A method for constructing a drainage pipe network data model based on the structure of a multi-aerial root banyan tree

Abstract

The present invention relates to a method for constructing a drainage pipe network data model based on the structure of a multi-aerial root banyan tree. The method includes: classifying urban drainage pipe network facilities into pipe points and pipelines, where the pipelines store the starting pipe points and the ending pipe points to form an urban drainage pipe network, and the data structure is a single main root tree or a multi-aerial root banyan tree structure. A data model is established for the drainage pipe network data through the multi-aerial root banyan tree structure. A longest chain is selected from this tree graph structure as the pivot chain, and sub-tree sets are divided along the pivot chain in the reverse water flow order. Each sub-tree set includes only one such pivot pipe point. The sub-trees are ordered and modeled according to the reverse water flow order of the pivot chain, and thus the data model construction of the entire pipe network can be quickly completed. Through the ordered modeling of the multi-aerial root banyan tree structure data, the present invention lays a solid foundation for information applications such as the acquisition, processing, database building, updating of pipe network data, and urban governance based on pipe network data.

Description

Technical Field

[0001] The present invention belongs to the fields of geographic information and Internet technology, and particularly relates to a method for constructing a drainage pipe network data model based on the structure of multi-aerial root banyan trees. Background Art

[0002] Urban drainage pipe networks are an important part of urban lifelines, and their safe operation is of great significance for the healthy economic and social development of cities. Currently, most cities across the country have established city-level comprehensive underground pipeline databases through underground pipeline surveys, and some provinces have even established provincial-level comprehensive underground pipeline databases. As an important part of the comprehensive underground pipeline database, drainage pipelines are also the only pipelines with gravity flow and flow direction. However, drainage pipelines are not laid along only one path, but are laid crisscross like a network. The centralized management of massive drainage pipe network data not only needs to consider the storage form of data, but also pays more attention to the internal logic of data.

[0003] In urban management, higher requirements are put forward for the sharing of drainage pipe network data information resources in many aspects such as planning and design, flood prevention and disaster reduction, emergency rescue, and drainage traceability. And the construction of drainage pipe network databases faces the following problems that need to be solved urgently:

[0004] 1. How to uniformly number drainage pipe network facilities according to rules to ensure that the numbers are unique, concise, intuitive, convenient to identify and trace, which is the basis for the informatization of drainage pipe networks;

[0005] 2. How to quickly distinguish main pipes and branch pipes to facilitate planners and designers to understand the overall trend, water collection direction of pipes in the entire drainage system, and the coverage of each subsystem (small watershed);

[0006] 3. How to quickly trace the source. When arbitrarily selecting a drainage well from massive drainage pipe network data, the subsystem (small watershed) to which the well belongs, the corresponding drainage outlet, and the drainage household (the first well where users discharge into the drainage system) can be quickly extracted;

[0007] 4. How to enable pipe network inspection personnel to obtain the number of downstream wells faster through manhole cover markings, and can also roughly estimate the distance from the manhole to the drainage outlet, which is convenient for the daily management and maintenance of pipe networks;

[0008] 5. How to quickly obtain all the confluence points of branch pipes in a single drainage system, which is of great significance for emergency rescue.

[0009] In summary, it is necessary to analyze the urban drainage pipe network and establish a data model suitable for smart city management. The facilities of the urban drainage pipe network are mainly divided into pipe points and pipelines. The pipelines store the starting pipe points and ending pipe points to form the urban drainage pipe network. The data structure is a directed tree graph structure: most of the pipe network data has only one water outlet, which is a tree structure with a single main root; some pipe network data has multiple water outlets, which is similar to a banyan tree with multiple aerial roots; there are also some pipe network data with loop problems due to data production or actual construction issues. These data need to be detected, and on-site confirmation and modification should be carried out in a timely manner or the anomalies should be marked; there are also some that may have no water outlet, but are still a tree structure with a single main root or a banyan tree with multiple aerial roots. Therefore, we construct the drainage pipe network data model into a data model based on the banyan tree structure with multiple aerial roots. Summary of the Invention

[0010] The purpose of the present invention is to provide a method for constructing a drainage pipe network data model based on the banyan tree structure with multiple aerial roots, which solves the requirements of the geographic information system for the uniqueness of objects in the entire drainage data set, the requirement that the identifier is readable (certain information can be directly read through the number), and the requirement for quickly distinguishing the main pipeline / branch pipeline.

