A method for identifying potential waterlogging pipe sections of a municipal drainage pipe network

Abstract

The application discloses a method for identifying potential waterlogging-causing pipe sections of a city drainage pipe network, and belongs to the field of city drainage pipe networks. The application solves the problems of low accuracy and low efficiency of traditional methods for identifying pipe sections in a city underground drainage pipe network structure which may cause waterlogging risks, and high complexity of the identification method. Based on a topological structure diagram file of the drainage pipe network, the application abstracts components such as inspection wells, drainage outlets and pipes into points and edges, and constructs a two-dimensional matrix to represent the connection relationship and topological characteristics of the pipes in the drainage pipe network system. Without using a hydraulic model, the application quickly and accurately locates reverse slope pipes and pipes in which a large pipe is connected to a small pipe, i.e. locates key problem pipe sections which may cause city waterlogging, thereby providing a reliable solution for city pipe network optimization design and waterlogging treatment, and realizing quick and accurate identification of potential waterlogging-causing pipe sections of the drainage pipe network. The method of the application can be applied to identification of potential waterlogging-causing pipe sections of a city drainage pipe network.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of urban drainage pipe network, and particularly relates to a method for identifying potential waterlogging-causing pipe sections of an urban drainage pipe network. BACKGROUND

[0002] With the increasing frequency of extreme rainfall events under the influence of global climate change and the acceleration of urbanization, the operation pressure of drainage pipe networks gradually increases, and urban waterlogging problems become increasingly prominent, which seriously affects the economy, transportation and people's life safety of the city. Identifying the key pipe sections that cause urban waterlogging in the urban drainage pipe network can provide guidance for the renovation of the urban drainage pipe network and is of great significance for alleviating urban waterlogging.

[0003] Traditional drainage pipe network analysis methods mainly focus on hydraulic simulation by establishing a hydraulic model or artificial experience judgment. Such methods not only require high professional knowledge and complex calculation tools, but also have problems such as complicated pre-modeling steps, great difficulty in model calibration, long analysis period, low efficiency, and results depending on human experience, making it difficult to accurately identify the pipe sections that cause urban waterlogging in the urban underground drainage pipe network structure. Therefore, there is an urgent need for a scientific, systematic, simple and efficient method to automatically identify the key pipe sections that may cause waterlogging in the drainage pipe network, thereby providing a reliable basis for pipe network optimization design and waterlogging control. SUMMARY

[0004] The purpose of the present application is to solve the problems of poor accuracy and low efficiency of traditional methods in identifying the pipe sections that cause urban waterlogging in the urban underground drainage pipe network structure, as well as the high complexity of the identification method, and a method for identifying potential waterlogging-causing pipe sections of an urban drainage pipe network is proposed.

[0005] The technical solution adopted by the present application to solve the above technical problems is: a method for identifying potential waterlogging-causing pipe sections of an urban drainage pipe network, which specifically comprises the following steps:

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

[0007] Step 2: Calculate the connectivity, out-degree and in-degree of each node in the drainage pipe network system according to the node-node relationship matrix, and determine the hub nodes and terminal points in the drainage pipe network system according to the connectivity, out-degree and in-degree of each node, all hub nodes forming a hub node set junction;

[0008] Step three, for any one of the hub nodes in the hub node set junction, the shortest path between the hub node and each end point in the drainage pipe network system is calculated respectively, and the shortest path length corresponding to the hub node is recorded;

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

[0010] The level value of the end point in the drainage pipe network system is set to 0, the shortest path lengths corresponding to the hub nodes are sorted in ascending order, the level values of the hub nodes are 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 turn on the branch, the end node number of the branch and the level of the end hub node of the branch are recorded in the form of a list, and the level of the end hub node of the branch is taken as the number of the branch;

[0011] Step four, according to the node-pipe relationship matrix and the upstream and downstream elevation information matrix of the pipe, the pipe segment slope information vector of the drainage pipe network system is calculated, and the pipe numbers corresponding to the elements with negative values in the pipe segment slope information vector are listed in the inverse slope list;

