Automatic analysis method for mixed and wrong connections upstream of river outlets based on breadth-first algorithm

Abstract

This invention discloses an automatic analysis method for upstream misconnections at river outlets based on a breadth-first search algorithm. It includes using the difference in drainage systems of pipes connected to the same node as an identification feature to determine whether a node is misconnected; introducing a node hierarchy, starting from the end outlet upwards, with an initial node hierarchy of 1; when the current node has only one connection to an upstream node, the upstream node has the same hierarchy as the current node; when the current node has multiple connections to an upstream node, the upstream node's hierarchy is incremented by 1 relative to the current node; the node hierarchy where the misconnection occurs represents the hierarchy of the misconnection, helping to define the degree of influence of the misconnected node, and combining this with the number of misconnections at the outlet for joint judgment. This invention can improve the time for tracing and analyzing river outlets by more than 5 times, saving a significant amount of mechanical labor time and improving work efficiency.

Description

Technical Field

[0001] This invention belongs to the field of municipal engineering technology, specifically relating to an automatic analysis method for upstream misconnection of river outlets based on a breadth-first search algorithm. Background Technology

[0002] The essence of the outlet problem is upstream misconnection. Solving this problem requires accurate identification and location of the misconnection points. Currently, identifying misconnections mainly relies on manual investigation, which is inefficient and time-consuming. Furthermore, most projects don't specifically trace the source of misconnections at outlets; instead, they conduct large-scale surveys of the regional pipe network data. Finding upstream misconnections at outlets then requires manual sifting through massive amounts of network information, resulting in extremely low efficiency and a high risk of omissions. Many cities have now digitized their drainage network data, with many adopting GIS-based management models and some establishing drainage network monitoring systems, achieving a transition from information-based to digital models. With the widespread adoption of digital information management technologies, it has become possible to automatically analyze and trace misconnections at outlets using computer programs. Therefore, there is an urgent need for a highly automated, fast, and accurate investigation method to improve efficiency. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of the aforementioned background technology and provide an automatic analysis method for upstream misconnection of river outlets based on a breadth-first search algorithm.

[0004] The technical solution adopted in this invention is: an automatic analysis method for upstream misconnection of river outlets based on breadth-first search algorithm, including the following steps: using the difference in drainage system of pipes connected to the same node as an identification feature to determine whether a node is misconnected; introducing a node hierarchy, starting from the end outlet upwards, the initial node hierarchy is set to 1, when the current node has only one connection with the upstream node, the upstream node has the same hierarchy as the current node; when the current node has multiple connections with the upstream node, the upstream node's hierarchy is increased by 1 relative to the current node; using the node hierarchy where the misconnection occurs to represent the hierarchy of the misconnection, to help define the degree of influence of the misconnected node, and combining it with the number of misconnections at the outlet for joint judgment.

[0005] Specifically including

[0006] Step 1: Organize and summarize the topological relationship data of river channels, outlets, and pipelines, including river data (river name, outlet code), pipeline segment data (at least including number, pipe diameter, start and end node numbers, drainage system, etc.), and node data (at least including number, coordinates, drainage system, etc.).

[0007] Step 2: Enqueue the first outlet node of the river channel and define the initial node level i = 1; the upstream node has a higher level than the downstream node;

[0008] Step 3: Using the head node as the current node, search for nodes connected to the current node;

[0009] Step 4: Determine if only one node is connected to the current node; if yes, the level of the connected node is the same as that of the current node; if no, the level of the connected node is increased by 1 compared to the current node.

[0010] Step 5: Determine if the connection types are the same. If they are the same, enqueue the upstream node of the current node. If they are different, first record the hybrid connection result, and then enqueue the upstream node of the current node. The level of the hybrid connection point is the same as the level of the current node connected by the pipe.

[0011] Step 6: Dequeue the current node;

[0012] Step 7: Determine if the queue is empty. If it is empty, complete the cross-connection check for this outlet and export the check results. If it is not empty, return to step 3 and repeat steps 3 to 7.

[0013] Step 8: After the queue is cleared, determine whether there are other exit points. If so, return to step 2 and repeat steps 2 to 8.

