Water-grain-energy-ecological association system collaborative configuration method considering unconventional water utilization

Abstract

The invention discloses a water-grain-energy-ecology association system collaborative configuration method considering unconventional water utilization, which comprises the following steps: firstly, constructing a water-grain-energy-ecology association system collaborative configuration model, and quantitatively analyzing the interaction relationship among water resource distribution, agricultural production, energy utilization and ecological protection; a vine copula method is adopted to quantify a complex interdependence relationship among a plurality of random variables; vine copula and a multi-stage stochastic optimization method are integrated to solve the model, and the influence of the brackish water utilization rate, the joint default probability and the incoming water level on the WFEE association system is analyzed. According to the method, cooperative configuration of unconventional and conventional water resources is considered, the pressure of shortage of regional water resources is relieved, and the complex mutual influence relationship among the subsystems is reflected.

Description

Technical Field

[0001] The present invention belongs to the field of information and communication technology specifically suitable for management or supervision purposes, and in particular relates to a water-food-energy-ecological system collaborative configuration model considering unconventional water utilization. Background Art

[0002] Due to factors such as climate change, population growth, and the development of social and environmental data, the problem of water shortage is becoming more and more serious. At present, the world is still facing serious water shortage; however, China's unconventional water resources (recycled water, brackish water, etc.) have huge potential for development and utilization, especially the large distribution area of ​​brackish water in the country. Since desalinated water effectively increases the availability of water resources, it has become an important strategic reserve and supplement for freshwater resources, and plays an important role in promoting the sustainable use of water resources. In addition, as a core resource for maintaining social and economic development and ecological and environmental health, water shortage will threaten food security and energy supply, and lead to ecological problems such as wetland forest degradation and lake shrinkage. At the same time, crop planting and energy production will affect water quantity and quality, and a healthy ecological environment is also the key to maintaining water resource circulation and ensuring food and energy security. It can be seen that water resources, food, energy and ecology are interrelated and influence each other, forming a water-food-energy-ecological nexus (WFEE) system.

[0003] With the rapid development of society and the continuous improvement of people's living standards, it has become crucial to carry out research on the coordinated allocation of unconventional water and conventional water resources in response to the shortage of freshwater resources and the growing demand for water. This study aims to rationally allocate regional water resources, alleviate the contradiction between water supply and demand, ensure the safety of the water-food-energy-ecological nexus (WFEE) system, and promote social sustainable development. However, existing research on the WFEE association system mainly focuses on the optimal allocation of conventional water resources, including surface water and groundwater. On this basis, the present invention considers the utilization of unconventional water resources such as brackish water, industrial wastewater and domestic sewage, and constructs a coordinated configuration model of the water-food-energy-ecological association system. The present invention aims to improve the utilization efficiency of unconventional water resources, alleviate the pressure of regional water shortage, promote the sustainable utilization of water resources and economic development, provide technical support for improving the coordinated optimization configuration mechanism of unconventional water and conventional water resources, and provide experience and reference for the coordinated configuration of WFEE systems in water-scarce areas. Summary of the invention

[0004] In view of the problems raised in the background technology, the present invention discloses a water-food-energy-ecological system collaborative configuration model considering unconventional water utilization, which is characterized by comprising the following steps:

[0005] Step A: Consider the coordinated allocation of unconventional water and conventional water resources, and build a coordinated allocation model of the water-food-energy-ecological linkage system to balance the competition for water resources among different regions and users, and quantitatively analyze the interactive relationship between water resource allocation, agricultural production, energy utilization and ecological protection;

[0006] Step B: Using the vine copula method, we quantify the complex interdependencies among multiple random variables and analyze the impact of joint default risk on the system, thereby reflecting the trade-offs and synergies among the subsystems.

[0007] Step C: Integrate vine copula and multi-stage stochastic optimization method to solve the model and analyze the impact of brackish water utilization, joint default probability and water inflow level on the WFEE associated system.

