Method, device, equipment and medium for selecting geographical entities for artificial river network

Abstract

The present application discloses a method, device, equipment and medium for selecting geographic entities for artificial river networks, and relates to the comprehensive field of maps in the surveying and mapping geographic information industry. The method includes: obtaining geographic entity data of the artificial river network to be selected, constructing a planar directed graph, and extracting a facet set and its half-edge information, and further calculating the half-edge divided area. Using the Stroke model, the adjacent half-edges are divided into continuous line segments, and the continuous line segments are evaluated based on the total length and the total divided area. By determining the locking state of each continuous line segment and combining the preset selection number, the key continuous line segments are intelligently selected, and the unselected line segments are marked as discarded, thereby obtaining the selection results of the geographic entities of the artificial river network to be selected. The present application realizes the efficient and accurate selection of the geographical entities of the artificial river network, which not only improves the selection efficiency, but also ensures the accuracy and rationality of the selection results.

Description

Technical Field

[0001] The present application relates to the field of map integration in the surveying and mapping geographic information industry, and in particular to a method, device, equipment and medium for selecting geographic entities for artificial river networks. Background Art

[0002] In the surveying and mapping geographic information industry, with the rapid development of Geographic Information System (GIS) and remote sensing technology, a large amount of geographic data has been collected and accumulated. These data contain rich geographic entity information, such as rivers, lakes, roads, buildings, etc., which are of great significance to urban planning, environmental monitoring, disaster warning and other fields.

[0003] As an important part of geographic entities, the accuracy and completeness of the geographic information of artificial river networks are crucial for decision-making and planning in related fields. However, in practical applications, due to the complexity and diversity of artificial river networks, traditional geographic entity selection methods are often difficult to extract the required information efficiently and accurately. Especially when processing large-scale geographic data, these methods are not only time-consuming and laborious, but also prone to introduce errors, affecting subsequent analysis and application.

[0004] Therefore, there is an urgent need to develop a new method for selecting geographic entities for artificial river networks, which can achieve rapid identification and accurate selection of geographic entities in artificial river networks through intelligent means, so as to meet the high requirements for accuracy and timeliness of geographic information in fields such as urban planning and environmental monitoring. Summary of the invention

[0005] The purpose of this application is to provide a method, device, equipment and medium for selecting geographical entities of artificial river networks, which can solve the problem of lack of adaptability in automatic selection of geographical entities of artificial river networks in complex environments.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a method for selecting geographical entities for an artificial river network, comprising:

[0008] Acquire geographic entity data of the artificial river network to be selected; the geographic entity data includes location information, geometric information, semantic information and connection relationship of each entity constituting the artificial river network to be selected;

[0009] According to the geographic entity data of the artificial river network to be selected, each entity edge constituting the artificial river network entity is used as an internal half-edge and an external half-edge to construct a planar directed graph of the artificial river network to be selected; wherein the internal half-edge and the external half-edge are in opposite directions; the planar directed graph includes a vertex and a directed edge set; the vertex represents an end point of the edge of the artificial river network entity to be selected, and the directed edge represents an internal half-edge or an external half-edge of the artificial river network entity to be selected;

[0010] Extracting a facet set of the planar directed graph of the artificial river network to be selected, and respectively determining all the half-edges constituting each facet to obtain a half-edge information set of each facet; the facet represents a closed area surrounded by half-edges inside a plurality of entities;

[0011] Calculate the area of ​​each patch, and calculate the half-edge divided area of ​​each internal half-edge in the patch according to the ratio of the length of each internal half-edge in the half-edge information set of each patch;

[0012] The half-edge information sets of all facets are input into the Stroke model to obtain a continuous line segment set, and the total length and total divided area of ​​each continuous line segment in the continuous line segment set are calculated according to the half-edge divided area; the Stroke model is used to divide the adjacent internal half-edges connected head to tail into a continuous line segment according to the semantic information and geometric information of the half-edge information sets of all facets;

[0013] Determine the locking state of each continuous line segment in the continuous line segment set according to the total length and the total divided area of ​​each continuous line segment;

[0014] A preset number of continuous line segments are selected based on the locking state and the total divided area of ​​each continuous line segment, and unselected continuous line segments are marked as discarded to obtain the geographical entity selection result of the artificial river network to be selected.

