Method for identifying potential waterlogging-causing pipe section of urban drainage pipe network

Abstract

The invention discloses a method for identifying a potential waterlogging-causing pipe section of an urban drainage pipe network, and belongs to the field of urban drainage pipe networks. According to the method, the problems of poor accuracy, low efficiency and high complexity of the identification method for identifying the pipe section causing the waterlogging risk in the urban underground drainage pipe network structure by using the traditional method are solved. On the basis of a topological structure diagram file of the drainage pipe network, components such as an inspection well, a drainage port and a pipeline are abstracted as points and edges, a two-dimensional matrix is constructed to represent the connection relation and topological characteristics of the pipeline in the drainage pipe network system, and the construction efficiency is improved under the condition that a hydraulic model is not used. According to the method, reverse slope pipelines and pipelines formed by connecting large pipes with small pipes are quickly and accurately positioned by using the topological graph of the drainage pipe network, namely key problem pipe sections possibly causing urban waterlogging are positioned, a reliable solution is provided for optimal design of the urban pipe network and waterlogging treatment, and the potential waterlogging-causing pipe sections of the drainage pipe network are quickly and accurately identified. The method can be applied to identification of potential waterlogging-causing pipe sections of the urban drainage pipe network.

Description

Technical Field

[0001] The invention belongs to the field of urban drainage pipe networks, and in particular relates to a method for identifying potential waterlogging-causing pipe sections of urban drainage pipe networks. Background Art

[0002] With the frequent occurrence of extreme rainfall events under the influence of global climate change and the acceleration of urbanization, the operating pressure of drainage networks has gradually increased, and the problem of urban waterlogging has become increasingly prominent, causing serious impacts on urban economy, transportation and people's life safety. Identifying the key pipe sections that cause urban waterlogging in urban drainage networks can provide guidance for the renewal and transformation of urban drainage networks, which is of great significance to alleviating urban waterlogging.

[0003] Traditional drainage network analysis methods mostly focus on hydraulic simulation or manual experience judgment by establishing hydraulic models. This method not only requires high professional knowledge and complex computing tools, but also has problems such as cumbersome early modeling steps, difficult model calibration, long analysis cycle, low efficiency, and results relying on human experience. It is difficult to accurately identify the pipe sections in the urban underground drainage network structure that may cause waterlogging in an efficient and comprehensive manner. Therefore, there is an urgent need for a scientific, systematic, simple and efficient method to automatically identify the key pipe sections in the drainage network that may cause waterlogging, so as to provide a reliable basis for the optimization design of the network and waterlogging control. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of poor accuracy and low efficiency in identifying pipe sections with the risk of causing waterlogging in urban underground drainage pipe network structures by traditional methods, as well as high complexity of the identification method, and to propose a method for identifying potential waterlogging-causing pipe sections in urban drainage pipe networks.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a method for identifying potential waterlogging sections of urban drainage pipe networks, the method specifically comprising the following steps:

[0006] Step 1: Obtain all nodes and pipes in the drainage network topology structure source file, and then construct a node-node relationship matrix, a node-pipeline relationship matrix, and a pipeline elevation information matrix;

[0007] Step 2: Calculate the connectivity, out-degree and in-degree of each node in the drainage network system according to the node-node relationship matrix, and determine the hub nodes and end points in the drainage network system according to the connectivity, out-degree and in-degree of each node. All hub nodes constitute the hub node set junction;

[0008] Step 3: For any hub node in the hub node set junction, calculate the shortest path between the hub node and each end point in the drainage network system, and record the shortest path length corresponding to the hub node;

[0009] After traversing each hub node in the hub node set junction, the shortest path length corresponding to each hub node is obtained;

[0010] The grade value of the end point in the drainage pipe network system is set to 0, and the shortest path lengths corresponding to each hub node are sorted in order from small to large. The grade value of each hub node is numbered according to the sorting result, and each branch connecting two hub nodes is obtained; for each branch, the starting node number of the branch, the pipe numbers connected in sequence on the branch, the end node number of the branch, and the grade of the hub node at the end of the branch are recorded in a list form, and the grade of the hub node at the end of the branch is used as the number of the branch;

[0011] Step 4: Calculate the pipe segment slope information vector of the drainage pipe network system according to the node-pipeline relationship matrix and the upstream and downstream elevation information matrix of the pipe, and list the pipe numbers corresponding to the elements with negative values ​​in the pipe segment slope information vector into the reverse slope list;

[0012] Step 5: Process the branches obtained in step 3 in order from small to large branch numbers to locate the pipes in the drainage pipe network system where the large pipes connect to the small pipes; then list the numbers of the located pipes in the Bwave_diameter list and the Bproblem_diameter list;

[0013] Step 6: Determine whether the downstream pipeline of each hub node in the hub node set junction is a large pipe connected to a small pipe, and add the number of the downstream pipeline that is a large pipe connected to a small pipe to the Jwave_diameter list;

[0014] Step 7: Add the pipe numbers in the Jwave_diameter list to the Bwave_diameter list, and delete the duplicate pipe numbers to obtain the final Bwave_diameter list. The pipes corresponding to all the numbers in the reverse slope list, Bwave_diameter list, and Bproblem_diameter list are regarded as potential waterlogging-causing pipes in the drainage network system.

