An optimized scheduling method for multi-source ecological water replenishment in segmented seasonal rivers

Abstract

The present invention discloses an optimized scheduling method for segmented multi-source ecological water replenishment of seasonal rivers. The method comprises the following steps: Step 1, divide the seasonal river into river reaches and determine their ecological flow rates and water quality targets for each segment; Step 2, determine the ecological water replenishment requirements for each river reach of the seasonal river; Step 3, identify the potential water supply sources for each river reach of the seasonal river and their water quantity and water quality characteristics; Step 4, construct an ecological water replenishment system and quantitatively evaluate the ecological water replenishment effect; Step 5, determine the optimized scheduling target for the ecological water replenishment of the seasonal river; Step 6: Based on the multi-objective evolutionary algorithm, determine the optimal solution of the decision variables and implement the optimized scheduling of the ecological water replenishment. The method of the present invention can implement the optimized scheduling of the ecological water replenishment according to the ecological water demand of the seasonal river and its temporal and spatial variation characteristics, conduct precise and efficient water replenishment, which is beneficial to promoting energy conservation and driving the improvement of the service function and the virtuous cycle of the seasonal river ecosystem.

Description

Technical Field

[0001] The present invention belongs to the technical field of river management and water resources scheduling, and particularly relates to an optimized scheduling method for segmented multi-source ecological water replenishment of seasonal rivers. Background Technique

[0002] Seasonal rivers are widely distributed in the river network and have important ecological service values. Due to the influence of climate change and strong human activity disturbances, seasonal rivers are facing prominent problems of ecosystem degradation and damage. In recent years, ecological water replenishment, as an important means to ensure river ecological flow and maintain the health of damaged ecosystems, has been widely adopted. For seasonal rivers, scientific and reasonable ecological water replenishment can artificially regulate and supplement a certain amount of ecological water volume in the dry season or specific periods of seasonal rivers, thereby curbing the damage of water shortage to the structure and function of the ecosystem, restoring the self-regulating ability of the ecosystem, and promoting the health and stability of the ecosystem. It has become an important way for the current protection and ecological restoration of seasonal rivers.

[0003] From the current research and practice, the ecological water replenishment measures for seasonal rivers lack systematic design and the optimized scheduling is relatively weak, thus causing a series of problems, which are mainly manifested in the following aspects: First, the existing ecological water replenishment mostly adopts the methods of river pumping and reservoir water diversion. The water sources are single and a large amount of energy is required to extract or transport the water sources, increasing the energy consumption of ecological water replenishment and possibly causing negative impacts on the environment; Second, the basis for determining the ecological water replenishment flow is insufficient. Most of the seasonal rivers are ecologically replenished according to perennial rivers. Since the ecosystems of seasonal rivers have adapted to the natural hydrological cycle changes, excessive ecological water replenishment will disrupt the ecological balance, lead to a decrease in biodiversity, and even cause ecosystem degradation; Third, the existing ecological water replenishment systems are highly subjective. The ecological water replenishment decisions mostly rely on the experience of the person in charge, lacking modern control means that can take into account multiple objective requirements and adaptively adjust according to the characteristics of the new environment. Therefore, how to implement accurate, objective, and efficient ecological water replenishment according to the characteristics of the ecological water demand of seasonal rivers has become an important technical problem that needs to be solved urgently in this field. Summary of the Invention

[0004] The purpose of the present invention is to provide an optimized scheduling method for segmented multi-source ecological water replenishment of seasonal rivers to solve the above technical problems.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] The present invention discloses an optimized scheduling method for segmented multi-source ecological water replenishment of seasonal rivers, which is characterized in that the method includes the following steps:

[0007] Step 1: Divide the seasonal river into reaches and determine its ecological flow and water quality objectives for each reach: Divide the seasonal river into reaches, determine the distribution of the reaches of the seasonal river, and select the control sections of the reaches; according to the divided reaches, determine the ecological flow objectives and water quality objectives for each reach of the seasonal river segment by segment.

[0008] Step 2: Determine the ecological water replenishment requirements for each reach of the seasonal river: According to the characteristics of the seasonal river, establish a distributed water cycle model, based on the monitoring data of the seasonal river, carry out the calibration and verification of the parameters of the distributed water cycle model, calculate the runoff generation and concentration results in combination with rainfall data, predict the water volume of each reach of the seasonal river under the condition of no water replenishment, and determine the ecological water replenishment requirements at different times for each reach of the seasonal river in combination with the ecological flow objective requirements for each reach of the seasonal river.

[0009] Step 3: Identify the potential water supply sources and their water quantity and quality characteristics for each reach of the seasonal river: For the reaches of the seasonal river that need water replenishment, identify the potential water supply sources for each reach, and calculate the maximum possible ecological water replenishment volume of each potential water supply source; and through the monitoring data of each water source, extract the change process of water quality indicators of different water sources, and identify the concentration of water quality indicators of each water source.

[0010] Step 4: Construct an ecological water replenishment system and conduct a quantitative evaluation of the ecological water replenishment effect: According to the characteristics of each water source and each reach of the seasonal river, construct an ecological water replenishment system, including a transmission system, an energy system, and a scheduling system; conduct an integrated quantitative evaluation of the "quantity-quality-energy" effect of the ecological water replenishment system for the seasonal river, including the water volume evaluation of the control section, the water quality evaluation of the control section, and the energy consumption evaluation of the ecological water replenishment system.

[0011] Step 5: Determine the optimization scheduling objectives for the ecological water replenishment of the seasonal river: First, clarify that the decision variables are the opening degrees of the control water conservancy projects including gates, pumping stations, and valves from the water source to the reach, and then calculate the ecological water replenishment volume from the water source to the reach; then determine the objective function for the optimization scheduling of the ecological water replenishment of the seasonal river; finally, determine the constraint conditions.

[0012] Step 6: Determine the optimal solution of the decision variables based on the multi-objective evolutionary algorithm and implement the optimization scheduling of the ecological water replenishment: Use the non-dominated sorting genetic algorithm to obtain the Pareto optimal solution set of the decision variables, that is, the opening degrees of the control water conservancy projects, and the corresponding set of objective function values through simulating the natural selection and genetic processes, forming the Pareto optimal front; according to the importance of the ecological systems of different reaches of the seasonal river and the factors of water resources management requirements, combined with the distribution and characteristics of the Pareto optimal fronts of different objectives, give the Pareto optimal solution, that is, the optimal opening degrees of the control water conservancy projects; according to the optimal opening degrees, implement the optimization scheduling of the ecological water replenishment.

[0013] Furthermore, the specific process of segmenting the seasonal river in Step 1 is as follows: Based on the characteristics of the seasonal river basin, comprehensively considering the runoff and ecosystem characteristics of its main and tributary rivers, and combining the basic data of meteorological hydrology, topography and geomorphology, soil vegetation, water resources, water ecosystem and water environment, the seasonal river is segmented; The specific process of selecting the control section of the selected river section is as follows: Consider the water conservancy and hydropower project section, the section requirements of relevant plans and implementation plans, and the hydrological station factors to select the control section.