[0015] In a second aspect, the present application provides a geographical entity selection device for an artificial river network, comprising:

[0016] A data acquisition module is used to acquire geographic entity data of the artificial river network to be selected; the geographic entity data includes location information, geometric information, semantic information and connection relationship of each entity constituting the artificial river network to be selected;

[0017] A directed graph construction module is used to construct a planar directed graph of the artificial river network to be selected based on the geographic entity data of the artificial river network to be selected, taking each entity edge constituting the artificial river network entity as an internal half-edge and an external half-edge; wherein the internal half-edge and the external half-edge are in opposite directions; the planar directed graph includes a vertex and a directed edge set; the vertex represents an end point of the edge of the artificial river network entity to be selected, and the directed edge represents an internal half-edge or an external half-edge of the artificial river network entity to be selected;

[0018] A patch and half-edge information extraction module is used to extract a patch set of the planar directed graph of the artificial river network to be selected, and respectively determine all the half-edges constituting each patch to obtain a half-edge information set of each patch; the patch represents a closed area surrounded by half-edges inside a plurality of entities;

[0019] A half-edge partition area calculation module is used to calculate the area of ​​each patch, and calculate the half-edge partition area of ​​each internal half-edge in the patch according to the ratio of the length of each internal half-edge in the half-edge information set of each patch;

[0020] A continuous line segment acquisition module is used to input the half-edge information sets of all face patches into the Stroke model to obtain a continuous line segment set, and calculate the total length and total divided area of ​​each continuous line segment in the continuous line segment set according to the half-edge divided area; the Stroke model is used to divide the adjacent internal half-edges connected head to tail into a continuous line segment according to the semantic information and geometric information of the half-edge information sets of all face patches;

[0021] A locking state calculation module, used for determining the locking state of each continuous line segment in the continuous line segment set according to the total length and the total divided area of ​​each continuous line segment;

[0022] The geographic entity selection module is used to select a preset number of continuous line segments based on the locking state and total divided area of ​​each continuous line segment, and mark the unselected continuous line segments as discarded to obtain the geographic entity selection results of the artificial river network to be selected.

[0023] In a third aspect, the present application provides a computer device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of any of the above-mentioned methods for selecting geographic entities for an artificial river network.

[0024] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-mentioned methods for selecting geographic entities for an artificial river network.

[0025] According to the specific embodiments provided in this application, this application has the following technical effects:

[0026] The present application provides a method, device, equipment and medium for selecting geographic entities for artificial river networks. By acquiring the geographic entity data of the artificial river network to be selected, including the location information, geometric information, semantic information and connection relationship of each entity constituting the river network, a solid foundation is laid for the subsequent intelligent selection. According to the acquired geographic entity data, a planar directed graph of the artificial river network to be selected is constructed, and the complex river network structure is converted into an intuitive graphical representation, which provides convenience for the subsequent selection. By extracting the face set of the planar directed graph and determining all the half edges constituting each face, a half edge information set is obtained, and the half edge partition area of ​​each half edge is calculated. Then the half edge information set of all facets is input into the Stroke model. The Stroke model divides the adjacent half edges connected end to end into a continuous line segment according to the semantic information and geometric features of the half edge information set, so as to further simplify the complex river network structure into a series of continuous line segments, which provides a more intuitive basis for the subsequent selection. After obtaining the continuous line segment set, the total length and total partition area of ​​each continuous line segment are calculated according to the half edge partition area. The locking state of the continuous line segments is determined according to the total length and total divided area of ​​each continuous line segment, and a preset number of continuous line segments are selected based on the locking state and total divided area of ​​each continuous line segment, taking into account the geometric characteristics and importance of the continuous line segments, ensuring that key line segments will not be omitted during the selection process, thereby ensuring the accuracy and completeness of the selection results. The unselected continuous line segments are marked as discarded, thus obtaining the final geographic entity selection results.

