Multifunctional regulation and storage pond optimization method based on rainfall flood regulation and control and reclaimed water regulation and storage

Abstract

The invention provides a multifunctional regulation and storage pool optimization method based on rainfall flood regulation and control and reclaimed water regulation and storage, which comprises the following steps: firstly, carrying out rainfall flood regulation and control optimization design of a regulation and storage pool based on short-duration rainfall to obtain a series of Pareto solution sets, and then carrying out optimization design on the volume, water supply and scheduling strategies of rainwater-reclaimed water combined regulation and storage based on long-duration rainfall to obtain a series of Pareto solution sets. And finally, an optimal scheme is selected through comprehensive evaluation, so that the comprehensive function value of the obtained regulation and storage tank is remarkably improved through multi-level, comprehensive and long-time sequence optimization design, and a more efficient and sustainable solution is provided for modern urban water resource management.

Description

Technical Field

[0001] This application belongs to the fields of municipal engineering, environmental engineering, and computer technology, and particularly relates to an optimization method for a multi-functional storage tank based on rainwater flood control and reclaimed water storage. Background Art

[0002] In recent years, with the intensification of climate change, rainstorms and floods have occurred frequently, and urban drainage systems have faced huge pressures, resulting in increasingly serious waterlogging problems, which have had a serious impact on infrastructure, people's livelihood security, and the environment. To address this challenge, storage tanks, as an effective solution, have been gradually widely used. Rainwater storage tanks temporarily store rainwater during rainstorms, reduce peak flood flows, smooth out peak flood fluctuations, relieve the pressure on the drainage system, and thus reduce the risk of flood disasters.

[0003] Currently, the design optimization methods for storage tanks have shifted from traditional mathematical formula calculations to comprehensive optimization design methods based on mathematical models to more accurately simulate rainwater flow and system responses. Currently, various hydrological models (such as the SWMM model) are usually combined with various optimization algorithms such as genetic algorithms and simulated annealing algorithms to design and optimize storage tanks. When optimizing, not only the volume of the storage tank is considered, but also multiple factors such as the layout, location, and inlet and outlet scheduling rules of the storage tank are usually considered to achieve optimization under different rainfall scenarios, different drainage pipe conditions, and different regions.

[0004] However, due to the usually high construction costs of storage tanks at the urban scale, and the existing optimization methods for storage tanks mainly aim at rainwater volume storage and utilization, usually only using storage tanks to reduce the risk of waterlogging and relieve the occurrence of flood disasters, without fully exploring the multi-functional application potential of storage tanks, such as insufficient attention has been given to the comprehensive functions of reclaimed water storage, dry-season water supply regulation, and rainy-season rainwater flood management. As a result, the storage tanks are idle for a long time on sunny days, and the utilization rate is significantly reduced. In addition, the existing technology usually only considers the response ability to short-term extreme rainfall events when optimizing storage tanks, without fully considering the impact of long-duration rainfall on storage tanks, so only designs and optimizes according to short-duration rainfall, without fully evaluating and testing the performance of storage tanks under long-duration rainfall events, which may lead to the finally selected storage tank scheme being unable to fully adapt to the actual hydrological conditions and requirements.

[0005] Therefore, a new technical solution needs to be proposed to overcome the above technical problems, to achieve the optimized design of a multi-functional storage tank based on rainwater flood control and reclaimed water storage, and to fully consider short-duration rainfall and long-duration rainfall during the optimized design to obtain an efficient and sustainable storage tank design scheme. Summary of the Invention

[0006] A multi-functional storage pond optimization method based on rainwater and flood regulation and reclaimed water storage is used to solve the above technical problems. First, based on short-duration rainfall, the rainwater and flood regulation 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 strategies of the combined rainwater-reclaimed water storage are optimized. Finally, the optimal solution is selected through comprehensive evaluation. Thus, through multi-level, comprehensive, and long-time series optimization design, the comprehensive functional value of the obtained storage pond is significantly improved, providing a more efficient and sustainable solution for modern urban water resource management.

[0007] Specifically, the embodiment of the present application provides a multi-functional storage pond optimization method based on rainwater and flood regulation and reclaimed water storage, which is characterized by including the following steps:

[0008] S1. Under the short-duration rainfall scenario, a multi-objective optimization model for the storage pond for rainwater and flood regulation is constructed. The objective function is constructed based on the storage pond cost, overflow reduction rate, and peak flood reduction rate. The decision variables are constructed based on the storage pond volume, inlet pipe diameter and offset, and the storage pond outlet flow rate. Constraints are set based on the storage pond volume, inlet pipe diameter and offset, storage pond outlet flow rate, and waterlogging control.

[0009] S2. The NSGA-II algorithm is used to solve the multi-objective optimization model to obtain the Pareto solution set.

[0010] S3. Based on the Pareto solution set, under the long-duration rainfall scenario, the volume, water supply, and scheduling strategies of the combined rainwater-reclaimed water storage of the storage pond are designed, a comprehensive framework covering rainfall-water demand matching, combined storage volume optimization, water supply, and scheduling strategies is constructed, and alternative solutions are formed.

[0011] S4. Through the TOPSIS method, using economic indicators, reclaimed water reuse indicators, and urban waterlogging indicators as evaluation indicators, each solution in the alternative solutions is ranked to obtain the optimal solution.