[0014] Furthermore, the specific process of segmentally determining the ecological flow target of the seasonal river in Step 1 is as follows: First, establish the hydrological-ecological response relationship of the seasonal river. Based on the ecological system survey, analyze the response relationship between key aquatic species, riparian vegetation and hydrology, and adopt the water balance method, water exchange cycle method, habitat method, minimum water level method and comprehensive function method. Considering the functional requirements in terms of river morphology, biodiversity, habitat needs, and ecological service functions, calculate the ecological flow target to maintain the basic ecological functions of the seasonal river. For rivers where the local water management department has clearly defined the ecological flow target requirements, compare and analyze with the ecological flow target calculated by the former, and take the maximum value of the two, as shown in the following formula:

[0015] Ds i,t =max(D1 i,t ,D2 i,t ) (1)

[0016] In the formula, Ds i,t is the ecological flow target requirement for the i-th river section at the t-th time, m 3 ; D1 i,t is the ecological flow target determined by using hydrology, hydrodynamics and comprehensive analysis methods when there is no control target requirement for the ecological flow of the i-th river section at the t-th time, m 3 ; D2 i,t is the control target requirement for the ecological flow of the i-th river section at the t-th time by relevant government policies, m 3 ;

[0017] The specific process of segmentally determining the water quality target of the seasonal river is as follows: Comprehensively consider the target requirements of water environment protection, including the drinking water source protection area, drinking water intake, natural reserves, scenic spots, important wetlands, habitats of key protected and rare aquatic organisms, natural spawning grounds, feeding grounds, wintering grounds and migration channels of important aquatic organisms, fishery waters of natural fishing grounds and water quality concentration requirements of aquatic germplasm resource protection areas. According to the requirements of water quality management of rivers and lakes in China, the water quality indicators include chemical oxygen demand COD, permanganate index COD Mn, Total phosphorus TP, for lake and reservoir types, the total nitrogen TN index is added. For seasonal rivers, the water quality index concentrations at different river sections are taken as the minimum values of various control requirements, as shown in the following formula:

[0018] Dc i,t = min(Dc1 i,t , Dc2 i,t ,... Dcn o,t ) (2)

[0019] In the formula, Dc o,t is the water quality index concentration requirement at the i-th river section at time t, mg / l; Dc1 i,t , Dc2 i,t and Dcn i,t are the various control requirement limits of the water quality concentration index at the i-th river section at time t, specifically including wetland protection, functional area control, and other policy requirements.

[0020] Furthermore, the formula for predicting the water volume of each river section of the seasonal river without water replenishment in step 2 is:

[0021] S′ i,t = S i,t-1 + P i,t × Ae i × Kc i × 10 -3 + Se i,t - Ee i,t (3)

[0022] In the formula, S′ i,t is the channel water volume of the i-th river section of the seasonal river at time t without water replenishment, m 3 ; S i,t-1 is the channel water volume of the i-th river section of the seasonal river at time t - 1, m 3 ; P i,t is the rainfall of the i-th river section of the seasonal river at time t, mm; Ae i is the catchment area of the i-th river section of the seasonal river, m 2 ; Kc i is the runoff coefficient of the catchment area of the i-th river section of the seasonal river, dimensionless; Se i,t is the other inflow volume of the i-th river section of the seasonal river at time t, including the inflow of transit water, the inflow of inter-basin water transfer, the return water or drainage of human production and life, m 3 ; Ee i,t is the water volume loss term of the i-th river section of the seasonal river at time t, including evapotranspiration, groundwater recharge, the outflow of transit water or the transfer out of inter-basin water, the water intake of human production and life, and other channel outflow losses, m 3 ;

[0023] The formula for determining the ecological water replenishment requirements of each section of the seasonal river at different times is as follows:

[0024]

[0025] In the formula, K i,t is the ecological water replenishment requirement of the i-th section at the t-th time, and its value equal to 1 means water replenishment is needed, while the value equal to 0 means no water replenishment is needed.

[0026] Furthermore, the potential recharge water sources described in step 3 include reservoir water, river water, groundwater, reclaimed water, desalinated seawater, externally diverted water, and other water sources;

[0027] The formula for calculating the maximum possible ecological water replenishment volume of each potential recharge water source is as follows:

[0028]

[0029] In the formula, Y i,j,t is the maximum possible ecological water replenishment volume of the j-th water source for the i-th section at the t-th time, in m 3 ; Y i,t is the maximum possible ecological water replenishment volume of all water sources for the i-th section at the t-th time, in m 3 ; J is the number of potential recharge water sources for ecological water replenishment of the seasonal river, in number, and j = 1, 2, …… J.

[0030] Furthermore, the transmission system described in step 4 is responsible for transporting ecological water from the water source to the sections of the seasonal river that need water replenishment. Considering technical feasibility and economic rationality, according to the geographical locations of each water source and each section of the seasonal river and the topographical and geomorphic features along the line, the transmission path is selected considering the terrain conditions, construction difficulty, and construction and operation cost conditions, and the forms of river channels, canals, and pipelines are adopted;

[0031] The energy system is introduced according to the geomorphic and topographic features of the potential recharge water source and the seasonal river. Based on electric energy, the use of renewable energy is combined;

[0032] The dispatching system includes pumping stations, gates, and valves, and is used to control and dynamically dispatch the water replenishment volume of the ecological water replenishment system.

[0033] Furthermore, the evaluation of the water volume at the control section in step 4 is specifically as follows: After ecological water replenishment through each water source, the water volume at the control section of each section of the seasonal river is increased by relevant water replenishment calculations based on formula (3), and the formula is as follows:

[0034]

[0035] In the formula, S i,tThe water volume of the $i$-th river section at the $t$-th time after implementing ecological water replenishment, $m$ 3 ; B i,j,t The ecological water replenishment volume from the $j$-th water source to the $i$-th river section at the $t$-th time, $m$ 3 ; T i,j,t The transmission loss during the water replenishment process from the $j$-th water source to the $i$-th river section at the $t$-th time, $m$ 3 ;

[0036] For the river channel or canal transmission type, its transmission loss includes two parts: the leakage loss of the sluice dam and the leakage loss of the river channel. The first part is the leakage loss of the sluice dam, which is determined according to the exploration and design results of the sluice dam. The leakage loss rate of the sluice dam is taken as a certain proportion of the water storage volume, and the said proportion is 1% - 3%. The second part is the leakage loss of the river channel, and the empirical formula is used to calculate the river channel leakage volume. The specific calculation formula is:

[0037]

[0038] T1 p,t = Vs p,t × X p (8)

[0039]

[0040] In the formula, T1 p,t is the leakage loss of the $p$-th sluice dam in the river channel at the $t$-th time, $m$ 3 ; T2 x,t is the leakage loss of the $x$-th water conveyance river section in the river channel at the $t$-th time, $m$ 3 ; Vs p,t is the water storage volume of the $p$-th sluice dam at the $t$-th time, $m$ 3 ; X p is the leakage coefficient of the $p$-th sluice dam, which is determined according to the exploration and design parameters of the sluice dam, dimensionless; Vd x,t is the flow velocity of the $x$-th water conveyance river section at the $t$-th time, $m / s$; S x,t is the original water volume of the $x$-th water conveyance river section at the $t$-th time, $m$ 3 ; C x is the leakage parameter of the $x$-th water conveyance river section. This parameter is mainly affected by the soil type. The values for sandy loam, clay and clay loam are 0.34 - 0.66, for volcanic ash soil are 0.68 - 0.98, for sandy soil and volcanic ash soil are 1.20, for sandy soil containing rocks are 1.68, and for sandy and gravelly soil are 2.20; P is the number of sluice dams from the $j$-th water source to the $i$-th river section, unit; X is the number of river sections between the $j$-th water source and the $i$-th river section, unit;