[0027] In summary, this application solves the complexity and uncertainty problems in the selection of artificial river network geographical entities. By constructing a planar directed graph, extracting facet sets and half-edge information, applying the Stroke model, and determining the locking state and selection number of continuous line segments, efficient and accurate selection of artificial river network geographical entities is achieved. This method not only improves the selection efficiency, but also ensures the accuracy and rationality of the selection results, providing a new solution for the map integration field of the surveying and mapping geographic information industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A flowchart of a method for selecting geographical entities for an artificial river network is provided in accordance with an embodiment of the present application.

[0030] Figure 2A flowchart of a method for selecting geographic entities for an artificial river network is provided in accordance with another embodiment of the present application.

[0031] Figure 3 A planar directed graph of an artificial river network provided in one embodiment of the present application.

[0032] Figure 4 A schematic diagram of functional modules of a geographic entity selection device for an artificial river network provided in one embodiment of the present application.

[0033] Figure 5 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0034] The relevant technology usually establishes an artificial river network selection model based on "knowledge decision-making". The artificial river network selection model takes into account five factors in the complex artificial river network, including river channel attributes, length, connectivity, spatial relationship between rivers and channels, and river network density. By establishing a multi-criteria decision-making model, each alternative river channel is evaluated equally, and based on the evaluation results, intervals are selected from small to large according to the possibility of selection, so as to better maintain the network characteristics of the artificial river network.

[0035] However, the automatic selection technology of complex artificial river networks that take into account network characteristics has limitations in maintaining the overall river network characteristics, and cannot control the local density contrast after selection. Specifically, for areas where ditch data collection is irregular, the selection results do not maintain the regional graphic structure characteristics. The automatic selection of artificial river networks with different mapping areas, different geographical environments, different scales, and different spatial distribution characteristics lacks adaptability, and the selection effect is not ideal in complex environments. Specifically, when selecting dense and complex artificial ditch networks, the technology cannot make choices based on the relationship between the selection of ditches and other water system elements. For example, when there are a large number of lake groups and ditches interlaced, many ditches and length selection indicators between lake groups are obviously different, but because they are connected to lakes, ditches that do not meet the density classification are still selected.

[0036] Moreover, the core of the automatic selection technology of complex artificial river networks taking into account network characteristics is to establish a multi-criteria decision-making model. The accuracy of the model directly affects the evaluation results, and then affects the selection results. However, in actual production operations, factors such as different data sources, different geographical environments, and different mapping purposes seriously affect the calculation accuracy of the model, and it is difficult to directly achieve it in one step. The multi-criteria decision-making model outputs the selection results based on the parity of the candidate river channel sequence number after comprehensive evaluation of each candidate river channel. There must be some artificial river sections that should be abandoned but have not been abandoned or have been abandoned by mistake. This is an inevitable situation for automatic selection. In view of this situation, it is necessary to rely on human judgment and adopt an intelligent method of human-machine collaboration to select and process in order to obtain ideal results that meet actual production requirements.

[0037] In view of this, an embodiment of the present application provides a method for selecting geographical entities for an artificial river network.

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0040] In an exemplary embodiment, Figure 1 As shown, a method for selecting geographical entities for artificial river networks is provided, and the method includes the following steps 101 to 107. Among them:

[0041] Step 101, obtaining geographic entity data of the artificial river network to be selected; the geographic entity data includes location information, geometric information, semantic information and connection relationship of each entity constituting the artificial river network to be selected.

