A multifunctional storage pond optimization method based on rainwater regulation and recycled water storage

Abstract

This application provides a multifunctional storage pond optimization method based on rainwater and flood control and recycled water storage. First, based on short-duration rainfall, the rainwater and flood control optimization design of the storage pond is carried out to obtain a series of Pareto solution sets. Then, based on long-duration rainfall, the volume, water supply and scheduling strategy of the combined rainwater-recycled water storage are optimized. Finally, the optimal solution is selected through comprehensive evaluation. Therefore, through the multi-level, comprehensive and long-term optimization design, the comprehensive functional value of the storage pond is significantly improved, providing a more efficient and sustainable solution for modern urban water resources management.

Description

Technical Field

[0001] The present application belongs to the fields of municipal engineering, environmental engineering, and computer technology, and in particular relates to a multifunctional storage pond optimization method based on rainwater regulation and recycled water storage. Background Art

[0002] In recent years, with the intensification of climate change, heavy rains and flooding have become more frequent, placing enormous pressure on urban drainage systems. This has led to increasingly severe waterlogging, severely impacting infrastructure, public safety, and the environment. To address this challenge, storage ponds have become increasingly popular as an effective solution. By temporarily storing rainwater during periods of heavy rainfall, these ponds reduce peak flows, smooth out peak fluctuations, and alleviate pressure on drainage systems, thereby reducing the risk of flooding.

[0003] Currently, reservoir design optimization methods have shifted from traditional mathematical formulas to comprehensive optimization design methods based on mathematical models to more accurately simulate rainwater flow and system response. Currently, reservoir design optimization is typically performed using various hydrological models (such as the SWMM model) combined with optimization algorithms such as genetic algorithms and simulated annealing. These optimizations consider not only the reservoir's volume but also its layout, location, and inflow and outflow scheduling rules, among other factors, to achieve optimization under different rainfall scenarios, drainage pipe conditions, and regional conditions.

[0004] However, because the construction cost of urban-scale reservoirs is generally high, and the existing reservoir optimization methods are mostly based on the regulation and utilization of rainwater, they are usually only used to reduce the risk of urban flooding and alleviate the occurrence of flood disasters, but fail to fully expand the multifunctional application potential of reservoirs. For example, insufficient attention is paid to comprehensive functions such as recycled water storage, dry season water supply regulation, and rainy season stormwater management, resulting in long-term idleness of reservoirs on sunny days and a significant reduction in utilization rate. In addition, when optimizing reservoirs, existing technologies usually only consider the ability to cope with short-term extreme rainfall events, but fail to fully consider the impact of long-term rainfall on the reservoir. As a result, design optimization is only based on short-term rainfall, and the performance of the reservoir under long-term rainfall events is not fully evaluated and tested. This may result in the final selected reservoir scheme not being fully adapted to actual hydrological conditions and needs.

[0005] Therefore, it is necessary to propose a new technical solution to overcome the above technical problems, so as to realize the optimal design of a multifunctional regulating reservoir based on rainwater regulation and recycled water storage, and fully consider short-duration rainfall and long-duration rainfall in the optimization design to obtain an efficient and sustainable regulating reservoir design solution. Summary of the Invention

[0006] A multifunctional reservoir optimization method based on stormwater control and recycled water storage is designed to address the aforementioned technical issues. First, the reservoir's stormwater control optimization design is performed based on short-duration rainfall, yielding a series of Pareto solutions. Then, based on long-duration rainfall, the combined storage capacity, water supply, and scheduling strategies for rainwater and recycled water are optimized. Finally, the optimal solution is selected through comprehensive evaluation. This multi-level, comprehensive, and long-term optimization design significantly enhances the overall functional value of the reservoir, providing a more efficient and sustainable solution for modern urban water resource management.

[0007] Specifically, the embodiment of the present application provides a multifunctional storage pond optimization method based on rainwater regulation and recycled water storage, characterized in that it includes the following steps:

[0008] S1. Under short-duration rainfall scenarios, a multi-objective optimization model for stormwater management and flood control is constructed. The objective function is constructed based on the cost of the reservoir, the overflow reduction rate, and the flood peak reduction rate. The decision variables are constructed based on the reservoir volume, the diameter and offset of the inlet pipe, and the outflow rate of the reservoir. Constraints are set based on the reservoir volume, the diameter and offset of the inlet pipe, the outflow rate of the reservoir, and waterlogging control.

[0009] S2. Solve the multi-objective optimization model using the NSGA-II algorithm to obtain a Pareto solution set;

[0010] S3. Based on the Pareto solution set, design the storage capacity, water supply, and scheduling strategies for combined rainwater and recycled water storage under long-duration rainfall scenarios, construct a comprehensive framework covering rainfall-demand matching, combined storage capacity optimization, water supply, and scheduling strategies, and then form alternative plans;

[0011] S4. Using the TOPSIS method, the economic index, recycled water reuse index, and urban waterlogging index are used as evaluation indicators to rank the alternative options and obtain the optimal option.

[0012] The objective function in step S1 is specifically:

[0013]

[0014] Among them, f1 is the cost of the storage tank, the unit is yuan, N is the total number of storage tanks, V n is the volume of the nth storage tank, in m 3 , A n is the area of ​​the nth storage tank, in m 2 , a, b, α are coefficients, E is the startup cost, the unit is yuan;

[0015] f2 is the overflow reduction rate, U is the total number of nodes, FQ u Add the overflow volume before the storage tank at the u-th node, in m 3 , Q u The overflow volume after adding the storage tank to the u-th node, in m 3 ;

[0016] f3 is the flood peak reduction rate, L is the total number of discharge outlets, Q pre,l is the peak flow rate of the lth outlet when no storage tank is added, in m 3 , Q l The peak flow rate of the lth discharge outlet after setting up the storage tank, in m 3 .

[0017] The decision variables in step S1 are specifically:

[0018] X=(a 0，n , H offset，n , H inflow，n , setting n );

[0019] Among them, a 0，n is the area parameter of the nth storage tank, H offset，n is the offset of the water inlet pipe of the nth storage tank, in m, H inflow，n The diameter of the water inlet pipe of the nth storage tank is in meters, setting n is the pump curve multiplier of the nth storage tank.

[0020] The constraints in step S1 are specifically:

[0021] S min ≤a0≤S max ;

[0022] 0≤H inflow ≤H link ;

[0023] 0≤H offset ≤H node -H inflow ;

[0024] 0≤setting≤10;

[0025] T pongding ≤0.5;

[0026]

[0027] Among them, a0 is the area parameter of the storage tank, the unit is m 2 , S min 、Smax The minimum and maximum allowable floor space of the storage tank, in m 2 ;H inflow is the diameter of the water inlet pipe of the storage tank, in m, H link H is the diameter of the upstream pipe of the water inlet pipe, in m; offset is the inlet pipe offset of the storage tank, in m, H node is the node depth of the node connected to the water inlet pipe of the storage tank, in meters; setting is the pump curve multiplier; T pongding The time for water to recede is h, h depth is the depth of accumulated water in cm, i is the ground slope in %, and V is the volume of accumulated water in m 3 , W is the width of the catchment area, in meters.

