Segmented multi-source ecological water replenishing optimization scheduling method for seasonal river

Abstract

The invention discloses a seasonal river segmented multi-source ecological water supplement optimization scheduling method. The method comprises the following steps: step 1, carrying out river reach division on a seasonal river and determining ecological flow and water quality targets of the seasonal river in a segmented manner; step 2, determining ecological water supplementing requirements of each river reach of the seasonal river; 3, identifying potential supply water sources and water quantity and water quality characteristics of each river reach of the seasonal river; step 4, constructing an ecological water supplementing system and performing quantitative evaluation on an ecological water supplementing effect; 5, determining a seasonal river ecological water replenishing optimization scheduling target; and step 6, determining an optimal solution of the decision variable based on a multi-objective evolutionary algorithm and implementing ecological water replenishing optimization scheduling. By means of the method, according to the seasonal river ecological water demand and spatial-temporal change characteristics, ecological water supplementing optimization scheduling can be implemented, accurate and efficient water supplementing is conducted, energy saving is promoted, and service function improvement and virtuous circle of a seasonal river ecological system are promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of river management and water resource scheduling, and in particular relates to a seasonal river segmented multi-source ecological water replenishment optimization scheduling method. Background Art

[0002] Seasonal rivers are widely distributed in the river network and have important ecological service value. Due to the influence of climate change and strong human activities, seasonal rivers face prominent problems of ecosystem degradation and destruction. In recent years, ecological water replenishment has been widely adopted as an important means to ensure the ecological flow of rivers and maintain the health of damaged ecosystems. For seasonal rivers, scientific and reasonable ecological water replenishment can replenish seasonal rivers with a certain amount of ecological water in the dry season or at a specific time through artificial regulation, thereby curbing the damage of water shortage to the structure and function of the ecosystem, restoring the self-regulation ability of the ecosystem, and promoting the health and stability of the ecosystem. It has become an important way to protect seasonal rivers and restore the ecology.

[0003] From the current research and practice, seasonal river ecological water replenishment measures lack systematic design and are relatively weak in optimization and scheduling, which leads to a series of problems, mainly in the following aspects: First, the existing ecological water replenishment mostly adopts river pumping and reservoir water diversion. The water source is single and requires a lot of energy to extract or transport water, which increases the energy consumption of ecological water replenishment and may also have a negative impact on the environment; second, the basis for determining the flow of ecological water replenishment is insufficient. Most seasonal rivers are treated as perennial rivers for ecological water replenishment. Since the ecosystem of seasonal rivers has adapted to the natural hydrological cycle changes, excessive ecological water replenishment will destroy the ecological balance, lead to reduced biodiversity, and even lead to ecosystem degradation; third, the existing ecological water replenishment system is highly subjective and relies on the experience of the competent person to make ecological water replenishment decisions. It lacks modern control means that take into account multi-objective requirements and can be adaptively adjusted according to the characteristics of the new environment. Therefore, how to implement accurate, objective and efficient ecological water replenishment according to the characteristics of seasonal river ecological water demand has become an important technical problem that needs to be solved in this field. Summary of the invention

[0004] The purpose of the present invention is to provide a seasonal river segmented multi-source ecological water replenishment optimization scheduling method to solve the above technical problems.

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

[0006] The present invention discloses a seasonal river segmented multi-source ecological water replenishment optimization scheduling method, characterized in that the method comprises the following steps:

[0007] Step 1: Divide seasonal rivers into river sections and determine their ecological flow and water quality targets by section: Divide seasonal rivers into river sections, determine the distribution of seasonal river sections, and select control sections of river sections; determine seasonal river ecological flow targets and water quality targets by section based on the divided river sections;

[0008] Step 2: Determine the ecological water replenishment demand of each section of seasonal rivers: According to the characteristics of seasonal rivers, establish a distributed water cycle model, carry out parameter calibration and model verification of the distributed water cycle model based on the monitoring data of seasonal rivers, calculate the runoff results in combination with rainfall data, predict the water volume of each section of seasonal rivers without water replenishment, and determine the ecological water replenishment demand of each section of seasonal rivers at different times in combination with the ecological flow target requirements of each section of seasonal rivers;

[0009] Step 3, identify the potential water supply sources and water quantity and quality characteristics of each section of seasonal rivers: for the seasonal river sections that need water replenishment, identify the potential water supply sources of each section, calculate the maximum possible ecological water replenishment of each potential water supply source; and extract the change process of water quality indicators of different water sources through the monitoring data of each water source, and identify the water quality indicator concentration of each water source;

[0010] Step 4: Construct an ecological water replenishment system and conduct a quantitative evaluation of the ecological water replenishment effect: Construct an ecological water replenishment system, including a transmission system, an energy system, and a dispatching system, based on the characteristics of each water source and each section of a seasonal river; conduct an integrated quantitative evaluation of the ecological water replenishment "quantity-quality-energy" effect of the seasonal river ecological water replenishment system, including a water volume evaluation of the control section, a water quality evaluation of the control section, and an energy consumption evaluation of the ecological water replenishment system;

[0011] Step 5: Determine the target of seasonal river ecological water replenishment optimization scheduling: First, define the decision variables as the control water conservancy projects from the water source to the river section, including the gates, pumping stations and the opening degree of valves, and then calculate the ecological water replenishment from the water source to the river section; then determine the target function of seasonal river ecological water replenishment optimization scheduling; finally determine the constraint conditions;

[0012] Step 6: Determine the optimal solution of decision variables based on multi-objective evolutionary algorithm and implement ecological water replenishment optimization scheduling: Use non-dominated sorting genetic algorithm to simulate natural selection and genetic process to obtain the Pareto optimal solution set of decision variables, i.e., the opening degree of controlling water conservancy projects, and the corresponding set of objective function values ​​to form the Pareto optimal frontier; According to the importance of ecosystems in different sections of seasonal rivers and water resources management demand factors, combined with the distribution and characteristics of Pareto optimal frontiers with different objectives, give the Pareto optimal solution, i.e., the optimal opening degree of controlling water conservancy projects; Based on the optimal opening degree, implement ecological water replenishment optimization scheduling.