[0015] Furthermore, the nodes in the drainage network topology structure diagram source file include inspection wells, forebays and drainage outlets;

[0016] The node-node relationship matrix is ​​denoted as node node ∈R n×n, where n represents the number of nodes in the drainage network system;

[0017]

[0018] Among them, A ij Represents the matrix node node The element in row i and column j of ;

[0019]

[0020] The node-pipeline relationship matrix is ​​denoted as node edge _direct∈R n×m , where m represents the number of pipes in the drainage network system;

[0021]

[0022] Among them, when node i is the starting point of pipeline k, F ik = 1, when node i is the end point of pipeline k, F ik = -1, when node i is not the starting point or end point of pipeline k, F ik =0;

[0023] The upstream and downstream elevation information matrix of the pipeline is recorded as node edge ∈R n×m :

[0024]

[0025] When node i is the starting point of pipeline k, E ik = c, c is the elevation of the inner bottom of the starting point of pipe segment k. When node i is the end point of pipe k, E ik = d, d is the end point of pipe segment k, when node i is not the start or end point of pipe k, E ik =0.

[0026] Furthermore, in step 2, the connectivity, out-degree and in-degree of each node in the drainage network system are calculated according to the node-node relationship matrix, specifically:

[0027]

[0028] Where degree(i) is the connectivity of node i;

[0029]

[0030] Among them, A ij >0, degree in (i) is the in-degree of node i;

[0031]

[0032] Among them, A ij <0, degree out (i) is the out-degree of node i.

[0033] Furthermore, the hub node in the drainage pipe network system is a node with a connectivity greater than or equal to 3;

[0034] The end point in the drainage network system is a node with an in-degree greater than or equal to 1 and an out-degree of 0.

[0035] Furthermore, the specific process of step 4 is as follows:

[0036]

[0037] Among them, L1, L2, ..., L m-1 , L m are the lengths of the first pipe, the second pipe, ..., the m-1th pipe, and the mth pipe in the drainage pipe network system respectively; S is the pipe segment slope information vector, and S is a vector composed of the slope values ​​of each pipe.

[0038] Furthermore, the specific process of step five is as follows:

[0039] Step 51: Initialize the number of branches p=1;

[0040] Step 52: Initialize the wave_diameter list and the problem_diameter list to be empty sets;

[0041] Step 53: Sort the pipes on the p-th branch line in ascending order of pipe diameter, and compare the obtained sorting result with the original pipe numbering sequence on the p-th branch line;

[0042] If the obtained sorting result is consistent with the original pipeline numbering sequence on the p-th branch, then there is no pipeline with a large pipe connected to a small pipe on the p-th branch, and step 50 is continued;

[0043] If the obtained sorting result is inconsistent with the original pipeline number sequence on the pth branch, the original number of the pipeline whose sorting has changed is added to the wave_diameter list, and step 54 is executed;

[0044] Step 54: Initialize l=1;

[0045] Step 55: Search for the downstream pipe a1 directly connected to the lth pipe in the wave_diameter list on the pth branch, and compare the pipe diameters of the lth pipe in the wave_diameter list with the downstream pipe a1:

[0046] If the diameter of the lth pipe in the wave_diameter list is less than or equal to the diameter of the downstream pipe a1, continue to execute step 59;

[0047] If the diameter of the lth pipe in the wave_diameter list is larger than the diameter of the downstream pipe a1, continue to execute steps five and six;

[0048] Step 56: Compare the pipeline design capacity of the lth pipeline in the wave_diameter list with the downstream pipeline a1:

[0049] If the pipeline design capacity of the downstream pipeline a1 is greater than the pipeline design capacity of the lth pipeline in the wave_diameter list, the number of the lth pipeline in the wave_diameter list is deleted from the wave_diameter list, and step 59 is continued;

[0050] If the pipeline design capacity of the downstream pipeline a1 is less than or equal to the pipeline design capacity of the lth pipeline in the wave_diameter list, continue to execute step 57;