[0041] For the pipeline transmission type, its water volume transmission loss considers the pipeline leakage water volume, and the calculation formula is:

[0042]

[0043] In the formula, C1 k is the influence coefficient of the covering soil of the k-th water replenishment pipeline on the leakage outflow, which is determined according to the pipe diameter. For DN15 - DN50, it takes the value of 0.96; for DN75 - DN300, it takes the value of 0.95; for those larger than DN300, it takes the value of 0.94, dimensionless; C2 is the flow coefficient, taking the value of 0.6, dimensionless; g is the acceleration due to gravity, m / s 2 ; H k is the average control pressure of the k-th water replenishment pipeline, m; D k is the leakage hole area of the k-th water replenishment pipeline, m 2 ; Le k is the leakage time of the k-th water replenishment pipeline, s;

[0044] The specific evaluation of the water quality at the control section is as follows: After each water source conducts ecological water replenishment on the seasonal river section from different distances, the concentration of the water quality index at the control section is obtained through the method of quantitative simulation by the water quality model. If the water replenishment points of multiple water replenishment sources are in the same position, the concentration of the water quality index at the water replenishment point is approximated as a constant near the water replenishment point. The calculation formula is as follows:

[0045]

[0046] In the formula, C i,t and C i-1,t are respectively the concentrations of the water quality indexes at the control sections of the i-th river section and the (i - 1)-th river section at the t-th time, mg / l; C i,j,t is the concentration of the water quality index of the j-th water source in the i-th river section at the t-th time, mg / l; k0 is the comprehensive degradation rate coefficient of pollutants, 1 / s; L is the length of the water replenishment point from the control section, m; u t is the river flow velocity at the control section at the t-th time, m / s;

[0047] The specific evaluation of the energy consumption of the ecological water replenishment system is as follows: If the ecological water replenishment system uses a pumping station for water lifting, its energy consumption calculation formula is as follows:

[0048] De i,j,t = ρ × g × H i,j × B i,j,t × η (12)

[0049] In the formula, De i,j,t is the energy consumption of the pumping station from the j-th water source to the i-th river section at the t-th time, kWh; ρ is the density of water, kg / m 3 ; H i,j is the lifting height from the j-th water source to the i-th river section, m; η is the efficiency of the lifting pumping station, dimensionless.

[0050] Furthermore, the specific calculation of the ecological water replenishment volume from the water source to the river reach in step 5 is as follows: Calculate the ecological water replenishment volume B from the j-th water source to the i-th river reach at the t-th time i,j,t , as shown in the following formula:

[0051]

[0052] In the formula, Y i,j is the number of controlled water conservancy projects between the j-th water source and the i-th river reach, in units; V y,t is the opening degree of the y-th controlled water conservancy project at the t-th time, between 0 and 1, dimensionless; U y,t is the maximum water replenishment volume of the y-th controlled water conservancy project at the t-th time, m 3 .

[0053] Furthermore, the objective function for determining the optimal scheduling of ecological water replenishment for seasonal rivers in step 5 includes three aspects: the maximum satisfaction of ecological flow, the best water quality improvement effect, and the minimum energy consumption. The specific objective function is:

[0054] F t = min(F1 t , F2 t , F3 t ) (14)

[0055] In the formula, F t is the objective function for the optimal scheduling of ecological water replenishment for seasonal rivers at the t-th time; F1 t is the non-satisfaction rate of ecological flow at the control section of seasonal rivers at the t-th time, %; F2 t is the non-satisfaction rate of water quality indicators at the control section of seasonal rivers at the t-th time, %; F3 t is the energy consumption of ecological water replenishment for seasonal rivers at the t-th time, kWh;

[0056] F1 t , F2 t , F3 t The calculation formulas of are as follows:

[0057]

[0058] In the formula, De i,j,t is the energy amount required for ecological water replenishment from the j-th water source to the i-th river reach at the t-th time, kWh;

[0059] The determination of the constraint conditions is specifically as follows: The ecological water replenishment volume of each water source satisfies the maximum water replenishment volume constraint of each water source, that is, the sum of the ecological water replenishment volumes from all the j-th water sources is less than or equal to the maximum possible ecological water replenishment volume of the j-th water source:

[0060]

[0061] In the formula, B i,j,t is the ecological water replenishment volume from the j-th water source to the i-th river section at the t-th time, m 3 ; Y i,t is the maximum possible ecological water replenishment volume of all water sources in the i-th river section at the t-th time, m 3 .

[0062] The beneficial effects of the present invention are as follows: The method for optimizing the scheduling of segmented multi-source ecological water replenishment for seasonal rivers according to the present invention can implement the optimized scheduling of ecological water replenishment and carry out accurate and efficient water replenishment according to the ecological water demand and spatio-temporal variation characteristics of seasonal rivers; the method can realize the automatic control and adaptive adjustment of ecological water replenishment for seasonal rivers, and has the characteristics of operability, stability, accuracy and economy, which is beneficial to promoting energy conservation, providing technical support for the differential protection, restoration and management of seasonal rivers, and promoting the improvement of the service function and the virtuous cycle of the seasonal river ecosystem.

[0063] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 is a schematic flow chart of the method according to the present invention;

[0065] Figure 2 is a schematic structural diagram of the ecological water replenishment system;

[0066] Figure 3 is a schematic structural diagram of the river water system and the ecological water replenishment system in Embodiment 1;

[0067] Figure 4 is a schematic diagram of the multi-objective comprehensive trade-off result of the ecological water replenishment of the seasonal river in Embodiment 1;

[0068] Figure 5 is a schematic diagram of the optimized result of the monthly ecological water replenishment of each river section of the seasonal river in Embodiment 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0069] The present invention discloses a method for optimizing the scheduling of segmented multi-source ecological water replenishment for seasonal rivers. As Figure 1 shown, the method includes the following steps:

[0070] Step 1: Divide the seasonal river into river sections and determine its ecological flow and water quality objectives for each section:

[0071] According to the characteristics of seasonal river basins, comprehensively consider the runoff and ecosystem characteristics of their main and tributary rivers, and combine the basic data of meteorological hydrology, topography and geomorphology, soil vegetation, water resources, water ecosystem and water environment to divide the reaches of seasonal rivers, determine the distribution of seasonal river reaches, and select the control sections of the reaches. The selection of control sections should consider factors such as the sections of water conservancy and hydropower projects, the sections required by relevant plans and implementation plans, and hydrological stations.

