the entire simulation period is not lower than a preset probability threshold. At that time, it is determined that the water quality constraints are met, and the minimum allowable water level under the water quality constraints is determined accordingly. .

5. The method for determining the target water level of lakes and wetlands in summer based on runoff prediction and multi-constraint synergy, as described in claim 4, is characterized in that... The expression for pollutant concentration is: ， in, Let t be the water volume of the lake-wetland system corresponding to time period t. Let be the mass of the j-th pollutant in the lake-wetland system during time period t.

6. The method for determining the summer target water level of lakes and wetlands based on runoff prediction and multi-constraint synergy as described in claim 1, characterized in that, Determining the target water levels for the basin in summer and winter includes: Determining the winter ecological security baseline water level based on a multi-constraint system and the bottom line water level for summer ecological security The summer ecological security baseline water level will be used as the initial value for the target water level. Predicted runoff is obtained based on hydrological models, and daily inflow into the lake is determined by combining human water use index data. The lake-wetland water level process line is obtained by back-calculating the daily inflow of water into the lake based on the correspondence between lake-wetland water level and water body capacity. Determine the winter assessment period and detect the proportion of time during which the water level in the lake-wetland water level process line is not lower than the winter ecological safety baseline water level. When the statistical proportion is not lower than the preset threshold, the corresponding summer target water level scheme is deemed to meet the winter ecological return constraint; otherwise, the summer target water level is gradually increased according to the preset step size until the winter ecological return constraint is met, and the summer minimum water level is determined.

Images