[0028] The economic indicators in step S4 include: the construction cost of the regulating reservoir, the construction cost of the pump station, the construction cost of the recycled water network, the power cost of the pump station, and the employee salary and welfare costs. The specific calculation formula is:

[0029]

[0030] C3=C 31 +C 32 ,

[0031] C5=(G+S+F)A

[0032] Among them, C1 is the construction cost of the storage tank, the unit is RMB, P1 is the percentage of the operation and maintenance cost of the storage tank, the unit is %, and C is the construction cost per unit volume, the unit is RMB / m 3 , V n is the volume of the nth storage tank, in m 3 , N is the total number of storage tanks;

[0033] C2 is the construction cost of the pump station, in RMB, P2 is the percentage of the operation and maintenance cost of the water pump, in %, f is the cost of the pump station per kilowatt capacity, in RMB / kW, τ is the reserve coefficient of the pump station unit, N+1 is the total number of rainwater lifting pump stations and recycled water pump stations, Q n 、H n ,η n is the water supply, head and efficiency of the nth pumping station, in units of L / s, m, and % respectively; mp is the economic efficiency coefficient of the pumping station;

[0034] C4 is the construction cost of the recycled water network, in RMB, P3 is the percentage of the network's operation and maintenance costs, in %, G is the total number of recycled water supply pipelines, C gis the construction cost per unit length of the g-th pipeline, in yuan / m, w, r, α are pipeline statistical parameters, d g is the diameter of the g-th pipe, in m, l g is the length of the g-th pipe, in meters;

[0035] C3 is the power cost of the pump station, in yuan; C 31 is the power cost of reclaimed water lifting, in RMB, J is the total number of reclaimed water lifting times, α is the proportion of the cost of sludge removal and backwashing in the pumping station, e is the electricity price of the pumping station, in RMB / KW·h, ρ is the liquid density, in kg / m 3 , g is the acceleration due to gravity, unit is m / s 2 , Q j The jth recycled water lift volume, in m 3 / d,H j is the jth recycled water lifting head, in m, η is the pumping station efficiency, C 32 The power cost of rainwater lifting, in yuan, W n is the power of the nth water pump, in kW h.

[0036] C5 is the employee salary and welfare expenses, in yuan; G is the sum of the staffing numbers of positions in charge of the unit, administrative management, technical management, financial and asset management, and water administration supervision, in people; S is the sum of the staffing numbers of operation and observation positions, in people; F is the staffing number of auxiliary positions, in people; A is the average annual salary and welfare expenses of each employee, in yuan / person / year.

[0037] The reclaimed water reuse index in step S4 includes: water-saving benefits, environmental benefits, water supply guarantee rate, abandoned water volume, and the total number of starts and stops of the reclaimed water pump station. The specific calculation formula is:

[0038] B1=(TW)V reuse ;

[0039] B2=B 21 +B 22 ,

[0040] B5=∑J

[0041] B1 is the water-saving benefit of recycled water reuse, in RMB, and T is the unit price of tap water, in RMB / m 3 , W is the unit price of recycled water, in yuan / m 3 , V reuse is the total amount of recycled water reused, in m 3 .

[0042] B2 is the environmental benefit of recycled water reuse, in yuan; 21 is the carbon fixation and oxygen release benefit of recycled water, in yuan. is the carbon tax, in RMB / ton, is the carbon sequestration rate per unit area of ​​green land, in tons / year, is the price of industrial oxygen production, in yuan / m 3 , Q is the oxygen release rate per unit area of ​​green space, in tons / year, max，j is the maximum water demand of the jth green space, q G，j is the jth green space water supply, A G is the green area; B 22 The unit is RMB for air purification efficiency. is the SO2 industrial processing cost, in yuan / ton, The annual SO2 absorption capacity of green land per unit area, in tons / year, P ZC is the cost of industrial dust treatment, in yuan / ton, H GZ Annual dust retention capacity per unit area of ​​green space, in tons / year, A R is the road area, in m 2 , H RZ is the annual dust retention capacity of the road per unit area, in tons / year;

[0043] B3 is the water supply guarantee rate, V j is the water demand at the jth water supply, in m 3 , W j is the water supply volume during the jth water supply, in m 3 ;

[0044] B4 is the amount of discarded water, Q i is the amount of reclaimed water discharged from the storage pool before the i-th rainfall, and I is the total number of rainfall events;

[0045] B5 is the total number of starts and stops of the recycled water pump station, and J is the total number of times the recycled water is lifted.

[0046] The urban waterlogging indicators in step S4 include: total node overflow volume, total node overflow duration, and average number of overflow nodes per field. The specific calculation formula is:

[0047]

[0048] Among them, S1 is the total overflow of the nodes in the study area, in m 3 , Flood i，u is the overflow of the u-th node during the i-th rainfall, in m 3 , U is the total number of nodes, I is the total number of rainfall events;

[0049] S2 is the total overflow duration of the nodes in the study area, in h. i，u is the total overflow duration of the u-th node in the i-th rainfall, in h;

[0050] S3 is the average number of overflow nodes in the study area; Num i is the number of overflow nodes in the i-th rainfall.

[0051] Wherein, the step S4 specifically includes:

[0052] S41. Establish a forward matrix, construct a forward data matrix X containing n schemes to be evaluated and m evaluation indicators, X = (x ij ) nm , x ij represents the value of the jth evaluation index of the i-th evaluation scheme, where when the jth index of the i-th evaluation scheme is a negative index, x ij is the value after the original index value is positively processed;

[0053] S42, data normalization, obtain the standardized matrix Z, Z = z ij , z ij It represents the normalized value of the jth evaluation indicator of the i-th scheme to be evaluated;

[0054] S43, establish the optimal and worst moment values, and obtain the positive ideal solution Z + and negative ideal solution Z - , specifically:

[0055]

[0056] S44. Calculate the Euclidean distance between the positive and negative ideal solutions. Use the Euclidean distance method to calculate the distance between each of the solutions to be evaluated and the positive and negative ideal solutions. Specifically:

[0057]

[0058] in, is the distance between the i-th scheme to be evaluated and the positive ideal solution, is the distance between the i-th evaluated solution and the negative ideal solution, ω j is the weight of the j-th evaluation index;

[0059] S45. Calculate the ideal closeness of each solution and normalize it. Specifically:

[0060]

[0061] Among them, S i represents the ideal closeness of the i-th scheme to be evaluated, represents the normalized ideal closeness of the i-th scheme to be evaluated;

[0062] S46. Sort the schemes to be evaluated according to their normalized ideal closeness, and select the scheme with the largest normalized ideal closeness as the optimal scheme.