[0042] Step 102, based on the geographic entity data of the artificial river network to be selected, each entity edge constituting the artificial river network entity is taken as an internal half-edge and an external half-edge, and a planar directed graph of the artificial river network to be selected is constructed; wherein the internal half-edge and the external half-edge are in opposite directions; the planar directed graph includes a set of vertices and directed edges; a vertex represents an endpoint of an edge of the artificial river network entity to be selected, and a directed edge represents an internal half-edge or an external half-edge of the artificial river network entity to be selected.

[0043] Step 103, extracting a facet set of the planar directed graph of the artificial river network to be selected, and determining all the half-edges constituting each facet respectively, to obtain a half-edge information set of each facet; the facet represents a closed area surrounded by multiple internal half-edges of entities.

[0044] Step 104, calculating the area of ​​each patch, and calculating the half-edge divided area of ​​each internal half-edge in the patch according to the ratio of the length of each internal half-edge in the half-edge information set of each patch.

[0045] Step 105, input the half-edge information sets of all facets into the Stroke model to obtain a continuous line segment set, and calculate the total length and total divided area of ​​each continuous line segment in the continuous line segment set according to the half-edge divided area; the Stroke model is used to divide the adjacent internal half-edges connected end to end into a continuous line segment according to the semantic information and geometric information of the half-edge information sets of all facets.

[0046] Step 106, determining the locking state of each continuous line segment in the continuous line segment set according to the total length and the total divided area of ​​each continuous line segment.

[0047] Step 107, based on the locking state of each continuous line segment and the total divided area, a preset number of continuous line segments are selected, and the unselected continuous line segments are marked as discarded, thereby obtaining the geographical entity selection result of the artificial river network to be selected.

[0048] By implementing the above steps 101 to 107, the present application can also significantly improve the intelligence level and efficiency of selecting geographical entities of artificial river networks.

[0049] In another exemplary embodiment of the present application, after step 102, the following steps are further included:

[0050] Initialization selection is performed on the planar directed graph of the artificial river network to be selected; the initialization selection includes deleting isolated artificial river sections and suspended artificial river sections that are less than a preset length index.

[0051] In another exemplary embodiment of the present application, in step 104, the calculation formula for the half-divided area is:

[0052] .

[0053] .

[0054] in, Indicates i The first j The area is divided into two halves of the inner half. Indicates i The first j The inner half, Indicates i The first j The half length of the inner half, Indicates i The sum of the lengths of all inner half-edges of a face, Indicates i The total area of ​​the patches, n Indicates i The total number of vertices in a patch, k =1,2,..., n , indicating the i The first k Vertices, and Respectively represent i The first k The horizontal and vertical coordinates of the vertices, and Respectively represent i The first k +1 The horizontal and vertical coordinates of the vertices.

[0055] In another exemplary embodiment of the present application, in step 106, the method for determining the locking state is:

[0056] If a continuous line segment meets any of the following preset conditions, the continuous line segment is determined to be locked; the preset conditions include that the continuous line segment is a key entity, the continuous line segment is associated with a natural river or lake, the continuous line segment has a name, the selection level of the continuous line segment is 2, the total length of the continuous line segment is greater than 20 mm and the correlation is greater than 5, and the total area of ​​the continuous line segment is greater than 80 cm 2 .

[0057] In another exemplary embodiment of the present application, step 107 specifically includes:

[0058] Sort the total area divided by each continuous line segment from small to large to obtain a set of areas divided by continuous line segments.

[0059] It is determined whether the current continuous line segment in the continuous line segment partition area set meets a preset determination condition, and a determination result is obtained; the preset determination condition includes that the continuous line segment is in a locked state or the continuous line segment contains an external half-edge.

[0060] If the judgment result is yes, the current continuous line segment is selected.