[0072] According to the divided reaches, determine the ecological flow targets for seasonal rivers section by section. First, establish the hydrological-ecological response relationship of seasonal rivers. On the basis of ecosystem surveys, based on the analysis of the response relationships between key aquatic species, riparian vegetation and hydrology, use methods such as the water balance method, the water replacement cycle method, the habitat method, the minimum water level method and the comprehensive function method, and consider functional requirements in aspects such as river morphology, biodiversity, habitat needs, and ecological service functions to calculate the ecological flow targets for maintaining the basic ecological functions of seasonal rivers. Of course, for rivers where the local water management department has clearly defined the requirements for ecological flow targets, a comparative analysis should be carried out with the ecological flow targets calculated by the former, and the maximum value of the two should be taken, as shown in the following formula:

[0073] Ds i,t =max(D1 i,t ,D2 i,t ) (1)

[0074] In the formula, Ds i,t is the ecological flow target requirement for the i-th reach at the t-th time, m 3 ; D1 i,t is the ecological flow target determined by methods such as hydrology, hydrodynamics, and comprehensive analysis when there is no control target requirement for the ecological flow in the i-th reach at the t-th time, m 3 ; D2 i,t is the control target requirement for the ecological flow in the i-th reach at the t-th time by relevant government policies (such as water resources and water ecological environment planning, water volume allocation plans), m 3 .

[0075] According to the divided reaches, determine the water quality targets for seasonal rivers section by section. Comprehensively consider the target requirements for water environment protection, including the water quality concentration requirements in aspects such as drinking water source protection areas, drinking water intakes, natural protection areas and scenic spots related to water, important wetlands, habitats of key protected and rare aquatic organisms, natural spawning grounds, feeding grounds, wintering grounds and migration channels of important aquatic organisms, fishery waters such as natural fishing grounds, and aquatic germplasm resource protection areas. According to the current requirements for river and lake water quality management in China, the main water quality indicators include chemical oxygen demand (COD) and permanganate index (COD Mn) and total phosphorus (TP). For lakes and reservoirs, the total nitrogen (TN) index should be added. The water quality index concentrations at different reaches of seasonal rivers should take the minimum values of the limits of various control requirements, so as to reduce the water environment risk to the lowest level.

[0076] Dc i,t =min(Dc1 i,t ,Dc2 i,t ,...Dcn i,t ) (2)

[0077] In the formula, Dc i,t is the water quality index (including COD, COD Mn , TP, TN, etc.) concentration requirement for the i-th reach at the t-th time, mg / l; Dc1 i,t , Dc2 i,t and Dcn i,t are the limits of various control requirements for the water quality concentration index of the i-th reach at the t-th time, specifically including wetland protection, functional area control, and other policy requirements, etc.

[0078] Step 2: Determine the ecological water replenishment requirements for each reach of the seasonal river:

[0079] The ecological water replenishment requirements for each reach of the seasonal river are mainly affected by aspects such as the incoming water conditions and the requirements of the ecological water demand guarantee target. Therefore, it is particularly important to identify which reaches need water replenishment and the amount of water to be replenished, which is an important basis for the design of the ecological water replenishment system of the seasonal river.

[0080] According to the characteristics of the seasonal river, establish a distributed water cycle model, such as representative models like WEP and VIC; based on the monitoring data of the seasonal river, carry out the work of calibrating the parameters of the distributed water cycle model and validating the model. Calculate the runoff generation and concentration results in combination with rainfall data, and predict the water volume of each reach of the seasonal river under the condition of no water replenishment at the t-th time. The basic balance principle is shown in the following formula:

[0081] S′ i,t =S i,t-1 +P i,t ×Ae i ×Kc i ×10 -3 +Se i,t -Ee i,t (3)

[0082] In the formula, S′ i,j is the channel water volume of the i-th reach of the seasonal river at the t-th time under the condition of no water replenishment, m 3 ; S i,j-1 is the channel water volume of the i-th reach of the seasonal river at the (t - 1)-th time, m 3 ; P i,tRainfall at the i-th reach of the seasonal river at time t, mm; Ae i Catchment area of the i-th reach of the seasonal river, m 2 ; Kc i Runoff coefficient of the catchment area of the i-th reach of the seasonal river, dimensionless; Se i,j Other inflow at the i-th reach of the seasonal river at time t, such as inflow of transit water, diverted water from other basins, wastewater or drainage from human production and living, etc., m 3 ; Ee i,t Water loss term at the i-th reach of the seasonal river at time t, including evapotranspiration, groundwater recharge, outflow of transit water or diverted water to other basins, water withdrawal for human production and living, and other river channel outflow losses, m 3 .

[0083] Based on the above calculations, combined with the ecological flow target requirements of each reach of the seasonal river, determine the ecological water replenishment requirements of each reach of the seasonal river at different times. The formula is as follows:

[0084]

[0085] In the formula, K i,j Ecological water replenishment requirement at the i-th reach at time t, whose value is equal to 1 indicating water replenishment is needed, and equal to 0 indicating no water replenishment is needed.

[0086] Step 3: Identify the potential water replenishment sources and their water quantity and quality characteristics of each reach of the seasonal river:

[0087] For the reaches of the seasonal river that need water replenishment (i.e., the ecological water replenishment requirement K i,j value is 1), identify the potential water replenishment sources of each reach. Various water sources available for ecological water replenishment of the seasonal river mainly consider the following types: namely, reservoir water, river water, groundwater, reclaimed water, desalinated seawater, diverted water from other regions, and other water sources.

[0088] Calculate the maximum possible ecological water replenishment volume of each potential water replenishment source, as shown in the following formula:

[0089]

[0090] In the formula, Y i,j,t Maximum possible ecological water replenishment volume of the j-th water source for the i-th reach at time t, m 3 ; Y i,t Maximum possible ecological water replenishment volume of all water sources for the i-th reach at time t, m 3 ; J is the number of potential water replenishment sources for ecological water replenishment of the seasonal river, unit, j = 1, 2, …… J.

[0091] Extract the changing processes of water quality indicators for different water sources from the monitoring data of each water source, and identify the concentrations of water quality indicators for each water source.

[0092] Step 4: Construct an ecological water replenishment system and conduct a quantitative assessment of the ecological water replenishment effect:

[0093] According to the characteristics of each water source and each section of the seasonal river, construct an ecological water replenishment system, including a transmission system, an energy system, and a scheduling system, as Figure 2 shown.

[0094] Specifically, the transmission system: undertakes the task of transporting ecological water from water sources (including reservoir water, river water, groundwater, reclaimed water, desalinated seawater, externally diverted water, and other water sources) to the sections of the seasonal river that need water replenishment. Considering technical feasibility and economic rationality, according to the geographical locations of each water source and each section of the seasonal river and the topographical and geomorphic features along the line, consider the terrain conditions, construction difficulty, and construction and operation cost conditions to select the transmission path, and mostly use river channels, canals, and pipelines.

[0095] The energy system: According to the geomorphic and topographic features of potential recharge water sources and the seasonal river, an energy system needs to be introduced into the ecological water replenishment system. On the basis of traditional electric energy, the use of renewable energy such as solar energy and wind energy can be combined to reduce the system's dependence on traditional fossil energy, thereby reducing the long-term operation cost and reducing greenhouse gas emissions.

[0096] The scheduling system: The scheduling system of the seasonal river ecological water replenishment system includes pumping stations, gates, and valves, etc., which are used to control and dynamically schedule the water replenishment volume of the ecological water replenishment system.