[0063] In step S3, the storage tank capacity, water supply and scheduling strategies for the combined regulation of rainwater and recycled water are designed to construct a comprehensive framework covering rainfall-water demand matching, combined regulation storage capacity optimization, water supply and scheduling strategies, specifically including:

[0064] S31. Calculate the daily water consumption under low water demand, medium water demand, and high water demand in the study area;

[0065] S32. Calculate the storage period under different water demands based on the daily water consumption under different water demands, specifically:

[0066]

[0067] Among them, V rain The volume of the storage tank corresponding to each solution in the Pareto solution set obtained in step S2, in m 3 , V d，min 、V d，mid 、V d，max The daily water consumption under low, medium and high water demand respectively, in m 3 , T min 、T mid 、T max is the storage period corresponding to each demand, in d;

[0068] S33. Calculate the water supply and waste water volume of the regulating reservoir within one scheduling cycle. Specifically:

[0069]

[0070] Where T represents a complete scheduling cycle. For low, medium and high water demand, T is T min 、T mid 、T max , V d Indicates daily water consumption. For low, medium and high water demand, V d Take V d，min 、V d，mid 、V d，max , t rain Indicates the time point when the first rainfall occurs in a scheduling cycle.

[0071] The long-duration rainfall scenario in step S3 refers to the daily rainfall data of the study area in the past 20 years.

[0072] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0073] The present invention provides a multifunctional regulating and storage pond optimization method based on rainwater and flood control and recycled water storage. First, based on short-duration rainfall, the rainwater and flood control optimization design of the regulating and storage pond is carried out to obtain a series of Pareto solution sets. Then, based on long-duration rainfall, the volume, water supply and scheduling strategy of the combined regulation of rainwater and recycled water are optimized. Finally, the optimal solution is selected through comprehensive evaluation. Therefore, through the multi-level, comprehensive and long-term series optimization design, the comprehensive functional value of the regulating and storage pond is significantly improved, providing a more efficient and sustainable solution for modern urban water resources management.

[0074] Specifically, the present invention can improve the ability of the regulating reservoir to cope with extreme rainfall events by optimizing the design parameters of the regulating reservoir under short-duration rainfall scenarios. By comprehensively evaluating the actual rainfall and recycled water demand under long-duration rainfall scenarios, the most suitable volume solution can be obtained. Moreover, by designing reasonable water supply and scheduling strategies, it can ensure that the regulating reservoir can efficiently realize the rapid conversion between rainwater and recycled water storage functions, further enhancing the flexibility and adaptability of the system. Finally, the optimal solution is selected through comprehensive evaluation of each solution, so that the final regulating reservoir design solution can achieve the optimal comprehensive performance under different hydrological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art.

[0076] Figure 1 This is a flow chart of a multifunctional storage pond optimization method based on rainwater regulation and recycled water storage provided in an embodiment of the present application;

[0077] Figure 2 This is a page for setting the bottom area of ​​the storage pond based on the SWMM model provided in the embodiment of the present application;

[0078] Figure 3 This is a control statement writing page based on the SWMM model provided in the embodiment of the present application;

[0079] Figure 4 Schematic diagram of a storage tank scheduling method provided in an embodiment of the present application;

[0080] Figure 5 It is a schematic diagram of the overall operation process of the multifunctional regulating storage tank provided in the embodiment of the present application. DETAILED DESCRIPTION

[0081] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0082] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0083] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0084] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0085] In addition, in the description of this application specification and the appended claims, the terms "first", "second", "third", "fourth", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0086] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0087] The following are explanations of the terms used in this invention:

[0088] Reservoir: A reservoir is a device that stores excess water during rainfall so that it can be gradually released after the rain to avoid flooding problems such as urban waterlogging. It can regulate water flow, reduce peak flow caused by heavy rain, and reduce the burden on the drainage system.

[0089] Stormwater control: Stormwater control refers to taking measures to control the flow of rainwater and flood water to prevent urban waterlogging or other floods, usually including the establishment of storage ponds, rainwater collection and discharge systems, etc.

[0090] Recycled water storage: Recycled water storage refers to the storage and utilization of treated wastewater as an unconventional water resource for urban irrigation, industrial cooling and other purposes.

[0091] SWMM model: SWMM (Storm Water Management Model) is a software developed by the U.S. Environmental Protection Agency for urban runoff simulation. It is widely used in stormwater management and drainage system design. It can simulate rainfall, surface runoff, runoff processes, and the behavior of drainage pipe networks.

[0092] Peak flood reduction: Peak flood reduction involves reducing peak flows in drainage systems after heavy rains through various means to mitigate the risk of flooding. Reservoirs are often used to store excess water, reducing the amount of water flowing into the drainage system over a short period of time.

[0093] Rainfall return period: The return period of rainfall refers to the probability of a rainfall event of a certain intensity occurring again within a certain time frame. For example, a 50-year rainfall event refers to an extreme rainfall event that is likely to occur once within 50 years.

[0094] Inlet pipe diameter: The inlet pipe diameter refers to the diameter of the pipe through which water flows into the reservoir. The size of the pipe directly affects the flow rate. Optimizing the pipe diameter can improve the system's operating efficiency and flow regulation capabilities.

[0095] Pump Curve: A pump curve describes the relationship between a pump's flow rate and head. Different types of pumps have different flow and head characteristics. Pump curves are used in reservoir design to determine pump performance under varying flow conditions.

[0096] Pump multiplier: The pump multiplier is a parameter used to adjust the pump flow rate in the optimization model. By adjusting the multiplier, the output flow rate of the pump can be controlled under different operating conditions.

[0097] Overflow reduction rate: The overflow reduction rate is an important indicator to measure the effectiveness of a reservoir in preventing waterlogging. It represents the proportion of the original overflow volume that is reduced by the reservoir design.

[0098] Short-duration rainfall: refers to rainfall events under design rainfall conditions, typically involving a short duration of rainfall, typically a few hours, with high rainfall intensity. This is often calculated using rainfall models such as the Chicago Storm Model and used in design analysis for short-duration, heavy rainfall.

[0099] Long-duration rainfall refers to rainfall events that last for a long time, typically several days or longer, with relatively uniform rainfall intensity. This is often used to analyze the impact of rainfall accumulation over long periods of time on the design and performance of storage tanks.

[0100] Offset: refers to the difference between the bottom elevation of the water inlet pipe of the regulating reservoir and the bottom elevation of the access pipe, which can control the water inflow time of the regulating reservoir. Specific embodiments

[0102] Figure 1 A flowchart of a multifunctional storage tank optimization method based on rainwater regulation and recycled water storage is shown in the embodiment of the present application. Figure 1 As shown, the multifunctional storage pond optimization method based on rainwater regulation and recycled water storage specifically includes:

[0103] S1. Under short-duration rainfall scenarios, a multi-objective optimization model for stormwater management and flood control is constructed. The objective function is constructed based on the cost of the reservoir, the overflow reduction rate, and the flood peak reduction rate. The decision variables are constructed based on the reservoir volume, the diameter and offset of the inlet pipe, and the outflow rate of the reservoir. Constraints are set based on the reservoir volume, the diameter and offset of the inlet pipe, the outflow rate of the reservoir, and waterlogging control.