[0061] If the judgment result is no, the current continuous line segment is marked as discarded, and the adjacent facets of each internal half-edge of the current continuous line segment are merged, and the planar directed graph of the artificial river network to be selected is updated; based on the updated planar directed graph of the artificial river network to be selected, the continuous line segment associated with the merged facets is marked as locked and added to the continuous line segment set.

[0062] The next continuous line segment in the continuous line segment divided area set is used as the current continuous line segment, and the step of "determining whether the current continuous line segment in the continuous line segment divided area set meets the preset judgment condition and obtaining the judgment result" is returned until the preset selection quantity is met, and the geographical entity selection result of the artificial river network to be selected is obtained.

[0063] As an optional implementation, in step 107, the preset selection quantity is determined based on the square root law, and the formula is:

[0064] .

[0065] in, Indicates the preset number of selected continuous line segments. N represents the total number of continuous line segments, m The denominator of the original image scale of the artificial river network to be selected. It represents the target scale denominator after the artificial river network is selected. x Indicates the selection level.

[0066] Wherein, in implementing this embodiment, after step 107, the following steps are further included:

[0067] Manual adjustment operation is performed on the geographical entity selection result of the artificial river network to be selected to obtain the geographical entity adjustment result; the manual adjustment operation includes: marking as a discard state or a selection state.

[0068] The continuous line segments marked as discarded in the geographic entity adjustment result are deleted to obtain the final selection result of the geographic entity of the artificial river network to be selected.

[0069] In another exemplary embodiment, Figure 2 As shown, a method for selecting geographical entities for artificial river networks is provided, which specifically includes:

[0070] Step 1: Obtain the geographic entity data of the artificial river network to be selected, regard each edge of the artificial river network entity to be selected as two half edges in opposite directions, and construct a planar directed graph G (V, E) of the artificial river network to be selected based on the Half Edge model, as shown in Figure 3 As shown. Where G is a non-connected graph, V is a vertex set, E is a half-edge set, and each half-edge in the set is set e=u→v, u is the starting point of the half-edge, and v is the end point of the half-edge. Figure 3 In the example, the vertex set = {v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15, v16}; the face set = {f1, f2, f3, f4, f5, f6, f7}; the internal half-edge set = {e1, e2, e3, e4, e5, e6, e7, e8, e9, e10, e11, e12 , e13, e14, e15, e16, e17, e18, e19, e20, e21, e22, e23, e24, e25, e26, e27, e28, e29, e30, e31, e32}; external half-edge set = {e33, e34, e35, e36, e37, e38, e39, e40, e41, e42, e43, e44}. Take f1 in the face set as an example. Specifically, the face f1, which is composed of the artificial river with v1, v2, v3, and v4 as vertices, is composed of four internal half-edges e1, e2, e3, and e4, and two external half-edges e33 and e34. The structures of f2, f3, f4, f5, f6, and f7 in the face set are similar to those of f1, and will not be repeated here.

[0071] Step 2: Initialize and select based on the constructed planar directed graph G (V, E), and discard isolated artificial river sections and suspended artificial river sections that are less than the preset length index. An isolated artificial river section refers to a single river section that is not connected to other river sections; a suspended artificial river section refers to a river section that is connected to other river sections at one end but suspended at the other end. The preset length indexes of isolated artificial river sections and suspended artificial river sections can be the same or different.

[0072] Step 3, calculate the face set Faces = {f1, f2, f3, ...} of the planar directed graph G (V, E), calculate the internal Half Edge information associated with each Face (f1 = {e1, e2, e3, e4, ...}), and set the geometric point set that constitutes each Face ={v1(x 1 ,y 1 ),v2(x 2 ,y 2 ),v3(x 3 ,y 3 ),…}, calculate the area of ​​each Face , use Depth-First Search (DFS) to traverse the entire planar directed graph G (V, E) to find the connected component (maximum connected subgraph) to which each node v belongs. Traverse each Face and calculate the area divided by all Half Edges based on the length ratio of each Half Edge that makes up the current Face ,in, Indicates i The first j The area is divided into two halves of the inner half. Indicates i The first j The inner half, Indicates i The first j The half length of the inner half, Indicates i The sum of the lengths of all inner half-edges of a face, Indicates i The total area of ​​the patches, n Indicates i The total number of vertices in a patch, k =1,2,..., n , indicating the i The first k Vertices, and Respectively represent i The first k The horizontal and vertical coordinates of the vertices, and Respectively represent i The first k +1 The horizontal and vertical coordinates of the vertices.

