Comprehensive evaluation and optimization method for urban large drainage system project
By constructing a "table-shallow-deep" three-dimensional engineering system and a multi-criteria decision-making model, problems such as insufficient river channel discharge capacity in urban large drainage systems have been solved, and a systematic drainage capacity improvement and optimization layout have been achieved, providing a comprehensive evaluation and optimization method for urban large drainage system projects.
Patent Information
- Application Number
- CN202510493290.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-18
- Publication Date
- 2025-08-05
AI Technical Summary
The existing technology has failed to scientifically guide the optimization layout of urban large drainage system efficiency improvement projects, especially the problems of insufficient discharge capacity of river channels, few stagnant storage facilities, insufficient strong discharge capacity, and mismatch with the river channel storage capacity in large drainage systems.
A hydrodynamic coupled simulation mathematical model is adopted, combining one-dimensional hydrodynamic equations and two-dimensional shallow water equations to build a "table-shallow-deep" three-dimensional engineering system, combined with expert consultation and multi-criteria decision-making methods, an evaluation system containing multiple criterion layers and multiple core evaluation indicators is established, and an evaluation and optimization model is constructed based on the hierarchical analysis method, the advantage and inferior solution distance method and the entropy weight method.
The systematized drainage capacity has been improved from macro to micro, and the hydrological response of different engineering measures has been accurately simulated through the one-dimensional and two-dimensional coupled hydrodynamic model, a comprehensive evaluation system covering technical performance, economic benefits and social impact has been built, and a theoretical method basis for the optimization layout of urban large drainage system engineering is provided.
Smart Images
Figure CN120430646A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of urban waterlogging control engineering, and in particular relates to a comprehensive evaluation and optimization method for urban large-scale drainage system engineering. Background Art
[0002] Urban drainage and flood control systems are divided into three types: micro, small, and large. Micro drainage systems consist of source-reduction facilities such as residential rain gardens and sunken green spaces, primarily serving to reduce runoff and purify initial rainwater. Small drainage systems, comprised of rainwater collection and transportation facilities such as stormwater pipes, pumping stations, and online storage tanks, primarily serve to collect rainwater, transport floodwater, and eliminate accumulated water. Large drainage systems, comprised of drainage channels (drainage channels, roads, and tunnels), detention facilities (lakes, wetlands, depressions, and large storage tanks), and drainage sluices and pumps, primarily serve to discharge floodwater and store retained water. Large drainage systems primarily address low-probability, long-duration rainfall events (once in 20 to 100 years), playing a crucial role in urban drainage and flood control.
[0003] However, large-scale drainage systems face challenges such as insufficient river discharge capacity, a lack of detention and storage facilities, insufficient forced drainage capacity that is mismatched with river storage and drainage capacity, and high water levels in external rivers (lakes) during flood season that impact internal river drainage. Optimizing and improving the efficiency of large-scale drainage systems presents a challenge. Existing research generally focuses on the layout and construction of individual projects, such as drainage channels and storage facilities, without examining evaluation and optimization methods from the perspective of the overall layout and system integration of urban large-scale drainage systems. This has resulted in a lack of scientific guidance for optimizing the layout of projects to improve the efficiency of urban large-scale drainage systems. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a comprehensive evaluation and optimization method for urban large-scale drainage system projects, so as to solve the defect that the existing technology fails to scientifically guide the optimization layout of urban large-scale drainage system efficiency improvement projects.
[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A comprehensive evaluation and optimization method for urban large-scale drainage system projects, comprising the following steps: In urban space, a hydrodynamic coupling simulation mathematical model is used to combine one-dimensional hydrodynamic equations, two-dimensional shallow water equations and coupled calculation processes to construct a "surface-shallow-deep" three-dimensional engineering system; Using expert consultation and a multi-criteria decision-making approach, we investigated and analyzed the large-scale drainage system, including drainage channels and storage facilities. We established an evaluation system with multiple criteria layers and multiple core evaluation indicators, ultimately forming a comprehensive evaluation standard that can quantify the evaluation of engineering solutions. An evaluation and optimization model is constructed based on the analytic hierarchy process, the distance between good and bad solutions and the entropy weight method.