[0104] The objective function in step S1 includes economic objectives, water volume objectives, and system load objectives.

[0105] The economic goal is to minimize the cost of the regulating reservoir, which is represented by the regulating reservoir construction cost f1. The water volume target is the reduction rate of the overflow volume of the regional node after the construction of the regulating reservoir, which is represented by the overflow reduction rate f2. The peak flow of the pipeline can usually reflect the load capacity of the rainwater system, and the system load target is represented by the flood peak reduction rate f3.

[0106] Specifically, the objective function in step S1 is:

[0107]

[0108] Among them, f1 is the cost of the storage tank, the unit is yuan, N is the total number of storage tanks, V n is the volume of the nth storage tank, in m 3 (i.e. cubic meters), A n is the area of ​​the nth storage tank, in m 2(i.e. square meters), a, b, α are coefficients, E is the startup cost, the unit is yuan; preferably, a is 2000, α is 0.69, b is 500, and E is 50000;

[0109] f2 is the overflow reduction rate, U is the total number of nodes, FQ u Add the overflow volume before the storage tank at the u-th node, in m 3 (i.e. cubic meters), Q u The overflow volume after adding the storage tank to the u-th node, in m 3 (i.e. cubic metres);

[0110] Nodes are rainwater nodes, which are actually rainwater wells. When rainwater exceeds the pipe load, it overflows from the well. The amount of overflow at a node reflects the amount of water accumulation near the node. The greater the overflow, the greater the risk of waterlogging. Therefore, the overflow reduction rate before and after the placement of the storage tank is used as one of the objective functions.

[0111] f3 is the flood peak reduction rate, L is the total number of discharge outlets, Q pre,l is the peak flow rate of the lth outlet when no storage tank is set up, in m 3 (i.e. cubic meters), Q l The peak flow rate of the lth discharge outlet after setting up the storage tank, in m 3 (i.e. cubic meters).

[0112] The discharge outlet refers to the outlet at the end of the stormwater pipe network, where rainwater is discharged into rivers. Measuring the flow rate at the discharge outlet generally reflects the stormwater pipe network's ability to handle rainfall. The peak flood reduction rate is a key indicator for evaluating the flood control effectiveness of a reservoir. It reflects the extent to which the reservoir can reduce peak inflows during heavy rainfall. The peak flood reduction rate can be used to accurately assess flood control effectiveness, and is therefore used as one of the objective functions.

[0113] The decision variables in step S1 include: volume, diameter and offset of the water inlet pipe, and outflow rate of the regulating reservoir;

[0114] The present invention obtains the above decision variables based on the SWMM model.

[0115] In the SWMM model, the volume of the storage tank is composed of the product of the bottom area and the height. The bottom area setting page is as follows: Figure 2As shown, the shape of the regulating reservoir is selected in the form of [Function], the bottom area is set as a function of the depth, and the relationship between the depth and the bottom area is set by the coefficient a1, the exponent a2, and the constant a0. In order to simplify the setting of decision variables, the present invention sets a1 and a2 to 0, and the area of ​​the regulating reservoir is a0; and the height is usually not set as a decision variable when designing the regulating reservoir, because the height changes during the optimization process, which will cause errors in the connection between the inlet and outlet pipes of the regulating reservoir and the regulating reservoir, and then cause the model to report an error. Therefore, the present invention sets the height of the regulating reservoir [Max.Depth] to 5m, and by setting a0 as the decision variable, the volume of the regulating reservoir is identified.

[0116] The inlet pipe diameter is obtained by setting [Max.Depth] as the decision variable, the inlet pipe offset is obtained by setting [Inlet Offset] as the decision variable, and the system offset is set in depth form.

[0117] In SWMM, the flow rate of a pump is usually set in the form of a pump curve. There are five types of pump curves:

[0118] a. Type 1 sets the pump flow rate based on the relationship curve between the pump flow rate and the available volume of the water collection well;

[0119] b. Type 2 sets the pump flow rate based on the relationship curve between the pump flow rate and the depth of the water inlet node;

[0120] c. Type 3 sets the pump flow rate based on the relationship curve between the pump flow rate and the head difference between the inlet and outlet nodes;

[0121] d. Type 4 variable speed online water pump, set the water pump flow rate according to the curve of continuous change of water pump flow rate with the depth of water inlet node;

[0122] e. The Type 5 pump flow rate is equal to the inflow rate of the inlet node.

[0123] The present invention selects Type 2, sets the flow rate at each depth to a fixed flow rate, and the flow rate is initially set to increase by 1000m within 12 hours. 3 Rainwater. When setting a curve, it is usually necessary to set the starting and ending parameters, such as the flow rate under various depth conditions. If it is directly set as the decision variable for the outflow flow, it will cause one outflow flow decision variable to be composed of multiple variables, which will result in too many variables being set. The SWMM model sets a control rule [Control] module, which can dynamically control the on / off and operating status of the water pump by writing control statements. It is usually used to simulate the variable speed drive of the water pump. The water pump curve multiplier [Setting] is used to identify the overall increase or decrease multiplier of the water pump flow. The control statement writing page is as follows Figure 3As shown in the figure, by setting the value of the control statement [Setting] as the decision variable, the overall control of the flow rate of each pump can be achieved.

[0124] Therefore, the decision variables in step S1 are specifically:

[0125] X=(a 0，n , H offset，n , H inflow，n , setting n );

[0126] Among them, a 0，n is the area parameter of the nth storage tank, H offset，n is the offset of the water inlet pipe of the nth storage tank, in m, H inflow，n The diameter of the water inlet pipe of the nth storage tank is in meters, setting n is the pump curve multiplier of the nth storage tank.

[0127] The constraints in step S1 include the water inlet pipe diameter constraint, offset constraint, bottom area constraint, water pump multiplier constraint, and waterlogging control constraint.

[0128] Among them, for the water pump multiplier constraint, the initial flow rate of the water pump is set to empty 1000m3 within 12 hours. 3 Rainwater, based on a 50-year rainfall scenario, runs the SWMM model, and the maximum water inflow to each storage tank does not exceed 10,000 m 3 , so the maximum value of the water pump multiplier is set to no more than 10 and no less than 0;

[0129] Regarding waterlogging control constraints, according to the "Code for Design of Outdoor Drainage" (GB50014-2021), the depth of ground waterlogging should be less than 15 cm, and the drainage time for ground waterlogging should be less than 0.5 hours. In the SWMM model, depth can be represented by the volume of ponded water, the width of the catchment area, and the ground slope.