[0012] Step five, the branches obtained in step three are processed in ascending order of branch number, and the positioning of the pipe belonging to large pipe connecting small pipe in the drainage pipe network system is realized; then the numbers of the positioned pipes are listed in the Bwave_diameter list and the Bproblem_diameter list;

[0013] Step six, whether the downstream pipe of each hub node in the hub node set junction belongs to large pipe connecting small pipe is judged respectively, and the numbers of the downstream pipes belonging to large pipe connecting small pipe are added to the Jwave_diameter list;

[0014] Step seven, the pipe numbers in the Jwave_diameter list are added to the Bwave_diameter list, and the duplicate pipe numbers are deleted to obtain the final Bwave_diameter list, and the pipes corresponding to all numbers in the inverse slope list, the Bwave_diameter list and the Bproblem_diameter list are taken as the potential waterlogging pipes in the drainage pipe network system.

[0015] Further, the nodes in the drainage pipe network topology diagram source file include inspection wells, forepools and drainage outlets;

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

[0017]

[0018] wherein A ij represents the element in the ith row and jth column of the matrix node node ;

[0019]

[0020] The node-pipe relationship matrix is denoted as node edge _direct∈R n×m wherein m represents the number of pipes in the sewer network system;

[0021]

[0022] wherein F ik = 1 when node i is the start point of pipe k, F ik =-1 when node i is the end point of pipe k, and F ik = 0 when node i is neither the start point nor the end point of pipe k;

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

[0024]

[0025] wherein E ik =c when node i is the start point of pipe k, c is the in-pipe bottom elevation of the start point of pipe segment k, E ik =d when node i is the end point of pipe k, d is the in-pipe bottom elevation of the end point of pipe segment k, and E ik = 0 when node i is neither the start point nor the end point of pipe k.

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

[0027]

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

[0029]

[0030] wherein 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 nodes in the drainage network system are nodes with a connectivity degree greater than or equal to 3;

[0034] In a drainage network system, the endpoint 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 four is as follows:

[0036]

[0037] Where L1, L2, ..., L m-1 L m These are the lengths of the 1st, 2nd, ..., (m-1)th, and mth pipes in the drainage network system; S is a vector of pipe slope information, which 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 both the wave_diameter list and the problem_diameter list to be empty sets;

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

[0042] If the sorting result obtained is consistent with the original pipe numbering order on the p-th branch, then there is no pipe connecting the large pipe to the small pipe on the p-th branch, and continue to execute step fifty;

[0043] If the sorting result obtained is inconsistent with the original pipe numbering order on the p-th branch, the original number of the pipe whose sorting has changed is added to the wave_diameter list, and step five four is executed.

[0044] Step 54: Initialize l = 1;

[0045] Step 55: On the p-th branch, search for the downstream pipe a1 that is directly connected to the l-th pipe in the wave_diameter list, and compare the pipe diameter of the l-th pipe in the wave_diameter list with that of the downstream pipe a1.

[0046] If the diameter of the 1th 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 1th pipe in the wave_diameter list is greater than the diameter of the downstream pipe a1, continue to execute step 56;

[0048] Step 56, compare the pipe design capacity of the 1th pipe in the wave_diameter list with the downstream pipe a1:

[0049] If the pipe design capacity of the downstream pipe a1 is greater than the pipe design capacity of the 1th pipe in the wave_diameter list, delete the number of the 1th pipe in the wave_diameter list, and continue to execute step 59;

[0050] If the pipe design capacity of the downstream pipe a1 is less than or equal to the pipe design capacity of the 1th pipe 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 pipe a1 is the terminal pipe of the pth branch, execute step 50;

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

[0054] Step 58, determine whether the diameter of the pipe a1 is equal to the diameter of the pipe a2;

[0055] If yes, return to execute step 57 for the pipe a2 (i.e. when returning to execute step 57, the pipe a2 is treated as the downstream pipe a1 in step 57);

[0056] If no, execute step 59;

[0057] Step 59, whether all the pipes in the wave_diameter list have been traversed;

[0058] If yes, execute step 50;

[0059] If all the branches are not traversed, then let p = p + 1 and return to step 53.

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

[0061] Further determine whether all the branches are traversed:

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

[0063] If all the branches are not traversed, then let p = p + 1 and return to step 53.