[0051] Step 57: Add the original number of the downstream pipe a1 to the problem_diameter list, and determine whether the downstream pipe a1 is the terminal pipe of the pth branch;

[0052] If the downstream pipeline a1 is the terminal pipeline of the pth branch, execute step 50;

[0053] If the downstream pipe a1 is not the terminal pipe of the p-th branch, then search for the downstream pipe a2 directly connected to the downstream pipe a1 on the p-th branch, and continue to execute step 58;

[0054] Step 58: Determine whether the diameter of pipeline a1 is equal to the diameter of pipeline a2;

[0055] If satisfied, then the pipeline a2 returns to step 57 (that is, when returning to step 57, the pipeline a2 is processed as the downstream pipeline a1 in step 57);

[0056] If not satisfied, execute step 59;

[0057] Step 59: Whether to traverse each pipeline in the wave_diameter list;

[0058] If the traversal reaches each pipe in the wave_diameter list, execute step 50;

[0059] If all the pipes in the wave_diameter list have not been traversed, then l=l+1 is set, and the process returns to step 55;

[0060] Step 50, add the remaining pipe numbers in the wave_diameter list to the Bwave_diameter list, add the remaining pipe numbers in the problem_diameter list to the Bproblem_diameter list, and initialize the wave_diameter list and the problem_diameter list to be empty;

[0061] Then determine whether all branches have been traversed:

[0062] If all branches are traversed, the Bwave_diameter list and the Bproblem_diameter list are obtained;

[0063] If all branches have not been traversed, set p=p+1 and return to execute step 53.

[0064] Furthermore, the specific process of step six is ​​as follows:

[0065] Step 61: Initialize q=1;

[0066] Step 62: Determine whether the qth hub node in the hub node set junction satisfies: the in-degree is greater than or equal to 2 and the out-degree is greater than or equal to 1;

[0067] If satisfied, execute step 63;

[0068] If not satisfied, execute step 65;

[0069] Step 63: Determine whether the current hub node satisfies: the sum of the diameters of all upstream pipelines directly connected to the current hub node is greater than the sum of the diameters of all downstream pipelines directly connected to the current hub node;

[0070] If satisfied, execute step 64;

[0071] If not satisfied, execute step 65;

[0072] Step 64: Determine whether the current hub node satisfies: the sum of the design capacities of all upstream pipelines directly connected to the current hub node is greater than the sum of the design capacities of all downstream pipelines directly connected to the current hub node;

[0073] If it is satisfied, then add the numbers of all downstream pipelines directly connected to the current hub node into the Jwave_diameter list, and then execute step 65;

[0074] If not satisfied, directly execute step 65;

[0075] Step 65: Determine whether all the hub nodes in the hub node set junction have been traversed;

[0076] If all the hub nodes in the hub node set junction are traversed, the final Jwave_diameter list is obtained;

[0077] Otherwise, set q=q+1 and return to execute step 62.

[0078] Furthermore, the calculation process of the pipeline design capacity is:

[0079] For pipe number k:

[0080]

[0081] Where: Q k represents the flow rate of the pipe numbered k; n is the Manning coefficient; D k represents the flow cross-sectional area of ​​the pipe numbered k; R is the hydraulic radius; S k Indicates the slope of the pipe numbered k.

[0082] Furthermore, the calculation method of the hydraulic radius R is:

[0083]

[0084] Where: P is the wetted perimeter.

[0085] The beneficial effects of the present invention are:

[0086] The present invention is based on the topological structure diagram file of the drainage network, abstracts components such as inspection wells, drainage outlets, and pipelines into points and edges, and constructs a two-dimensional matrix to characterize the connection relationship and topological characteristics of the pipelines in the drainage network system, thereby realizing rapid and accurate identification of potential waterlogging-causing pipe sections of the drainage network. The method of the present invention can use the topological diagram of the drainage network to quickly and accurately locate reverse slope pipes and pipes where large pipes connect to small pipes without using a hydraulic model, that is, locate key problematic pipe sections that may cause urban waterlogging, which not only avoids the shortcomings of traditional methods based on manual screening and hydraulic modeling, but also provides a reliable solution for the optimization design of urban pipe networks and waterlogging control. Since the process of manual hydraulic model construction, calibration, and empirical judgment is avoided, the complexity of the identification method is reduced, while the waste of human resources is reduced, and work efficiency and accuracy are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 It is a flow chart of a method for identifying a potential waterlogging-causing pipe section of an urban drainage pipe network of the present invention;

[0088] Figure 2It is a schematic diagram of the branch between two hub nodes. DETAILED DESCRIPTION