[0006] Preferably, in the urban space, the hydrodynamic coupling simulation mathematical model is used as a means to combine the one-dimensional hydrodynamic equation, the two-dimensional shallow water equation and the coupling calculation process to construct a "surface-shallow-deep" three-dimensional engineering system, and the sub-steps are: S1.1. Based on basin topographic data, urban drainage network information, and key node bottleneck analysis, through hydrological and hydraulic calculations and spatial overlay analysis, clarify drainage needs and constraints at the basin, city, and node levels. Coordinate the needs of the basin-city-node three-level space, analyze existing drainage capacity, and determine optimization goals and implementation priorities for the "surface-shallow-deep" system. S1.2. Based on the one-dimensional hydrodynamic equation and the two-dimensional shallow water equation, the river cross-section data, pipe network topology, and surface DEM data were integrated to construct a one- and two-dimensional dynamic coupling model. The one- and two-dimensional dynamic coupling model was verified by setting coupling boundary conditions and calibrating the Manning roughness. S1.3. Utilize the storage capacity of lakes and depressions to improve drainage capacity through river dredging, embankment raising, and additional pumping stations, and formulate a specific engineering plan; S1.4. Build underground storage tanks based on rainstorm analysis, determine the volume and inlet and outlet control levels, and design peak-cutting facilities; S1.5. When the surface layer is insufficient, study the deep tunnel route, diameter, and shaft layout to assess the feasibility of construction; S1.6. Input the simulation results of the one- and two-dimensional dynamic coupling model into the "surface-shallow-deep" three-dimensional engineering system, verify the effect with the flooding reduction rate indicator, and provide feedback to optimize the engineering parameters to form the final optimization plan. Preferably, the one-dimensional hydrodynamic model is described by the Saint-Venant equations: (1); Where: Q For traffic; A is the cross-sectional area of water flow; v is the flow rate in the tube: h is the water depth in the pipe; t For time; x for distance; S f is the friction slope; S 0 is the bottom slope; q is the lateral inflow per unit length.
[0007] Preferably, the two-dimensional shallow water equation is expressed as follows: (2); (3); (4); Among them, formula (2) is the continuity equation, formula (3) and formula (4) are respectivelyx and y Momentum equation in direction; Where: h For water depth; or is the water level; u 、 v They are x and y Flow velocity in direction; g is the acceleration due to gravity; r is the density of water; t sx 、 t sy They are x and y Surface shear stress in the direction; t bx 、 t by They are x and y The bottom shear stress in the direction can be obtained by using the Manning formula: 、 ; in n is the Manning roughness; S is the source term; u s , v s is the source water flow velocity; 、 、 is the horizontal turbulence diffusion term.
[0008] Preferably, the criteria layers include performance, investment, land, technology, and ecological landscape; The core evaluation indicators include drainage standards, water storage capacity of regulation and storage facilities, system matching, redundancy coefficient, total project investment, annual operation and maintenance costs, land area, land feasibility, technical difficulty, regulatory compliance, ecological benefits, and landscape benefits; among them, drainage standards, water storage capacity of regulation and storage facilities, system matching and redundancy coefficient are the performance criterion layer; total project investment and annual operation and maintenance costs are the investment criterion layer; land area and land feasibility are the land criterion layer; technical difficulty and regulatory compliance are the technical criterion layer; ecological benefits and landscape benefits are the ecological landscape criterion layer.