[0008] In step A, the consideration of the coordinated configuration of unconventional water and conventional water resources to construct a coordinated configuration model of the water-food-energy-ecological system includes:

[0009] Step A1: Considering the utilization of unconventional water resources such as brackish water, industrial wastewater and domestic sewage, and taking the maximization of system benefits as the goal, construct the objective function:

[0010] Max=BEN_PRO+BEN_ECO+BEN_BRA+BEN_ENE-COS_TRW-COS_AGR

[0011] Water distribution benefits for production departments:

[0012]

[0013] Where i is the administrative region; j is the user; k is the energy conversion technology; t is the period; PW ijt For unit water distribution efficiency, TARW ijt is the water distribution target; p h CW is the probability of water coming; ijt It is a penalty for insufficient water supply; SW ijht GW is the surface water allocation ijht IRW is the groundwater allocation; ijht The amount of industrial wastewater allocated; DRW ijht BW is the amount of domestic sewage allocated; ijht is the amount of brackish water; α ijt and β ijt are the reuse rates of industrial wastewater and domestic sewage; BR ijt Reuse of water for the unit; TIC ijt and TDC ijt They are the unit industrial wastewater and domestic sewage treatment costs respectively;

[0014] Ecological water distribution benefits:

[0015]

[0016] Where, BT t and BA t TSW is the transport benefit and fishery benefit per unit water volume of rivers and lakes; ht is the available amount of surface water; jt Efficiency of water allocation to production and ecological sectors; γ kt Efficiency of water distribution for the energy sector; ESW ikht Surface water allocation for the energy sector; WKL t is the ecological flow downstream of the reservoir; GWD jt is the water demand per ecological user; CR jt Value of serving climate regulation; WR jt Serve the value of water conservation; SC jt Serve value for soil formation and protection; ST jt Serving the value of waste treatment; BD jt Value of serving biodiversity conservation; FP jt Value of serving food production; RM jt Serve value for raw materials; RA jt Serve the value of entertainment culture; CWD jt Penalty for insufficient water allocation;

[0017] Net benefits of brackish water distribution:

[0018]

[0019] In the formula, SUB ijt and SUEB ikt Subsidy for brackish water for production and energy sector units; CEB ijt and CEEB ikt are the costs of brackish water desalination for the production and energy sectors, respectively;

[0020] Net energy benefits:

[0021]

[0022] Where, PEW kt Water distribution benefits for energy sector units; TAREW ikt Water allocation targets for the energy sector; ikt , η ikt and θ ikt They are cooling water, boiler water, desulfurization water and other water consumption coefficients in the energy conversion process; ESW ikhtAllocation of surface water for the energy sector; EGW ikht Groundwater allocation for the energy sector; EDRW ikht Allocation of domestic wastewater for the energy sector; EBW ikht Allocation of brackish water for the energy sector; CEW kt penalties for under-allocation of water to the energy sector;

[0023] Crop planting costs:

[0024]

[0025] Where, QF ijt PF is the amount of fertilizer used per unit area; ijt is the unit price of fertilizer; LF ijt Irrigation and leaching share; WPC ijt is the water requirement of crops per unit area; it The installation rate of drip irrigation and sprinkler irrigation; CELE t The power consumption per unit area for drainage, drip irrigation, sprinkler irrigation, etc.; YA ijt is the crop yield per unit area; EAGP jt Power consumption of agricultural product processing units; KLD jt CKL is the diesel consumption per unit area of ​​agricultural farming equipment; t Cost of diesel fuel used in crop machinery; FC ijt Fixed costs of farmland irrigation.

[0026] Water distribution costs:

[0027]

[0028] In the formula, CE jt For electricity prices; is the surface water head; lifting water head for groundwater; is the groundwater pressure head; Loss of head for groundwater; for surface water extraction efficiency; is the pumping efficiency; For power efficiency;

[0029] Step A2: With the availability of conventional water resources, the availability and utilization rate of unconventional water resources, irrigation-power generation water distribution balance, brackish water irrigation, ecological land protection, energy and water consumption as constraints:

[0030] Constraints on the availability of conventional water resources:

[0031]

[0032] Constraints on the availability of unconventional water resources (constraints on sewage treatment capacity):