[0089] Specific implementation method 1: Combination Figure 1 The present embodiment describes a method for identifying a potential waterlogging section of an urban drainage network, the method specifically comprising the following steps:

[0090] Step 1: Obtain all nodes and pipes (including actual pipes and water pumps) in the drainage network topology structure source file (such as CAD file, GIS file), and then construct a node-node relationship matrix, a node-pipeline relationship matrix, and a pipeline elevation information matrix; use the constructed node-node matrix and node-pipeline matrix to characterize the connection relationship and topological characteristics of the drainage system;

[0091] Step 2: Calculate the connectivity, out-degree and in-degree of each node in the drainage network system according to the node-node relationship matrix, and determine the hub node and end point (i.e., river mouth) in the drainage network system according to the connectivity, out-degree and in-degree of each node. All hub nodes constitute the hub node set junction;

[0092] Step 3: For any hub node in the hub node set junction, use the Dijkstra algorithm to calculate the shortest path between the hub node and each end point in the drainage pipe network system, and record the shortest path length corresponding to the hub node (that is, for any end point, calculate the shortest path length between the hub node and the end point, and then arrange the shortest path lengths corresponding to each end point in descending order, and take the length ranked first as the shortest path length corresponding to the hub node);

[0093] After traversing each hub node in the hub node set junction, the shortest path length corresponding to each hub node is obtained;

[0094] The grade value of the end point in the drainage pipe network system is set to 0, and the shortest path lengths corresponding to each hub node are sorted in order from small to large. The grade value of each hub node is numbered according to the sorting result (the smaller the shortest path length value corresponding to the hub node, the closer the hub node is to the end of the drainage pipe network system, that is, the smaller the grade value of the hub node. When the shortest path length values ​​corresponding to multiple hub nodes are equal, the same grade value is set for multiple hub nodes with equal shortest path length values, and the grade values ​​of non-end points in the sorting result are sorted from 1), and the branches connecting the two hub nodes are obtained (it should be noted that there may be no branch between the two hub nodes, or there may be multiple branches between the two hub nodes); Figure 2As shown, for each branch, the starting node number of the branch, the pipe numbers connected in sequence on the branch (i.e., the pipe numbers that the water flow passes through in sequence), the end node number of the branch, and the level of the hub node at the end of the branch are recorded in a list form, and the level of the hub node at the end of the branch is used as the number of the branch;

[0095] Step 4: Calculate the pipe segment slope information vector of the drainage pipe network system according to the node-pipeline relationship matrix and the upstream and downstream elevation information matrix of the pipe, and list the pipe numbers corresponding to the elements with negative values ​​in the pipe segment slope information vector into the reverse slope list;

[0096] Step 5: Process the branches obtained in step 3 in order from small to large branch numbers to locate the pipes in the drainage pipe network system where the large pipes connect to the small pipes; then list the numbers of the located pipes in the Bwave_diameter list and the Bproblem_diameter list;

[0097] Step 6: Determine whether the downstream pipeline of each hub node in the hub node set junction is a large pipe connected to a small pipe, and add the number of the downstream pipeline that is a large pipe connected to a small pipe to the Jwave_diameter list;

[0098] Step 7: Add the pipe numbers in the Jwave_diameter list to the Bwave_diameter list, and delete the duplicate pipe numbers to obtain the final Bwave_diameter list. The pipes corresponding to all the numbers in the reverse slope list, Bwave_diameter list, and Bproblem_diameter list are regarded as potential waterlogging-causing pipes in the drainage network system.

[0099] Specific implementation method 2: This implementation method is different from the specific implementation method 1 in that the nodes in the drainage network topology structure source file include inspection wells, forebays and drainage outlets;

[0100] The node-node relationship matrix is ​​denoted as node node ∈R n×n , where n represents the number of nodes in the drainage network system;

[0101]

[0102] Among them, A ij Represents the matrix node node The element in row i and column j of ;

[0103]

[0104] The node-pipeline relationship matrix is ​​denoted as node edge_direct∈R n×m , where m represents the number of pipes in the drainage network system;

[0105]

[0106] Among them, when node i is the starting point of pipeline k, F ik = 1, when node i is the end point of pipeline k, F ik = -1, when node i is not the starting point or end point of pipeline k, F ik =0;

[0107] The upstream and downstream elevation information matrix of the pipeline is recorded as node edge ∈R n×m :

[0108]

[0109] When node i is the starting point of pipeline k, E ik = c, c is the elevation of the inner bottom of the starting point of pipe segment k. When node i is the end point of pipe k, E ik = d, d is the end point of pipe segment k, when node i is not the start or end point of pipe k, E ik =0.