[0064] Further, the specific process of step 6 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 yes, then execute step 63;

[0068] If no, then execute step 65;

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

[0070] If yes, then execute step 64;

[0071] If no, then execute step 65;

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

[0073] If yes, then add the numbers of all the downstream pipes directly connected to the current hub node to the Jwave_diameter list, and then execute step 65;

[0074] If no, then directly execute step 65;

[0075] Step six, judge whether all the hub nodes in the hub node set junction are traversed;

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

[0077] Otherwise, let q = q + 1, and return to execute step six two.

[0078] Further, the calculation process of the pipe design capacity is:

[0079] For the pipe numbered k:

[0080]

[0081] Wherein: Q k represents the flow of the pipe numbered k; n is the Manning coefficient; D k represents the flow area of the pipe numbered k; R is the hydraulic radius; S k represents the slope of the pipe numbered k.

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

[0083]

[0084] Wherein: P is the wet perimeter.

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

[0086] The present application is based on the topological structure diagram file of the drainage pipe network, and the inspection well, the drainage outlet, the pipe and other components are abstracted as points and edges, and a two-dimensional matrix is constructed to represent the connection relationship and topological characteristics of the pipes in the drainage pipe network system, so that the potential waterlogging-causing pipe section of the drainage pipe network is quickly and accurately identified. The method of the present application can quickly and accurately locate the reverse slope pipe and the pipe connecting a large pipe with a small pipe using the topological graph of the drainage pipe network without using the hydraulic model, that is, the key problem pipe section that may cause urban waterlogging is located, which not only avoids the shortcomings of the traditional artificial screening and water modeling methods, but also provides a reliable solution for urban pipe network optimization design and waterlogging control. Since the process of manually building, calibrating and empirically judging the hydraulic model is avoided, the complexity of the identification method is reduced, the waste of human resources is reduced, and the work efficiency and accuracy are improved. BRIEF DESCRIPTION OF DRAWINGS

[0087] Figure 1 is a flow chart of a potential waterlogging-causing pipe section identification method of a city drainage pipe network of the present application;

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

[0089] DETAILED DESCRIPTION Figure 1 The present embodiment is described. The method for identifying a potential waterlogging pipe section of a city drainage pipe network in the present embodiment specifically comprises the following steps:

[0090] Step one, all nodes and pipes (including actual pipes and water pumps) in the topological structure diagram source file (such as CAD file, GIS file) of the drainage pipe network are obtained, and then a node-node relationship matrix, a node-pipe relationship matrix and an elevation information matrix of the pipes are constructed; the connection relationship and topological characteristics of the drainage system are represented by using the constructed node-node matrix and node-pipe matrix;

[0091] Step two, the connection degree, out-degree and in-degree of each node in the drainage pipe network system are calculated according to the node-node relationship matrix, and the hub nodes and the terminal points (i.e. the river outlet) in the drainage pipe network system are determined according to the connection degree, out-degree and in-degree of each node; all hub nodes form a hub node set junction.

[0092] Step three, for any hub node in the hub node set junction, the shortest path between the hub node and each terminal point in the drainage pipe network system is calculated by using the Dijkstra algorithm, and the shortest path length corresponding to the hub node is recorded (i.e. for any terminal point, the shortest path length between the hub node and the terminal point is calculated, and the shortest path lengths corresponding to various terminal points are arranged in descending order, and the length arranged in the first place is taken 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 level value of the terminal point in the drainage pipe network system is set to 0, the shortest path lengths corresponding to various hub nodes are sorted in ascending order, the level values of the hub nodes are numbered according to the sorting result (the smaller the shortest path length value corresponding to the hub node, the closer the hub node to the end of the drainage pipe network system, i.e. the smaller the level value of the hub node, when the shortest path length values corresponding to multiple hub nodes are equal, the multiple hub nodes with equal shortest path length values are given the same level value, and the level values of the hub nodes which are not terminal points in the sorting result are sorted from 1), and each branch connecting two hub nodes is obtained (it should be noted that there may be no branch between two hub nodes, or there may be multiple branches between two hub nodes); for example, Figure 2The starting node number of the branch, the pipe numbers connected in sequence on the branch (i.e. the pipe numbers through which the water flows in sequence), the end node number of the branch, and the level of the end hub node of the branch are recorded in a list for each branch, and the level of the end hub node of the branch is taken as the number of the branch;