[0013] Furthermore, the division of seasonal river sections described in step 1 is specifically as follows: based on the characteristics of the seasonal river basin, the characteristics of the runoff and ecosystem of its main and tributary rivers are comprehensively considered, and the basic data of meteorology and hydrology, topography, soil and vegetation, water resources, water ecosystems and water environment are combined to divide the seasonal rivers into river sections; the selection of control sections of river sections is specifically as follows: the control sections are selected by considering the sections of water conservancy and hydropower projects, the sections required by relevant plans and implementation plans, and the factors of hydrological stations.

[0014] Furthermore, the specific process of determining the seasonal river ecological flow target in sections described in step 1 is as follows: first, establish the seasonal river hydrological-ecological response relationship; based on the ecosystem survey, analyze the relationship between key aquatic species, riparian vegetation and hydrological response; use water balance method, water exchange cycle method, habitat method, minimum water level method and comprehensive function method; consider river morphology, biodiversity, habitat requirements, and ecological service function requirements; calculate the ecological flow target to maintain the basic ecological function of seasonal rivers; for rivers for which the local water management department has clearly defined the ecological flow target requirements, compare and analyze the ecological flow target calculated with 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] Where Ds i,t is the ecological flow target requirement of the i-th river section at time t, m 3 ;D1 i,t When there is no control target requirement for ecological flow at the ith river section at time t, the ecological flow target is determined by hydrology, hydrodynamics, and comprehensive analysis methods, m 3 ;D2 i,t is the control target requirement of the government policy for the ecological flow of the i-th river section at the t-th time, m 3 ;

[0017] The specific process of determining seasonal river water quality targets in sections is as follows: comprehensively consider the target requirements of water environment protection, including drinking water source protection areas, drinking water intakes, water-related nature reserves, scenic spots, important wetlands, habitats of key protected and rare aquatic organisms, natural spawning grounds and feeding grounds, wintering grounds and migration channels of important aquatic organisms, natural fishing grounds, fishery water bodies, and water quality concentration requirements of aquatic germplasm resources protection areas; based on the requirements of my country's river and lake water quality management, water quality indicators include chemical oxygen demand (COD), permanganate index (COD) Mn, total phosphorus TP, total nitrogen TN index is added for lake and reservoir types, and the water quality index concentration of different sections of seasonal rivers takes the minimum value 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] Where Dc o,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 They are the various control requirements and limit values ​​of water quality concentration indicators in the ith river section at the tth time, including wetland protection, functional area control and other policy requirements.

[0020] Furthermore, the formula for predicting the water volume of each 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 water volume of the seasonal river at the ith river section at time t without water replenishment, m 3 ; S i,t-1 is the water volume of the seasonal river at the ith river section at time t-1, m 3 ;P i,t is the rainfall at the tth time in the ith section of the seasonal river, mm; Ae i is the catchment area of ​​the ith river section of a seasonal river, m 2 ; Kc i Se is the runoff coefficient of the ith river section of a seasonal river, dimensionless; i,t is the other inflow of the seasonal river at the ith river section at time t, including the inflow of transit water, the inflow of inter-basin water transfer, and the withdrawal or drainage of human production and life, m 3 ;Ee i,t is the water loss item of the ith river section of the seasonal river at time t, including evapotranspiration, groundwater recharge, transit water outflow or inter-basin water transfer, water withdrawal for human production and life, and other river outflow losses, m 3 ;

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

[0024]

[0025] In the formula, K i,t is the ecological water replenishment demand of the ith river section at time t. Its value is 1 if water replenishment is needed, and its value is 0 if water replenishment is not needed.

[0026] Furthermore, the potential water supply sources in step 3 include reservoir water, river water, groundwater, recycled water, desalinated seawater, external water and other water sources;

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

[0028]

[0029] Where Y i,j,t is the maximum possible ecological water replenishment for the i-th river section from the j-th water source at time t, m 3 ; Y i,t is the maximum possible ecological water replenishment of all water sources in the i-th river section at time t, m 3 ; J is the number of potential water sources for seasonal river ecological replenishment, 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 river section of the seasonal river that needs water replenishment, taking into account the technical feasibility and economic rationality, and selecting the transmission path according to the geographical location of each water source and each river section of the seasonal river and the topographic and geomorphic characteristics along the line, taking into account the terrain conditions, the difficulty of construction, and the construction and operation costs, in the form of rivers, channels and pipelines;

[0031] The energy system is introduced based on the geomorphic and topographical features of potential water recharge sources and seasonal rivers, and combines the use of renewable energy with electric energy;

[0032] The dispatching system includes a pump station, a gate and a valve, which are used to control and dynamically dispatch the water replenishment volume of the ecological water replenishment system.