[0110] The other steps and parameters are the same as those in the first embodiment.

[0111] Specific implementation method three: This implementation method is different from specific implementation methods one or two in that, in step two, the connectivity, out-degree and in-degree of each node in the drainage network system are calculated according to the node-node relationship matrix, specifically:

[0112]

[0113] Where, degree(i) is the connectivity of node i; connectivity represents the number of pipe segments connected to the node (such as a manhole) in the drainage network system, including upstream pipe segments (node ​​i is the downstream node of the pipe segment) and downstream pipe segments (node ​​i is the upstream node of the pipe segment);

[0114]

[0115] Among them, A ij >0, degree in (i) is the in-degree of node i; the out-degree represents the number of downstream pipe sections connected to node i in the drainage network system;

[0116]

[0117] Among them, A ij <0, degreeout (i) is the out-degree of node i; the in-degree represents the number of upstream pipe sections connected to node i in the drainage network system.

[0118] The other steps and parameters are the same as those in the first or second embodiment.

[0119] Specific implementation method 4: This implementation method is different from any one of specific implementation methods 1 to 3 in that the hub node in the drainage pipe network system is a node with a connectivity greater than or equal to 3;

[0120] The end point in the drainage network system is a node with an in-degree greater than or equal to 1 and an out-degree of 0.

[0121] The other steps and parameters are the same as those in Specific Embodiments 1 to 3.

[0122] Specific implementation method 5: This implementation method is different from the specific implementation methods 1 to 4 in that the specific process of step 4 is as follows:

[0123]

[0124] Among them, L1, L2, ..., L m-1 , L m are the lengths of the first pipe, the second pipe, …, the m-1th pipe, and the mth pipe in the drainage pipe network system respectively; S is the pipe segment slope information vector, and S is a vector composed of the slope values ​​of each pipe.

[0125] The other steps and parameters are the same as those in Specific Embodiments 1 to 4.

[0126]

[0127] Specific implementation method 6: This implementation method is different from the specific implementation methods 1 to 5 in that the specific process of step 5 is as follows:

[0128] Step 51: Initialize the number of branches p=1;

[0129] Step 52: Initialize the wave_diameter list and the problem_diameter list to be empty sets;

[0130] Step 53: Sort the pipes on the p-th branch line in ascending order of pipe diameter, and compare the obtained sorting result with the original pipe numbering sequence on the p-th branch line;

[0131] If the obtained sorting result is consistent with the original pipeline numbering sequence on the p-th branch, then there is no pipeline with a large pipe connected to a small pipe on the p-th branch, and step 50 is continued;

[0132] If the obtained sorting result is inconsistent with the original pipeline number sequence on the pth branch, the original number of the pipeline whose sorting has changed is added to the wave_diameter list, and step 54 is executed;

[0133] For example, the original pipe number sequence on the branch is 1-2-3-4-5, and the order of pipe diameter from small to large is 5-2-3-4-1, so pipe numbers 1 and 5 are included in the wave_diameter list;

[0134] Step 54: Initialize l=1 (when traversing the pipelines in the wave_diameter list, traverse in order from the upstream pipeline to the downstream pipeline);

[0135] Step 55: Search for the downstream pipe a1 directly connected to the lth pipe in the wave_diameter list on the pth branch, and compare the pipe diameters of the lth pipe in the wave_diameter list with the downstream pipe a1:

[0136] If the diameter of the lth pipe in the wave_diameter list is less than or equal to the diameter of the downstream pipe a1, continue to execute step 59;

[0137] If the diameter of the lth pipe in the wave_diameter list is larger than the diameter of the downstream pipe a1, continue to execute steps five and six;

[0138] Step 56: Compare the pipeline design capacity of the lth pipeline in the wave_diameter list with the downstream pipeline a1:

[0139] If the pipeline design capacity of the downstream pipeline a1 is greater than the pipeline design capacity of the lth pipeline in the wave_diameter list, the number of the lth pipeline in the wave_diameter list is deleted from the wave_diameter list, and step 59 is continued;

[0140] If the pipeline design capacity of the downstream pipeline a1 is less than or equal to the pipeline design capacity of the lth pipeline in the wave_diameter list, continue to execute step 57;

[0141] Step 57: Add the original number of the downstream pipe a1 to the problem_diameter list, and determine whether the downstream pipe a1 is the terminal pipe of the pth branch;

[0142] If the downstream pipeline a1 is the terminal pipeline of the pth branch, execute step 50;