[0097] Conduct an integrated quantitative assessment of the "quantity-quality-energy" effect of ecological water replenishment for the seasonal river ecological water replenishment system, including the assessment of the water volume at the control section, the assessment of the water quality at the control section, and the assessment of the energy consumption of the ecological water replenishment system.

[0098] 1) Assessment of the water volume at the control section: After ecological water replenishment through each water source, the water volume at the control section of each section of the seasonal river is further increased by adding relevant water replenishment calculations on the basis of formula (3), and the formula is as follows:

[0099]

[0100] In the formula, S i,t is the water volume of the i-th section at the t-th time after implementing ecological water replenishment, m 3 ; B i,j,t is the ecological water replenishment volume from the j-th water source to the i-th section at the t-th time, m 3 ; T i,j,t is the transmission loss during the water replenishment process from the j-th water source to the i-th section at the t-th time, m 3 .

[0101] For the river channel (or canal) transmission type, its transmission loss (T i,j,t ) mainly includes two parts: the leakage loss of the sluice dam and the leakage loss of the river channel. The first part is the leakage loss of the sluice dam on the river channel, which can be determined according to the exploration and design results of the sluice dam. The leakage loss rate of the sluice dam can also be taken as a certain proportion of the water storage volume, usually between 1% and 3%. The second part is the leakage loss of the river channel. The leakage volume of the river channel can be calculated using an empirical formula. The specific calculation formula is:

[0102]

[0103] T1 p,t = Vs p,t × X p (8)

[0104]

[0105] In the formula, T1 p,t is the leakage loss of the p-th sluice dam in the river channel at the t-th time, m 3 ; T2 x,t is the leakage loss of the x-th water conveyance river section in the river channel at the t-th time, m 3 ; Vs p,t is the water storage volume of the p-th sluice dam at the t-th time, m 3 ; X p is the leakage coefficient of the p-th sluice dam, determined according to the exploration and design parameters of the sluice dam, dimensionless; Vd x,t is the flow velocity of the x-th water conveyance river section at the t-th time, m / s; S x,t is the original water volume of the x-th water conveyance river section at the t-th time, m 3 ; C x is the leakage parameter of the x-th water conveyance river section. This parameter is mainly affected by the soil type. Usually, the values for sandy loam, clay, and silt clay are 0.34 - 0.66, for volcanic ash soil are 0.68 - 0.98, for sandy soil and volcanic ash soil are 1.20, for sandy soil containing rocks are 1.68, and for sandy and gravelly soil are 2.20; P is the number of sluice dams from the j-th water source to the i-th river section, unit; X is the number of river sections between the j-th water source and the i-th river section, unit.

[0106] For the pipeline transmission type, its water transmission loss (T i,j,t ) mainly considers the water leakage of the pipeline. The calculation formula is:

[0107]

[0108] In the formula, C1 kis the coefficient of influence of soil covering on leakage outflow of the kth water supply pipe, which is determined according to the pipe diameter, usually 0.96 for DN15-DN50, 0.95 for DN75-DN300, and 0.94 for values ​​larger than DN300, dimensionless; C2 is the flow coefficient, usually 0.6, dimensionless; g is the acceleration of gravity, m / s 2 ;H k is the average control pressure of the kth water supply pipeline, m; D k is the area of ​​the leakage hole of the kth water supply pipeline, m 2 ;Le k is the leakage time of the kth water supply pipe, s.

[0109] 2) Control section water quality assessment: After each water source provides ecological water replenishment to seasonal river sections from different distances, the water quality index concentration of the control section can be obtained through quantitative simulation of the water quality model. If the water replenishment points of multiple water replenishment sources are at the same location, the water quality index concentration of the water replenishment point is approximated as a constant near the water replenishment point. The simplified calculation formula is as follows:

[0110]

[0111] In the formula, C i,t and C i-1,t are the water quality index concentrations of the control sections of the i-th river section and the i-1-th river section (upstream adjacent section) at time t, mg / l; C i,j,t is the water quality index concentration of the jth water source in the i-th river section at time t, mg / l; k0 is the comprehensive degradation rate coefficient of pollutants, 1 / s; L is the distance between the water replenishment point and the control section, m; u t is the river velocity of the control section at time t, m / s.

[0112] 3) Energy consumption assessment of ecological water replenishment system: If the ecological water replenishment system needs to use a pump station to pump water, the energy consumption calculation formula is as follows:

[0113] De i,j,t =ρ×g×H i,j ×B i,j,t ×η (12)

[0114] In the formula, De i,j,t is the energy consumption of the pumping station from the jth water source to the ith river section at time t, kWh; ρ is the density of water, kg / m 3 ;H i,j is the lifting height from the jth water source to the ith river section, m; η is the efficiency of the lifting pump station, dimensionless.

[0115] Step 5: Determine the optimization scheduling target of seasonal river ecological water replenishment:

[0116] First, clarify the decision variables: The decision variables are the opening degrees of the controlled water conservancy projects (including gates, pumping stations, and valves) from the j-th water source to the i-th river section. Then, calculate the ecological water replenishment volume B from the j-th water source to the i-th river section at the t-th time, as follows: i,j,t , as shown in the following formula:

[0117]

[0118] In the formula, Y i,j is the number of controlled water conservancy projects between the j-th water source and the i-th river section, in units; V y,t is the opening degree of the y-th controlled water conservancy project at the t-th time, ranging from 0 to 1, dimensionless; U y,t is the maximum water replenishment volume of the y-th controlled water conservancy project at the t-th time, in m 3 .

[0119] Then, determine the objective function for the optimal scheduling of ecological water replenishment in seasonal rivers: Based on the construction of the ecological water replenishment system in seasonal rivers and the quantitative evaluation of the ecological water replenishment effect, determine the optimal scheduling strategy for ecological water replenishment in seasonal rivers; starting from maximizing the comprehensive efficiency of ecological water replenishment in seasonal rivers, the objective function for the optimal scheduling of ecological water replenishment in seasonal rivers includes multiple aspects such as the maximum satisfaction of ecological flow, the best water quality improvement effect, and the minimum energy consumption. The specific objective function is as follows:

[0120] F t = min(F1 t , F2 t , F3 t ) (14)

[0121] In the formula, F t is the objective function for the optimal scheduling of ecological water replenishment in seasonal rivers at the t-th time; F1 t is the non-satisfaction rate of ecological flow at the control section of seasonal rivers at the t-th time, in %; F2 t is the non-satisfaction rate of water quality indicators at the control section of seasonal rivers at the t-th time, in %; F3 t is the energy consumption of ecological water replenishment in seasonal rivers at the t-th time, in kWh.

[0122] The calculation formulas for F1 t , F2 t , and F3 t are as follows:

[0123]

[0124] In the formula, De i,j,t is the energy amount required for ecological water replenishment from the j-th water source to the i-th river section at the t-th time, in kWh.