[0033] Constraints on the availability of brackish water:

[0034]

[0035] Brackish water treatment capacity constraints:

[0036]

[0037] Brackish water irrigation constraints:

[0038]

[0039] Constraints on the utilization rate of unconventional water resources:

[0040]

[0041] Joint probability constraints:

[0042] C(1-p1,1-p2,1-p3)=1-P

[0043]

[0044] Pr[(ESW ikht +EGW ikht +EDRW ikht +EBW ikht )×θ ikt ≥FED ikt ]≥1-p1,k=3,4,5,6

[0045]

[0046] Pr[(SW ijht +GW ijht +DRW ijht +BW ijht ) / GWD jt ≥TDE ijt ]≥1-p3,j=6,...,9 Irrigation-power generation water balance constraints:

[0047]

[0048] Agricultural power consumption constraints:

[0049]

[0050] Energy consumption constraints:

[0051]

[0052] Constraints on salinity control in cultivated land:

[0053]

[0054] Bosten Lake Ecological Water Constraints:

[0055]

[0056] Energy and water consumption constraints:

[0057]

[0058] In the formula, TSW ht is the surface water availability; WRR t Groundwater return rate; TGW t is the available groundwater volume; Maximum capacity for treating wastewater for industrial users, Maximum capacity for treating sewage for domestic users; TBA t TBA is the amount of brackish water available during period t; t-1 is the amount of brackish water available in the previous period; ijt The upper limit of the proportion of brackish water irrigation; The maximum desalination capacity of brackish water; PWR t is the minimum recycled water repetition rate; PWB t The lower limit of the utilization ratio of brackish water; FED ikt is the total power demand; TFD it is the food demand; TDE ijt Minimum coverage area for ecological land; PEN t The largest proportion of energy and water consumption; PIN t It accounts for the largest proportion of water used for irrigation; The maximum available amount in the agricultural production process; KLD jt The diesel consumption per unit area of ​​agricultural farming equipment; The upper limit of diesel consumption in agricultural farming process; TLW t The maximum allowable water consumption for salt leaching; WKL t is the ecological flow downstream of the reservoir; BEW t The minimum ecological water requirement for Bosten Lake; TWE it Maximum available water volume for energy.

[0059] The step B further comprises:

[0060] Step B1, select the C-vine copula structure and four common copula functions, use the maximum likelihood method to estimate parameters, and select the optimal joint distribution function through the minimum square Euclidean distance;

[0061] Step B2: The joint risk value of food, energy and ecological land demand obtained based on the C-vine copula function is used in the constraints of the optimization model to reveal the interactive impact relationship between water resources, agriculture, energy and ecosystems.

[0062] The four common copula functions are: Gaussian function, Gumbel function, Clayton function and FrankCopula function

[0063] In the step C, the integrated vine copula-multi-stage stochastic optimization method is used to solve the model, including:

[0064] Step C1: Obtain input data by searching historical documents and statistical yearbooks, and discretize the continuous function into three levels: high, medium, and low. The corresponding probability of each water level is p h and

[0065] Step C2: Couple vine copula and multi-stage stochastic optimization method to solve the optimization model and obtain system benefits, food production, energy utilization, ecological protection and water resources allocation plans under different scenarios.

[0066] Compared with the prior art, the present invention has the following beneficial effects:

[0067] On the basis of optimizing the allocation of conventional water resources, the present invention also considers the utilization of unconventional water resources such as brackish water, industrial wastewater and domestic sewage, and conducts research on the comprehensive management of water-food-energy-ecological correlation system based on the coordinated allocation of unconventional and conventional water resources. In addition, the coupling of vine copula and multi-stage stochastic optimization method can not only effectively deal with the dynamic pursuit problem of random variables in regional water resources management, but also quantify the complex mutual influence relationship between water resources, agriculture, energy and ecosystems. The results of this study can improve the utilization efficiency of conventional and unconventional water resources, reduce water use conflicts between subsystems, help decision makers to strike a balance between risk aversion and system benefits, and provide technical support for achieving coordinated and sustainable development of the region as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 A schematic flow chart of a method for collaborative configuration of a water-food-energy-ecological system developed by the present invention taking into account unconventional water utilization;