[0143] If the downstream pipe a1 is not the terminal pipe of the p-th branch, then search for the downstream pipe a2 directly connected to the downstream pipe a1 on the p-th branch, and continue to execute step 58;

[0144] Step 58: Determine whether the diameter of pipeline a1 is equal to the diameter of pipeline a2;

[0145] If satisfied, then the pipeline a2 returns to step 57 (that is, when returning to step 57, the pipeline a2 is processed as the downstream pipeline a1 in step 57);

[0146] If not satisfied, execute step 59;

[0147] Step 59: Whether to traverse each pipeline in the wave_diameter list;

[0148] If the traversal reaches each pipe in the wave_diameter list, execute step 50;

[0149] If all the pipes in the wave_diameter list have not been traversed, then l=l+1 is set, and the process returns to step 55;

[0150] Step 50, add the remaining pipe numbers in the wave_diameter list to the Bwave_diameter list, add the remaining pipe numbers in the problem_diameter list to the Bproblem_diameter list, and initialize the wave_diameter list and the problem_diameter list to be empty;

[0151] Then determine whether all branches have been traversed:

[0152] If all branches are traversed, the Bwave_diameter list and the Bproblem_diameter list are obtained;

[0153] If all branches have not been traversed, set p=p+1 and return to execute step 53.

[0154] The other steps and parameters are the same as those in Specific Implementation Methods 1 to 5.

[0155] In the present invention, the process is performed in order of branch numbers from small to large. For branches with the same branch number, for example, three branches with branch number 2, the three branches can be randomly numbered 2-1, 2-2 and 2-3, and then each branch is processed in the order of 2-1, 2-2 and 2-3.

[0156] Specific implementation method 7: This implementation method is different from one of the specific implementation methods 1 to 6 in that the specific process of step 6 is as follows:

[0157] Step 61: Initialize q=1;

[0158] Step 62: Determine whether the qth hub node in the hub node set junction satisfies: the in-degree is greater than or equal to 2 and the out-degree is greater than or equal to 1;

[0159] If satisfied, execute step 63;

[0160] If not satisfied, execute step 65;

[0161] Step 63: Determine whether the current hub node satisfies: the sum of the diameters of all upstream pipelines directly connected to the current hub node is greater than the sum of the diameters of all downstream pipelines directly connected to the current hub node;

[0162] If satisfied, execute step 64;

[0163] If not satisfied, execute step 65;

[0164] Step 64: Determine whether the current hub node satisfies: the sum of the design capacities of all upstream pipelines directly connected to the current hub node is greater than the sum of the design capacities of all downstream pipelines directly connected to the current hub node;

[0165] If it is satisfied, then add the numbers of all downstream pipelines directly connected to the current hub node into the Jwave_diameter list, and then execute step 65;

[0166] If not satisfied, directly execute step 65;

[0167] Step 65: Determine whether all the hub nodes in the hub node set junction have been traversed;

[0168] If all the hub nodes in the hub node set junction are traversed, the final Jwave_diameter list is obtained;

[0169] Otherwise, set q=q+1 and return to execute step 62.

[0170] The other steps and parameters are the same as those in Specific Embodiments 1 to 6.

[0171] In the present invention, the traversal is performed in the order of the hub node level numbers from small to large. For hub nodes of the same level with the same level number, the hub nodes of the same level can be traversed in any order.

[0172] Specific implementation eight: This implementation differs from any one of the specific implementations one to seven in that the calculation process of the pipeline design capacity (that is, the pipeline design flow capacity) is as follows:

[0173] For pipe number k:

[0174]

[0175] Where: Q k Indicates the flow rate of the pipe numbered k, in m 3 / s; n is the Manning coefficient (determined according to the pipe material); D k Indicates the flow cross-sectional area of ​​the pipe numbered k, in m 2 ; R is the hydraulic radius, the unit is m; S k Indicates the slope of the pipe numbered k.

[0176] The other steps and parameters are the same as those in Specific Embodiments 1 to 7.

[0177] Specific implementation method 9: This implementation method is different from specific implementation methods 1 to 8 in that the calculation method of the hydraulic radius R is:

[0178]

[0179] Where: P is the wetted perimeter (i.e. the length of the inner wall of the pipe in contact with water), the unit is m.

[0180] The other steps and parameters are the same as those in Specific Embodiments 1 to 8.