[0009] Preferably, the method adopts expert consultation and multi-criteria decision-making methods to conduct research and analysis on large drainage systems including drainage channels and storage facilities, establish an evaluation system including multiple criteria layers and multiple core evaluation indicators, and ultimately form a comprehensive evaluation standard that can quantify the evaluation of engineering solutions; including the following sub-steps: S2.1. Conduct a comprehensive survey of the city's existing drainage channels, storage facilities, and forced drainage facilities, collect hydrological data, engineering parameters, and operation records, and establish a basic database to provide data support for subsequent analysis; S2.2. Organize a discussion among drainage experts and use the Delphi method to collect professional opinions; S2.3. Based on the survey results and expert opinions, preliminary evaluation indicators were selected from five dimensions: efficiency, investment, land, technology, and ecological landscape. Through correlation analysis and importance ranking, 12 core evaluation indicators were finally determined; S2.4. Establish a three-level evaluation framework: "goal layer - criteria layer - indicator layer", clarify the quantification method and weight distribution principle of each indicator, and form a complete evaluation indicator system; S2.5. Based on the characteristics of different indicators, select the evaluation method that combines quantitative and qualitative analysis of the analytic hierarchy process and cost-benefit analysis, and formulate specific scoring standards and calculation models; S2.6. Test the applicability of the evaluation system through typical cases, adjust the indicator weights and scoring standards based on the test results, and ultimately form an operational evaluation tool.
[0010] Preferably, the evaluation and optimization model is constructed based on the analytic hierarchy process, the superior and inferior solution distance method and the entropy weight method; comprising the following steps: S3.1. Calculate the indicator weights using the AHP method; S3.2. Perform data normalization: Use the "Range 0~1" method to normalize the data: (8); (9); Where: and Indicators The minimum and maximum values of ; m is the number of measures in the program layer, ; S3.3. Calculate indicator weights using the entropy weight method: Using the formula: , H i For the i The entropy value of the indicator, , Indicates the indicator, , Indicates measures, in, , , when When, agreed ; Then, the weight of the entropy weight method is calculated using formula (10): : (10); S3.4. Assign weights to the subjective and objective combinations of indicators: Combine AHP method and entropy weight method to perform combined weighting to improve the accuracy of weights; Combined weighting The calculation method is as follows: (11); Where: W AHPi is the weight of the analytic hierarchy process (AHP).
[0011] S3.5. Calculate the weighted decision matrix: The combined weight of each indicator The standardized decision matrix formed Multiply them together to get the weighted decision matrix ; (12); S3.6. Determine the ideal solution vector and negative ideal solution vector for each measure: Ideal solution vector and negative ideal solution vector The calculation methods are shown in formula (13) and formula (14): (13); (14); Where: ; ; S3.7. Calculate the Euclidean distance between each measure and the ideal solution and the negative ideal solution: Euclidean distance between each measure and the ideal solution and the negative ideal solution and The calculation methods of are shown in formula (15) and formula (16): , j =1, 2 ,…, m (15); , j =1, 2 ,…, m (16); S3.8. Calculate the relative closeness of each measure to the optimal value: Relative closeness of each measure The calculation method is as follows: , j =1, 2 ,…, m (17); The larger the value, the better the measure. Therefore, the optimal measure is The greatest measure; Preferably, the sub-steps of S3.1 are: ①Construct a judgment matrix; manually determine n indicators in the indicator layer For the weights of the target layers, select two of them and Perform pairwise comparisons, and let , we can get the judgment matrix: (5); Where: , , ( i , j =1, 2, ..., n ); The 1~9 scale method proposed by Satty was used to determine the The bigger the description Compare More important for the target layer; ②Calculate the sorting weight vector; first find the judgment matrix The maximum eigenvalue of , and then find The corresponding eigenvector is normalized to obtain the weight vector of each indicator layer relative to the target layer. ; ③Consistency test; consistency index and consistency ratio The calculation methods are shown in formula (6) and formula (7) respectively; when When , it is considered that the ranking weight solved through consistency test can be used as the final weight, otherwise the judgment matrix needs to be reconstructed; (6); (7); Where: n is the judgment matrix The order of is the average random consistency index.
[0012] A comprehensive evaluation and optimization system for urban large-scale drainage system projects adopts the above-mentioned comprehensive evaluation and optimization method for urban large-scale drainage system projects; comprising: "Surface-shallow-deep" three-dimensional engineering system equipment: In urban space, using hydrodynamic coupling simulation mathematical models as a means, combining one-dimensional hydrodynamic equations, two-dimensional shallow water equations and coupled calculation processes, to construct a "surface-shallow-deep" three-dimensional engineering system; Comprehensive evaluation standard construction equipment: Using expert consultation and multi-criteria decision-making methods, we conduct research and analysis on large drainage systems, including drainage channels and storage facilities, and establish an evaluation system with multiple criteria layers and multiple core evaluation indicators, ultimately forming a comprehensive evaluation standard that can quantify the evaluation of engineering solutions; Evaluation and optimization model: An evaluation and optimization model is constructed based on the analytic hierarchy process, the distance between good and bad solutions and the entropy weight method.