[0069] Figure 2 Schematic diagram of a water-food-energy-ecological system synergistic configuration model developed by the present invention considering unconventional water utilization;

[0070] Figure 3 Schematic diagram of system benefits and water resource allocation results of 96 embodiments;

[0071] Figure 4 Schematic diagram of agricultural land and ecological land area under different scenarios. DETAILED DESCRIPTION

[0072] The specific implementation method of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0073] Those skilled in the art should understand that the step numbers used herein are only for convenience of description and are not intended to limit the order in which the steps are to be executed. Figure 2 This is the system framework diagram developed. First, based on basic data such as social environment data, hydrology and water resources, and ecological environment, a water-food-energy-ecological system collaborative configuration model is constructed, and vinecopula and multi-stage stochastic programming are introduced to solve the model, thereby dealing with the complexity and uncertainty in the associated system and reflecting the complex interdependence between multiple random variables. In specific practice, the implementation process includes the following steps:

[0074] Step A: Consider the coordinated allocation of unconventional water and conventional water resources, and build a coordinated allocation model of the water-food-energy-ecological system to balance the competition for water resources among different regions and users, and quantitatively analyze the interactive relationship between water resource allocation, agricultural production, energy utilization and ecological protection; Step A is specifically divided into:

[0075] Step A1: Considering the utilization of unconventional water resources such as brackish water, industrial wastewater and domestic sewage, and taking the maximization of system benefits as the goal, construct the objective function:

[0076] Max=BEN_PRO+BEN_ECO+BEN_BRA+BEN_ENE-COS_TRW-COS_AGR

[0077] Water distribution benefits for production departments:

[0078]

[0079] Where i is the administrative region; j is the user; k is the energy conversion technology; t is the period; PW ijt For unit water distribution efficiency, TARW ijt is the water distribution target; p h CW is the probability of water coming; ijt It is a penalty for insufficient water supply; SW ijhtGW is the surface water allocation ijht IRW is the groundwater allocation; ijht The amount of industrial wastewater allocated; DRW ijht BW is the amount of domestic sewage allocated; ijht is the amount of brackish water; α ijt and β ijt are the reuse rates of industrial wastewater and domestic sewage; BR ijt Reuse of water for the unit; TIC ijt and TDC ijt They are the unit industrial wastewater and domestic sewage treatment costs respectively.

[0080] The above-mentioned water allocation targets, water supply probability, penalty for insufficient water allocation, surface water allocation, groundwater allocation, industrial wastewater allocation, domestic sewage allocation, brackish water allocation, industrial wastewater and domestic sewage reuse rates, unit reuse water benefits, and unit industrial wastewater and domestic sewage treatment costs are sourced from CAwater, literature, and statistical yearbooks, etc.

[0081] Ecological water distribution benefits:

[0082]

[0083] Where, BT t and BA t TSW is the transport benefit and fishery benefit per unit water volume of rivers and lakes; ht is the available amount of surface water; jt Efficiency of water allocation to production and ecological sectors; γ kt Efficiency of water distribution for the energy sector; ESW ikht Surface water allocation for the energy sector; WKL t is the ecological flow downstream of the reservoir; GWD jt is the water demand per ecological user; CR jt Value of serving climate regulation; WR jt Serve the value of water conservation; SC jt Serve value for soil formation and protection; ST jt Serving the value of waste treatment; BD jt Value of serving biodiversity conservation; FP jt Value of serving food production; RM jt Serve value for raw materials; RA jt Serve the value of entertainment culture; CWD jt It is a penalty for insufficient water supply.

[0084] Net benefits of brackish water distribution:

[0085]

[0086] In the formula, SUB ijt and SUEB ikt Subsidy for brackish water for production and energy sector units; CEB ijt and CEEB ikt and for the brackish water desalination costs for the production and energy sectors, respectively.