[0125] Finally, determine the constraint conditions: the ecological water replenishment volume of each water source should meet the maximum water replenishment volume constraint of each water source, that is, the sum of the ecological water replenishment volumes from the j-th water source should be less than or equal to the maximum possible ecological water replenishment volume of the j-th water source:

[0126]

[0127] In the formula, B i,j,t is the ecological water replenishment volume from the j-th water source to the i-th river reach at time t, m 3 ; Y i,t is the maximum possible ecological water replenishment volume of all water sources in the i-th river reach at time t, m 3 .

[0128] Step 6: Determine the optimal solution of the decision variables based on the multi-objective evolutionary algorithm and implement the optimal scheduling of ecological water replenishment:

[0129] The Non-dominated Sorting Genetic Algorithm (NSGA) is used to obtain the Pareto optimal solution set of the decision variables (the opening degrees of the controlled water conservancy projects) and the corresponding objective function value set through simulating natural selection and genetic processes, forming the Pareto optimal front. The specific calculation steps include randomly generating the initial population, establishing the fitness function, population selection, crossover, mutation and update, and continuously performing iterative calculations until the maximum number of iterations or other convergence conditions are reached and the operation ends, and then outputting the results.

[0130] According to factors such as the importance of the ecological systems of different reaches of the seasonal river and the requirements of water resources management, combined with the distribution and characteristics of the Pareto optimal fronts of different objectives, a recommended optimal solution (Pareto optimal solution) is given, that is, the optimal opening degrees of the ecological water replenishment controlled water conservancy projects (including gates, pumping stations, valves). Based on the optimal opening degrees of the controlled water conservancy projects, implement the ecological water replenishment scheduling to achieve precise control of the ecological water replenishment from different water sources to different reaches of the seasonal river, and promote the protection and improvement of the seasonal river ecological system.

[0131] Example 1

[0132] This example is an application example of the above method.

[0133] This example applies the above method to the seasonal river in a certain city in northern China. Its river water system and ecological water replenishment system are as Figure 3As shown in the figure. Among them, River Sections 1 to 4 are seasonal river sections. There are two water supply sources, namely the river water in River Section 5 (j = 1) and the high-quality reclaimed water from one reclaimed water plant (j = 2). There are 5 control sections in the system. Among them, through the lift pump station and the water supply pipeline, the river water (j = 1) is transported to the four seasonal river sections, and then flows downstream back to the Nansha River to form a circulating water network. The high-quality reclaimed water (j = 2) can be directly supplemented to River Section 5. This ecological water supply system realizes the ecological water supply to the four seasonal river sections through the linkage of two water sources and multiple controlled water conservancy projects (including 4 valves, 1 sluice gate and 1 pump station). The energy used by the pump station is electric energy. The diameters of the water supply pipelines are DN1200 (Pipeline a, from water source j = 1 to Valve 1), DN800 (Pipeline b, from Valve 1 to Valve 3) and DN600 (Pipeline c, from Valve 3 to Valve 4) respectively.

[0134] Taking the typical year under the 75% incoming water frequency condition of the long series (1956 - 2016) as an example, the ecological water supply calculation is carried out month by month. Using the NSGA algorithm for programming calculation, with the population number of 2000 and the number of generations of 30, taking March as an example, the Pareto front results of the three-objective trade-off with the maximum satisfaction degree of ecological flow, the best water quality improvement effect and the minimum energy consumption are as Figure 4 shown. The five-pointed star mark in the figure is the optimal solution (Pareto optimal solution). The corresponding three objective function values are that the non-satisfaction rate of ecological water volume is 1.80%, the non-satisfaction rate of water quality index is 2.82%, and the energy consumption is 180,900 kWh. Of course, there is still room for further improvement in the objectives of the non-satisfaction rate of ecological water volume and the non-satisfaction rate of water quality index, mainly restricted by the maximum possible water supply volume of the water sources.

[0135] In the optimal solution of this embodiment, the opening degrees of the controlled water conservancy projects (including sluice gates, pump stations, valves) of the seasonal rivers are shown in Table 1. It can be seen that the maximum opening degree of the sluice gate (i.e., equal to 1.0) is mainly distributed from March to May, and the maximum opening degree of the pump station (i.e., equal to 1.0) is also concentrated in March. Under the existing project conditions, the control system for the ecological water supply scheduling of the seasonal rivers in March realizes the maximum opening, mainly restricted by the available water supply volumes of the two water sources. There is still room for further improvement in the effect of the ecological water supply. The two objectives of the non-satisfaction rate of ecological water volume and the non-satisfaction rate of water quality index can still be further reduced through the optimization design and renovation of the subsequent water supply system.

[0136] Table 1 Opening degrees of each sluice and dam of the seasonal rivers in the recommended scheme (dimensionless)

[0137]

[0138]

[0139] After this embodiment is implemented according to the optimal solution, the ecological water replenishment volumes of each river section and the monthly process are as follows Figure 5 shown. It can be seen that the ecological water replenishment of this seasonal river is mainly concentrated in the non-flood season, especially from March to May. Among them, the total ecological water replenishment volume of the four river sections in March reaches 15.457 million m 3 , and the ecological water replenishment volume of River Section 1 is the largest, reaching 4.366 million m 3 . Since fish usually spawn from March to May in spring, especially April to May is the peak spawning period, the ecological water demand is large, while the natural water inflow is insufficient. Ecological water replenishment is conducive to promoting the growth and reproduction of fish and promoting the healthy development of the ecosystem. During the flood season, except in June, due to the large water inflow from July to September, ecological water replenishment can be not carried out, and the ecological system function of the seasonal river is mainly maintained by natural water inflow.

[0140] It should be noted that the ecological water replenishment calculation in this case is carried out under the condition of 75% water inflow frequency of the long series (1956 - 2016). If other drier frequency (or extreme drought) water inflow conditions are selected, the opening degree and water replenishment volume of the ecological water replenishment system can be quantitatively identified by the method described in the present invention, and ecological water replenishment can also be carried out in the flood season months. In the process of realizing multi-objective balance, implementing the optimal scheduling of ecological water replenishment is conducive to promoting energy conservation and promoting the ecological recovery and sustainable development of seasonal rivers.