[0013] A computer device comprising: one or more processors; The processor is configured to store one or more programs; When the one or more programs are executed by the one or more processors, a comprehensive evaluation and optimization method for urban large-scale drainage system projects as described in any one of claims 1 to 9 is implemented.
[0014] The present invention can achieve the following beneficial effects: The present invention provides a comprehensive evaluation and optimization method for urban large-scale drainage system projects. By clarifying the theoretical framework for improving and optimizing the efficiency of urban large-scale drainage systems, an evaluation index system and an optimization model for urban large-scale drainage system projects are constructed, providing a theoretical methodological basis for optimizing the layout of urban large-scale drainage system projects.
[0015] This invention proposes a three-level coordination of "watershed-city-node" and a three-dimensional engineering system of "surface-shallow-deep", realizing a systematic improvement of drainage capacity from macro to micro, and accurately simulating the hydrological responses of different engineering measures through one-dimensional and two-dimensional coupled hydrodynamic models.
[0016] This invention constructs a comprehensive evaluation system consisting of 12 specific indicators in five criterion layers, covering multiple dimensions such as technical performance, economic benefits, and social impact. The indicator system is rationally designed, taking into account both short-term engineering effects and long-term sustainable development needs. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will be further described below with reference to the accompanying drawings and examples: Figure 1 A schematic diagram of the method flow provided by an embodiment of the present invention; Figure 2 This is a theoretical framework diagram for optimizing the performance of the urban drainage system according to the present invention; Figure 3 This is a calculation flow chart of the two-dimensional coupling model of the present invention. DETAILED DESCRIPTION
[0018] The preferred solution is Figure 1 to Figure 3 As shown, a comprehensive evaluation and optimization method for urban large-scale drainage system projects includes the following steps: Step 1: Propose a theoretical framework for improving and optimizing the efficiency of urban drainage systems.
[0019] In the limited space of the city, we should coordinate the river basin, city and node, establish a large drainage system efficiency improvement optimization method based on mathematical model and evaluation model (step 3), and build a three-dimensional engineering system of "surface-shallow-deep", such as Figure 2 As shown in the figure, "basin-city-node" refers to the comprehensive consideration and coordinated arrangement of three different scales and levels of objects, namely basin, city, and node, as an organic whole when planning and managing urban drainage systems. A river basin is a large natural geographical area encompassing a series of interconnected water bodies, such as rivers, lakes, and streams, as well as the surrounding land. Within urban drainage systems, coordination at the river basin level primarily considers the region's overall hydrological cycle, water resource distribution, and flood formation and evolution patterns. For example, by analyzing processes such as precipitation, evaporation, and surface runoff within the river basin, water storage, water diversion, and drainage facilities can be rationally planned to ensure water security and the rational use of water resources throughout the basin. At the same time, water demand and drainage relationships between different regions within the basin are coordinated to prevent local development and construction from adversely affecting the aquatic ecosystem of the entire basin.
[0020] Cities: As areas with a high concentration of population and economic activity, urban drainage systems are directly related to the quality of life of urban residents and the normal operation of the city. At the city level, it is necessary to rationally layout urban drainage networks, pumping stations, and storage facilities based on factors such as the city's topography, land use planning, and population distribution. For example, more rainwater storage facilities should be installed in low-lying areas of the city to address water accumulation during heavy rains. In the construction of new urban areas, drainage systems that separate rainwater and sewage should be adopted to improve sewage treatment efficiency and water resource recycling. At the same time, the connection between urban drainage systems and surrounding natural water bodies must be considered to ensure that urban drainage can be smoothly discharged into rivers or lakes within the basin.