[0087] Net energy benefits:

[0088]

[0089] Where, PEW kt Water distribution benefits for energy sector units; TAREW ikt Water allocation targets for the energy sector; ikt , η ikt and θ ikt They are cooling water, boiler water, desulfurization water and other water consumption coefficients in the energy conversion process; ESW ikht Allocation of surface water for the energy sector; EGW ikht Groundwater allocation for the energy sector; EDRW ikht Allocation of domestic wastewater for the energy sector; EBW ikht Allocation of brackish water for the energy sector; CEW kt Penalties for under-allocation of water to the energy sector.

[0090] Crop planting costs:

[0091]

[0092] Where, QF ijt PF is the amount of fertilizer used per unit area; ijt is the unit price of fertilizer; LF ijt Irrigation and leaching share; WPC ijt is the water requirement of crops per unit area; it The installation rate of drip irrigation and sprinkler irrigation; CELE t The power consumption per unit area for drainage, drip irrigation, sprinkler irrigation, etc.; YA ijt is the crop yield per unit area; EAGP jt Power consumption of agricultural product processing units; KLD jt CKL is the diesel consumption per unit area of ​​agricultural farming equipment; t Cost of diesel fuel used in crop machinery; FC ijt Fixed costs of farmland irrigation.

[0093] Water distribution costs:

[0094]

[0095] In the formula, CE jt For electricity prices; is the surface water head; lifting water head for groundwater; is the groundwater pressure head; Loss of head for groundwater; for surface water extraction efficiency; is the pumping efficiency; For power efficiency.

[0096] Step A2: With the availability of conventional water resources, the availability and utilization rate of unconventional water resources, irrigation-power generation water distribution balance, brackish water irrigation, ecological land protection, energy and water consumption as constraints:

[0097] Constraints on the availability of conventional water resources:

[0098]

[0099] Constraints on the availability of unconventional water resources (constraints on sewage treatment capacity):

[0100]

[0101] Constraints on the availability of brackish water:

[0102]

[0103] Brackish water treatment capacity constraints:

[0104]

[0105] Brackish water irrigation constraints:

[0106]

[0107] In this embodiment, the brackish water is used in the industrial, domestic and energy sectors after being desalinated; the brackish water is used in the agricultural and ecological sectors through mixed irrigation and rotation irrigation in a ratio of 1:1 between brackish water and fresh water.

[0108] Constraints on the utilization rate of unconventional water resources:

[0109]

[0110] Joint probability constraints:

[0111] C(1-p1,1-p2,1-p3)=1-P

[0112]

[0113] Pr[(ESW ikht +EGW ikht+EDRW ikht +EBW ikht )×θ ikt ≥FED ikt ]≥1-p1,k=3,4,5,6

[0114]

[0115] Pr[(SW ijht +GW ijht +DRW ijht +BW ijht ) / GWD jt ≥TDE ijt ]≥1-p3,j=6,...,9

[0116] In this embodiment, the joint probability constraint means that during different planning periods, the electricity, food and ecological land of each county and each user should meet their minimum demand; in addition, in order to deal with the problem of joint random uncertainty, this constraint is set based on vine copula stochastic planning, where p1 is the probability of default of electricity demand, p2 is the probability of default of food security, and p3 is the probability of default of ecological land.

[0117] Irrigation-power generation water balance constraints:

[0118]

[0119] Agricultural power consumption constraints:

[0120]

[0121] Energy consumption constraints:

[0122]

[0123] Constraints on salinity control in cultivated land:

[0124]

[0125] Bosten Lake Ecological Water Constraints:

[0126]

[0127] Energy and water consumption constraints:

[0128]