[0130] The constraints in step S1 are specifically:

[0131] S min ≤a0≤S max ;

[0132] 0≤H inflow ≤H link ;

[0133] 0≤H offsed ≤H node -H inflow ;

[0134] 0≤setting≤10;

[0135] T pongding ≤0.5;

[0136]

[0137] Among them, a0 is the area parameter of the storage tank, the unit is m 2 , S min 、S max The minimum and maximum allowable floor space of the storage tank, in m 2 ;H inflow is the diameter of the water inlet pipe of the storage tank, in m, H link H is the diameter of the upstream pipe of the water inlet pipe, in m; offset is the inlet pipe offset of the storage tank, in m, H node is the node depth of the node connected to the water inlet pipe of the storage tank, in meters; setting is the pump curve multiplier; T pongding The time for water to recede is h, h depth is the depth of accumulated water in cm, i is the ground slope in %, and V is the volume of accumulated water in m 3 , W is the width of the catchment area, in meters.

[0138] S2. Solve the multi-objective optimization model using the NSGA-II algorithm to obtain a Pareto solution set;

[0139] The NSGA-II algorithm is a commonly used evolutionary algorithm for solving multi-objective optimization problems. It simulates the process of natural selection to optimize a population of individuals to achieve an optimal balance between different objectives. It is particularly well-suited for complex water resource management systems like reservoirs. Therefore, this paper employs the NSGA-II algorithm to solve the constructed multi-objective optimization model and obtains a Pareto solution set.

[0140] The basic principle of the NSGA-II algorithm is to find the best compromise between multiple objectives through a non-dominated sorting and crowding distance mechanism. The specific optimization process of the NSGA-II algorithm is consistent with existing technologies and includes: individual encoding and initialization, goal evaluation, non-dominated sorting, crowding distance calculation, crossover and mutation selection, population update and iteration, and termination condition determination.

[0141] S3. Based on the Pareto solution set, design the storage capacity, water supply, and scheduling strategies for combined rainwater and recycled water storage under long-duration rainfall scenarios, construct a comprehensive framework covering rainfall-demand matching, combined storage capacity optimization, water supply, and scheduling strategies, and then form alternative plans;

[0142] To achieve urban stormwater control, existing technologies typically configure reservoir capacities based on different rainfall return periods, tailored to specific needs. For example, to control urban flooding, the return period is set to 10-100 years, while to meet total runoff control requirements, the return period is set to 1-2 years. However, this approach only considers the ability to respond to a single extreme rainfall event, ignoring regional variations in rainfall characteristics. For example, in areas with sparse rainfall, adopting a 100-year design standard can significantly incur cost overhead.

[0143] On the other hand, for recycled water supply, the regulating and storage tank plays the role of temporary water storage. Its volume is determined by parameters such as the storage period and water quota. A longer storage period and water quota will result in a larger volume. At the same time, when the rainfall interval in the study area is short and the frequency is high, in order to reduce the amount of recycled water discarded, a smaller regulating and storage tank has a greater advantage. A smaller regulating and storage tank is also more advantageous for cold areas such as the north where there is no municipal water demand in autumn and winter. However, a small volume cannot play its due role in the face of extreme rainfall.

[0144] Therefore, for multifunctional regulating and storage ponds, it is unreasonable to design the capacity directly based on a single parameter, such as rainfall, or according to a certain water storage capacity. This paper selects daily rainfall data from the study area over the past 20 years and calculates the balance between water consumption, water abandonment, and rainfall for reservoirs of different capacities over a continuous time period. This design then designs the reservoir capacity, water supply, and scheduling strategies for combined rainwater and recycled water regulation. Furthermore, it calculates factors such as reservoir overflow volume, number of overflows, water abandonment, and construction costs for different capacity schemes. After conducting technical and economic comparisons, the capacity is determined to obtain the optimal reservoir design.

[0145] Specifically, in step S3, the storage tank capacity, water supply and scheduling strategies for the combined rainwater-recycled water storage are designed to construct a comprehensive framework covering rainfall-water demand matching, combined storage capacity optimization, water supply and scheduling strategies, including:

[0146] S31. Calculate the daily water consumption under low water demand, medium water demand, and high water demand in the study area;

[0147] When a reservoir is used to store and supply water, its capacity design needs to consider water demand, water quotas, and storage cycles. Furthermore, unconventional water resources such as recycled water are primarily used for green space irrigation, road irrigation, and landscape water bodies. These water demands may vary in timing and volume. For example, road irrigation may require concentrated, high-volume water, while green space irrigation may be more dispersed and continuous. Setting different storage cycles for different water demands can help rationally allocate these unconventional water resources based on their diversity and stability.

[0148] Among them, the storage period refers to how many days the water in the reservoir can be stored at one time.

[0149] S32. Calculate the storage period under different water demands based on the daily water consumption under different water demands, specifically:

[0150]

[0151] Among them, V rain The volume of the storage tank corresponding to each solution in the Pareto solution set obtained in step S2, in m 3 , V d，min 、V d，mid 、V d，maz The daily water consumption under low, medium and high water demand respectively, in m 3 , T min 、T mid 、T max is the storage period corresponding to each demand, in d;

[0152] For road sprinkler water, the water quotas are 3.0, 2.5, and 2.0 L / (m2) for high, medium, and low water demands, respectively. 2 d); For green space irrigation, the water quotas are 3.0, 2.0, and 1.0 L / (m2) for high, medium, and low water demands, respectively. 2 ·d).

[0153] The storage tank is used to store and supply water on sunny days and to store rainwater on rainy days. Therefore, its operation rules need to be designed, that is, the scheduling design. This paper designs the scheduling strategy for water supply and water abandonment of the storage tank based on the assumption that the rainfall forecast information within 3 days is accurate and reliable. Figure 4 As shown in the figure, where T represents a complete scheduling cycle, which is defined by the complete consumption of recycled water resources in the storage tank or a rainfall event; t rain It represents the time point when the first rainfall occurs in a scheduling cycle. At this time point, the scheduling cycle is divided into days. The entire scheduling process is subdivided into three steps: prediction, decision-making and information update, and it is iterated according to the rolling cycle mode of forecast-decision-update.

[0154] In the present invention, the forecasting link focuses on integrating rainfall forecast data into the control model, while the decision-making link is divided into two parts: water supply decision-making and water abandonment decision-making. The water supply decision is made based on the prediction model's prediction of the rainfall situation in the next three days. If the forecast shows that rainfall will occur, only the amount of water required before the first rainfall will be provided; conversely, if the water storage period of the regulating reservoir is expected to exceed 3 days and the forecast shows that there will be no rainfall during this period, the full amount of water required for the entire water storage period will be provided. The rolling update cycle of the water supply decision is consistent with the scheduling cycle, that is, whenever the water resources in the regulating reservoir are exhausted or rainfall occurs, it is regarded as the end of a cycle. The rolling cycle of the water abandonment decision is shortened to 1 day. The probability of rainfall the next day is evaluated based on the daily rainfall forecast results. Once signs of rainfall are found and there is water accumulation in the regulating reservoir, the emptying operation is immediately performed to minimize the possibility of waterlogging during rainfall.

[0155] Furthermore, the method further includes S33, calculating the water supply and water abandonment of the regulating reservoir within a scheduling cycle, including:

[0156]

[0157] Where T represents a complete scheduling cycle. For low, medium and high water demand, T is T min 、T mid 、T max , V d Indicates daily water consumption. For low, medium and high water demand, V d Take V d，min 、V d，mid 、V d，max , t rain Indicates the time point when the first rainfall occurs in a scheduling cycle.