[0095] Step four, the pipe segment slope information vector of the drainage pipe network system is calculated according to the node-pipe relationship matrix and the upstream and downstream elevation information matrix of the pipe, and the pipe numbers corresponding to the negative elements in the pipe segment slope information vector are listed in the inverse slope list;

[0096] Step five, each branch obtained in step three is processed in order from small to large according to the branch number, so as to realize the positioning of the pipe belonging to large pipe connecting small pipe in the drainage pipe network system; and the numbers of the positioned pipes are listed in the Bwave_diameter list and the Bproblem_diameter list;

[0097] Step six, whether the downstream pipe of each hub node in the hub node set junction belongs to large pipe connecting small pipe is judged respectively, and the numbers of the downstream pipes belonging to large pipe connecting small pipe are added to the Jwave_diameter list;

[0098] Step seven, the pipe numbers in the Jwave_diameter list are added to the Bwave_diameter list, and the repeated pipe numbers are deleted to obtain the final Bwave_diameter list, and the pipes corresponding to all numbers in the inverse slope list, the Bwave_diameter list and the Bproblem_diameter list are taken as the potential waterlogging pipes in the drainage pipe network system.

[0099] Specific implementation method two: the difference between this implementation method and the specific implementation method one is that the nodes in the drainage pipe network topology graph source file include inspection wells, forepools and drainage outlets;

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

[0101]

[0102] Wherein, A ij represents the element in the i-th row and j-th column of the matrix node node ;

[0103]

[0104] The node-pipe relationship matrix is denoted as node edgedirect ∈ R n×m wherein m represents the number of pipes in the drainage pipe network system;

[0105]

[0106] wherein F ik = 1 when node i is the start point of pipe k, F ik =-1 when node i is the end point of pipe k, and F ik = 0 when node i is neither the start point nor the end point of pipe k;

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

[0108]

[0109] wherein E ik = c when node i is the start point of pipe k, c is the elevation of the bottom of the pipe at the start point of pipe k, E ik =d when node i is the end point of pipe k, d is the elevation of the bottom of the pipe at the end point of pipe k, and E ik = 0 when node i is neither the start point nor the end point of pipe k.

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

[0111] The third embodiment is different from the first or second embodiment in that, in step two, the degree, out-degree and in-degree of each node in the drainage pipe network system are calculated according to the node-node relationship matrix, specifically:

[0112]

[0113] wherein degree(i) is the degree of node i; the degree represents the number of pipe sections connected to the node (such as a manhole) in the drainage pipe network system, including upstream pipe sections (node i is the downstream node of the pipe section) and downstream pipe sections (node i is the upstream node of the pipe section);

[0114]

[0115] wherein 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 pipe network system;

[0116]

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

[0118] Other steps and parameters are the same as in specific implementation method one or two.

[0119] Specific Implementation Method Four: This implementation method differs from one of the specific implementation methods one to three in that the hub node in the drainage pipe network system is a node with a connectivity degree greater than or equal to 3;

[0120] In a drainage network system, the endpoint 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 one of the specific implementation methods one to three.

[0122] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the specific process of step four is as follows:

[0123]

[0124] Where L1, L2, ..., L m-1 L m These are the lengths of the 1st, 2nd, ..., m-1th pipes in the drainage pipe network system, respectively; S is the pipe segment slope information vector, which is a vector composed of the slope values ​​of each pipe.

[0125] The other steps and parameters are the same as those in one of the specific implementation methods one to four.