[0129] In the formula, TSW ht is the surface water availability; WRR t Groundwater return rate; TGW t is the available groundwater volume; Maximum capacity for treating wastewater for industrial users, Maximum capacity for treating sewage for domestic users; TBA t TBA is the amount of brackish water available during period t; t-1 is the amount of brackish water available in the previous period; ijt The upper limit of the proportion of brackish water irrigation; The maximum desalination capacity of brackish water; PWR t is the minimum recycled water repetition rate; PWB t The lower limit of the utilization ratio of brackish water; FED ikt is the total power demand; TFD it is the food demand; TDE ijt Minimum coverage area for ecological land; PEN t The largest proportion of energy and water consumption; PIN t It accounts for the largest proportion of water used for irrigation; The maximum available amount in the agricultural production process; KLD jt The diesel consumption per unit area of ​​agricultural farming equipment; The upper limit of diesel consumption in agricultural farming process; TLW t The maximum allowable water consumption for salt leaching; WKL t is the ecological flow downstream of the reservoir; BEW t The minimum ecological water requirement for Bosten Lake; TWE it Maximum available water volume for energy.

[0130] Step B: Use the vine copula method to quantify the complex interdependencies between multiple random variables and analyze the impact of joint default risk on the system, thereby reflecting the trade-offs and synergies between subsystems. Step B is divided into:

[0131] Step B1, select the C-vine copula structure and four common copula functions (Gaussian, Gumbel, Clayton and Frank Copula), use the maximum likelihood method to estimate parameters, and select the optimal joint distribution function through the minimum square Euclidean distance;

[0132] In this embodiment, in order to explore the impact of food, energy and ecological land demand on the WFEE association system, the present invention considers four joint default probabilities (p = 0.05, 0.1, 0.15 and 0.2) and generates 24 different individual default probability level combination scenarios.

[0133] Step B2: The joint risk value of food, energy and ecological land demand obtained based on the C-vine copula function is used in the constraints of the optimization model to reveal the interactive impact relationship between water resources, agriculture, energy and ecosystems.

[0134] Step C, integrate vine copula and multi-stage stochastic optimization method to solve the model, and analyze the impact of brackish water utilization rate, joint default probability and water level on the WFEE correlation system. Step C is divided into:

[0135] Step C1: Obtain input data by searching historical documents and statistical yearbooks, and discretize the continuous function into three levels: high, medium, and low. The corresponding probability of each water level is p h and

[0136] Step C2: Couple vine copula and multi-stage stochastic optimization method to solve the optimization model and obtain system benefits, food production, energy utilization, ecological protection and water resources allocation plans under different scenarios.

[0137] In this embodiment, the multi-stage stochastic optimization method can effectively solve the dynamic pursuit problem of random variables. That is, when the water allocation target cannot be met, a corresponding penalty will be generated, thereby correcting and compensating the water resource allocation decision in the previous stage to reduce the penalty risk and obtain the best compromise solution.

[0138] In this example, 24 joint default probabilities, 3 water inflow levels, and 4 brackish water utilization rate scenarios are considered to analyze their impacts on the water-food-energy-ecological linkage system. Figure 3 The system benefits and water resource allocation schemes under 96 scenarios are shown. The results show that the system benefits vary significantly with the probability of joint default. For example, the system benefits of scenario 79 (without considering brackish water, the probability of joint default of the system p = 0.2, p1 = 0.004, p2 = 0.004, p3 = 0.145) are the lowest, which is 2.44×10 12 Yuan; Scenario 95 (without considering brackish water, system joint default probability p = 0.2, p1 = 0.195, p2 = 0.004, p3 = 0.004) has the highest system benefit (115.04 × 10 12 In addition, the water allocation under different brackish water utilization rate scenarios varies significantly. For example, the total water allocation under the high brackish water utilization rate scenario (S15) is the highest, which is 12.12×10 12 m 3 ; When the use of brackish water is not considered (S88), the total water supply is the lowest, which is 10.18×10 12 m 3 Considering the utilization of brackish water can alleviate the shortage pressure of conventional water resources, promote the sustainable utilization and development of water resources, and provide a reference for decision makers.

[0139] In addition, the results also show that under different joint default probability scenarios, the crop, ecological planting area and energy production have changed, reflecting the interactive relationship between water resources, food, energy and ecosystems. By changing the level of joint default probability, it is helpful for decision makers to choose different management plans according to different risk response attitudes under random uncertainty conditions. Among them, with the increase of joint default probability, agricultural water allocation will increase by 0.59% to 2.83%, and ecological sector water allocation will decrease by 2.42%-7.5%. This is because as the level of joint probability increases, the demand for food, ecology and energy decreases, but at the same time the risk of system violation of constraints increases. Therefore, decision makers need to adopt different water resource allocation plans for different brackish water utilization rates, water inflow scenarios and different risk response attitudes.