[0181] The above calculation examples of the present invention are only used to explain the calculation model and calculation process of the present invention in detail, and are not intended to limit the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for identifying potential waterlogging sections in urban drainage networks, characterized in that: The method specifically comprises the following steps: Step 1: Obtain all nodes and pipes in the drainage network topology structure source file, and then construct a node-node relationship matrix, a node-pipeline relationship matrix, and a pipeline elevation information matrix; Step 2: Calculate the connectivity, out-degree and in-degree of each node in the drainage network system according to the node-node relationship matrix, and determine the hub nodes and end points in the drainage network system according to the connectivity, out-degree and in-degree of each node. All hub nodes constitute the hub node set junction; Step 3: For any hub node in the hub node set junction, calculate the shortest path between the hub node and each end point in the drainage network system, and record the shortest path length corresponding to the hub node; After traversing each hub node in the hub node set junction, the shortest path length corresponding to each hub node is obtained; The grade value of the end point in the drainage pipe network system is set to 0, and the shortest path lengths corresponding to each hub node are sorted in order from small to large. The grade value of each hub node is numbered according to the sorting result, and each branch connecting two hub nodes is obtained; for each branch, the starting node number of the branch, the pipe numbers connected in sequence on the branch, the end node number of the branch, and the grade of the hub node at the end of the branch are recorded in a list form, and the grade of the hub node at the end of the branch is used as the number of the branch; Step 4: Calculate the pipe segment slope information vector of the drainage pipe network system according to the node-pipeline relationship matrix and the upstream and downstream elevation information matrix of the pipe, and list the pipe numbers corresponding to the elements with negative values ​​in the pipe segment slope information vector into the reverse slope list; Step 5: Process the branches obtained in step 3 in order from small to large branch numbers to locate the pipes in the drainage pipe network system where the large pipes connect to the small pipes; then list the numbers of the located pipes in the Bwave_diameter list and the Bproblem_diameter list; Step 6: Determine whether the downstream pipeline of each hub node in the hub node set junction is a large pipe connected to a small pipe, and add the number of the downstream pipeline that is a large pipe connected to a small pipe to the Jwave_diameter list; Step 7: Add the pipe numbers in the Jwave_diameter list to the Bwave_diameter list, and delete the duplicate pipe numbers to obtain the final Bwave_diameter list. The pipes corresponding to all the numbers in the reverse slope list, Bwave_diameter list, and Bproblem_diameter list are regarded as potential waterlogging-causing pipes in the drainage network system.

2. A method for identifying potential waterlogging sections in urban drainage networks according to claim 1, characterized in that: The nodes in the drainage network topology structure source file include inspection wells, forebays and drainage outlets; The node-node relationship matrix is ​​denoted as node node ∈R n×n , where n represents the number of nodes in the drainage network system; Among them, A ij Represents the matrix node bode The element in row i and column j of ; The node-pipeline relationship matrix is ​​denoted as node edge _direct∈R n×m , where m represents the number of pipes in the drainage network system; Among them, when node i is the starting point of pipeline k, F ik =1, when node i is the end point of pipeline k, F ik = -1, when node i is not the starting point or end point of pipeline k, F ik =0; The upstream and downstream elevation information matrix of the pipeline is recorded as node edge ∈R n×m : When node i is the starting point of pipeline k, E ik = c, c is the elevation of the inner bottom of the starting point of pipe segment k. When node i is the end point of pipe k, E ik = d, d is the elevation of the inner bottom of the end of pipe segment k. When node i is not the starting point or the end point of pipe k, E ik =0.

3. A method for identifying potential waterlogging sections in urban drainage networks according to claim 2, characterized in that: In the second step, the connectivity, out-degree and in-degree of each node in the drainage network system are calculated according to the node-node relationship matrix, specifically: Where degree(i) is the connectivity of node i; Among them, A ij >0,degree in (i) is the in-degree of node i; Among them, A ij <0, degree out (i) is the out-degree of node i.

4. A method for identifying potential waterlogging sections in urban drainage networks according to claim 3, characterized in that: The hub node in the drainage network system is a node with a connectivity greater than or equal to 3; The end point in the drainage network system is a node with an in-degree greater than or equal to 1 and an out-degree of 0.

5. A method for identifying potential waterlogging sections in urban drainage networks according to claim 4, characterized in that: The specific process of step 4 is as follows: Among them, L1, L2, …, L m-1 ,L m are the lengths of the first pipe, the second pipe, …, the m-1th pipe, and the mth pipe in the drainage pipe network system respectively; S is the pipe segment slope information vector, and S is a vector composed of the slope values ​​of each pipe.