[0033] Furthermore, the water volume assessment of the control section in step 4 is specifically as follows: after ecological water replenishment through various water sources, the water volume of the control section of each river section of the seasonal river is calculated by adding water replenishment related calculations on the basis of formula (3), and the formula is as follows:

[0034]

[0035] In the formula, S i,tis the water volume of the i-th river section at time t after the implementation of ecological water replenishment, m 3 ; B i,j,t is the ecological water replenishment from the jth water source to the ith river section at time t, m 3 ; T i,j,t is the transmission loss during the water replenishment process from the jth water source to the i-th river section at time t, m 3 ;

[0036] For the river or channel transmission type, the transmission loss includes two parts: the dam leakage loss and the river leakage loss. The first part is the dam leakage loss, which is determined according to the survey and design results of the dam. The dam leakage loss rate is determined according to a certain proportion of the water storage capacity, which is 1% to 3%. The second part is the river leakage loss, and the river leakage is calculated using an empirical formula. The specific calculation formula is:

[0037]

[0038] T1 p,t =Vs p,t ×X p (8)

[0039]

[0040] Where, T1 p,t is the seepage loss of the pth dam in the river at time t, m 3 ; T2 x,t is the leakage loss of the xth water delivery section of the river at time t, m 3 ; Vs p,t is the water storage capacity of the pth dam at time t, m 3 ;X p Vd is the leakage coefficient of the pth dam, which is determined according to the survey and design parameters of the dam and is dimensionless; x,t is the flow velocity of the x-th water delivery section at time t, m / s; S x,t is the original water volume of the x-th water delivery section at time t, m 3 ; C x is the leakage parameter of the x-th water delivery section, which is mainly affected by soil type. The values ​​of sandy loam, clay and sub-clay are 0.34-0.66, volcanic ash soil is 0.68-0.98, sand and volcanic ash soil is 1.20, sand containing rocks is 1.68, and sand and gravel soil is 2.20; P is the number of dams from the j-th water source to the i-th river section, pieces; X is the number of river sections from the j-th water source to the i-th river section, sections;

[0041] For pipeline transmission type, the water transmission loss takes into account the water loss in the pipeline, and the calculation formula is:

[0042]

[0043] Where C1 k is the coefficient of influence of soil covering on leakage outflow of the kth water supply pipe, which is determined according to the pipe diameter. The value of DN15-DN50 is 0.96, the value of DN75-DN300 is 0.95, and the value of greater than DN300 is 0.94, dimensionless; C2 is the flow coefficient, which is 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 pipeline, s;

[0044] The water quality assessment of the control section is specifically as follows: after each water source performs ecological water replenishment on the seasonal river section from different distances, the water quality index concentration of the control section is obtained by 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 calculation formula is as follows:

[0045]

[0046] 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 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 at the control section at time t, m / s;

[0047] The energy consumption evaluation of the ecological water replenishment system is as follows: If the ecological water replenishment system uses a pump station to pump water, the 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 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.

[0050] Furthermore, the calculation of the ecological water replenishment from the water source to the river section in step 5 is specifically as follows: Calculate the ecological water replenishment B from the jth water source to the ith river section at time t i,j,t , as shown below:

[0051]

[0052] Where Y i,j is the number of control water conservancy projects from the jth water source to the ith river section, V y,t is the opening degree of the yth controlled water conservancy project at the tth time, between 0 and 1, dimensionless; U y,t is the maximum water replenishment of the yth controlled water conservancy project at time t, m 3 .

[0053] Furthermore, the objective function for determining the optimal scheduling of seasonal river ecological water replenishment in step 5 includes three aspects: maximum ecological flow satisfaction, best water quality improvement effect, and 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 F1 is the objective function for optimizing the scheduling of seasonal river ecological water replenishment at time t; t F2 is the ecological flow dissatisfaction rate of the seasonal river control section at time t, %; t F3 is the rate of failure to meet water quality indicators in the seasonal river control section at time t, %; t is the energy consumption of seasonal river ecological water replenishment at time t, kWh;

[0056] F1 t 、F2 t 、F3 t The calculation formulas are:

[0057]

[0058] In the formula, De i,j,t is the energy required to replenish ecological water from the jth water source to the i-th river section at time t, kWh;

[0059] The determination constraint condition is specifically: the ecological water replenishment of each water source meets the maximum water replenishment constraint of each water source, that is, the sum of all ecological water replenishments from the j-th water source is less than or equal to the maximum possible ecological water replenishment of the j-th water source:

[0060]

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

[0062] The beneficial effects of the present invention are as follows: a seasonal river segmented multi-source ecological water replenishment optimization scheduling method described in the present invention can implement ecological water replenishment optimization scheduling and perform precise and efficient water replenishment according to the seasonal river ecological water demand and temporal and spatial variation characteristics; the method can realize automatic control and adaptive adjustment of seasonal river ecological water replenishment, has the characteristics of operability, stability, precision and economy, is conducive to promoting energy conservation, provides technical support for the differentiated protection, restoration and management of seasonal rivers, and promotes the improvement of the service function and virtuous cycle of seasonal river ecosystems.

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

[0064] Figure 1 It is a schematic diagram of the process of the method of the present invention;

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

[0066] Figure 3 This is a schematic diagram of the structure of the river system and ecological water replenishment system of Example 1;

[0067] Figure 4 This is a schematic diagram of the comprehensive weighing results of multiple objectives of seasonal river ecological water replenishment in Example 1;

[0068] Figure 5 This is a schematic diagram of the monthly ecological water replenishment optimization results for each section of a seasonal river in Example 1. DETAILED DESCRIPTION

[0069] The present invention discloses a seasonal river segmented multi-source ecological water replenishment optimization scheduling method, such as Figure 1 As shown, the method comprises the following steps:

[0070] Step 1: Divide seasonal rivers into sections and determine their ecological flow and water quality targets:

[0071] According to the characteristics of seasonal river basins, the runoff and ecosystem characteristics of its main and tributary rivers are comprehensively considered, and the basic data of meteorology, hydrology, topography, soil vegetation, water resources, water ecosystem and water environment are combined to divide the seasonal rivers into sections, determine the distribution of seasonal river sections, and select the control sections of the river sections. The selection of control sections should take into account factors such as the sections of water conservancy and hydropower projects, the sections required by relevant plans and implementation plans, and the hydrological stations.