[0126]

[0127] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the specific process of step five is as follows:

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

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

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

[0131] If the sorting result obtained is consistent with the original pipe numbering order on the p-th branch, then there is no pipe connecting the large pipe to the small pipe on the p-th branch, and continue to execute step fifty;

[0132] If the sorting result is inconsistent with the original pipe number sequence on the pth branch, the original number of the pipe whose sorting is 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 sorting result obtained by sorting in the order of pipe diameter from small to large is 5-2-3-4-1, then the pipe numbers 1 and 5 are listed in the wave_diameter list;

[0134] Step 54, initialize l = 1 (when traversing the pipes in the wave_diameter list, the pipes are traversed in the order from upstream to downstream);

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

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

[0137] If the pipe diameter of the lth pipe in the wave_diameter list is greater than that of the downstream pipe a1, step 56 is continued;

[0138] Step 56, compare the pipe design capacity of the lth pipe in the wave_diameter list with that of the downstream pipe a1:

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

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

[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 pipe a1 is the terminal pipe of the pth branch, step 50 is executed;

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

[0144] Step 58, determine whether the diameter of the pipe a1 is equal to the diameter of the pipe a2;

[0145] If yes, return to execute step 57 for the pipe a2 (i.e. when returning to execute step 57, the pipe a2 is treated as the downstream pipe a1 in step 57);

[0146] If no, execute step 59;

[0147] Step 59, whether all the pipes in the wave_diameter list have been traversed;

[0148] If yes, execute step 50;

[0149] If no, let l = l + 1, and return to execute step 55;

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

[0151] Determine whether all the branches have been traversed:

[0152] If yes, obtain the Bwave_diameter list and the Bproblem_diameter list;

[0153] If no, let p = p + 1, and return to execute step 53.

[0154] The other steps and parameters are the same as one of the first to fifth embodiments.

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

[0156] The seventh embodiment is different from one of the first to sixth embodiments in that the specific process of step 6 is as follows:

[0157] Step six one, initialize q = 1;

[0158] Step six two, judge whether the qth hub node in the hub node set junction meets: the in-degree is greater than or equal to 2 and the out-degree is greater than or equal to 1;

[0159] If yes, execute step six three;

[0160] If no, execute step six five;

[0161] Step six three, judge whether the current hub node meets: the sum of the pipe diameters of all upstream pipes directly connected to the current hub node is greater than the sum of the pipe diameters of all downstream pipes directly connected to the current hub node;

[0162] If yes, execute step six four;

[0163] If no, execute step six five;

[0164] Step six four, judge whether the current hub node meets: the sum of the design capacities of all upstream pipes directly connected to the current hub node is greater than the sum of the design capacities of all downstream pipes directly connected to the current hub node;

[0165] If yes, add the numbers of all downstream pipes directly connected to the current hub node to the Jwave_diameter list, and then execute step six five;

[0166] If no, directly execute step six five;

[0167] Step six five, judge whether all hub nodes in the hub node set junction have been traversed;

[0168] If yes, obtain the final Jwave_diameter list;

[0169] Otherwise, let q = q + 1, and return to execute step six two.

[0170] The other steps and parameters are the same as one of the first to sixth embodiments.

[0171] In the present application, the hub nodes are traversed 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] The eighth embodiment is different from one of the first to seventh embodiments in that the calculation process of the pipe design capacity (i.e. the design flow capacity of the pipe) is as follows:

[0173] For the pipe numbered k:

[0174]

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

[0176] The other steps and parameters are the same as one of the first to seventh embodiments.

[0177] The ninth embodiment is different from one of the first to eighth embodiments in that the calculation method of the hydraulic radius R is as follows:

[0178]

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

[0180] The other steps and parameters are the same as one of the first to eighth embodiments.

[0181] The above calculation examples of the present application are only to illustrate the calculation model and calculation process of the present application, and are not to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art, and it is impossible to enumerate all the embodiments here. Any changes or variations that belong to the technical solutions of the present application and are derived from the obvious changes or variations are still within the protection scope of the present application.