[0011] To achieve the above purpose, the technical solution of the present invention is: a method for constructing a drainage pipe network data model based on the banyan tree structure with multiple aerial roots, which divides the urban drainage pipe network facilities into pipe points and pipelines to form urban drainage pipe network data. The structure of the urban drainage pipe network data is a tree structure with a single main root or a banyan tree structure with multiple aerial roots. Select the longest chain from the tree structure with a single main root or the banyan tree structure with multiple aerial roots as the pivot chain, divide the subtree set along the reverse water flow order of the pivot chain, and each subtree set only includes one pivot pipe point. Order the subtrees according to the reverse water flow order of the pivot chain to quickly complete the construction of the entire urban drainage pipe network data model. The specific implementation of this method is as follows:

[0012] S01. Starting from any pipe point, search for all pipe points in the reverse water flow order from the end point to the starting point. If a pipe point is not the end point on any pipeline in the urban drainage pipe network, it is marked as a leaf pipe point. If a pipe point is not the starting point on any pipeline in the urban drainage pipe network, it is marked as a root pipe point. Other pipe points are stem pipe points, and values are assigned to each corresponding pipe point. A pipe network with only one root pipe point is a tree structure with a single main root, and a pipe network with multiple root pipe points is a banyan tree structure with multiple aerial roots;

[0013] S02. Select the longest chain from the single main root tree structure or the multi-aerial root banyan tree structure as the pivot chain subtree. The rules for the pivot chain subtree are as follows: For any pipe point in the single main root tree structure or the multi-aerial root banyan tree structure, select the subtree structure with this pipe point as the initial pipe point, accumulate the number of sub-pipe points and cascaded sub-pipe points in the subtree structure and label it as the number of upstream pipe points, use the accumulated result as the weight of the initial pipe point, and record the number of inlet pipes and outlet pipes of the initial pipe point at the same time; The root pipe points on the pivot chain subtree, that is, the main root pipe points. If it is a multi-aerial root banyan tree structure, there are other root pipe points in the multi-aerial root banyan tree structure, that is, the aerial root pipe points.

[0014] S03. Sort along the pivot chain subtree from the main root pipe point to divide the main root tree subtree set. The pivot chain subtree is marked as the main trunk pipe, and other subtrees are marked as branch trunk pipes. Each branch trunk pipe only contains one pipe point on the pivot chain subtree, that is, the pivot pipe point.

[0015] S04. Perform sequential modeling on the main root tree subtrees according to the reverse order of the pivot chain subtree: Number the pivot chain subtree in the reverse order of the water flow from the root pipe point to the leaf pipe point to establish a data model, and achieve a directed increment of the numbers, that is, increment sequentially from the water outlet to the drainage household; After the pivot chain subtree completes sequential modeling, perform sequential modeling on other subtrees of the main root tree.

[0016] S05. After all the main root tree subtrees complete sequential modeling, divide the aerial root tree subtree set if there are aerial root pipe points, and perform sequential modeling on the aerial root tree subtrees. The pipe points that have been modeled in the sequential modeling of the main root tree subtrees do not participate in the modeling of the aerial root tree subtrees.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention performs sequential modeling on urban drainage pipe network facilities through a multi-aerial root banyan tree structure, divides the urban drainage system into independent sub-drainage systems, and each sub-drainage system is modeled independently. First, classify the pipe points into root pipe points, diameter pipe points, and leaf pipe points; then determine the main root pipe points and aerial root pipe points through the pivot chain, divide the main trunk and branch trunks of the pipe network, and record the number of inlet pipes, outlet pipes, and the number of upstream pipe points of each pipe point at the same time; Then gradually establish the main trunk pivot chain model, branch trunk pivot chain sub-model, and aerial root chain model according to the reverse order of the water flow.

[0018] The advantages of the present invention are as follows:

[0019] 1. Through the sequential modeling of the multi-aerial root banyan tree structure data, it lays a solid foundation for information applications such as the acquisition, processing, database building, updating of pipe network data, and urban governance based on pipe network data. It solves the requirements of the geographic information system for the uniqueness of objects in the entire drainage data set, the requirement that the identifier is readable (directly read certain information through the number), and the requirement for quick distinction between the main trunk pipe / branch trunk pipe.

[0020] 2. Adding information such as the number of the pipe point, main pipe / branch pipe information, the number of inlet pipes and outlet pipes of the pipe point, and the number of upstream pipe points to the manhole cover nameplate enhances the recognition of manhole covers during the inspection of the pipe network. Integrated into the special database, it improves the scalability and usage efficiency of the database.