[0072] According to the divided river sections, the ecological flow targets of seasonal rivers are determined in sections. First, the hydrological-ecological response relationship of seasonal rivers is established. On the basis of the ecosystem survey, based on the analysis of the relationship between key aquatic species, riparian vegetation and hydrological response, the water balance method, water exchange cycle method, habitat method, minimum water level method and comprehensive functional method are used, taking into account the functional requirements of river morphology, biodiversity, habitat needs, ecological service functions, etc., 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 ecological flow target requirements, a comparative analysis should be conducted with the ecological flow target 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] Where Ds i,t is the ecological flow target requirement of the i-th river section at time t, m 3 ;D1 i,t When there is no control target requirement for ecological flow at the ith river section at time t, the ecological flow target is determined by hydrology, hydrodynamics, comprehensive analysis and other methods, m 3 ;D2 i,t is the control target requirement of the ecological flow of the ith river section at time t according to relevant government policies (such as water resources and water ecological environment planning, water allocation plan), m 3 .

[0075] According to the divided river sections, seasonal river water quality targets are determined section by section. Comprehensively consider the target requirements of water environment protection, including water quality concentration requirements in drinking water source protection areas, drinking water intakes, water-related nature reserves, scenic spots, important wetlands, habitats of key protected and rare aquatic organisms, natural spawning grounds and feeding grounds, wintering grounds and migration channels of important aquatic organisms, natural fishing grounds and other fishery water bodies, and aquatic germplasm resource protection areas. According to the current requirements of river and lake water quality management in my country, the main water quality indicators include chemical oxygen demand (COD) and permanganate index (COD Mn) and total phosphorus (TP), and total nitrogen (TN) should be added for lakes and reservoirs. The concentration of water quality indicators in different sections of seasonal rivers should take the minimum value of the limit values ​​required by various management 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] Where Dc i,t is the water quality index (including COD, COD Mn , TP and TN, etc.) concentration requirements, mg / l; Dc1 i,t ,Dc2 i,t and Dcn i,t They are the various control requirements and limit values ​​of water quality concentration indicators in the ith river section at the tth time, including wetland protection, functional area control and other policy requirements.

[0078] Step 2: Determine the ecological water replenishment demand for each section of seasonal rivers:

[0079] The ecological water replenishment demand of each section of seasonal rivers is mainly affected by water conditions, ecological water demand guarantee target requirements, etc. Therefore, it is particularly important to identify which sections of rivers need water replenishment and the amount of water replenishment required, which is an important basis for the design of seasonal river ecological water replenishment system.

[0080] According to the characteristics of seasonal rivers, a distributed water cycle model is established, such as WEP, VIC and other representative models; based on the monitoring data of seasonal rivers, the distributed water cycle model parameter calibration and model verification work are carried out. Combined with rainfall data, the runoff results are calculated to predict the water volume of each section of the seasonal river at time t without water replenishment. 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 water volume of the seasonal river at the ith river section at time t without water replenishment, m 3 ; S i,j-1 is the water volume of the seasonal river at the ith river section at time t-1, m 3 ;P i,tis the rainfall at the tth time in the ith section of the seasonal river, mm; Ae i is the catchment area of ​​the ith river section of a seasonal river, m 2 ; Kc i Se is the runoff coefficient of the ith river section of a seasonal river, dimensionless; i,j is the other inflow of the seasonal river at the ith river section at time t, such as the inflow of transit water, the amount of water transferred across river basins, the withdrawal or drainage of human production and life, etc., m 3 ;Ee i,t is the water loss item of the ith river section of the seasonal river at time t, including evapotranspiration, groundwater recharge, transit water outflow or inter-basin water transfer, water withdrawal for human production and life, and other river outflow losses, m 3 .

[0083] On the basis of the above calculations, combined with the ecological flow target requirements of each section of seasonal rivers, the ecological water replenishment demand of each section of seasonal rivers at different times is determined. The formula is as follows:

[0084]

[0085] In the formula, K i,j is the ecological water replenishment demand of the ith river section at time t. Its value is 1 if water replenishment is needed, and its value is 0 if water replenishment is not needed.

[0086] Step 3: Identify potential recharge water sources and their water quantity and quality characteristics for each section of seasonal rivers:

[0087] For those who need water replenishment (i.e. ecological water replenishment demand K i,j The seasonal river sections with a value of 1) are used to identify the potential water sources for replenishment in each section. Seasonal rivers can be used for various water sources for ecological replenishment, mainly considering the following types: reservoir water, river water, groundwater, recycled water, desalinated seawater, external water and other water sources.

[0088] Calculate the maximum possible ecological water replenishment for each potential water recharge source as shown in the following formula:

[0089]

[0090] Where Y i,j,t is the maximum possible ecological water replenishment for the i-th river section from the j-th water source at time t, m 3 ; Y i,t is the maximum possible ecological water replenishment of all water sources in the i-th river section at time t, m 3 ; J is the number of potential water sources for seasonal river ecological replenishment, j=1,2,…J.

[0091] By monitoring the data of various water sources, the change process of water quality indicators of different water sources is extracted and the concentration of water quality indicators of each water source is identified.

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

[0093] According to the characteristics of each water source and each section of seasonal rivers, an ecological water replenishment system is constructed, including a transmission system, an energy system and a dispatching system, such as Figure 2 shown.