[0012] Among them, the objective function in step S1 is specifically:

[0013]

[0014] Among them, f1 is the cost of the storage pond, in yuan, N is the total number of storage ponds, V n is the volume of the nth storage pond, in m 3 , A n is the area of the nth storage pond, in m 2 , a, b, and α are coefficients, and E is the start-up cost, in yuan;

[0015] $f_2$ is the overflow reduction rate, $U$ is the total number of nodes, $FQ$ u is the overflow volume before adding a storage tank to the $u$-th node, with the unit of $m$ 3 , $Q$ u is the overflow volume after adding a storage tank to the $u$-th node, with the unit of $m$ 3 ;

[0016] $f_3$ is the peak flow reduction rate, $L$ is the total number of outfalls, $Q$ pre,l is the peak flow of the $l$-th outfall before adding a storage tank, with the unit of $m$ 3 , $Q$ l is the peak flow of the $l$-th outfall after setting a storage tank, with the unit of $m$ 3 .

[0017] Among them, 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 $n$-th storage tank, $H$ offset，n is the offset of the inlet pipe of the $n$-th storage tank, with the unit of $m$, $H$ inflow，n is the diameter of the inlet pipe of the $n$-th storage tank, with the unit of $m$, setting n is the pump curve multiplier of the $n$-th storage tank.

[0020] Among them, the constraint conditions in step S1 are specifically:

[0021] $S$ min ≤$a_0$≤$S$ 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, $a_0$ is the area parameter of the storage tank, with the unit of $m$ 2 , $S$ min , $S$max is the minimum and maximum allowable floor area of the storage pond, with the unit of m 2 ; H inflow is the pipe diameter of the inlet pipe of the storage pond, with the unit of m, H link is the pipe diameter of the upstream pipe of the inlet pipe, with the unit of m; H offset is the offset of the inlet pipe of the storage pond, with the unit of m, H node is the node depth of the node connected to the inlet pipe of the storage pond, with the unit of m; setting is the pump curve multiplier; T pongding is the water accumulation drainage time, with the unit of h, h depth is the water accumulation depth, with the unit of cm, i is the ground slope, with the unit of %, V is the water accumulation volume, with the unit of m 3 , W is the width of the catchment area, with the unit of m.

[0028] Among them, the economic indicators in step S4 include: the construction cost of the storage pond, the construction cost of the pumping station, the construction cost of the reclaimed water pipe network, the power cost of the pumping station, and the personnel salary and welfare cost. 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 pond, with the unit of yuan, P1 is the percentage of the operation and maintenance cost of the storage pond, with the unit of %, C is the construction cost per unit volume, with the unit of yuan / m 3 , V n is the volume of the nth storage pond, with the unit of m 3 , N is the total number of storage ponds;

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

[0034] C4 is the construction cost of the reclaimed water pipe network, with the unit of yuan, P3 is the percentage of the operation and maintenance cost of the pipe network, with the unit of %, G is the total number of reclaimed water supply pipes, C g$C_{g}$ is the construction cost per unit length of the $g$-th pipeline, in yuan / m. $w$, $r$, $\alpha$ are pipeline statistical parameters, $d$ g is the pipe diameter of the $g$-th pipeline, in m, $l$ g is the length of the $g$-th pipeline, in m;

[0035] $C_{3}$ is the pumping station power cost, in yuan; $C$ 31 is the reclaimed water lifting power cost, in yuan, $J$ is the total number of reclaimed water liftings, $\alpha$ is the cost ratio of sludge discharge and backwashing in the pumping station, $e$ is the electricity price for the pumping station cost, in yuan / kW·h, $\rho$ is the liquid density, in kg / m 3 , $g$ is the acceleration due to gravity, in m / s 2 , $Q$ j is the reclaimed water lifting volume for the $j$-th time, in m 3 / d, $H$ j is the reclaimed water lifting head for the $j$-th time, in m, $\eta$ is the pumping station efficiency, $C$ 32 is the rainwater lifting power cost, in yuan, $W$ n is the power of the $n$-th water pump, in kW·h.

[0036] $C_{5}$ is the personnel salary and welfare cost, in yuan, $G$ is the sum of the staffing numbers for the unit responsible, administrative management, technical management, financial and asset management, and water administration supervision positions, in persons, $S$ is the sum of the staffing numbers for the operation and observation positions, in persons, $F$ is the auxiliary staffing, in persons, $A$ is the average annual salary and welfare of each employee, in yuan / person·year.

[0037] Among them, the reclaimed water reuse indicators in step S4 include: water saving benefit, environmental benefit, water supply guarantee rate, water discharge, and total number of starts and stops of the reclaimed water pumping station. The specific calculation formulas are:

[0038] $B_{1}=(T - W)V$ reuse ;

[0039] $B_{2}=B$ 21 +B 22 ,

[0040] $B_{5}=\sum J$

[0041] $B_{1}$ is the water saving benefit of reclaimed water reuse, in yuan, $T$ is the unit price of tap water, in yuan / m 3 , $W$ is the unit price of reclaimed water, in yuan / m 3 , $V$ reuse is the total amount of reclaimed water reuse, in m 3 .