[0021] Nodes are key components of a city's drainage system, including intersections of drainage pipes, pumping stations, stormwater inlets, and outfalls. These nodes play a crucial role in controlling water flow, regulating flow, and raising water levels. Coordinated management of nodes ensures that each node functions properly and coordinates with the overall drainage system. For example, pumping station operations are optimized, adjusting pumping capacity based on real-time water level and flow data. Outfalls are renovated and maintained to ensure smooth drainage and prevent issues such as sewage and seawater backflow.
[0022] The purpose of coordinating "watershed-city-node" is to achieve comprehensive and systematic planning and management of urban drainage systems from macro to micro, from overall to local, so as to improve the comprehensive efficiency of urban drainage systems and ensure the city's water security and ecological environment.
[0023] On the surface, tap into the storage capacity of lakes, depressions and other storage facilities; improve the water level control capacity of urban drainage rivers through dredging and widening river channels, raising embankments, and adding external drainage pumping stations. In the shallow layer, tap the storage potential of shallow space and build large underground storage pools.
[0024] In the deep layer, when the potential of the surface and shallow layers is fully tapped and still cannot meet the drainage requirements, the deep storage and drainage capacity should be developed and large-diameter drainage channels (deep tunnels) should be built.
[0025] Among them, the mathematical model refers to the hydrodynamic coupling simulation model of the urban large drainage system, which is used to simulate the water level and flow process of rivers and lakes under different engineering measures.
[0026] The one-dimensional hydrodynamic model is described by the Saint-Venant equations.
[0027] (1) Where: Q For traffic; A is the cross-sectional area of water flow; v is the flow rate in the tube: h is the water depth in the pipe; t For time; x for distance; S f is the friction slope; S 0 is the bottom slope; q is the lateral inflow per unit length.
[0028] The two-dimensional shallow water equation can be expressed as follows, where Equation (2) is the continuity equation, and Equations (3) and (4) are respectively x and y Momentum equation in direction: (2) (3) (4) Where: h For water depth; or is the water level; u 、 v They are x and y Flow velocity in direction; g is the acceleration due to gravity; r is the density of water; t sx 、 t sy They are x and y Surface shear stress in the direction; t bx 、 t by They are x and y The bottom shear stress in the direction can be obtained by using the Manning formula 、 (in n is the Manning roughness); S is the source term; ( u s , v s ) is the source water flow velocity; 、 、 is the horizontal turbulence diffusion term.
[0029] The calculation process of the one- and two-dimensional coupling model is shown in Figure 3 .
[0030] Step 2: Construct an evaluation index system for urban drainage system projects.
[0031] We conducted investigations, research, and in-depth analysis on large drainage systems, including drainage channels, rainwater storage facilities, and forced drainage facilities. After consulting experts, repeatedly summarizing and comprehensively screening, and applying specific quantitative and qualitative analysis methods, we finally proposed a comprehensive evaluation index system consisting of 12 evaluation indicators from five criterion levels, including efficiency, investment, land, technology, and ecological landscape. See Table 1.
[0032] Table 1 Evaluation index system for urban drainage system projects
[0033] Step 3: Construct an urban drainage system engineering evaluation and optimization model.
[0034] An evaluation and optimization model is constructed based on methods such as the Analytic Hierarchy Process (AHP), Topsis, and Entropy Weight Method. The main steps in constructing the evaluation and optimization model are as follows: (1) Calculate the index weight using the AHP method: It is divided into the following 3 steps: ① Construct a judgment matrix. It is necessary to manually determine the n indicators in the indicator layer. For the weights of the target layers, two of them can be selected and Perform pairwise comparisons, and let , we can get the judgment matrix: (5) Where: , , ( i , j =1, 2, ..., n ). The 1~9 scale method proposed by Satty (Table 2) was used to determine The bigger the description Compare It is more important for the target layer.
[0035] Table 21~9 Scaling method
[0036] ②Calculate the sorting weight vector. First find the judgment matrix The maximum eigenvalue of , and then find The corresponding eigenvector is normalized to obtain the weight vector of each indicator layer relative to the target layer. .
[0037] ③Consistency test. Consistency index and consistency ratio The calculation methods are shown in formula (6) and formula (7). When , it is considered that the ranking weight solved through consistency test can be used as the final weight, otherwise the judgment matrix needs to be reconstructed.