[0094] Specifically, the transmission system is responsible for transporting ecological water from water sources (including reservoir water, river water, groundwater, recycled water, desalinated seawater, external water and other water sources) to the river sections of seasonal rivers that need water replenishment. Taking into account the technical feasibility and economic rationality, the transmission path is selected according to the geographical location of each water source and each river section of the seasonal river and the topographic and geomorphic characteristics along the line, taking into account the terrain conditions, the difficulty of construction and the construction and operation costs. Rivers, channels and pipelines are mostly used.

[0095] Energy system: According to the geomorphic and topographical characteristics of potential water supply sources and seasonal rivers, 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 long-term operating costs and reducing greenhouse gas emissions.

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

[0097] An integrated quantitative evaluation of the “quantity-quality-energy” effects of ecological water replenishment in seasonal river ecological water replenishment systems is conducted, including water quantity assessment in controlled sections, water quality assessment in controlled sections, and energy consumption assessment of ecological water replenishment systems.

[0098] 1) Assessment of water volume in controlled sections: After ecological water replenishment through various water sources, the water volume in the controlled sections of each section of seasonal rivers is further calculated based on formula (3) by adding water replenishment related calculations. The formula is as follows:

[0099]

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

[0101] For the river (or channel) transmission type, the transmission loss (T i,j,t ) mainly includes two parts: sluice dam leakage loss and river channel leakage loss: the first part is the sluice dam leakage loss on the river channel, which can be determined according to the survey and design results of the sluice dam. The leakage loss rate of the sluice dam can also be determined according to a certain proportion of the water storage capacity, usually 1%-3%; the second part is the river channel leakage loss, and the river channel leakage 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] Where, T1 p,t is the seepage loss of the pth dam in the river at time t, m 3 ; T2 x,t is the leakage loss of the xth water delivery section of the river at time t, m 3 ; Vs p,t is the water storage capacity of the pth dam at time t, m 3 ;X p Vd is the leakage coefficient of the pth dam, which is determined according to the survey and design parameters of the dam and is dimensionless; x,t is the flow velocity of the x-th water delivery section at time t, m / s; S x,t is the original water volume of the x-th water delivery section at time t, m 3 ; C x is the leakage parameter of the x-th water diversion section, which is mainly affected by the soil type. Usually, the values ​​of sandy loam, clay and sub-clay are 0.34-0.66, the values ​​of volcanic ash soil are 0.68-0.98, the values ​​of sandy soil and volcanic ash soil are 1.20, the values ​​of sandy soil containing rocks are 1.68, and the values ​​of sandy and gravelly soil are 2.20; P is the number of dams from the j-th water source to the i-th river section, pieces; X is the number of river sections from the j-th water source to the i-th river section, sections.

[0106] For pipeline transmission type, the water transmission loss (T i,j,t ) mainly considers the amount of water loss in the pipeline, and the calculation formula is:

[0107]

[0108] Where 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, the decision variables are defined: the decision variables are the opening degree of the controlling water conservancy project (including gates, pumping stations, and valves) from the jth water source to the ith river section, and then the ecological water replenishment B from the jth water source to the ith river section at time t is calculated. i,j,t , as shown below:

[0117]

[0118] Where Y i,j is the number of control water conservancy projects from the jth water source to the ith river section, V y,t is the opening degree of the yth controlled water conservancy project at the tth time, between 0 and 1, dimensionless; U y,t is the maximum water replenishment of the yth controlled water conservancy project at time t, m 3 .

[0119] Then determine the objective function of seasonal river ecological water replenishment optimization scheduling: based on the construction of seasonal river ecological water replenishment system and the quantitative evaluation of ecological water replenishment effect, determine the seasonal river ecological water replenishment optimization scheduling strategy; starting from the maximization of the comprehensive efficiency of seasonal river ecological water replenishment, the seasonal river ecological water replenishment optimization scheduling objective function includes multiple aspects such as maximum ecological flow satisfaction, best water quality improvement effect, and 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 F1 is the objective function for optimizing the scheduling of seasonal river ecological water replenishment at time t; t F2 is the ecological flow dissatisfaction rate of the seasonal river control section at time t, %; t F3 is the rate of failure to meet water quality indicators in the seasonal river control section at time t, %; t is the energy consumption of seasonal river ecological water replenishment at time t, kWh.

[0122] F1 t 、F2 t 、F3 t The calculation formulas are:

[0123]

[0124] In the formula, De i,j,t The amount of energy required to replenish ecological water from the j-th water source to the i-th river section at time t, kWh.

[0125] Finally, the constraint conditions are determined: the ecological water replenishment of each water source should meet the maximum water replenishment constraint of each water source, that is, the sum of all ecological water replenishments from the jth water source should be less than or equal to the maximum possible ecological water replenishment of the jth water source:

[0126]

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

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

[0129] The non-dominated sorting genetic algorithm (NSGA) is used to simulate natural selection and genetic processes to obtain the Pareto optimal solution set of the decision variable (the degree of controllable water conservancy project opening) and the corresponding objective function value set to form the Pareto optimal frontier. The calculation steps specifically include randomly generating the initial population, establishing the fitness function, population selection, crossover, mutation and update, and continuously iterating the calculation until the maximum number of iterations or other convergence conditions are reached and the calculation ends, and the result is output.

[0130] According to the importance of the ecosystems of different sections of seasonal rivers, the demand for water resources management and other factors, combined with the distribution and characteristics of the Pareto optimal frontiers of different objectives, the recommended optimal solution (Pareto optimal solution) is given, that is, the optimal opening degree of the ecological water replenishment control water conservancy project (including gates, pumping stations, valves). According to the optimal opening degree of the control water conservancy project, the ecological water replenishment scheduling is implemented to achieve the precise control of ecological water replenishment from different water sources to different seasonal river sections, and promote the protection and improvement of seasonal river ecosystems.