[0042] B2 is the environmental benefit of reclaimed water reuse, in yuan; B 21 is the carbon sequestration and oxygen release benefit of reclaimed water, in yuan, is the carbon tax, in yuan / ton, is the carbon sequestration rate per unit area of green space, in tons / year, is the industrial oxygen production price, in yuan / m 3 , is the oxygen release rate per unit area of green space, in tons / year, Q max，j is the maximum water demand of the green space for the jth time, q G，j is the water supply of the green space for the jth time, A G is the green space area; B 22 is the air purification benefit, in yuan, is the industrial treatment cost of SO2, in yuan / ton, is the annual SO2 absorption amount per unit area of green space, in tons / year, P ZC is the industrial dust treatment cost, 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 per unit area of road, in tons / year;

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

[0044] B4 is the amount of wasted water, Q i is the amount of reclaimed water strongly drained from the storage tank before the ith rainfall, and I is the total number of rainfall events;

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

[0046] Among them, the urban waterlogging indexes in step S4 include: the total amount of node overflows, the total duration of node overflows, and the number of nodes with overflows per rainfall event. The specific calculation formulas are as follows:

[0047]

[0048] Among them, S1 is the total amount of node overflows in the research area, in m 3 , Flood i，u is the overflow amount of the uth node during the ith rainfall, in m 3 , U is the total number of nodes, and I is the total number of rainfall events;

[0049] S2 is the total duration of node overflow in the research area, with the unit of h, Time i，u is the total duration of overflow of the u-th node in the i-th rainfall, with the unit of h;

[0050] S3 is the number of nodes with overflow per rainfall in the research area; Num i is the number of nodes with overflow in the i-th rainfall.

[0051] Among them, the specific steps of step S4 include:

[0052] S41. Establish a positive matrix, construct a positive data matrix X containing n alternative evaluation schemes and m evaluation indicators, X = (x ij ) nm , x ij represents the value of the j-th evaluation indicator of the i-th alternative evaluation scheme. Among them, when the j-th indicator of the i-th alternative evaluation scheme is a negative indicator, x ij is the value after positive transformation of the original indicator value;

[0053] S42. Data normalization to obtain a standardized matrix Z, Z = z ij , z ij represents the value of the j-th evaluation indicator of the i-th alternative evaluation scheme after normalization;

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

[0055]

[0056] S44. Calculate the Euclidean distances between the positive and negative ideal solutions, and use the Euclidean distance method to calculate the distances between each alternative evaluation scheme and the positive and negative ideal solutions, specifically:

[0057]

[0058] Among them, is the distance between the i-th alternative evaluation scheme and the positive ideal solution, is the distance between the i-th alternative evaluation scheme and the negative ideal solution, ω j is the weight of the j-th evaluation indicator;

[0059] S45. Calculate the ideal closeness of each scheme and normalize it, specifically:

[0060]

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

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

[0063] Among them, in step S3, the storage tank volume, water supply and scheduling strategy for rainwater-reclaimed water joint regulation are designed, and a comprehensive framework covering rainfall-water demand matching, joint regulation volume optimization, water supply and scheduling strategy is constructed, specifically including:

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

[0065] S32. Calculate the storage cycle under different water demands based on the daily water consumption under different water demands. Specifically:

[0066]

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

[0068] S33. Calculate the water supply volume and the water abandonment volume within one scheduling cycle of the storage tank. Specifically:

[0069]

[0070] Among them, T represents a complete scheduling cycle. For low, medium, and high water demands, T takes T min , T mid , T max , V d represents the daily water consumption. For low, medium, and high water demands, V d takes V d，min , V d，mid , V d，max , t rain represents the time point when the first rainfall occurs within one scheduling cycle.

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

[0072] The beneficial effects of the embodiments of the present application compared with the prior art are as follows:

[0073] The present invention provides a multi-functional storage tank optimization method based on rainstorm flood regulation and reclaimed water storage. First, based on short-duration rainfall, the rainstorm flood regulation optimization design of the storage tank is carried out to obtain a series of Pareto solution sets. Then, based on long-duration rainfall, the volume, water supply, and scheduling strategies of the combined storage of rainwater and reclaimed water are optimized. Finally, the optimal solution is selected through comprehensive evaluation. Thus, through multi-level, comprehensive, and long-time series optimization design, the comprehensive functional value of the obtained storage tank is significantly improved, providing a more efficient and sustainable solution for modern urban water resource management.

[0074] Specifically, by optimizing the design parameters of the storage tank in the short-duration rainfall scenario, the present invention can improve its ability to cope with extreme rainfall events. By comprehensively evaluating the actual rainfall and reclaimed water demand in the long-duration rainfall scenario, the most suitable volume plan can be obtained. And by designing reasonable water supply and scheduling strategies, it can ensure that the storage tank can efficiently realize the rapid conversion between the rainwater and reclaimed water storage functions, further enhancing the flexibility and adaptability of the system. Finally, by comprehensively evaluating each solution to select the optimal solution, it can make the final storage tank design plan achieve the optimal comprehensive efficiency under different hydrological conditions. Description of the Drawings

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

[0076] Figure 1 is a flowchart of a multi-functional storage tank optimization method based on rainstorm flood regulation and reclaimed water storage provided by an embodiment of the present application;

[0077] Figure 2 is a page for setting the bottom area of the storage tank based on the SWMM model provided by an embodiment of the present application;

[0078] Figure 3 is a page for writing control statements based on the SWMM model provided by an embodiment of the present application;

[0079] Figure 4 is a schematic diagram of the storage tank scheduling method provided by an embodiment of the present application;

[0080] Figure 5 is a schematic diagram of the overall operation process of the multi-functional storage tank provided by an embodiment of the present application. Detailed Embodiments

[0081] In the following description, specific details such as specific system architectures, technologies, etc. are presented for purposes of illustration and not limitation in order to provide a thorough understanding of the embodiments of the present application. However, those skilled in the art should understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to impede the description of the present application with unnecessary details.