Claims

1. A method for collaborative configuration of water-food-energy-ecological system considering unconventional water utilization, characterized in that: The following steps are involved: Step A: Consider the coordinated allocation of unconventional water and conventional water resources, and build a coordinated allocation model of the water-food-energy-ecological linkage system to balance the competition for water resources among different regions and users, and quantitatively analyze the interactive relationship between water resource allocation, agricultural production, energy utilization and ecological protection; Step B: Using the vine copula method, we quantify the complex interdependencies among multiple random variables and analyze the impact of joint default risk on the system, thereby reflecting the trade-offs and synergies among the subsystems. Step C: Integrate vine copula and multi-stage stochastic optimization method to solve the model and analyze the impact of brackish water utilization, joint default probability and water inflow level on the WFEE associated system.

2. The method for collaborative configuration of water-food-energy-ecological system considering unconventional water utilization according to claim 1 is characterized in that: The step A comprises: Step A1: Considering the utilization of unconventional water resources such as brackish water, industrial wastewater and domestic sewage, and taking the maximization of system benefits as the goal, construct the objective function: Max=BEN_PRO+BEN_ECO+BEN_BRA+BEN_ENE-COS_TRW-COS_AGR Water distribution benefits for production departments: Where i is the administrative region; j is the user; k is the energy conversion technology; t is the period; PW ijt For unit water distribution efficiency, TARW ijt is the water distribution target; p h CW is the probability of water coming; ijt It is a penalty for insufficient water supply; SW ijht GW is the surface water allocation ijht IRW is the groundwater allocation; ijht The amount of industrial wastewater allocated; DRW ijht BW is the amount of domestic sewage allocated; ijht is the amount of brackish water; α ijt and β ijt are the reuse rates of industrial wastewater and domestic sewage; BR ijt Reuse of water for the unit; TIC ijt and TDC ijt They are the unit industrial wastewater and domestic sewage treatment costs respectively; Ecological water distribution benefits: Where, BT t and BA t TSW is the transport benefit and fishery benefit per unit water volume of rivers and lakes; ht is the available amount of surface water; jt Efficiency of water allocation to production and ecological sectors; γ kt Efficiency of water distribution for the energy sector; ESW ikht Surface water allocation for the energy sector; WKL t is the ecological flow downstream of the reservoir; GWD jt is the water demand per ecological user; CR jt Value of serving climate regulation; WR jt Serve the value of water conservation; SC jt Serve value for soil formation and protection; ST jt Serving the value of waste treatment; BD jt Value of serving biodiversity conservation; FP jt Value of serving food production; RM jt Serve value for raw materials; RA jt Serve the value of entertainment culture; CWD jt Penalty for insufficient water allocation; Net benefits of brackish water distribution: In the formula, SUB ijt and SUEB ikt Subsidy for brackish water for production and energy sector units; CEB ijt and CEEB ikt are the costs of brackish water desalination for the production and energy sectors, respectively; Net energy benefits: Where, PEW kt Water distribution benefits for energy sector units; TAREW ikt Water allocation targets for the energy sector; ikt , η ikt and θ ikt They are cooling water, boiler water, desulfurization water and other water consumption coefficients in the energy conversion process; ESW ikht Allocation of surface water for the energy sector; EGW ikht Groundwater allocation for the energy sector; EDRW ikht Allocation of domestic wastewater for the energy sector; EBW ikht Allocation of brackish water for the energy sector; CEW kt penalties for under-allocation of water to the energy sector; Crop planting costs: Where, QF ijt PF is the amount of fertilizer used per unit area; ijt is the unit price of fertilizer; LF ijt Irrigation and leaching share; WPC ijt is the water requirement of crops per unit area; it The installation rate of drip irrigation and sprinkler irrigation; CELE t The power consumption per unit area for drainage, drip irrigation, sprinkler irrigation, etc.; YA ijt is the crop yield per unit area; EAGP jt Power consumption of agricultural product processing units; KLD jt CKL is the