[0073] Step 4: Build a stroke model based on the planar directed graph G (V, E), traverse each half edge in turn, and classify the adjacent half edges that are connected at the beginning and end into the same continuous line segment (stroke) according to the semantic information and the arc angle to obtain a continuous line segment set. And calculate the total length of each stroke in the continuous line segment set:

[0074] .

[0075] in, Represents the first The total length of the stroke. Represents the first Stroke, J represents the first stroke in the continuous line segment set. The total number of half sides of a stroke. =1,2,...,J, represents the first Stroke The inner half, Indicates The half-side length of the inner half-side.

[0076] Step 5, calculate the total area of ​​each stroke, and sort each stroke in the continuous line segment set according to the total area. The total area of ​​each stroke is calculated as follows:

[0077] .

[0078] in, Represents the first The total area divided by the strokes, Indicates Divide the area into two halves.

[0079] Step 6: Check whether each stroke is a key entity cri (Yes: 1, No: 0), Is it related to natural rivers and lakes? hydro (Yes: 1, No: 0), Is there a name? name (Yes: 1, No: 0), Select level grade (Main channel: 2, Branch channel: 1, Other or no selection level: 0), Total length length , total area divided area , correlation link The seven indicators are used to calculate the locking status (importance) of each Stroke, and the initial "skeleton" of the artificial river network to be selected is obtained. The initial locked Stroke set is SkeletonStrokes. The calculation rule for each Stroke to be judged as locked is: cri , hydro , name Any of the values ​​is 1; or grade The value is 2; or the total length length Branch canals with diameter greater than 20 mm and a correlation greater than 5; or a branch canal with a ... 2 Among them, the indicators can be appropriately adjusted according to the characteristics of different geographical areas and mapping purposes.

[0080] Step 7: Determine the number of selections based on the open root law. The formula is:

[0081] .

[0082] in, Indicates the preset number of selected continuous line segments. N represents the total number of continuous line segments, m The denominator of the original image scale of the artificial river network to be selected. It represents the target scale denominator after the artificial river network is selected. x Indicates the selection level. The number of strokes discarded .

[0083] Starting from the Stroke with the smallest total divided area value, determine whether the continuous line segment in the continuous line segment divided area set meets the preset judgment conditions to obtain the judgment result; the preset judgment conditions include that the continuous line segment is in a locked state or the continuous line segment contains an external half edge (e33, e34, e35, ..., e44); if the judgment result is yes, select the Stroke; if the judgment result is no, mark the Stroke as discarded, and merge the adjacent Faces of each Half Edge, update the topological structure of the planar directed graph, and add the Stroke associated with the merged Face to SkeletonStrokes and mark it as locked.

[0084] Step 8: Repeat step 7 until the preset number of selections is met. If all strokes are traversed and the preset number of selections is still not met, restore to the initial locked SkeletonStrokes state and repeat step 7.

[0085] Step 9, all the strokes marked as discarded are highlighted in the map window, and the unreasonable selections are manually fine-tuned. The fine-tuning method is as follows: the machine obtains the manually selected data input of the artificial river sections that should be discarded but are not discarded, and the data input of the artificial river sections that are mistakenly discarded by the algorithm according to different operation commands. The machine marks them as discarded or selected (cancel discard) according to the above two situations, and obtains the fine-tuned selection result output of the entire stroke.