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

[0083] It should also be understood that the term "and / or" as used in the specification of the present application and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

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

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

[0086] Reference to "one embodiment" or "some embodiments" or the like described in the specification of the present application means that a specific feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in another way. The terms "comprising", "including", "having", and their variants all mean "including but not limited to", unless otherwise specifically emphasized in another way.

[0087] The following explains the nouns that appear in the present invention:

[0088] Storage Pond: A storage pond is a device that stores excess water during rainfall for gradual release after the rain to avoid flood problems such as urban waterlogging; it can regulate the water flow, reduce the peak flow caused by heavy rain, and relieve the burden on the drainage system.

[0089] Rainfall and Flood Regulation: Rainfall and flood regulation refers to taking measures to control the flow of rainwater and floods to prevent urban waterlogging or other flood disasters, usually including the establishment of storage ponds, rainwater collection and drainage systems, etc.

[0090] Reclaimed Water Storage: Reclaimed water storage refers to the storage and utilization of treated wastewater, which is used as an unconventional water resource for urban irrigation, industrial cooling, etc.

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

[0092] Peak Flow Reduction: Peak flow reduction refers to reducing the peak flow in the drainage system after heavy rain through various means to reduce the risk of waterlogging. Storage ponds are usually used to store excess water and reduce the amount of water flowing into the drainage system in a short time.

[0093] Rainfall Return Period: The rainfall return period refers to the likelihood of a rainfall event of a certain intensity occurring again within a certain time range. For example, a 50-year return period rainfall refers to an extreme rainfall event that may occur once in 50 years.

[0094] Inlet Pipe Diameter: The inlet pipe diameter refers to the diameter of the pipe through which water flows into the storage pond. The size of the pipe diameter directly affects the water flow rate. Optimizing the pipe diameter can improve the working efficiency and flow regulation ability of the system.

[0095] Pump Curve: The pump curve describes the relationship between the flow rate and head of a pump. Different types of pumps have different flow rate and head characteristics. The pump curve is used in the design of storage ponds to determine the performance of pumps under different flow rate conditions.

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

[0097] Overflow Reduction Rate: The overflow reduction rate is an important indicator to measure the effectiveness of a storage pond in preventing waterlogging. It represents the proportion of the reduced overflow volume to the original overflow volume through the design of the storage pond.

[0098] Short-duration rainfall: Refers to rainfall events under design rainfall conditions, usually referring to rainfall scenarios with relatively short precipitation durations. The typical rainfall duration is several hours, and the precipitation intensity is relatively high. It is often calculated through rainfall models such as the Chicago Storm Model and is used for the design analysis of short-duration heavy rainfall.

[0099] Long-duration rainfall: Refers to rainfall events with relatively long precipitation durations, usually lasting for several days or longer, and the precipitation intensity is relatively uniform. It is often used to analyze the impact of rainfall accumulation over a long period on the design and performance of storage ponds.

[0100] Offset: Refers to the difference in elevation between the bottom of the inlet pipe of the storage pond and the bottom of the connected pipe, which can control the inlet time of the storage pond. Specific embodiments

[0102] Figure 1 The flowchart of a multifunctional storage pond optimization method based on rainwater and flood regulation and reclaimed water storage provided by an embodiment of the present application is shown, as Figure 1 shown. The multifunctional storage pond optimization method based on rainwater and flood regulation and reclaimed water storage specifically includes:

[0103] S1. In the short-duration rainfall scenario, construct a multi-objective optimization model for the storage pond for rainwater and flood regulation. Based on the storage pond cost, overflow reduction rate, and peak flood reduction rate, construct the objective function. Based on the storage pond volume, inlet pipe diameter and offset, and storage pond outlet flow rate, construct the decision variables. Based on the storage pond volume, inlet pipe diameter and offset, storage pond outlet flow rate, and waterlogging control, set the constraint conditions;

[0104] Among them, the objective function in step S1 includes an economic objective, a water volume objective, and a system load objective.

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

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

[0107]

[0108] Among them, f1 is the cost of the storage pond, with the unit of yuan, N is the total number of storage ponds, V n is the volume of the nth storage pond, with the unit of m 3 (i.e., cubic meters), A n is the area of the nth storage pond, with the unit of m 2(i.e., square meters), where a, b, and α are coefficients, and E is the startup cost in 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, and FQ u is the overflow volume before adding a storage tank to the u-th node, in m 3 (i.e., cubic meters), and Q u is the overflow volume after adding a storage tank to the u-th node, in m 3 (i.e., cubic meters);

[0110] Among them, the node is a rainwater node, and its actual meaning is a rainwater well. When it rains and the rainwater exceeds the pipeline load, it overflows from the well. The size of the node overflow volume can reflect the water accumulation situation near the node. The larger the overflow volume, the greater the risk of waterlogging. Therefore, the overflow reduction rate before and after installing the storage tank is used as one of the objective functions.

[0111] f3 is the peak flood reduction rate, L is the total number of outfalls, and Q pre,l is the peak flood flow of the l-th outfall without a storage tank, in m 3 (i.e., cubic meters), and Q l is the peak flood flow of the l-th outfall after installing a storage tank, in m 3 (i.e., cubic meters).