Claims

1. A method for identifying potential flooding pipe sections of a municipal sewer network, characterized in that, The method specifically comprises the following steps: Step one, obtaining all nodes and pipes in the source file of the drainage pipe network topology structure diagram, and then constructing a node-node relationship matrix, a node-pipe relationship matrix, and an elevation information matrix of the pipes; Step two, calculating the connection degree, out-degree, and in-degree of each node in the drainage pipe network system according to the node-node relationship matrix, and determining the hub nodes and the terminal points in the drainage pipe network system according to the connection degree, out-degree, and in-degree of each node, wherein all the hub nodes form a hub node set junction; Step three, for any hub node in the hub node set junction, the shortest path between the hub node and each terminal point in the drainage pipe network system is calculated respectively, and the shortest path length corresponding to the hub node is recorded; After traversing each hub node in the hub node set junction, the shortest path length corresponding to each hub node is obtained respectively; The level value of each terminal point in the drainage pipe network system is set to 0, the shortest path lengths corresponding to the hub nodes are sorted in ascending order, the level values of the hub nodes are 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 level of the end hub node of the branch are recorded in the form of a list, and the level of the end hub node of the branch is taken as the number of the branch; Step four, calculating the pipe segment slope information vector of the drainage pipe network system according to the node-pipe relationship matrix and the upstream and downstream elevation information matrix of the pipes, and listing the pipe numbers corresponding to the elements with negative values in the pipe segment slope information vector in the inverse slope list; Step five, processing each branch obtained in step three in ascending order of the branch number, so as to locate the pipes belonging to large pipe connecting small pipes in the drainage pipe network system; and then listing the numbers of the located pipes in the Bwave_diameter list and the Bproblem_diameter list; Step six, judging whether the downstream pipes of each hub node in the hub node set junction belong to large pipe connecting small pipes respectively, and adding the numbers of the downstream pipes belonging to large pipe connecting small pipes to the Jwave_diameter list; Step seven, adding the pipe numbers in the Jwave_diameter list to the Bwave_diameter list, deleting the duplicate pipe numbers, obtaining the final Bwave_diameter list, and taking the pipes corresponding to all the numbers in the inverse slope list, the Bwave_diameter list, and the Bproblem_diameter list as the potential waterlogging pipes in the drainage pipe network system.

2. The method for identifying potential flooding pipe section of urban drainage network according to claim 1, characterized in that, The nodes in the source file of the drainage pipe network topology structure diagram include inspection wells, forepools, and drainage outlets; Let the node-node relationship matrix be denoted as node node ∈R n×n where n represents the number of nodes in the sewer network system; where A ij denotes the matrix node bode the element in the i-th row and j-th column of the matrix Let the node-pipe relation matrix be denoted as node edge _direct ∈ R n×m where m represents the number of pipes in the drainage network system; Where, when node i is the starting point of pipe k, F ik =1, when node i is the end point of pipe k, F ik =-1, when node i is neither the start nor the end point of pipeline k, F ik =0; Let the upstream and downstream elevation information matrix of the pipeline be denoted as node edge ∈R n×m : Where, when node i is the starting point of pipe k, E ik =c, where c is the bottom elevation of the pipe segment k, and E is the starting point of the pipe segment k. ik =d, where d is the bottom elevation of the pipe segment k at its end. When node i is neither the start nor the end of pipe k, E ik =0.

3. The method for identifying potential flooding pipe sections of a municipal drainage network according to claim 2, characterized in that, In step two, the connection degree, out-degree, and in-degree of each node in the drainage pipe network system are calculated according to the node-node relationship matrix, specifically as follows: wherein degree(i) is the connection degree of node i. where A ij > 0, degree in (i) is the in-degree of node i; where A ij <0, degree out (i) is the out-degree of node i.

4. The method for identifying potential flooding pipe sections of a municipal sewer network according to claim 3, characterized in that, The hub node in the sewer network system is a node with a connection degree greater than or equal to 3; The terminal point in the sewer network system is a node with an in-degree greater than or equal to 1 and an out-degree of 0.