diesel consumption per unit area of ​​agricultural farming equipment; t Cost of diesel fuel used in crop machinery; FC ijt Fixed costs of farm irrigation; Water distribution costs: Where, CE jt For electricity prices; is the surface water head; lifting water head for groundwater; is the groundwater pressure head; Loss of head for groundwater; for surface water extraction efficiency; is the pumping efficiency; For power efficiency; Step A2: With the availability of conventional water resources, the availability and utilization rate of unconventional water resources, irrigation-power generation water distribution balance, brackish water irrigation, ecological land protection, energy and water consumption as constraints: Constraints on the availability of conventional water resources: Constraints on the availability of unconventional water resources (constraints on sewage treatment capacity): Constraints on the availability of brackish water: Brackish water treatment capacity constraints: Brackish water irrigation constraints: Constraints on the utilization rate of unconventional water resources: Joint probability constraints: C(1-p1,1-p2,1-p3)=1-P Pr[(ESW ikht +EGW ikht +EDRW ikht +EBW ikht )×θ ikt ≥FED ikt ]≥1-p1,k=3,4,5,6 Pr[(SW ijht +GW ijht +DRW ijht +BW ijht ) / GWD jt ≥TDE ijt ]≥1-p3,j=6,...,9 Irrigation-power generation water balance constraints: Agricultural power consumption constraints: Energy consumption constraints: Constraints on salinity control in cultivated land: Bosten Lake Ecological Water Constraints: Energy and water consumption constraints: In the formula, TSW ht is the surface water availability; WRR t Groundwater return rate; TGW t CIM is the available groundwater volume; it max Maximum capacity for treating wastewater for industrial users, CDM it max Maximum capacity for treating sewage for domestic users; TBA t TBA is the amount of brackish water available during period t; t-1 is the amount of brackish water available in the previous period; ijt The upper limit of the proportion of brackish water irrigation; The maximum desalination capacity of brackish water; PWR t is the minimum recycled water repetition rate; PWB t The lower limit of the utilization ratio of brackish water; FED ikt is the total power demand; TFD it is the food demand; TDE ijt Minimum coverage area for ecological land; PEN t The largest proportion of energy and water consumption; PIN t It accounts for the largest proportion of water used for irrigation; The maximum available amount in the agricultural production process; KLD jt The diesel consumption per unit area of ​​agricultural farming equipment; The upper limit of diesel consumption in agricultural farming process; TLW t The maximum allowable water consumption for salt leaching; WKL t is the ecological flow downstream of the reservoir; BEW t The minimum ecological water requirement for Bosten Lake; TWE it Maximum available water volume for energy.

3. The method for collaborative configuration of water-food-energy-ecological system considering unconventional water utilization according to claim 1 is characterized in that: The step B comprises: Step B1, select the C-vine copula structure and four common copula functions, use the maximum likelihood method to estimate parameters, and select the optimal joint distribution function through the minimum square Euclidean distance; Step B2: The joint risk value of food, energy and ecological land demand obtained based on the C-vine copula function is used in the constraints of the optimization model to obtain the interactive impact relationship between water resources, agriculture, energy and ecosystems.

4. The method for collaborative configuration of water-food-energy-ecological system considering unconventional water utilization according to claim 3 is characterized in that: The four common copula functions are: Gaussian function, Gumbel function, Clayton function and Frank Copula function.

5. The method for collaborative configuration of water-food-energy-ecological system considering unconventional water utilization according to claim 1, characterized in that: The step C comprises: Step C1: Obtain input data by searching historical documents and statistical yearbooks, and discretize the continuous function into three levels: high, medium, and low. The corresponding probability of each water level is p h and Step C2: Couple vine copula and multi-stage stochastic optimization method to solve the optimization model and obtain system benefits, food production, energy utilization, ecological protection and water resources allocation plans under different scenarios.

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