[0112] Among them, the outfall refers to the discharge outlet at the end of the rainwater pipe network, that is, the rainwater is discharged into the river from this outfall. Detecting the flow rate of the outfall can usually reflect the ability of the rainwater pipe network to face rainfall. The peak flood reduction rate is a key indicator for evaluating the flood regulation effect of the storage tank. It reflects the degree to which the storage tank can reduce the incoming peak flood during a rainstorm. Through the peak flood reduction rate, its flood prevention effect can be accurately evaluated. Therefore, the peak flood reduction rate is used as one of the objective functions.

[0113] Among them, the decision variables in step S1 include: volume, inlet pipe diameter and offset, and storage tank outlet flow rate;

[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 setting page of the bottom area is as Figure 2As shown, the shape of the storage pond is selected as the [Function] form, and the bottom area is set as a function of the depth. The relationship between the depth and the bottom area is set through the coefficient a1, the exponent a2, and the constant a0. In order to simplify the setting of decision variables in the present invention, both a1 and a2 are set to 0, then the area of the storage pond is a0; and when designing the storage pond, the height is usually not set as a decision variable, because if the height changes during the optimization process, it will cause errors in the connection between the inlet and outlet pipes of the storage pond, and then lead to model errors. Therefore, in the present invention, the height of the storage pond [Max.Depth] is set to 5m, then by setting a0 as a decision variable, the volume of the storage pond is identified.

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

[0117] In SWMM, the flow rate of the pump is usually set in the form of a pump curve [Pump Curve]. There are 5 types of curves in [Pump Curve]:

[0118] a. Type1 sets the pump flow rate according to the curve of the pump flow rate and the available volume of the sump;

[0119] b. Type2 sets the pump flow rate according to the curve of the pump flow rate and the depth of the inlet node;

[0120] c. Type3 sets the pump flow rate according to the curve of the pump flow rate and the head difference between the inlet and outlet nodes;

[0121] d. Type4 is a variable-speed on-line pump, and the pump flow rate is set according to the curve of the pump flow rate continuously changing with the depth of the inlet node;

[0122] e. Type5 the pump flow rate is equal to the inflow rate of the inlet node.

[0123] The present invention selects Type2, sets the flow rate at each depth as a fixed flow rate, and the initial flow rate is set to lift 1000m 3 of rainwater within 12 hours. When setting the curve, it is usually necessary to set the start and end parameters, such as the flow rate under each depth condition. If the outlet flow rate is directly set as a decision variable, it will lead to a situation where one outlet flow rate decision variable is composed of multiple variables, resulting in too many variables being set. The SWMM model sets a control rule [Control] module, which can dynamically control the on, off, and operating states of the pump by writing control statements, and is usually used to simulate the variable-speed drive of the pump. The pump curve multiplier [Setting] is used to identify the multiplier factor for overall increase or decrease of the pump flow rate. The control statement writing page is as Figure 3As shown, the overall control of the flow rate of each water pump can be achieved by setting the value of the control statement [Setting] as the decision variable.

[0124] Therefore, the decision variable in the step S1 is 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 inlet pipe of the nth storage tank, in meters, H inflow，n is the diameter of the inlet pipe of the nth storage tank, in meters, setting n is the pump curve multiplier of the nth storage tank.

[0127] Among them, the constraint conditions in the step S1 include the constraint of the diameter of the inlet pipe of the storage tank, the offset constraint, the bottom area constraint of the storage tank, the pump multiplier constraint, and the waterlogging control constraint;

[0128] Among them, for the pump multiplier constraint, the initial flow rate of the pump is set to drain 1000 m 3 of rainwater within 12 hours. Based on the rainfall situation once in 50 years, the SWMM model is run, and the maximum inflow of each storage tank does not exceed 10000 m 3 . Therefore, the maximum value of the pump multiplier is set not to exceed 10 and not less than 0;

[0129] Among them, for the waterlogging control constraint, according to the waterlogging prevention standard in the "Code for Design of Outdoor Wastewater Engineering" (GB50014-2021), the ground waterlogging depth should be less than 15 cm, and the drainage duration of the ground waterlogging should be less than 0.5 h. The depth in the SWMM model can be expressed by the accumulated water volume, the width of the catchment area, and the ground slope.

[0130] The constraint conditions in the 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] wherein, a0 is the area parameter of the storage tank, with the unit of m 2 , S min , S max are the minimum and maximum allowable floor areas of the storage tank, with the unit of m 2 ; H inflow is the pipe diameter of the inlet pipe of the storage tank, with the unit of m, H link is the pipe diameter of the upstream pipe of the inlet pipe, with the unit of m; H offset is the offset of the inlet pipe of the storage tank, with the unit of m, H node is the node depth of the node connected to the inlet pipe of the storage tank, with the unit of m; setting is the pump curve multiplier; T pongding is the waterlogging drainage time, with the unit of h, h depth is the waterlogging depth, with the unit of cm, i is the ground slope, with the unit of %, V is the waterlogging volume, with the unit of m 3 , and W is the width of the catchment area, with the unit of m.

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

[0139] The NSGA-II algorithm is a commonly used evolutionary algorithm for solving multi-objective optimization problems. It optimizes the individual population by simulating the natural selection process to achieve the optimal balance between different objectives, and is especially suitable for complex water resource management systems such as storage tanks. Therefore, the present invention uses the NSGA-II algorithm to solve the constructed multi-objective optimization model to obtain the Pareto solution set.

[0140] The basic principle of the NSGA-II algorithm is to seek the best compromise solution among multiple objectives through the non-dominated sorting and crowding distance mechanisms. The specific optimization process of the NSGA-II algorithm is consistent with the prior art, including: individual coding and initialization, objective evaluation, non-dominated sorting, crowding distance calculation, selection, crossover and mutation, population update and iteration, termination condition judgment, etc.