5. The method for identifying potential flooding pipe section of urban drainage network according to claim 4, characterized in that, The specific process of step four is: wherein L1, L2, …, Lm-1, Lm are the lengths of the 1st, 2nd, …, m-1st, mth pipe of the sewer network system, respectively; S is the pipe segment slope information vector, and S is a vector composed of the slope values of each pipe. m-1 m wherein L1, L2, …, Lm-1, Lm are the lengths of the 1st, 2nd, …, m-1st, mth pipe of the sewer 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. The method for identifying potential flooding pipe sections of a municipal sewer network according to claim 5, characterized in that, The specific process of step five is: Step five one, initialize the number of branches p = 1; Step five two, initialize the wave_diameter list and the problem_diameter list to be empty sets; Step five three, sort the pipes on the pth branch in order of decreasing pipe diameter, and compare the obtained sorting result with the original pipe number order on the pth branch; If the obtained sorting result is consistent with the original pipe number order on the pth branch, there is no pipe with a large pipe connected to a small pipe on the pth branch, and step fifty is continued; If the obtained sorting result is inconsistent with the original pipe number order on the pth branch, the original number of the pipe whose sorting has changed is added to the wave_diameter list, and step five four is executed; Step five four, initialize l = 1; Step five five, search for a downstream pipe a1 directly connected to the lth pipe in the wave_diameter list on the pth branch, and compare the pipe diameter of the lth pipe in the wave_diameter list with that of the downstream pipe a1: If the pipe diameter of the lth pipe in the wave_diameter list is less than or equal to that of the downstream pipe a1, step fifty nine is continued; If the pipe diameter of the lth pipe in the wave_diameter list is greater than that of the downstream pipe a1, step five six is continued; Step five six, compare the pipe design capacity of the lth pipe in the wave_diameter list with that of the downstream pipe a1: If the pipe design capacity of the downstream pipe a1 is greater than that of the lth pipe in the wave_diameter list, the number of the lth pipe in the wave_diameter list is deleted from the wave_diameter list, and step fifty nine is continued; If the pipe design capacity of the downstream pipe a1 is less than or equal to that of the lth pipe in the wave_diameter list, step five seven is continued; Step five seven, 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 pipe a1 is the terminal pipe of the pth branch, step fifty is executed; If the downstream pipe a1 is not the terminal pipe of the pth branch, search for a downstream pipe a2 directly connected to the downstream pipe a1 on the pth branch, and step five eight is continued; Step five eight, determine whether the pipe diameter of pipe a1 is equal to that of pipe a2; If yes, return to step five seven for pipe a2; If no, step fifty nine is executed; Step fifty nine, whether all pipes in the wave_diameter list have been traversed; If each pipe in the wave_diameter list is traversed, step 50 is executed; If each pipe in the wave_diameter list is not traversed, l=l+1 is executed, and step 55 is returned to be executed; Step 50, the remaining pipe number in the wave_diameter list is added to the Bwave_diameter list, the Bproblem_diameter list in the problem_diameter list is added, and the wave_diameter list and the problem_diameter list are initialized to be empty; It is judged whether all branches are traversed: If all branches are traversed, the Bwave_diameter list and the Bproblem_diameter list are obtained; If all branches are not traversed, p=p+1 is executed, and step 53 is returned to be executed.

7. The method for identifying potential flooding pipe sections of a municipal drainage network according to claim 6, characterized in that, The specific process of step 6 is as follows: Step 61, q=1 is initialized; Step 62, it is judged 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 yes, step 63 is executed; If no, step 65 is executed; Step 63, it is judged whether the current hub node satisfies: the sum of the pipe diameters of all upstream pipes directly connected to the current hub node is greater than the sum of the pipe diameters of all downstream pipes directly connected to the current hub node; If yes, step 64 is executed; If no, step 65 is executed; Step 64, it is judged whether the current hub node satisfies: the sum of the design capacities of all upstream pipes directly connected to the current hub node is greater than the sum of the design capacities of all downstream pipes directly connected to the current hub node; If yes, the number of all downstream pipes directly connected to the current hub node is added to the Jwave_diameter list, and step 65 is executed; If no, step 65 is directly executed; Step 65, it is judged whether all hub nodes in the hub node set junction are traversed; If all hub nodes in the hub node set junction are traversed, the final Jwave_diameter list is obtained; Otherwise, q=q+1 is executed, and step 62 is returned to be executed.

8. The method for identifying potential flooding pipe sections of a municipal drainage network according to claim 7, characterized in that, The calculation process of the pipe design capacity is as follows: For the pipe with number k: where: Q k represents the flow 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 represents the slope of the pipe numbered k.

9. The method for identifying potential flooding pipe sections of a municipal drainage network according to claim 8, characterized in that, The calculation method of the hydraulic radius R is as follows: Wherein, P is the wet perimeter.

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