[0131] Embodiment 1

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

[0133] This embodiment applies the above method to a seasonal river in a city in northern my country, whose river system and ecological water replenishment system are as follows: Figure 3As shown in the figure. Among them, river sections 1 to 4 are seasonal river sections, and there are two water sources for replenishment, namely, river water (j=1) of river section 5 and high-quality reclaimed water (j=2) of a recycled water plant. There are 5 control sections in the system. Among them, river water (j=1) is transported to four seasonal river sections through lifting pump stations and water replenishment pipelines, and then flows downstream back to Nansha River to form a circulating water network. High-quality reclaimed water (j=2) can be directly replenished to river section 5. The ecological water replenishment system realizes ecological water replenishment for four sections of seasonal rivers through the linkage of two water sources and multiple control water conservancy projects (including 4 valves, 1 gate and 1 pump station). The energy used by the pump station is electricity, and the diameters of the water replenishment pipelines are DN1200 (pipeline a, water source j=1 to valve 1), DN800 (pipeline b, from valve 1 to valve 3) and DN 600 (pipeline c, from valve 3 to valve 4).

[0134] Taking a typical year with 75% water frequency in a long series (1956-2016) as an example, the ecological water replenishment calculation is carried out month by month. The NSGA algorithm is used for programming calculation, and the population size is selected as 2000 and the number of generations is 30. Taking March as an example, the Pareto frontier results of the three-objective trade-off of maximum ecological flow satisfaction, best water quality improvement effect and minimum energy consumption are obtained as follows: Figure 4 As shown in the figure, the five-pointed star symbolizes the optimal solution (Pareto optimal solution), and the corresponding three objective function values ​​are the ecological water quantity unsatisfaction rate of 1.80%, the water quality index unsatisfaction rate of 2.82%, and the energy consumption of 180,900 kWh. Of course, there is still room for further improvement in the ecological water quantity unsatisfaction rate and water quality index unsatisfaction rate targets, mainly due to the limitation of the maximum possible water replenishment of the water source.

[0135] The opening degree of seasonal river control water conservancy projects (including gates, pump stations, and valves) in the optimal solution of this embodiment is shown in Table 1. It can be seen that the maximum opening degree of the 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 engineering conditions, the control system of seasonal river ecological water replenishment scheduling in March achieves maximum opening, which is mainly limited by the water supply of two water sources. The effect of ecological water replenishment still has room for improvement. The two targets of ecological water quantity dissatisfaction rate and water quality index dissatisfaction rate can still be further reduced through the optimization design and renovation of the subsequent water replenishment system.

[0136] Table 1 Opening degree of each dam on seasonal rivers in the recommended scheme (dimensionless)

[0137]

[0138]

[0139] After the implementation of the optimal solution in this embodiment, the amount of ecological water replenishment for each river section and the monthly process are as follows: Figure 5 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. In March, the total ecological water replenishment of the four river sections reached 15.457 million m 3 The ecological water replenishment in river section 1 is the largest, reaching 4.366 million m 3 Since fish usually spawn in spring from March to May, especially from April to May, the peak spawning period, the ecological water demand is large, while the natural water supply 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 for June, ecological water replenishment is not required from July to September due to the large water supply. The ecosystem function of seasonal rivers is mainly maintained by natural water supply.

[0140] It should be noted that this case selected the ecological water replenishment calculation under the condition of 75% water inflow frequency in the long series (1956-2016). If other water inflow conditions with lower frequency (or extreme drought) are selected, the opening degree and water replenishment amount of the ecological water replenishment system can be quantitatively identified through the method described in the present invention, and ecological water replenishment can also be carried out in the flood season. In the process of achieving multi-objective balance, this method implements ecological water replenishment optimization scheduling, which 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 rather than to limit it. Although the present invention has been described in detail with reference to the preferred arrangement scheme, a person skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A seasonal river segmented multi-source ecological water replenishment optimization scheduling method, characterized in that: The method comprises the following steps: Step 1: Divide seasonal rivers into river sections and determine their ecological flow and water quality targets by section: Divide seasonal rivers into river sections, determine the distribution of seasonal river sections, and select control sections of river sections; determine seasonal river ecological flow targets and water quality targets by section based on the divided river sections; Step 2: Determine the ecological water replenishment demand of each section of seasonal rivers: According to the characteristics of seasonal rivers, establish a distributed water cycle model, carry out parameter calibration and model verification of the distributed water cycle model based on the monitoring data of seasonal rivers, calculate the runoff results in combination with rainfall data, predict the water volume of each section of seasonal rivers without water replenishment, and determine the ecological water replenishment demand of each section of seasonal rivers at different times in combination with the ecological flow target requirements of each section of seasonal rivers; Step 3, identify the potential water supply sources and water quantity and quality characteristics of each section of seasonal rivers: for the seasonal river sections that need water replenishment, identify the potential water supply sources of each section, calculate the maximum possible ecological water replenishment of each potential water supply source; and extract the change process of water quality indicators of different water sources through the monitoring data of each water source, and identify the water quality indicator concentration of each water source; Step 4: Construct an ecological water replenishment system and conduct a quantitative evaluation of the ecological water replenishment effect: Construct an ecological water replenishment system, including a transmission system, an energy system, and a dispatching system, based on the characteristics of each water source and each section of a seasonal river; conduct an integrated quantitative evaluation of the "quantity-quality-energy" effect of ecological water replenishment on the seasonal river ecological water replenishment system, including water quantity evaluation of the control section, water quality evaluation of the control section, and energy consumption evaluation of the ecological water replenishment system; Step 5: Determine the target of seasonal river ecological water replenishment optimization scheduling: First, define the decision variables as the control water conservancy projects from the water source to the river section, including the gates, pumping stations and the opening degree of valves, and then calculate the ecological water replenishment from the water source to the river section; then determine the target function of seasonal river ecological water replenishment optimization scheduling; finally determine the constraint conditions; Step 6: Determine the optimal solution of decision variables based on multi-objective evolutionary algorithm and implement ecological water replenishment optimization scheduling: Use non-dominated sorting genetic algorithm to simulate natural selection and genetic process to obtain the Pareto optimal solution set of decision variables, i.e., the opening degree of controlling water conservancy projects, and the corresponding set of objective function values ​​to form the Pareto optimal frontier; According to the importance of ecosystems in different sections of seasonal rivers and water resources management demand factors, combined with the distribution and characteristics of Pareto optimal frontiers with different objectives, give the Pareto optimal solution, i.e., the optimal opening degree of controlling water conservancy projects; Based on the optimal opening degree, implement ecological water replenishment optimization scheduling.