[0038] (6) (7) Where: n is the judgment matrix The order of is the average random consistency index, and the value is determined by looking up Table 3.
[0039] Table 3 Average random consistency index
[0040] (2) Data normalization processing: In order to eliminate the influence of different dimensions and magnitudes of the original data of the indicator layer, the “Range 0~1” method is used to normalize the data (Equation (8)), thereby constructing the standardized decision matrix R (Equation (9)).
[0041] (8) (9) Where: and Indicators The minimum and maximum values of ; m is the number of measures in the program layer, .
[0042] (3) Calculate the indicator weight using the entropy weight method: Using the formula , (number of indicators), (number of measures), of which, , , but when When, agreed .
[0043] Then, the weight of the entropy weight method is calculated using formula (10): : (10) (4) Weighting of subjective and objective combination of indicators: The weights determined by the AHP method are highly subjective; the entropy weight method can objectively reflect the contribution of specific data to the evaluation results. Therefore, the AHP method and the entropy weight method are combined to perform combined weighting to improve the accuracy of the weights. The calculation method is as follows: (11) (5) Calculate the weighted decision matrix: The combined weight of each indicator The standardized decision matrix formed Multiply them together to get the weighted decision matrix .
[0044] (12) (6) Determine the ideal solution vector and negative ideal solution vector of each measure: Ideal solution vector and negative ideal solution vector The calculation methods are shown in formula (13) and formula (14): (13) (14) Where: ; .
[0045] (7) Calculate the Euclidean distance between each measure and the ideal solution and the negative ideal solution: Euclidean distance between each measure and the ideal solution and the negative ideal solution and The calculation methods of are shown in formula (15) and formula (16): , j =1, 2 ,…, m (15) , j =1, 2 ,…, m (16) (8) Calculate the relative closeness of each measure to the optimal value: Relative closeness of each measure The calculation method is as follows: , j =1, 2 ,…, m (17) The larger the value, the better the measure. Therefore, the optimal measure is The biggest measure.
[0046] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention shall be the technical solutions set forth in the claims, including equivalent alternatives to the technical features of the technical solutions set forth in the claims. In other words, equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.
Claims
1. A comprehensive evaluation and optimization method for urban drainage system engineering, characterized by The following steps are involved: In urban spaces, a hydrodynamic coupling simulation mathematical model is used to combine one-dimensional hydrodynamic equations, two-dimensional shallow water equations, and coupled calculation processes to construct a "surface-shallow-deep" three-dimensional engineering system; Using expert consultation and a multi-criteria decision-making approach, we investigated and analyzed the large-scale drainage system, including drainage channels and storage facilities. We established an evaluation system with multiple criteria layers and multiple core evaluation indicators, ultimately forming a comprehensive evaluation standard that can quantify the evaluation of engineering solutions. An evaluation and optimization model is constructed based on the analytic hierarchy process, the distance between good and bad solutions and the entropy weight method.
2. A comprehensive evaluation and optimization method for urban drainage system engineering according to claim 1, characterized in that: In the urban space, the hydrodynamic coupling simulation mathematical model is used as a means to combine the one-dimensional hydrodynamic equation, the two-dimensional shallow water equation and the coupling calculation process to construct a "surface-shallow-deep" three-dimensional engineering system. The sub-steps are: S1.
1. Based on basin topographic data, urban drainage network information, and key node bottleneck analysis, through hydrological and hydraulic calculations and spatial overlay analysis, clarify drainage needs and constraints at the basin, city, and node levels. Coordinate the needs of the basin-city-node three-level space, analyze existing drainage capacity, and determine optimization goals and implementation priorities for the "surface-shallow-deep" system. S1.
2. Based on the one-dimensional hydrodynamic equation and the two-dimensional shallow water equation, the river cross-section data, pipe network topology, and surface DEM data were integrated to construct a one- and two-dimensional dynamic coupling model. The one- and two-dimensional dynamic coupling model was verified by setting coupling boundary conditions and calibrating the Manning roughness. S1.
3. Utilize the storage capacity of lakes and depressions to improve drainage capacity through river dredging, embankment raising, and additional pumping stations, and formulate a specific engineering plan; S1.