[0021] 3. Through the nameplate of any manhole in the drainage data set, the corresponding downstream drainage outlet, all upstream associated drainage households, and all upstream and downstream branch pipe confluence points can be quickly found. At the same time, the number of pipe segments (one segment between two wells) from the well to the drainage outlet or drainage household can be quickly calculated, providing data support for flood prevention, disaster reduction, and emergency rescue. Brief Description of the Drawings

[0022] Figure 1 It is a flowchart of the method steps of the present invention.

[0023] Figure 2 It is a schematic diagram for determining the tree structure.

[0024] Figure 3 It is a schematic diagram for selecting the pivot chain.

[0025] Figure 4 It is a schematic diagram for dividing the subtree set.

[0026] Figure 5 It is a schematic diagram for pivot chain ordering modeling.

[0027] Figure 6 It is a schematic diagram for subtree ordering modeling.

[0028] Figure 7 It is a schematic diagram for aerial root ordering modeling. Detailed Embodiment

[0029] The technical solution of the present invention will be specifically described below with reference to the accompanying drawings.

[0030] A method for constructing a drainage pipe network data model based on a multi-aerial root banyan tree structure according to the present invention divides the urban drainage pipe network facilities into pipe points and pipelines to form urban drainage pipe network data. The structure of the urban drainage pipe network data is a single main root tree structure or a multi-aerial root banyan tree structure. Select the longest chain from the single main root tree structure or the multi-aerial root banyan tree structure as the pivot chain, divide the subtree set along the reverse water flow order of the pivot chain, each subtree set only includes one pivot pipe point, and perform ordering modeling on the subtrees according to the reverse water flow order of the pivot chain, then the construction of the entire urban drainage pipe network data model can be quickly completed. The flowchart of the method of the present invention is as Figure 1 shown, and the specific steps are as follows:

[0031] S01. As Figure 2As shown, starting from the outlet pipe point or any pipe point, search and collect all pipe points in the reverse order of the water flow from the end point to the starting point. If a pipe point is not on the urban drainage pipe network as an end point, it is marked as a leaf pipe point. If a pipe point is not on the urban drainage pipe network as a starting point, it is marked as a root pipe point. Other pipe points are radial pipe points. A pipe network with only one root pipe point is a single main root tree structure, and a pipe network with multiple root pipe points is a multi-aerial root banyan tree structure.

[0032] The set obtained by this method is called a sub-drainage system (small watershed). Name the sub-drainage system and assign it to all objects in the set, then each object in the set has the corresponding sub-drainage system attribute; and divide the pipe points into root pipe points, leaf pipe points, and radial pipe points, and assign values to each corresponding pipe point. The leaf pipe points are drainage households, and the root pipe points are drainage outlets, providing an index for quickly marking and positioning the final drainage collection points (drainage outlets) and the starting points of drainage into the pipes (drainage households) in the massive drainage pipe network data set.

[0033] S02. As Figure 3 As shown, select the longest chain in the tree diagram structure as the pivot chain. The pivot chain subtree rules include: for any pipe point in the tree diagram structure, select the subtree structure with this pipe point as the initial pipe point, accumulate the number of sub-pipe points and cascaded sub-pipe points in this subtree structure and label it as the number of upstream pipe points, use the accumulated result as the weight of this pipe point, and record the number of inlet pipes and outlet pipes of this pipe point at the same time. The root pipe point on the pivot chain is the main root pipe point of this pipe network. If there are other root pipe points, they are aerial root pipe points.

[0034] It is an objective and common phenomenon that a sub-drainage system has multiple drainage outlets. The traditional mathematical model of the drainage pipe network is basically an ideal model, that is, a sub-drainage system has only one drainage outlet, which is difficult to solve practical problems. Through the pivot chain, the primary and secondary of the drainage outlets can be automatically distinguished, that is, the drainage outlet with more upstream drainage wells (greater weight) is the main drainage outlet (main root), and the drainage outlet with fewer upstream drainage wells is the secondary drainage outlet (aerial root), providing a model basis for data analysis.