2. According to claim 1, a seasonal river segmented multi-source ecological water replenishment optimization scheduling method is characterized in that: The specific steps of dividing the seasonal rivers in step 1 are as follows: dividing the seasonal rivers according to the characteristics of the seasonal river basins, taking into account the characteristics of the runoff and ecosystem of the main and tributary rivers, and combining the basic data of meteorology and hydrology, topography and landform, soil and vegetation, water resources, water ecosystem and water environment; the specific steps of selecting the control sections of the river sections are as follows: selecting the control sections by considering the sections of water conservancy and hydropower projects, the sections required by relevant plans and implementation plans, and the factors of hydrological stations.

3. According to claim 2, a seasonal river segmented multi-source ecological water replenishment optimization scheduling method is characterized in that: The specific process of determining the seasonal river ecological flow target in sections as described in step 1 is as follows: first, establish the seasonal river hydrological-ecological response relationship. On the basis of ecosystem survey, based on the analysis of the relationship between key aquatic species, riparian vegetation and hydrological response, use the water balance method, water exchange cycle method, habitat method, minimum water level method and comprehensive function method, consider the river morphology, biodiversity, habitat demand, and ecological service function requirements, and calculate the ecological flow target to maintain the basic ecological function of the seasonal river. For rivers where the local water management department has clearly defined the ecological flow target requirements, compare and analyze the ecological flow target calculated with the former, and take the maximum value of the two, as shown in the following formula: Ds i,t =max(D1 i,t ,D2 i,t ) (1) Where Ds i,t is the ecological flow target requirement of the i-th river section at time t, m 3 ; D1 i,t When there is no control target requirement for ecological flow at the ith river section at time t, the ecological flow target is determined by hydrology, hydrodynamics, and comprehensive analysis methods, m 3 ; D2 i,t is the control target requirement of the government policy for the ecological flow of the i-th river section at the t-th time, m 3 ; The specific process of determining seasonal river water quality targets in sections is as follows: comprehensively consider the target requirements of water environment protection, including drinking water source protection areas, drinking water intakes, water-related nature reserves, scenic spots, important wetlands, habitats of key protected and rare aquatic organisms, natural spawning grounds and feeding grounds, wintering grounds and migration channels of important aquatic organisms, natural fishing grounds, fishery water bodies, and water quality concentration requirements of aquatic germplasm resources protection areas; based on the requirements of my country's river and lake water quality management, water quality indicators include chemical oxygen demand (COD), permanganate index (COD) Mn , total phosphorus TP, total nitrogen TN index is added for lake and reservoir types, and the water quality index concentration of different sections of seasonal rivers takes the minimum value 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 They are the various control requirements and limit values ​​of water quality concentration indicators in the ith river section at the tth time, including wetland protection, functional area control and other policy requirements.

4. According to claim 3, a seasonal river segmented multi-source ecological water replenishment optimization scheduling method is characterized in that: The formula for predicting the water volume of each section of a seasonal river without water replenishment described in step 2 is: In the formula, S i ′ ,t is the water volume of the seasonal river at the ith river section at time t without water replenishment, m 3 ; S i,t-1 is the water volume of the seasonal river at the ith river section at time t-1, m 3 ;P i,t is the rainfall at the tth time in the ith section of the seasonal river, mm; Ae i is the catchment area of ​​the ith river section of a seasonal river, m 2 ; Kc i Se is the runoff coefficient of the ith river section of a seasonal river, dimensionless; i,t is the other inflow of the seasonal river at the ith river section at time t, including the inflow of transit water, the inflow of inter-basin water transfer, and the withdrawal or drainage of human production and life, m 3 ;Ee i,t is the water loss item of the ith river section of the seasonal river at time t, including evapotranspiration, groundwater recharge, transit water outflow or inter-basin water transfer, water withdrawal for human production and life, and other river outflow losses, m 3 ; The formula for determining the ecological water replenishment demand of each section of a seasonal river at different times is: In the formula, K i,t is the ecological water replenishment demand of the ith river section at time t. Its value is 1 if water replenishment is needed, and its value is 0 if water replenishment is not needed.

5. According to claim 4, a seasonal river segmented multi-source ecological water replenishment optimization scheduling method is characterized in that: The potential water supply sources mentioned in step 3 include reservoir water, river water, groundwater, recycled water, desalinated seawater, external water and other water sources; The formula for calculating the maximum possible ecological water replenishment of each potential water replenishment source is: Where Y i,j,t is the maximum possible ecological water replenishment for the i-th river section from the j-th water source at time t, m 3 ; Y i,t is the maximum possible ecological water replenishment of all water sources in the i-th river section at time t, m 3 ; J is the number of potential water sources for seasonal river ecological replenishment, j=1,2,…J.