4. Build underground storage tanks based on rainstorm analysis, determine the volume and inlet and outlet control levels, and design peak-cutting facilities; S1.
5. When the surface layer is insufficient, study the deep tunnel route, diameter, and shaft layout to assess the feasibility of construction; S1.
6. Input the simulation results of the one- and two-dimensional dynamic coupling model into the "surface-shallow-deep" three-dimensional engineering system, verify the effect using the flooding reduction rate indicator, and provide feedback to optimize the engineering parameters to form the final optimization plan.
3. A comprehensive evaluation and optimization method for urban drainage system engineering according to claim 2, characterized in that: The one-dimensional hydrodynamic model is described by the Saint-Venant equations: （1）； Where: Q For traffic; A is the cross-sectional area of water flow; v is the flow rate in the tube: h is the water depth in the pipe; t For time; x for distance; S f is the friction slope; S 0 is the bottom slope; q is the lateral inflow per unit length.
4. A comprehensive evaluation and optimization method for urban drainage system engineering according to claim 3, characterized in that: The two-dimensional shallow water equations are expressed as follows: （2）； （3）； （4）； Among them, formula (2) is the continuity equation, formula (3) and formula (4) are respectively x and y Momentum equation in direction; Where: h For water depth; η is the water level; u 、 v They are x and y Flow velocity in direction; g is the acceleration due to gravity; ρ is the density of water; τ sx 、 τ sy They are x and y Surface shear stress in the direction; τ bx 、 τ by They are x and y The bottom shear stress in the direction can be obtained by using the Manning formula: 、 ； in n is the Manning roughness; S is the source term; u s , v s is the source water flow velocity; 、 、 is the horizontal turbulence diffusion term.
5. The method for comprehensive evaluation and optimization of urban drainage system projects according to claim 1, characterized in that: The criteria layers include performance, investment, land, technology, and ecological landscape; The core evaluation indicators include drainage standards, water storage capacity of regulation and storage facilities, system matching, redundancy coefficient, total project investment, annual operation and maintenance costs, land area, land feasibility, technical difficulty, regulatory compliance, ecological benefits, and landscape benefits; among them, drainage standards, water storage capacity of regulation and storage facilities, system matching and redundancy coefficient are the performance criterion layer; total project investment and annual operation and maintenance costs are the investment criterion layer; land area and land feasibility are the land criterion layer; technical difficulty and regulatory compliance are the technical criterion layer; ecological benefits and landscape benefits are the ecological landscape criterion layer.
6. A comprehensive evaluation and optimization method for urban drainage system engineering according to claim 5, characterized in that: The aforementioned use of expert consultation and multi-criteria decision-making methods to investigate and analyze large drainage systems including drainage channels and storage facilities, establish an evaluation system consisting of multiple criteria layers and multiple core evaluation indicators, and ultimately form a comprehensive evaluation standard that can quantify the evaluation of engineering solutions; The following sub-steps are included: S2.
1. Conduct a comprehensive survey of the city's existing drainage channels, storage facilities, and forced drainage facilities, collect hydrological data, engineering parameters, and operation records, and establish a basic database to provide data support for subsequent analysis; S2.
2. Organize a discussion among drainage experts and use the Delphi method to collect professional opinions; S2.
3. Based on the survey results and expert opinions, preliminary evaluation indicators were selected from five dimensions: efficiency, investment, land, technology, and ecological landscape. Through correlation analysis and importance ranking, 12 core evaluation indicators were finally determined; S2.
4. Establish a three-level evaluation framework: "goal layer - criteria layer - indicator layer", clarify the quantification method and weight distribution principle of each indicator, and form a complete evaluation indicator system; S2.
5. Based on the characteristics of different indicators, select the evaluation method that combines quantitative and qualitative analysis of the analytic hierarchy process and cost-benefit analysis, and formulate specific scoring standards and calculation models; S2.
6. Test the applicability of the evaluation system through typical cases, adjust the indicator weights and scoring standards based on the test results, and ultimately form an operational evaluation tool.