[0158] Among them, the scheduling cycle refers to the time interval between two recycled water supplies.

[0159] The operations of opening and closing the valves and water pumps in the regulating reservoir under different situations are shown in the following table:

[0160]

[0161]

[0162] Through the detailed formulation of the above-mentioned regulation and storage tank scheduling rules and valve and water pump operation rules, the overall operation process of the multifunctional regulation and storage tank system is summarized as follows: Figure 5 As shown in the figure, the complete chain from rainfall prediction to water supply decision, water abandonment decision, and then to valve and pump operation control.

[0163] S4. Using the TOPSIS method, the economic index, recycled water reuse index, and urban waterlogging index are used as evaluation indicators to rank the alternative options and obtain the optimal option.

[0164] The economic indicators in step S4 include: storage tank construction costs, pump station construction costs, recycled water network construction costs, pump station power costs, and employee salary and welfare costs. The specific calculation formula is:

[0165]

[0166] C3=C 31 +C 32 ,

[0167] C5=(G+S+F)A

[0168] Among them, C1 is the construction cost of the storage tank, the unit is RMB, P1 is the percentage of the operation and maintenance cost of the storage tank, the unit is %, the preferred P1 = 2.4%, C is the unit volume construction cost, the unit is RMB / m 3 , preferably, C = 1700 yuan / m 3 , V n is the volume of the nth storage tank, in m 3 , N is the total number of storage tanks;

[0169] C2 is the construction cost of the pump station, in RMB, P2 is the percentage of the operation and maintenance cost of the water pump, in %, f is the cost of the pump station per kilowatt capacity, in RMB / kW, τ is the reserve coefficient of the pump station unit, N+1 is the total number of rainwater lifting pump stations and recycled water pump stations, Q n 、H n ,η n is the water supply, head and efficiency of the nth pumping station, in units of L / s, m, and % respectively; mp is the economic efficiency coefficient of the pumping station, which is 0.85;

[0170] C4 is the construction cost of the recycled water network, in RMB, P3 is the percentage of the network's operation and maintenance costs, in %, with the preferred P3 = 2.8%, G is the total number of recycled water supply pipelines, C g is the construction cost per unit length of the g-th pipeline, in yuan / m, w, r, α are pipeline statistical parameters, d g is the diameter of the g-th pipe, in m, l g is the length of the g-th pipe, in meters;

[0171] C3 is the pump station power cost, in RMB. This includes the electricity costs required to lift water at the rainwater dewatering pumping station and the recycled water supply pumping station, as well as the electricity costs for desludging and backwashing the storage tank. Because pump station power costs account for a significant portion of the total power cost, they are used as the base, with the remaining costs calculated at appropriate proportions. Recycled water power costs are calculated based on the power consumed per lift, while rainwater pump station power costs are calculated based on the optimized pump station dewatering flow and head, obtained through long-term statistical analysis using SWMM.

[0172] C 31 is the power cost of reclaimed water lifting, in RMB, J is the total number of reclaimed water lifting times; α is the proportion of the cost of sludge removal and backwashing in the pumping station, which is 0.2; e is the electricity price of the pumping station, in RMB / KW·h, which is 0.65 RMB / KW·h based on the local average; ρ is the liquid density, in kg / m 3 , g is the acceleration due to gravity, unit is m / s 2 , Q j The jth recycled water lift volume, in m 3 / d,H j is the jth recycled water lifting head, in m, η is the pumping station efficiency, C 32 The power cost of rainwater lifting, in yuan, W n is the power of the nth water pump, in kW h.

[0173] C5 is the employee salary and welfare expenses, in yuan; G is the sum of the staffing numbers of positions in charge of the unit, administrative management, technical management, financial and asset management, and water administration supervision, in people; S is the sum of the staffing numbers of operation and observation positions, in people; F is the staffing number of auxiliary positions, in people; A is the average annual salary and welfare expenses of each employee, which is generally given based on local actual conditions, in yuan / person / year.

[0174] The indicators for the reuse of recycled water in step S4 include: water-saving benefits, environmental benefits, water supply guarantee rate, amount of abandoned water, and the number of starts and stops of the recycled water pump station. Water-saving benefits refer to the water-saving benefits achieved by building a regulating reservoir for use in roads and green land irrigation, etc.; environmental benefits refer to the benefits of improving the environment by absorbing CO2 to lower the ambient temperature and absorbing atmospheric pollutants such as SO2 when recycled water is used for green land irrigation, and are calculated in terms of carbon fixation and oxygen release benefits and air purification benefits; the water supply guarantee rate can reflect the reliability and stability of recycled water supply in providing recycled water to greening and road irrigation projects; the amount of abandoned water refers to the amount of water resources that cannot be effectively utilized as originally planned when the regulating reservoir forcibly discharges the stored recycled water before rainfall. The number of starts and stops of the water pump will affect its service life. Therefore, the number of starts and stops of the water pump is considered to be a key indicator for the evaluation plan. The specific calculation formula is:

[0175] B1=(TW)Vreuse ;

[0176] B2=B 21 +B 22 ,

[0177] B5=ΣJ

[0178] B1 is the water-saving benefit of recycled water reuse, in RMB, and T is the unit price of tap water, in RMB / m 3 , take 2.97 yuan / m 3 , W is the unit price of recycled water, in yuan / m 3 , take 2.068 yuan / m 3 , V reuse is the total amount of recycled water reused, in m 3 .

[0179] T2 is the environmental benefit of recycled water reuse, in yuan; B 21 is the carbon fixation and oxygen release benefit of recycled water, in yuan. is the carbon tax, in RMB / ton, is the carbon sequestration rate per unit area of ​​green land, in tons / year, is the price of industrial oxygen production, in yuan / m 3 , Q is the oxygen release rate per unit area of ​​green space, in tons / year, max，j is the maximum water demand of the jth green space, q G，j is the jth green space water supply, A G is the green area; B 22 The unit is RMB for air purification efficiency. is the SO2 industrial processing cost, in yuan / ton, The annual SO2 absorption capacity of green land per unit area, in tons / year, P ZC is the cost of industrial dust treatment, in yuan / ton, H GZ Annual dust retention capacity per unit area of ​​green space, in tons / year, A R is the road area, in m 2 , H RZ is the annual dust retention capacity of the road per unit area, in tons / year;

[0180] B3 is the water supply guarantee rate, V j is the water demand at the jth water supply, in m 3 , W j is the water supply volume during the jth water supply, in m 3 ;

[0181] B4 is the amount of discarded water, Q iis the amount of reclaimed water discharged from the storage pool before the i-th rainfall, and I is the total number of rainfall events;

[0182] B5 is the total number of starts and stops of the recycled water pump station, and J is the total number of times the recycled water is lifted.

[0183] The urban waterlogging indicators in step S4 include: total node overflow volume, total node overflow duration, and average number of overflow nodes per field.