6. According to claim 5, a seasonal river segmented multi-source ecological water replenishment optimization scheduling method is characterized in that: The transmission system described in step 4 is responsible for transporting ecological water from the water source to the river sections of seasonal rivers that need water replenishment. The transmission path is selected in the form of rivers, channels and pipelines, taking into account the technical feasibility and economic rationality, the geographical location of each water source and each river section of the seasonal river and the topographic and geomorphic characteristics along the line, the terrain conditions, the difficulty of construction and the construction and operation costs; The energy system is introduced based on the geomorphic and topographical features of potential water recharge sources and seasonal rivers, and combines the use of renewable energy with electric energy; The dispatching system includes a pump station, a gate and a valve, which are used to control and dynamically dispatch the water replenishment volume of the ecological water replenishment system.

7. A seasonal river segmented multi-source ecological water replenishment optimization scheduling method according to claim 6, characterized in that: The water volume assessment of the control section in step 4 is as follows: after ecological water replenishment through various water sources, the water volume of the control section of each river section of the seasonal river is calculated by adding water replenishment related calculations on the basis of formula (3), and the formula is as follows: In the formula, S i,t is the water volume of the i-th river section at time t after the implementation of ecological water replenishment, m 3 ; B i,j,t is the ecological water replenishment from the jth water source to the ith river section at time t, m 3 ; T i,j,t is the transmission loss during the water replenishment process from the jth water source to the i-th river section at time t, m 3 ; For the river or channel transmission type, the transmission loss includes two parts: the dam leakage loss and the river leakage loss. The first part is the dam leakage loss, which is determined according to the survey and design results of the dam. The dam leakage loss rate is determined according to a certain proportion of the water storage capacity, which is 1% to 3%. The second part is the river leakage loss, and the river leakage is calculated using an empirical formula. The specific calculation formula is: T1 p,t =Vs p,t ×X p (8) Where, T1 p,t is the seepage loss of the pth dam in the river at time t, m 3 ; T2 x,t is the leakage loss of the xth water delivery section of the river at time t, m 3 ; Vs p,t is the water storage capacity of the pth dam at time t, m 3 ; X p Vd is the leakage coefficient of the pth dam, which is determined according to the survey and design parameters of the dam and is dimensionless; x,t is the flow velocity of the x-th water delivery section at time t, m / s; S x,t is the original water volume of the x-th water delivery section at time t, m 3 ; C c is the leakage parameter of the x-th water delivery section, which is mainly affected by soil type. The values ​​of sandy loam, clay and sub-clay are 0.34-0.66, volcanic ash soil is 0.68-0.98, sand and volcanic ash soil is 1.20, sand containing rocks is 1.68, and sand and gravel soil is 2.20; P is the number of dams from the j-th water source to the i-th river section, pieces; X is the number of river sections from the j-th water source to the i-th river section, sections; For pipeline transmission type, the water transmission loss takes into account the water loss in the pipeline, and the calculation formula is: Where C1 k is the coefficient of influence of soil covering on leakage outflow of the kth water supply pipe, which is determined according to the pipe diameter. The value of DN15-DN50 is 0.96, the value of DN75-DN300 is 0.95, and the value of greater than DN300 is 0.94, dimensionless; C2 is the flow coefficient, which is 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 pipeline, s; The water quality assessment of the control section is specifically as follows: after each water source performs ecological water replenishment on the seasonal river section from different distances, the water quality index concentration of the control section is obtained by 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 calculation formula is as follows: 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 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 at the control section at time t, m / s; The energy consumption evaluation of the ecological water replenishment system is as follows: If the ecological water replenishment system uses a pump station to pump water, the energy consumption calculation formula is as follows: Of i,j,t =ρ×g×H i,j ×B i,j,t ×η (12) 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.

8. According to claim 7, a seasonal river segmented multi-source ecological water replenishment optimization scheduling method is characterized in that: The calculation of the ecological water replenishment from the water source to the river section in step 5 is specifically as follows: Calculate the ecological water replenishment B from the jth water source to the ith river section at time t i,j,t , as shown below: Where Y i,j is the number of control water conservancy projects from the jth water source to the ith river section, V y,t is the opening degree of the yth controlled water conservancy project at the tth time, between 0 and 1, dimensionless; U y,t is the maximum water replenishment of the yth controlled water conservancy project at time t, m 3 .

9. A seasonal river segmented multi-source ecological water replenishment optimization scheduling method according to claim 8, characterized in that: The objective function for determining the optimal scheduling of seasonal river ecological water replenishment described in step 5 includes three aspects: maximum ecological flow satisfaction, best water quality improvement effect, and minimum energy consumption. The specific objective function is: In the formula, F t F1 is the objective function for optimizing the scheduling of seasonal river ecological water replenishment at time t; t F2 is the ecological flow dissatisfaction rate of the seasonal river control section at time t, %; t is the rate of failure to meet water quality indicators in the seasonal river control section at time t, %; F3 t is the energy consumption of seasonal river ecological water replenishment at time t, kWh; F1 t 、F2 t 、F3 t The calculation formulas are: In the formula, De i,j,t is the energy required to replenish ecological water from the jth water source to the i-th river section at time t, kWh; The determination constraint condition is specifically: the ecological water replenishment of each water source meets the maximum water replenishment constraint of each water source, that is, the sum of all ecological water replenishments from the j-th water source is less than or equal to the maximum possible ecological water replenishment of the j-th water source: In the formula, B i,j,t is the ecological water replenishment from the jth water source to the ith river section at time t, m 3 ; Y i,t is the maximum possible ecological water replenishment of all water sources in the i-th river section at time t, m 3 .

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