[0014] Step 9: Once all outlet statistics are completed, the task is finished.

[0015] It also includes: based on the report of mixed connections at the discharge outlets, counting the number of mixed connections upstream of each discharge outlet and the level of mixed connections.

[0016] By analyzing the quantity and severity of misconnections upstream of the discharge outlet, we can assist in determining the remediation measures for the discharge outlet. The specific judgment strategy is as follows:

[0017] 1) Let X be the total number of mixed and incorrect connections traced at the discharge outlet. Count the number of mixed connections at different levels x1, x2...xn, and introduce the influence coefficients for different levels. The higher the level, the closer the mixing point is to the end of the branched pipe network, the lower the influence coefficient, and the smaller the impact on the outlet.

[0018] 2) Calculate the number of standardized outlets The number and distribution of mixed and incorrect connections are determined by X and X` / X, which helps to analyze the remedial measures for the discharge outlet;

[0019] 3) The above measures for rectifying discharge outlets include interception at the end of the outlet, decentralized interception in the middle, and rectification of all mixed and incorrect connections.

[0020] This invention, based on data from a geographic information system for drainage pipe networks, utilizes a breadth-first search algorithm as a framework to establish an automatic analysis method for upstream misconnections at drainage outlets. Diagnostic results show that this method can quickly analyze the number of upstream misconnections at each outlet, locate the nodes of misconnections, and visually characterize the severity of misconnections. Furthermore, it prioritizes the urgency of outlet rectification through weighted allocation. This provides technical support for implementing a "one outlet, one policy" approach to outlet renovation using information technology. This invention can reduce the time required for source tracing analysis of river outlets by more than five times, saving significant amounts of mechanical labor time and improving work efficiency. Attached Figure Description

[0021] Figure 1 This is the overall flowchart of the present invention;

[0022] Figure 2 This is a schematic diagram for determining the number of node levels. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but these descriptions do not constitute a limitation on the present invention.

[0024] like Figure 1-2 As shown, Embodiment 1 of the present invention:

[0025] 1) Compile and summarize the pipeline topology data for one of the river channels, including pipe segment data (at least including number, diameter, elevation, length, and start and end node numbers), and node data (at least including number, elevation, and coordinates). The format and requirements for pipe segment data are shown in Table 1.

[0026] Table 1. Correspondence and related attributes between drainage pipe network and abstract network.

[0027]

[0028]

[0029] The above data was compiled and organized into an Excel data file.

[0030] 2) Enqueue the first outlet node in the river channel and define the initial node level i = 1; the upstream node has a higher level than the downstream node;

[0031] 3) Using the head node of the queue as the current node, search for nodes connected to the current node;

[0032] 4) Determine if only one node is connected to the current node; if yes, the connected node has the same level as the current node; if no, the connected node has one more level than the current node. See the illustration below. Figure 2 ;

[0033] 5) Determine if the connection types are the same. If they are the same, enqueue the upstream node of the current node. If they are different, record the hybrid connection result first, and then enqueue the upstream node of the current node. The level of the hybrid connection point is the same as the level of the current node connected by the pipe.

[0034] 6) Dequeue the current node;

[0035] 7) Determine if the queue is empty. If it is empty, complete the cross-connection check for this outlet and export the check results. If it is not empty, return to step 3) and repeat steps 3) to 7).

[0036] 8) After the queue is cleared, determine whether there are other outlets. If there are, return to step 2) and repeat steps 2)-8).

[0037] 9) Once all outlet statistics are completed, the task is finished;

[0038] 10) Based on the generated discharge outlet cross-connection report, count the number and severity of cross-connections upstream of each discharge outlet. Analyzing the number and severity of cross-connections upstream of the discharge outlet helps determine appropriate remediation measures. Specific judgment strategies are as follows:

[0039] Let X be the total number of mixed connections traced at the discharge outlet. Let x1, x2...xn be the number of mixed connections at different levels, and let the influence coefficients at different levels be introduced. The higher the level, the closer the mixing point is to the end of the branched pipe network, the lower the influence coefficient, and the smaller the impact on the outlet.