[0141] Finally, it should be noted that the above is only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred arrangement scheme, those of ordinary skill in the art should understand that the technical solution of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for optimizing the scheduling of multi-source ecological water replenishment for seasonal river segmentation, characterized in that, The method includes the following steps: Step 1: Divide the seasonal river into river reaches and determine the ecological flow and water quality objectives for each reach segment by segment: Divide the seasonal river into river reaches, determine the distribution of the seasonal river reaches, and select the control sections of the reaches; according to the divided river reaches, determine the ecological flow objectives and water quality objectives for the seasonal river segments by segment; Step 2: Determine the ecological water replenishment requirements for each reach of the seasonal river: According to the characteristics of the seasonal river, establish a distributed water cycle model, based on the monitoring data of the seasonal river, carry out the calibration and verification of the distributed water cycle model parameters, calculate the runoff generation and concentration results in combination with rainfall data, predict the water volume of each reach of the seasonal river under the condition of no water replenishment, and determine the ecological water replenishment requirements for different times of each reach of the seasonal river in combination with the ecological flow objective requirements of each reach of the seasonal river; Step 3: Identify the potential recharge water sources and their water quantity and quality characteristics for each reach of the seasonal river: For the reaches of the seasonal river that need water replenishment, identify the potential recharge water sources for each reach, and calculate the maximum possible ecological water replenishment volume of each potential recharge water source; and through the monitoring data of each water source, extract the change process of the water quality indicators of different water sources, and identify the concentration of the water quality indicators of each water source; Step 4: Construct an ecological water replenishment system and conduct a quantitative evaluation of the ecological water replenishment effect: According to the characteristics of each water source and each reach of the seasonal river, construct an ecological water replenishment system, including a transmission system, an energy system, and a scheduling system; conduct an integrated quantitative evaluation of the "quantity-quality-energy" effect of the ecological water replenishment system for the seasonal river, including the water volume evaluation of the control section, the water quality evaluation of the control section, and the energy consumption evaluation of the ecological water replenishment system; Step 5: Determine the optimization scheduling objective of the ecological water replenishment for the seasonal river: First, clarify that the decision variables are the opening degrees of the controlled water conservancy projects including gates, pumping stations, and valves from the water source to the reach, and then calculate the ecological water replenishment volume from the water source to the reach; then determine the objective function of the optimization scheduling of the ecological water replenishment for the seasonal river; finally, determine the constraint conditions; Step 6: Determine the optimal solution of the decision variables based on the multi-objective evolutionary algorithm and implement the optimization scheduling of the ecological water replenishment: Use the non-dominated sorting genetic algorithm to obtain the Pareto optimal solution set of the decision variables, that is, the opening degrees of the controlled water conservancy projects, and the corresponding set of objective function values through simulating the natural selection and genetic processes, forming the Pareto optimal front; according to the importance of the ecological systems of different reaches of the seasonal river and the factors of water resources management requirements, combined with the distribution and characteristics of the Pareto optimal fronts of different objectives, give the Pareto optimal solution, that is, the optimal opening degrees of the controlled water conservancy projects; according to the optimal opening degrees, implement the optimization scheduling of the ecological water replenishment.

2. The optimized scheduling method for multi-source ecological water replenishment in segmented seasonal rivers according to claim 1, characterized in that The specific description of dividing the seasonal river into river reaches in Step 1 is as follows: According to the characteristics of the seasonal river basin, comprehensively consider the runoff and ecological system characteristics of its main and tributary rivers, and combine the basic data of meteorological hydrology, topography and geomorphology, soil vegetation, water resources, water ecosystem, and water environment to divide the seasonal river into river reaches; the specific description of selecting the control sections of the reaches is as follows: Consider the sections of water conservancy and hydropower projects, the sections required by relevant plans and implementation plans, and the factors of hydrological stations to select the control sections.

3. The optimized scheduling method for multi-source ecological water replenishment in segmented seasonal rivers according to claim 2, characterized in that The specific process of segmentally determining the ecological flow target of the seasonal river described in Step 1 is as follows: First, establish the hydrological-ecological response relationship of the seasonal river. Based on the ecological system survey, analyze the response relationships of key aquatic species, riparian vegetation and hydrology, and adopt the water balance method, flushing cycle method, habitat method, minimum water level method and comprehensive function method. Considering the functional requirements in terms of river morphology, biodiversity, habitat needs, and ecological service functions, calculate the ecological flow target for maintaining the basic ecological functions of the seasonal river. For rivers where the local water management department has clearly defined the ecological flow target requirements, compare and analyze with the ecological flow target calculated previously, and take the maximum value of the two. The specific formula is as follows: Ds i,t = max(D1 i,t , D2 i,t ) (1) where Ds i,t is the ecological flow target requirement for the i-th river reach at time t, m 3 ; D1 i,t When there is no control target requirement for the ecological flow at the $i$-th river section at time $t$, it is the ecological flow target determined by using hydrological, hydrodynamic and comprehensive analysis methods, $m$ 3 ; D2 i,t is the control target requirement of the government's relevant policies for the ecological flow of the i-th river section at the t-th time, m 3 ; The specific process for segmentally determining the water quality objectives of seasonal rivers is as follows: comprehensively considering the objective requirements of water environment protection, including drinking water source protection areas, drinking water intakes, natural protection areas and scenic spots related to water, important wetlands, habitats of key protected and rare aquatic organisms, natural spawning grounds, feeding grounds, wintering grounds and migration channels of important aquatic organisms, water quality concentration requirements for fishery waters in natural fishing grounds and aquatic germplasm resource protection areas, and based on the requirements of water quality management of rivers and lakes in China, the water quality indicators include chemical oxygen demand (COD), permanganate index (COD Mn , total phosphorus (TP), and for lake and reservoir types, the total nitrogen (TN) indicator is added. The water quality indicator concentrations of different river segments of seasonal rivers take the minimum values of the limit values of various control requirements, as shown in the following formula: Dc i,t = min(Dc1 i,t , Dc2 i,t ,... Dcn i,t ) (2) where Dc i,t is the water quality index concentration requirement for the i-th river section at time t, mg / l; Dc1 i,t , Dc2 i,t and Dcn i,t are the limit values of various control requirements for the water quality concentration index of the i-th river section at time t, specifically including wetland protection, functional area control, and other policy requirements.

4. The optimized scheduling method for segmented multi-source ecological water replenishment of seasonal rivers according to claim 3, characterized in that The formula for predicting the water volume of each reach of the seasonal river without water replenishment described in Step 2 is: where S′ i,t is the water volume of the i-th section of the seasonal river at time t without water replenishment, m 3 ; S i,t-1 is the water volume of the river channel at the (i)-th reach of the seasonal river at time (t - 1), m 3 ; P i,t is the rainfall at the (i)-th reach of the seasonal river at time t, mm; Ae i is the catchment area of the (i)-th reach of the seasonal river, m 2 ; Kc i is the runoff coefficient of the catchment area of the (i)-th reach of the seasonal river, dimensionless; Se i,t is the other inflow at the (i)-th reach of the seasonal river at time t, including the inflow of passing water, the transferred water from cross-basin water transfer, the return water or drainage of human production and life, m 3 ; Ee i,t is the water loss term at the (i)-th reach of the seasonal river at time t, including evapotranspiration, groundwater recharge, the outflow of passing water or the transferred water to cross-basin, the water withdrawal for human production and life, and other river channel outflow losses, m 3 ; The formula for determining the ecological water replenishment demand of each reach of the seasonal river at different times is: Where K i,t is the ecological water replenishment demand of the i-th river section at time t, and its value equal to 1 indicates the need for water replenishment, while the value equal to 0 indicates no need for water replenishment.

5. The optimized scheduling method for segmented multi-source ecological water replenishment of seasonal rivers according to claim 4, characterized in that, The potential recharge water sources described in Step 3 include reservoir water, river channel water, groundwater, reclaimed water, desalinated seawater, transferred water from other regions, and other water sources; The formula for calculating the maximum possible ecological water replenishment volume of each potential recharge water source is: where Y i,j,t is the maximum possible ecological water replenishment volume from the j-th water source to the i-th river reach at the t-th time, m 3 ; Y i,t is the maximum possible ecological water replenishment volume of all water sources for the i-th river reach at the t-th time, m 3 ; J is the number of potential recharge water sources for ecological water replenishment of seasonal rivers, unit, j = 1, 2, …… J.