[0184] Node overflow refers to the amount of rainwater that is discharged through other facilities (such as manhole covers) when the water exceeds the pipe's capacity during rainfall. It is used to measure the stormwater system's ability to handle rainfall exceeding the design standard. The total duration of node overflow is used to assess the long-term impact of urban waterlogging on urban functions. The average number of overflowing nodes per site refers to the number of nodes where overflow occurs.

[0185] The specific calculation formula is:

[0186]

[0187] Among them, S1 is the total overflow of the nodes in the study area, in m 3 , Flood i，u is the overflow of the u-th node during the i-th rainfall, in m 3 , U is the total number of nodes, I is the total number of rainfall events;

[0188] S2 is the total overflow duration of the nodes in the study area, in h. i，u is the total overflow duration of the u-th node in the i-th rainfall, in h;

[0189] S3 is the average number of overflow nodes in the study area; Num i is the number of overflow nodes in the i-th rainfall.

[0190] Furthermore, based on the performance indicators of the multifunctional regulating and storage pond and the alternative schemes under the condition of long-term rainfall sequence, the present invention adopts the TOPSIS comprehensive evaluation method to optimize the various schemes to screen out the regulating and storage pond scheme that is most suitable for the study area.

[0191] Specifically, step S4 includes:

[0192] S41. Establish a forward matrix, construct a forward data matrix X containing n schemes to be evaluated and m evaluation indicators, X = (x ij ) nm , x ij represents the value of the jth evaluation index of the i-th evaluation scheme, where when the jth index of the i-th evaluation scheme is a negative index, x ij is the value after the original index value is positively processed;

[0193] Among them, positive indicators refer to indicators whose more the better, such as water saving, and negative indicators refer to indicators whose fewer the better; positiveization refers to taking the inverse or negative value of negative indicators to make them positive.

[0194] S42, data normalization, obtain the standardized matrix Z, Z = z ij , z ij It represents the normalized value of the jth evaluation indicator of the i-th scheme to be evaluated;

[0195] S43, establish the optimal and worst moment values, and obtain the positive ideal solution Z + and negative ideal solution Z - , specifically:

[0196]

[0197] S44. Calculate the Euclidean distance between the positive and negative ideal solutions. Use the Euclidean distance method to calculate the distance between each of the solutions to be evaluated and the positive and negative ideal solutions. Specifically:

[0198]

[0199] in, is the distance between the i-th scheme to be evaluated and the positive ideal solution, is the distance between the i-th evaluated solution and the negative ideal solution, ω j is the weight of the j-th evaluation index;

[0200] S45. Calculate the ideal closeness of each solution and normalize it. Specifically:

[0201]

[0202] Among them, S i represents the ideal closeness of the i-th scheme to be evaluated, represents the normalized ideal closeness of the i-th scheme to be evaluated;

[0203] S46. Sort the schemes to be evaluated according to their normalized ideal closeness, and select the scheme with the largest normalized ideal closeness as the optimal scheme.

[0204] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0205] In the embodiments provided in this application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0206] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0207] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A multifunctional storage pond optimization method based on rainwater regulation and recycled water storage, characterized in that: The following steps are involved: S1. Under short-duration rainfall scenarios, a multi-objective optimization model for stormwater management and control of a reservoir is constructed. The objective function is constructed based on the reservoir cost, overflow reduction rate, and flood peak reduction rate. The decision variables are constructed based on the reservoir volume, the diameter and offset of the inlet pipe, and the outflow rate of the reservoir. Constraints are set based on the reservoir volume, the diameter and offset of the inlet pipe, the outflow rate of the reservoir, and waterlogging control. The offset refers to the difference between the bottom elevation of the reservoir inlet pipe and the bottom elevation of the access pipe. S2. Solve the multi-objective optimization model using the NSGA-II algorithm to obtain a Pareto solution set; S3. Based on the Pareto solution set, design the storage capacity, water supply, and scheduling strategies for combined rainwater and recycled water storage under long-duration rainfall scenarios. Build a comprehensive framework covering rainfall-demand matching, combined storage capacity optimization, water supply, and scheduling strategies, and then develop alternative solutions. S4. Using the TOPSIS method, the economic index, the recycled water reuse index, and the urban waterlogging index are used as evaluation indicators to rank the alternative solutions and obtain the optimal solution; The objective function in step S1 is specifically: Among them, f1 is the cost of the storage tank, the unit is yuan, N is the total number of storage tanks, V n is the volume of the nth storage tank, in m 3 , A n is the area of ​​the nth storage tank, in m 2 , a, b, α are coefficients, E is the startup cost, the unit is yuan; f2 is the overflow reduction rate, U is the total number of nodes, FQ u Add the overflow volume before the storage tank at the u-th node, in m 3 , Q u The overflow volume after adding the storage tank to the u-th node, in m 3 ; f3 is the flood peak reduction rate, L is the total number of discharge outlets, Q pre,l is the peak flow rate of the lth outlet when no storage tank is added, in m 3 , Q l The peak flow rate of the lth discharge outlet after setting up the storage tank, in m 3 .

2. The method according to claim 1, wherein The decision variables in step S1 are specifically: X=(a 0，n ,H offset，n ,H inflow，n ,setting n ); Among them, a 0，n is the area parameter of the nth storage tank, H offset，n is the offset of the water inlet pipe of the nth storage tank, in m, H inflow，n The diameter of the water inlet pipe of the nth storage tank is in meters, setting n is the pump curve multiplier of the nth storage tank.

3. The method according to claim 2, wherein The constraints in step S1 are specifically: S min ≤a0≤S max ; 0≤H inflow ≤H link ; 0≤H offset ≤H node -H inflow ; 0≤setting≤10; T pongding ≤0.5； Among them, a0 is the area parameter of the storage tank, the unit is m 2 , S min 、S max The minimum and maximum allowable floor space of the storage tank, in m 2 ;H inflow is the diameter of the water inlet pipe of the storage tank, in m, H link H is the diameter of the upstream pipe of the water inlet pipe, in m; offset is the inlet pipe offset of the storage tank, in m, H node is the node depth of the node connected to the water inlet pipe of the storage tank, in meters; setting is the pump curve multiplier; T ponding The time for water to recede is h, h depth is the depth of accumulated water in cm, i is the ground slope in %, and V is the volume of accumulated water in m 3 , W is the width of the catchment area, in meters.