[0040] Calculate the number of standardized outlets The quantity of X and the size of X' / X help determine whether to implement end-of-pipe interception, decentralized mid-pipe interception, or complete mixed-connection modification for the discharge outlet:

[0041] ① If X>20 and X` / X<0.6, there are many mixed and incorrect connections, and the level of mixed connections is high. Most of the mixed connections occur upstream. It is advisable to consider using mid-end or end-end interception methods to quickly handle the situation.

[0042] ②X<20, and X` / X<0.6, the number of mixed connections is moderate, but the level of mixed connections is high, and the mixed connections mostly occur upstream. It is advisable to consider modifying all points or cutting off the flow in the middle of the pipeline.

[0043] ③X<20, and X` / X>0.6, the number of mixed and incorrect connections is moderate, but the level of mixed connections is low, and the mixed connections mostly occur downstream. It is advisable to consider modifying all points.

[0044] ④X>20 and X` / X>0.6, there are many mixed and incorrect connections, and the level of mixed connections is low. Most of the mixed connections occur downstream. It is advisable to consider modifying all points.

[0045] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

Claims

1. An automatic analysis method for upstream misconnection of river outlets based on breadth-first search algorithm, characterized in that: Includes the following steps: The difference in drainage systems among pipes connected to the same node is used as an identification feature to determine whether a node is incorrectly connected. A node hierarchy is introduced, starting from the end outlet and moving upwards. The initial node hierarchy is set to 1. When the current node has only one connection with the upstream node, the upstream node has the same hierarchy as the current node. When the current node has multiple connections with the upstream node, the upstream node's hierarchy is increased by 1 relative to the current node. The node hierarchy where the incorrect connection occurs represents the hierarchy of the incorrect connection, which helps to define the degree of influence of the incorrectly connected node and is combined with the number of incorrectly connected outlets for judgment. Specifically including Step 1: Organize and summarize the topological relationship data of river channels, outlets, and pipelines, including river data, pipeline segment data, and node data; Step 2: Enqueue the first outlet node of the river channel and define the initial node level i=1; the upstream node has a higher level than the downstream node; Step 3: Using the head node as the current node, search for nodes connected to the current node; Step 4: Determine if only one node is connected to the current node; if yes, the level of the connected node is the same as that of the current node; if no, the level of the connected node is increased by 1 compared to the current node. Step 5: Determine if the connection types are the same. If they are the same, enqueue the upstream node of the current node. If they are different, first record the hybrid connection result, and then enqueue the upstream node of the current node. The level of the hybrid connection point is the same as the level of the current node connected by the pipe. Step 6: Dequeue the current node; Step 7: Determine if the queue is empty. If it is empty, complete the cross-connection check for this outlet and export the check results. If it is not empty, return to step 3 and repeat steps 3 to 7. Step 8: After the queue is cleared, determine whether there are other exit points. If so, return to step 2 and repeat steps 2 to 8. Step 9: Once all outlet statistics are completed, the task is finished.

2. The automatic analysis method for upstream misconnection of river outlets based on breadth-first search algorithm according to claim 1, characterized in that: Also includes: Generate a report on misconnections at discharge outlets, and count the number of misconnections upstream of each discharge outlet and the level of misconnection.

3. The automatic analysis method for upstream misconnection of river outlets based on breadth-first search algorithm according to claim 2, characterized in that: By analyzing the quantity and severity of misconnections upstream of the discharge outlet, we can assist in determining the remediation measures for the discharge outlet. The specific judgment strategy is as follows: 1) Let X be the total number of mixed and incorrect connections traced at the discharge outlet. Count the number of mixed connections at different levels x1, x2...xn, and introduce the influence coefficients for different levels. The higher the level, the closer the mixing point is to the end of the branched pipe network, the lower the influence coefficient, and the smaller the impact on the outlet. 2) Calculate the number of standardized outlets Through X and / X jointly determine the number and distribution of misconnections, and assist in the analysis of remedial measures for discharge outlets; 3) Outlet remediation measures include interception at the end of the outlet, decentralized interception in the middle, and complete rectification of mixed and incorrect connections.

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