7. The method for comprehensive evaluation and optimization of urban drainage system projects according to claim 1, characterized in that: The evaluation and optimization model based on the hierarchical analysis method, the superior and inferior solution distance method and the entropy weight method is constructed; the following steps are included: S3.
1. Calculate the indicator weights using the AHP method; S3.
2. Perform data normalization: Use the "Range 0~1" method to normalize the data: （8）； （9）； Where: and Indicators The minimum and maximum values of ; m is the number of measures in the program layer, ; S3.
3. Calculate indicator weights using the entropy weight method: Using the formula: , H i For the i The entropy value of the indicator, , Indicates the indicator, , Indicates measures, in, , , when When, agreed ; Then, the weight of the entropy weight method is calculated using formula (10): : （10）； S3.
4. Assign weights to the subjective and objective combinations of indicators: Combine AHP method and entropy weight method to perform combined weighting to improve the accuracy of weights; Combined weighting The calculation method is as follows: （11）； Where: W AHPi is the weight of the AHP method. 8.S3.
5. Calculate the weighted decision matrix: The combined weight of each indicator The standardized decision matrix formed Multiply them together to get the weighted decision matrix ; （12）； S3.
6. Determine the ideal solution vector and negative ideal solution vector for each measure: Ideal solution vector and negative ideal solution vector The calculation methods are shown in formula (13) and formula (14): （13）； （14）； Where: ; ; S3.
7. Calculate the Euclidean distance between each measure and the ideal solution and the negative ideal solution: Euclidean distance between each measure and the ideal solution and the negative ideal solution and The calculation methods of are shown in formula (15) and formula (16): ， j =1, 2 ,…, m （15）； ， j =1, 2 ,…, m （16）； S3.
8. Calculate the relative closeness of each measure to the optimal value: Relative closeness of each measure The calculation method is as follows: ， j =1, 2 ,…, m （17）； The larger the value, the better the measure. Therefore, the optimal measure is The biggest measure.
9. The method for comprehensive evaluation and optimization of urban drainage system projects according to claim 1, characterized in that: The sub-steps of S3.1 are: ①Construct a judgment matrix; manually determine n indicators in the indicator layer For the weights of the target layers, select two of them and Perform pairwise comparisons, and let , we can get the judgment matrix: （5）； Where: , , ( i , j =1, 2, ..., n ); The 1~9 scale method proposed by Satty was used to determine the The bigger the description Compare More important for the target layer; ②Calculate the sorting weight vector; first find the judgment matrix The maximum eigenvalue of , and then find The corresponding eigenvector is normalized to obtain the weight vector of each indicator layer relative to the target layer. ; ③Consistency test; consistency index and consistency ratio The calculation methods are shown in formula (6) and formula (7) respectively; when When , it is considered that the ranking weight solved through consistency test can be used as the final weight, otherwise the judgment matrix needs to be reconstructed; （6）； （7）； Where: n is the judgment matrix The order of is the average random consistency index.
10. A comprehensive evaluation and optimization system for urban drainage system projects, characterized by: A comprehensive evaluation and optimization method for urban drainage system engineering according to claim 1 is adopted; comprising: "Surface-shallow-deep" three-dimensional engineering system equipment: In urban spaces, using a hydrodynamic coupling simulation mathematical model as a means, combining one-dimensional hydrodynamic equations, two-dimensional shallow water equations and coupled calculation processes, to construct a "surface-shallow-deep" three-dimensional engineering system; Comprehensive evaluation standard construction equipment: Using expert consultation and multi-criteria decision-making methods, we conduct research and analysis on large drainage systems, including drainage channels and storage facilities, and establish an evaluation system with multiple criteria layers and multiple core evaluation indicators, ultimately forming a comprehensive evaluation standard that can quantify the evaluation of engineering solutions; Evaluation and optimization model: An evaluation and optimization model is constructed based on the analytic hierarchy process, the distance between good and bad solutions and the entropy weight method.
11. A computer device, comprising: one or more processors; The processor is configured to store one or more programs; When the one or more programs are executed by the one or more processors, a comprehensive evaluation and optimization method for urban large-scale drainage system projects as described in any one of claims 1 to 9 is implemented.