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

[0142] To achieve the purpose of urban rainwater control, the prior art usually sets different rainfall return periods according to different requirements to configure the corresponding storage tank volume. For example, when meeting the urban waterlogging control requirements, the return period is set to once in 10 - 100 years, and when meeting the runoff volume control rate, the return period is set to once in 1 - 2 years. However, this setting only considers the response ability in the case of a single extreme rainfall, while ignoring the differences in regional rainfall characteristics. For example, in areas with scarce rainfall, adopting a design standard of once in 100 years will significantly cause cost redundancy.

[0143] On the other hand, for reclaimed water supply, the storage tank plays a role of temporary water storage, and its volume is determined by parameters such as the storage period and water use quota. Larger storage periods and water use quotas will result in a larger volume. At the same time, when the rainfall interval in the research area is short and the frequency is high, in order to reduce the amount of reclaimed water discarded, a storage tank with a smaller volume has greater advantages. Also, a storage tank with a smaller volume is more advantageous for cold regions in the north where there is no municipal water demand in autumn and winter. However, a small volume cannot play its due role when facing extreme rainfall.

[0144] Therefore, for a multi-functional storage tank, it is unreasonable to design the rainfall directly based on one parameter or design the volume according to a certain water storage capacity, etc. The present invention selects the daily rainfall data of the research area in the past 20 years, calculates the balance relationship of water consumption, water discard volume, and rainfall of storage tanks with different volumes in continuous time, designs the storage tank volume, water supply, and dispatching strategy for the combined rainwater - reclaimed water storage, and then calculates factors such as the overflow volume, overflow times, water discard volume, and construction cost of storage tanks with different volume schemes. After technical and economic comparison, the volume is determined to obtain the best storage tank design scheme.

[0145] Specifically, in step S3, the storage tank volume, water supply, and dispatching strategy for the combined rainwater - reclaimed water storage are designed, and a comprehensive framework covering rainfall - water demand matching, combined storage volume optimization, water supply, and dispatching strategy is constructed, including:

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

[0147] When the storage tank is used for storing water supply, its volume design needs to consider water demand, water use quota, and storage period, etc. At the same time, unconventional water resources such as reclaimed water are mainly used in scenarios such as green space watering, road watering, and landscape water bodies. These water demands may vary in time and quantity. For example, road watering may be more concentrated and large in quantity, while green space watering may be more dispersed and continuous. Setting different storage periods for different water demands helps to reasonably allocate these unconventional water resources according to the diversity and stability of water demands.

[0148] Among them, the storage period refers to the number of days that the water stored in the storage tank can be used for once.

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

[0150]

[0151] Among them, V rain is the volume of the storage tank corresponding to each scheme in the Pareto solution set obtained in step S2, with the unit of m 3 , V d，min , V d，mid , V d，maz are the daily water consumptions under low, medium, and high water usage demands respectively, with the unit of m 3 , T min , T mid , T max are the storage periods corresponding to each demand, with the unit of d;

[0152] Among them, for road sprinkling water, when the water usage demands are high, medium, and low, the water consumption quotas are selected as 3.0, 2.5, and 2.0 L / (m 2 ·d) respectively; for green space sprinkling water, when the water usage demands are high, medium, and low, the water consumption quotas are selected as 3.0, 2.0, and 1.0 L / (m 2 ·d) respectively.

[0153] The storage tank is used for water storage and water supply on sunny days and for rainwater regulation on rainy days. Therefore, it is necessary to design its operation rules, that is, the scheduling design. The present invention designs the water supply and water abandonment scheduling strategy of the storage tank on the premise that the rainfall prediction information within 3 days is accurate and reliable. Specifically as Figure 4 shown, where T represents a complete scheduling cycle, and its definition basis is that the reclaimed water resources in the storage tank are completely consumed or a rainfall event occurs; t rain represents the time point when the first rainfall occurs within a scheduling cycle. At this time point, the scheduling cycle is divided into days, and the entire scheduling process is divided into three steps: prediction, decision-making, and information update, and is iterated according to the rolling cycle mode of forecast - decision-making - update.

[0154] In the present invention, the prediction stage focuses on integrating rainfall prediction data into the control model, while the decision-making stage is refined into two parts: water supply decision-making and water discharge decision-making. The water supply decision-making is made based on the prediction of rainfall conditions in the next three days by the prediction model. If the prediction shows that rainfall will occur, only the amount of water required before the first rainfall is provided; conversely, if the water storage period of the storage tank is expected to exceed three days and the prediction shows no rainfall during this period, the full amount of water required for the entire water storage period is provided. The rolling update period of the water supply decision-making is consistent with the scheduling period, that is, whenever the water resources in the storage tank are exhausted or rainfall occurs, it is regarded as the end of a period. The rolling period of the water discharge decision-making is shortened to one day. Based on the daily rainfall prediction results, the rainfall probability for the next day is evaluated. Once signs of rainfall are detected and there is accumulated water in the storage tank, the drainage operation is immediately carried out to minimize the possibility of waterlogging during rainfall.

[0155] Furthermore, it also includes S33, calculating the water supply volume and water discharge volume within one scheduling period of the storage tank, including:

[0156]

[0157] Among them, T represents a complete scheduling period. For low, medium, and high water demand, T takes T min 、T mid 、T max respectively, V d represents the daily water consumption. For low, medium, and high water demand, V d takes V d，min 、V d，mid 、V d，max respectively, and t rain represents the time point when the first rainfall occurs within one scheduling period.