[0035] S03. As Figure 4 As shown, sort along the pivot chain from the main root pipe point and divide the subtree set. The pivot chain is marked as the main trunk pipe, and other subtrees are marked as branch trunk pipes. Each branch trunk pipe only includes one pivot pipe point, and order the subtrees according to the reverse order of the pivot chain for modeling. In this way, the main trunk pipe and the branch pipes can be quickly distinguished, which plays a crucial role in many aspects such as emergency rescue, flood prevention and drainage, and planning and design. When analyzing data, the specified data can be quickly extracted or closed according to this mark, thus solving the problem that it is difficult to automatically distinguish the main trunk pipe and the branch pipes of each independent drainage system in the massive drainage pipe network data set.

[0036] S04. As Figure 5As shown, according to the tree diagram structure model, the pivot chain is numbered in the reverse order of water flow from the root canal point to the leaf canal point to establish a data model, realizing a directed increment of the numbering (increasing sequentially from the water outlet to the drainage household).

[0037] S05. As Figure 6 shown, according to the tree diagram structure model, the initial numbering of the pivot chain subtree is the largest number that has been numbered in this pipe network, and the sequencing of the numbering is similar to the numbering order of the pivot chain and the pivot chain subtree.

[0038] S06. As Figure 7 shown, after the main root tree data model is established, the sequencing modeling continues for those with aerial roots. The pipe points that have been modeled do not participate in the modeling of the aerial root tree subtree, and the initial numbering is the largest number that has been numbered in this pipe network.

[0039] The above are the preferred embodiments of the present invention. All changes made according to the technical solution of the present invention, when the functions and effects generated do not exceed the scope of the technical solution of the present invention, shall fall within the protection scope of the present invention.

Claims

1. A method for constructing a drainage pipe network data model based on the structure of a multi-aerial root banyan tree, characterized in that, Divide the urban drainage pipe network facilities into pipe points and pipelines to form urban drainage pipe network data. The structure of the urban drainage pipe network data is a single-main-root tree structure or a multi-aerial-root banyan tree structure. Select the longest chain from the single-main-root tree structure or the multi-aerial-root banyan tree structure as the pivot chain, and divide the subtree set along the reverse water flow order of the pivot chain. Each subtree set only includes one pivot pipe point. Order the subtrees according to the reverse water flow order of the pivot chain to quickly complete the construction of the entire urban drainage pipe network data model. The specific implementation of this method is as follows: S01. Starting from any pipe point, search and collect all pipe points in the reverse water flow order from the end point to the starting point. If a pipe point is not the end point on any pipeline in the urban drainage pipe network, it is marked as a leaf pipe point. If a pipe point is not the starting point on any pipeline in the urban drainage pipe network, it is marked as a root pipe point. Other pipe points are stem pipe points, and assign values to each corresponding pipe point. A pipe network with only one root pipe point is a single-main-root tree structure, and a pipe network with multiple root pipe points is a multi-aerial-root banyan tree structure; S02. Select the longest chain from the single-main-root tree structure or the multi-aerial-root banyan tree structure as the pivot chain subtree. The rules for the pivot chain subtree are as follows: For any pipe point in the single-main-root tree structure or the multi-aerial-root banyan tree structure, select the subtree structure with this pipe point as the initial pipe point, accumulate the number of sub-pipe points and cascaded sub-pipe points in the subtree structure and label it as the number of upstream pipe points. Use the accumulated result as the weight of the initial pipe point, and record the number of inlet pipes and outlet pipes of the initial pipe point at the same time. The root pipe point on the pivot chain subtree, that is, the main root pipe point. If it is a multi-aerial-root banyan tree structure, there are other root pipe points in the multi-aerial-root banyan tree structure, that is, aerial root pipe points; S03. Starting from the main root pipe point, sort along the pivot chain subtree, divide the main root tree subtree set, mark the pivot chain subtree as the main trunk pipe, and mark other subtrees as branch trunk pipes. Each branch trunk pipe only includes one pipe point on the pivot chain subtree, that is, the pivot pipe point; S04. Order the main root tree subtrees according to the reverse water flow order of the pivot chain subtree: Number the pivot chain subtree in the reverse water flow order from the root pipe point to the leaf pipe point to establish a data model, and realize the directed increment of the numbering, that is, increment sequentially from the water outlet to the drainage household; After the pivot chain subtree completes the ordered modeling, perform the ordered modeling on other subtrees of the main root tree; S05. After all the main root tree subtrees complete the ordered modeling, divide the aerial root tree subtree set if there are aerial root pipe points, and perform the ordered modeling on the aerial root tree subtrees. The pipe points that have been modeled in the ordered modeling of the main root tree subtrees do not participate in the modeling of the aerial root tree subtrees.

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