4. The method according to claim 3, wherein The economic indicators in step S4 include: storage tank construction costs, pump station construction costs, recycled water network construction costs, pump station power costs, and employee salary and welfare costs. The specific calculation formula is: C3=C 31 +C 32 , C5=(G+S+F)A; Among them, C1 is the construction cost of the storage tank, the unit is RMB, P1 is the percentage of the operation and maintenance cost of the storage tank, the unit is %, and C is the construction cost per unit volume, the unit is RMB / m 3 , V n is the volume of the nth storage tank, in m 3 , N is the total number of storage tanks; C2 is the construction cost of the pump station, in RMB, P2 is the percentage of the operation and maintenance cost of the water pump, in %, f is the cost of the pump station per kilowatt capacity, in RMB / kW, τ is the reserve coefficient of the pump station unit, N+1 is the total number of rainwater lifting pump stations and recycled water pump stations, Q n 、H n ,η n is the water supply, head and efficiency of the nth pumping station, in units of L / s, m, and % respectively; mp is the economic efficiency coefficient of the pumping station; C4 is the construction cost of the recycled water network, in RMB, P3 is the percentage of the network's operation and maintenance costs, in %, G is the total number of recycled water supply pipelines, C g is the construction cost per unit length of the g-th pipeline, in yuan / m, w, r, α are pipeline statistical parameters, d g is the diameter of the g-th pipe, in m, l g is the length of the g-th pipe, in meters; C3 is the power cost of the pump station, in yuan, C 31 is the power cost of reclaimed water lifting, in RMB, J is the total number of reclaimed water lifting times, α is the proportion of the cost of sludge removal and backwashing in the pumping station, e is the electricity price of the pumping station, in RMB / KW·h, ρ is the liquid density, in kg / m 3 , g is the acceleration due to gravity, unit is m / s 2 , Q j The jth recycled water lift volume, in m 3 / d,H j is the jth recycled water lifting head, in m, η is the pumping station efficiency, C 32 The power cost of rainwater lifting, in yuan, W n is the power of the nth water pump, in KW·h; C5 is the employee salary and welfare expenses, in yuan; G is the sum of the staffing numbers of positions in charge of the unit, administrative management, technical management, financial and asset management, and water administration supervision, in people; S is the sum of the staffing numbers of operation and observation positions, in people; F is the staffing number of auxiliary positions, in people; A is the average annual salary and welfare expenses of each employee, in yuan / person / year.

5. The method according to claim 4, wherein The reclaimed water reuse indicators in step S4 include: water-saving benefits, environmental benefits, water supply guarantee rate, abandoned water volume, and the number of starts and stops of the reclaimed water pump station. The specific calculation formula is: B1=(TW)V reuse ; B2=B 21 +B 22 , B5=ΣJ; B1 is the water-saving benefit of recycled water reuse, in RMB, and T is the unit price of tap water, in RMB / m 3 , W is the unit price of recycled water, in yuan / m 3 , V reuse is the total amount of recycled water reused, in m 3 ; B2 is the environmental benefit of recycled water reuse, in yuan; 21 is the carbon fixation and oxygen release benefit of recycled water, in yuan. is the carbon tax, unit is RMB / ton, is the carbon sequestration rate per unit area of ​​green land, in tons / year, is the price of industrial oxygen production, in yuan / m 3 , Q is the oxygen release rate per unit area of ​​green space, in tons / year, max，j is the maximum water demand of the jth green space, q G，j is the jth green space water supply, A G is the green area; B 22 The unit is RMB for air purification efficiency. is the SO2 industrial processing cost, in yuan / ton, The annual SO2 absorption capacity of green land per unit area, in tons / year, P ZC is the cost of industrial dust treatment, in yuan / ton, H GZ Annual dust retention capacity per unit area of ​​green space, in tons / year, A R is the road area, in m 2 , H RZ is the annual dust retention capacity of the road per unit area, in tons / year; B3 is the water supply guarantee rate, V j is the water demand at the jth water supply, in m 3 , W j is the water supply volume during the jth water supply, in m 3 ; B4 is the amount of discarded water, Q i is the amount of reclaimed water discharged from the storage pool before the i-th rainfall, and I is the total number of rainfall events; B5 is the total number of starts and stops of the recycled water pump station, and J is the total number of times the recycled water is lifted.

6. The method according to claim 5, wherein The urban waterlogging indicators in step S4 include: total node overflow volume, total node overflow duration, and average number of overflow nodes per field. The specific calculation formula is: Among them, S1 is the total overflow of the nodes in the study area, in m 3 , Flood i，u is the overflow of the u-th node during the i-th rainfall, in m 3 , U is the total number of nodes, I is the total number of rainfall events; S2 is the total overflow duration of the nodes in the study area, in h. i，u is the total overflow duration of the u-th node in the i-th rainfall, in h; S3 is the average number of overflow nodes in the study area; Num i is the number of overflow nodes in the i-th rainfall.

7. The method according to claim 6, wherein The step S4 specifically includes: S41. Establish a forward matrix, construct a forward data matrix X containing n schemes to be evaluated and m evaluation indicators, X = (x ij ) nm , x ij represents the value of the jth evaluation index of the i-th evaluation scheme, where when the jth index of the i-th evaluation scheme is a negative index, x ij is the value after the original index value is positively processed; S42, data normalization, obtain the standardized matrix Z, Z = z ij , z ij It represents the normalized value of the jth evaluation indicator of the i-th scheme to be evaluated; S43, establish the optimal and worst moment values, and obtain the positive ideal solution Z + and negative ideal solution Z - , specifically: S44. Calculate the Euclidean distance between the positive and negative ideal solutions. Use the Euclidean distance method to calculate the distance between each of the solutions to be evaluated and the positive and negative ideal solutions. Specifically: in, is the distance between the i-th scheme to be evaluated and the positive ideal solution, is the distance between the i-th evaluated solution and the negative ideal solution, ω j is the weight of the j-th evaluation index; S45. Calculate the ideal closeness of each solution and normalize it. Specifically: Among them, S i represents the ideal closeness of the i-th scheme to be evaluated, represents the normalized ideal closeness of the i-th scheme to be evaluated; S46. Sort the schemes to be evaluated according to their normalized ideal closeness, and select the scheme with the largest normalized ideal closeness as the optimal scheme.

8. The method according to claim 7, wherein In step S3, the storage tank capacity, water supply and scheduling strategies for the combined regulation of rainwater and recycled water are designed to construct a comprehensive framework covering rainfall-water demand matching, combined regulation storage capacity optimization, water supply and scheduling strategies, specifically including: S31. Calculate the daily water consumption under low water demand, medium water demand, and high water demand in the study area; S32. Calculate the storage period under different water demands based on the daily water consumption under different water demands, specifically: Among them, V rain The volume of the storage tank corresponding to each solution in the Pareto solution set obtained in step S2, in m 3 , V d，min 、V d，mid 、V d，max The daily water consumption under low, medium and high water demand respectively, in m 3 , T min 、T mid 、T max is the storage period corresponding to each demand, in d; S33. Calculate the water supply and waste water volume of the regulating reservoir within one scheduling cycle. Specifically: Where T represents a complete scheduling cycle. For low, medium and high water demand, T is T min 、T mid 、T max , V d Indicates daily water consumption. For low, medium and high water demands, V d Take V d，min 、V d，mid 、V d，max , t rain Indicates the time point when the first rainfall occurs in a scheduling cycle.

9. The method according to claim 8, wherein The long-duration rainfall scenario in step S3 refers to the daily rainfall data of the study area in the past 20 years.

Images