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

[0159] The operations of opening and closing each valve and pump of the storage tank in different scenarios are shown in the following table:

[0160]

[0161]

[0162] Through the above detailed formulation of the scheduling rules of the storage tank and the operation rules of the valves and pumps, the overall operation process of the multi-functional storage tank system is comprehensively summarized. As Figure 5 shown, this figure shows the complete chain from rainfall prediction to water supply decision-making, water discharge decision-making, and then to the operation control of the valves and pumps.

[0163] S4. By using the TOPSIS method, with economic indicators, reclaimed water reuse indicators, and urban waterlogging indicators as evaluation indicators, each plan in the alternative plans is ranked to obtain the optimal plan.

[0164] The economic indicators in step S4 include: the construction cost of the storage tank, the construction cost of the pumping station, the construction cost of the reclaimed water pipe network, the power cost of the pumping station, and the personnel salary and welfare cost. 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, in yuan; P1 is the percentage of the operation and maintenance cost of the storage tank, in %, preferably P1 = 2.4%; C is the construction cost per unit volume, in yuan / m 3 , preferably, C = 1700 yuan / m 3 , V n is the volume of the nth storage tank, in m 3 , and N is the total number of storage tanks;

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

[0170] C4 is the construction cost of the reclaimed water pipe network, in yuan; P3 is the percentage of the operation and maintenance cost of the pipe network, in %; preferably P3 = 2.8%; G is the total number of reclaimed water supply pipes; C g is the construction cost per unit length of the gth pipe, in yuan / m, w, r, α are pipe statistical parameters; d g is the pipe diameter of the gth pipe, in m; l g is the length of the gth pipe, in m;

[0171] C3 is the power cost of the pump station, in yuan. The power cost of the pump station is the electricity cost required to lift the water volume of the rainwater pump station and the recycled water supply pump station, as well as the electricity cost of mud discharge and backwashing in the regulating reservoir. Since the power cost of the pump station accounts for a large proportion of the power cost, the electricity cost of the pump station is used as the base, and the remaining costs are calculated at an appropriate ratio. The power cost of recycled water is calculated by the power consumed each time it is lifted, and the power cost of the rainwater pump station is obtained from the statistics of the ultra-long duration based on the optimized pump station flow and head by running SWMM.

[0172] C 31 is the power cost of reclaimed water lifting, in RMB, J is the total number of times reclaimed water is lifted; α is the proportion of the cost of sludge discharge and backwashing in the pump station, which is 0.2; e is the electricity price of the pump 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 is the volume of water raised by the jth recycled water, in m 3 / d,H j is the jth recycled water lifting head, in m, η is the pumping station efficiency, C 32 is 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 the unit's responsible, administrative, technical, financial and asset management, and water administration supervision positions, 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 recycled water reuse 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 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 space watering, etc.; environmental benefits refer to the benefits of improving the environment when recycled water is used for green space watering by absorbing CO2 to reduce the ambient temperature and absorbing atmospheric pollutants such as SO2, which 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 watering 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 reclaimed water reuse, in yuan; T is the unit price of tap water, in yuan / m 3 , taking 2.97 yuan / m 3 , W is the unit price of reclaimed water, in yuan / m 3 , taking 2.068 yuan / m 3 , V reuse is the total amount of reclaimed water reuse, in m 3 .

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

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

[0181] B4 is the amount of water discarded, Q iis the regenerated water volume of the storage and drainage 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 reclaimed water pump station, and J is the total number of times of reclaimed water lifting.

[0183] The urban waterlogging indexes in step S4 include: the total amount of node overflow, the total duration of node overflow, and the number of overflow nodes per rainfall event.

[0184] The node overflow volume refers to the amount of rainwater that exceeds the pipeline conveying capacity during rainfall and is discharged through other facilities (such as manhole covers, etc.), which is used to measure the treatment capacity of the rainwater system when encountering rainfall exceeding the design standard. The total duration of node overflow is used to evaluate the long-term impact of waterlogging on urban functions; the number of overflow nodes per rainfall event refers to the number of nodes where overflow occurs.

[0185] The specific calculation formulas are as follows:

[0186]

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

[0188] S2 is the total duration of node overflow in the study area, with the unit of h, Time i，u is the total duration of overflow of the u-th node in the i-th rainfall event, with the unit of h;

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

[0190] Furthermore, based on the above-mentioned performance indexes and alternative schemes of the multifunctional storage and drainage pool under long-time series rainfall conditions, the TOPSIS comprehensive evaluation method is adopted to optimize each scheme, so as to screen out the most suitable storage and drainage pool scheme for the study area.

[0191] Specifically, step S4 includes:

[0192] S41. Establish a positive matrix, and construct a positive data matrix X containing n alternative schemes and m evaluation indexes, X = (x ij ) nm , x ij represents the value of the j-th evaluation index of the i-th alternative scheme, where when the j-th index of the i-th alternative scheme is a negative index, x ij is the value after positive processing of the original index value;

[0193] Among them, the positive index refers to the index where the more the better, such as the water saving amount, etc., and the negative index refers to the index where the less the better; positive transformation means taking the reciprocal, taking the negative value, etc. of the negative index to make it positive.