6. A method for identifying potential waterlogging sections in urban drainage networks according to claim 5, characterized in that: The specific process of step five is as follows: Step 51: Initialize the number of branches p=1; Step 52: Initialize the wave_diameter list and the problem_diameter list to be empty sets; Step 53: Sort the pipes on the p-th branch line in ascending order of pipe diameter, and compare the obtained sorting result with the original pipe numbering sequence on the p-th branch line; If the obtained sorting result is consistent with the original pipeline numbering sequence on the p-th branch, then there is no pipeline with a large pipe connected to a small pipe on the p-th branch, and step 50 is continued; If the obtained sorting result is inconsistent with the original pipeline number sequence on the pth branch, the original number of the pipeline whose sorting has changed is added to the wave_diameter list, and step 54 is executed; Step 54: Initialize l=1; Step 55: Search for the downstream pipe a1 directly connected to the lth pipe in the wave_diameter list on the pth branch, and compare the pipe diameters of the lth pipe in the wave_diameter list with the downstream pipe a1: If the diameter of the lth pipe in the wave_diameter list is less than or equal to the diameter of the downstream pipe a1, continue to execute step 59; If the diameter of the lth pipe in the wave_diameter list is larger than the diameter of the downstream pipe a1, continue to execute steps five and six; Step 56: Compare the pipeline design capacity of the lth pipeline in the wave_diameter list with the downstream pipeline a1: If the pipeline design capacity of the downstream pipeline a1 is greater than the pipeline design capacity of the lth pipeline in the wave_diameter list, the number of the lth pipeline in the wave_diameter list is deleted from the wave_diameter list, and step 59 is continued; If the pipeline design capacity of the downstream pipeline a1 is less than or equal to the pipeline design capacity of the lth pipeline in the wave_diameter list, continue to execute step 57; Step 57: Add the original number of the downstream pipe a1 to the problem_diameter list, and determine whether the downstream pipe a1 is the terminal pipe of the pth branch; If the downstream pipeline a1 is the terminal pipeline of the pth branch, execute step 50; If the downstream pipe a1 is not the terminal pipe of the p-th branch, then search for the downstream pipe a2 directly connected to the downstream pipe a1 on the p-th branch, and continue to execute step 58; Step 58: Determine whether the diameter of pipeline a1 is equal to the diameter of pipeline a2; If satisfied, return to step 57 for pipeline a2; If not satisfied, execute step 59; Step 59: Whether to traverse each pipeline in the wave_diameter list; If the traversal reaches each pipe in the wave_diameter list, execute step 50; If all the pipes in the wave_diameter list have not been traversed, then l=l+1 is set, and the process returns to step 55; Step 50, add the remaining pipe numbers in the wave_diameter list to the Bwave_diameter list, add the remaining pipe numbers in the problem_diameter list to the Bproblem_diameter list, and initialize the wave_diameter list and the problem_diameter list to be empty; Then determine whether all branches have been traversed: If all branches are traversed, the Bwave_diameter list and the Bproblem_diameter list are obtained; If all branches have not been traversed, set p=p+1 and return to execute step 53.

7. A method for identifying potential waterlogging sections in urban drainage networks according to claim 6, characterized in that: The specific process of step six is ​​as follows: Step 61: Initialize q=1; Step 62: Determine whether the qth hub node in the hub node set junction satisfies: the in-degree is greater than or equal to 2 and the out-degree is greater than or equal to 1; If satisfied, execute step 63; If not satisfied, execute step 65; Step 63: Determine whether the current hub node satisfies: the sum of the diameters of all upstream pipelines directly connected to the current hub node is greater than the sum of the diameters of all downstream pipelines directly connected to the current hub node; If satisfied, execute step 64; If not satisfied, execute step 65; Step 64: Determine whether the current hub node satisfies: the sum of the design capacities of all upstream pipelines directly connected to the current hub node is greater than the sum of the design capacities of all downstream pipelines directly connected to the current hub node; If it is satisfied, then add the numbers of all downstream pipelines directly connected to the current hub node into the Jwave_diameter list, and then execute step 65; If not satisfied, directly execute step 65; Step 65: Determine whether all the hub nodes in the hub node set junction have been traversed; If all the hub nodes in the hub node set junction are traversed, the final Jwave_diameter list is obtained; Otherwise, set q=q+1 and return to execute step 62.

8. A method for identifying potential waterlogging sections in urban drainage networks according to claim 7, characterized in that: The calculation process of the pipeline design capacity is: For pipe number k: Where: Q k represents the flow rate of the pipe numbered k; n is the Manning coefficient; D k represents the flow cross-sectional area of ​​the pipe numbered k; R is the hydraulic radius; S k Indicates the slope of the pipe numbered k.

9. A method for identifying potential waterlogging sections in urban drainage networks according to claim 8, characterized in that: The calculation method of the hydraulic radius R is: Where: P is the wetted perimeter.

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