6. The optimized scheduling method for segmented multi-source ecological water replenishment of seasonal rivers according to claim 5, characterized in that, The transmission system described in Step 4 is responsible for transporting the ecological water from the water source to the reach of the seasonal river that needs water replenishment. Considering the technical feasibility and economic rationality comprehensively, select the transmission path according to the geographical locations of each water source and each reach of the seasonal river and the topographical and geomorphic features along the line, and adopt the forms of river channels, canals and pipelines; The energy system is introduced according to the geomorphic and topographic features of the potential recharge water source and the seasonal river. Based on electric energy, combine the use of renewable energy; The scheduling system includes pumping stations, gates and valves, and is used to control and dynamically schedule the water replenishment volume of the ecological water replenishment system.

7. The optimized scheduling method for multi-source ecological water replenishment in segmented seasonal rivers according to claim 6, characterized in that The specific assessment of the water volume at the control section described in Step 4 is as follows: After ecological water replenishment through each water source, the water volume at the control section of each reach of the seasonal river is increased by relevant water replenishment calculations based on Formula (3). The formula is as follows: Where S i,t is the water volume of the i-th river reach at the t-th time after implementing ecological water replenishment, m 3 ; B i,j,t Ecological water replenishment volume from the j-th water source to the i-th river section at the t-th time, m 3 ; T i,j,t is the transmission loss during the water supply process from the j-th water source to the i-th river section at the t-th time, m 3 ; For the river channel or canal transmission type, its transmission loss includes two parts: the leakage loss of the sluice dam and the leakage loss of the river channel. The first part is the leakage loss of the sluice dam, which is determined according to the survey and design results of the sluice dam. The leakage loss rate of the sluice dam is taken as a certain proportion of the water storage volume, and the proportion is 1% - 3%. The second part is the leakage loss of the river channel, and the empirical formula is used to calculate the leakage volume of the river channel. The specific calculation formula is: T1 p,t = Vs p,t × X p (8) Where, T1 p,t is the leakage loss of the p-th sluice dam in the river channel at the t-th time, m 3 ; T2 x,t is the leakage loss of the x-th water conveyance section in the river channel at the t-th time, m 3 ; Vs p,t is the water storage volume of the p-th sluice dam at the t-th time, m 3 ; X p is the seepage coefficient of the p-th sluice dam, determined according to the exploration and design parameters of the sluice dam, dimensionless; Vd x,t is the flow velocity of the x-th water conveyance river section at the t-th time, m / s; S x,t is the original water volume of the x-th water conveyance river section at the t-th time, m 3 ; C x is the seepage parameter of the x-th water conveyance river section, which is mainly affected by the soil type. The values for sandy loam, clay and clay loam are 0.34 - 0.66, for volcanic ash soil are 0.68 - 0.98, for sandy soil and volcanic ash soil are 1.20, for sandy soil containing rocks are 1.68, and for sandy and gravelly soil are 2.20; P is the number of sluice dams from the j-th water source to the i-th river section, unit; X is the number of river sections between the j-th water source and the i-th river section, section; For the pipeline transmission type, its water volume transmission loss considers the water leakage of the pipeline, and the calculation formula is: Wherein, C1 k is the influence coefficient of the soil cover of the k-th water supply pipeline on the leakage outflow, which is taken according to the pipe diameter size. The value is 0.96 for DN15 - DN50, 0.95 for DN75 - DN300, and 0.94 for diameters larger than DN300, dimensionless; C2 is the flow coefficient, with a value of 0.6, dimensionless; g is the acceleration due to gravity, m / s 2 ; H k is the average control pressure of the k-th water supply pipeline, m; D k is the leakage hole area of the k-th water supply pipeline, m 2 ; Le k is the leakage time of the k-th water supply pipeline, s; The specific assessment of the water quality at the control section is as follows: After ecological water replenishment of each reach of the seasonal river from different distances by each water source, the concentration of the water quality index at the control section is obtained by the method of quantitative simulation using the water quality model. If the water replenishment points of multiple water replenishment sources are in the same position, the concentration of the water quality index at the water replenishment point is approximated as a constant near the water replenishment point. The calculation formula is as follows: Wherein, C i,t and C i-1,t are respectively the water quality index concentrations at the control sections of the i-th river reach and the (i - 1)-th river reach at the t-th time, mg / l; C i,j,t is the water quality index concentration of the j-th water source in the i-th river reach at the t-th time, mg / l; k0 is the comprehensive pollutant degradation rate coefficient, 1 / s; L is the length from the water replenishment point to the control section, m; u t is the river flow velocity at the control section at the t-th time, m / s; The specific assessment of the energy consumption of the ecological water replenishment system is as follows: If the ecological water replenishment system uses a pumping station for water lifting, its energy consumption calculation formula is as follows: De i,j,t = ρ × g × H i,j × B i,j,t × η (12) where, De i,j,t is the energy consumption of the pumping station from the j-th water source to the i-th river section at the t-th time, kWh; ρ is the density of water, kg / m 3 ; H i,j is the lifting height from the j-th water source to the i-th river section, m; η is the efficiency of the lifting pumping station, dimensionless.

8. The optimized scheduling method for multi-source ecological water replenishment in segmented seasonal rivers according to claim 7, characterized in that The specific calculation of the ecological water replenishment from the water source to the river reach in step 5 is as follows: Calculate the ecological water replenishment B from the j-th water source to the i-th river reach at the t-th time i,j,t , as shown in the following formula: Where Y i,j is the number of controlling water conservancy projects between the j-th water source and the i-th river section, in units of pieces; V y,t is the opening degree of the y-th controlling water conservancy project at the t-th time, ranging from 0 to 1, dimensionless; U y,t is the maximum water replenishment of the y-th controlling water conservancy project at the t-th time, m 3 .

9. The optimized scheduling method for multi-source ecological water replenishment in segmented seasonal rivers according to claim 8, characterized in that, The objective function for determining the optimal scheduling of ecological water replenishment for seasonal rivers described in Step 5 includes three aspects: the maximum satisfaction of ecological flow, the best water quality improvement effect, and the minimum energy consumption. The specific objective function is as follows: where F t is the optimal operation objective function for ecological water replenishment of seasonal rivers at time t; F1 t is the non-compliance rate of the ecological flow at the control section of seasonal rivers at time t, %; F2 t is the non-compliance rate of the water quality index at the control section of seasonal rivers at time t, %. F3 t It is the energy consumption for ecological water replenishment of seasonal rivers at the t-th time, kWh; F1 t 、F2 t 、F3 t The calculation formulas for are as follows: where De i,j,t is the energy required for ecological water replenishment from the j-th water source to the i-th river section at the t-th time, kWh; The specific determination of the constraint conditions is as follows: the ecological water replenishment volume of each water source satisfies the maximum water replenishment volume constraint of each water source, that is, the sum of the ecological water replenishment volumes from all the j-th water sources is less than or equal to the maximum possible ecological water replenishment volume of the j-th water source: Where B i,j,t is the ecological water replenishment volume from the j-th water source to the i-th river section at the t-th time, m 3 ; Y i,t is the maximum possible ecological water replenishment volume of all water sources in the i-th river section at the t-th time, m 3 .

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