[0194] S42. Normalize the data to obtain the standardized matrix Z, Z = z ij , z ij represents the value after the normalization process of the j-th evaluation index of the i-th alternative to be evaluated;

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

[0196]

[0197] S44. Calculate the Euclidean distances between the positive and negative ideal solutions, and use the Euclidean distance method to calculate the distances between each alternative to be evaluated and the positive ideal solution and the negative ideal solution. Specifically:

[0198]

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

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

[0201]

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

[0203] S46. Sort according to the normalized ideal closeness degree of each alternative to be evaluated, and select the alternative with the largest normalized ideal closeness degree as the optimal alternative.

[0204] Those of ordinary skill in the art can realize that, combining the units and algorithm steps of each example described in the embodiments disclosed in this article, can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0205] In the embodiments provided in the present application, it should be understood that the disclosed device / network device and method can be implemented in other ways. For example, the device / network device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, 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 displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in electrical, mechanical or other forms.

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

[0207] The above 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. And these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope 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 the short-duration rainfall scenario, a multi-objective optimization model of the regulating reservoir for rainwater and flood control is constructed. The objective function is constructed based on the regulating reservoir cost, overflow reduction rate, and flood peak reduction rate. The decision variables are constructed based on the regulating reservoir volume, the diameter and offset of the water inlet pipe, and the water outflow of the regulating reservoir. Constraints are set based on the regulating reservoir volume, the diameter and offset of the water inlet pipe, the water outflow of the regulating reservoir, and waterlogging control. S2, using NSGA-Ⅱ algorithm to solve the multi-objective optimization model and obtain a Pareto solution set; S3. Based on the Pareto solution set, the storage tank capacity, water supply and scheduling strategies of the combined regulation of rainwater and recycled water are designed under the long-duration rainfall scenario, and a comprehensive framework covering rainfall-water demand matching, combined regulation storage capacity optimization, water supply and scheduling strategies is constructed to form alternative plans; S4. Through the TOPSIS method, the economic index, recycled water reuse index and urban waterlogging index are used as evaluation indicators to rank the various alternative plans and obtain the optimal plan.

2. The method according to claim 1, characterized in that The objective function in step S1 is specifically: Among them, f1 is the cost of the storage tank, in 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 is added to 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 of the lth discharge outlet when no storage tank is added, in m 3 , Q l is the peak flow rate of the lth discharge outlet after setting up the storage tank, in m 3 .

3. The method according to claim 2, characterized in that 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 is the diameter of the water inlet pipe of the nth storage tank, in meters, setting n is the pump curve multiplier of the nth storage tank.

4. The method according to claim 3, characterized in that 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 regulating reservoir, in m, H link H is the diameter of the upstream pipe of the water inlet pipe, in m; offset is the water 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 regulating reservoir, in meters; setting is the pump curve multiplier; T pongding is the time for water to recede, in h, h depth is the depth of water accumulation in cm, i is the ground slope in %, and V is the volume of water accumulation in m 3 , W is the width of the catchment area, in meters.

5. The method according to claim 4, characterized in that The economic indicators in step S4 include: construction costs of the regulating reservoir, construction costs of the pump station, construction costs of the recycled water network, power costs of the pump station, and employee salary and welfare costs. The specific calculation formula is: C5=(G+S+F)A; Among them, C1 is the construction cost of the regulating reservoir, in RMB, P1 is the percentage of the operation and maintenance cost of the regulating reservoir, in %, and C is the construction cost per unit volume, in 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 operation and maintenance cost, 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 times reclaimed water is lifted, α is the proportion of the cost of sludge removal and backwashing in the pump station, e is the electricity price of the pump 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 is the volume of water raised by the jth recycled water, in m 3 / d,H j is the jth recycled water lifting head, in m, η is the pumping station efficiency, C 32 is 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 the unit's responsible, administrative, technical, financial and asset management, and water administration supervision positions, 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, and A is the average annual salary and welfare expenses of each employee, in Yuan / person / year.

6. The method according to claim 5, characterized in that The reclaimed water reuse index in step S4 includes: 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=∑J; 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; B 21 is the carbon fixation and oxygen release benefit of recycled water, in yuan, is the carbon tax, in yuan / ton, is the carbon fixation 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 jth maximum water demand of green space, q G，j is the water supply of the jth green space, A G is the green area; B 22 The air purification efficiency is in Yuan. for Industrial processing cost, in yuan / ton, is the annual absorption of SO2 by 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 at the jth water supply, in m 3 ; B4 is the amount of abandoned water, Q 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.

7. The method according to claim 6, characterized in that 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 amount of overflow at the nodes in the study area, in m 3 , Flood i，u is the overflow of the u-th node in 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, Time 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.

8. The method according to claim 7, characterized in that The step S4 specifically includes: S41, establish a positive matrix, construct a positive data matrix X containing n evaluation schemes 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 index 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, calculating the Euclidean distance between the positive and negative ideal solutions, using the Euclidean distance method to calculate the distance between each of the schemes to be evaluated and the positive ideal solution and the negative ideal solution, 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 solution to be evaluated 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.

9. The method according to claim 8, characterized in that In step S3, the storage tank capacity, water supply and scheduling strategy for the combined regulation of rainwater and recycled water are designed to construct a comprehensive framework covering rainfall-water demand matching, combined regulation capacity optimization, water supply and scheduling strategy, specifically including: S31. Calculate the daily water consumption under low water demand, medium water demand and high water demand in the area to be studied; 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 water abandonment of the regulating reservoir within a 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 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.

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

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