[0086] Step 10, use shortcut keys (such as Space) to perform batch deletion operations on all artificial river sections marked as abandoned (highlighted), and record the execution process in the program log and rollback collection for undo and rollback.

[0087] The present application also provides an application scenario, which applies the above-mentioned method for selecting geographical entities for artificial river networks. Specifically: The method for selecting geographical entities for artificial river networks provided in this embodiment can be applied in urban planning and management scenarios. The urban planning and management scenario includes data collection and processing links, geographical entity analysis links, and decision-making links. In the process of urban planning and management, the first step is to enter from the data collection and processing link, and obtain detailed geographical entity data of the artificial river network in the area to be planned or managed through technical means such as remote sensing and GIS. After cleaning and integration, these data enter the geographical entity analysis link. In the geographical entity analysis link, geographical entities are selected and enter the decision-making link. The method for selecting geographical entities for artificial river networks provided in this embodiment belongs to the data analysis and processing link in urban planning and management. Specifically, the collected geographical entity data is intelligently processed, and a series of steps such as constructing a plane directed graph, extracting a face set, calculating the half-edge divided area, using the Stroke model to divide continuous line segments, and determining the locked state are used to efficiently select representative and important geographical entities. Urban planners and managers can develop more scientific and reasonable urban planning and management plans based on this key information to optimize urban spatial layout, improve urban functional efficiency, and protect the urban ecological environment.

[0088] Based on the same inventive concept, the embodiment of the present application also provides a device for selecting geographical entities for artificial river networks for implementing the method for selecting geographical entities for artificial river networks mentioned above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more embodiments of the device for selecting geographical entities for artificial river networks provided below can refer to the limitations of the method for selecting geographical entities for artificial river networks above, and will not be repeated here.

[0089] In an exemplary embodiment, Figure 4 As shown, a geographical entity selection device for an artificial river network is provided, comprising:

[0090] The data acquisition module 201 is used to acquire the geographic entity data of the artificial river network to be selected; the geographic entity data includes the location information, geometric information, semantic information and connection relationship of each entity constituting the artificial river network to be selected.

[0091] The directed graph construction module 202 is used to construct a planar directed graph of the artificial river network to be selected based on the geographic entity data of the artificial river network to be selected, taking each entity edge that constitutes the artificial river network entity as an internal half-edge and an external half-edge; wherein the internal half-edge and the external half-edge are in opposite directions; the planar directed graph includes a vertex and a directed edge set; a vertex represents an endpoint of an edge of the artificial river network entity to be selected, and a directed edge represents an internal half-edge or an external half-edge of the artificial river network entity to be selected.

[0092] The patch and half-edge information extraction module 203 is used to extract a patch set of the planar directed graph of the artificial river network to be selected, and respectively determine all the half-edges that constitute each patch to obtain a half-edge information set of each patch; the patch represents a closed area surrounded by multiple internal half-edges of entities.

[0093] The half-edge divided area calculation module 204 is used to calculate the area of ​​each patch, and calculate the half-edge divided area of ​​each internal half-edge in the patch according to the ratio of the length of each internal half-edge in the half-edge information set of each patch.

[0094] The continuous line segment acquisition module 205 is used to input the half-edge information sets of all face patches into the Stroke model to obtain a continuous line segment set, and calculate the total length and total divided area of ​​each continuous line segment in the continuous line segment set according to the half-edge divided area; the Stroke model is used to divide the adjacent internal half-edges connected end to end into a continuous line segment according to the semantic information and geometric information of the half-edge information sets of all face patches.

[0095] The locking state calculation module 206 is used to determine the locking state of each continuous line segment in the continuous line segment set according to the total length and the total divided area of ​​each continuous line segment.

[0096] The geographic entity selection module 207 is used to select a preset number of continuous line segments based on the locking state and total divided area of ​​each continuous line segment, and mark the unselected continuous line segments as discarded to obtain the geographic entity selection result of the artificial river network to be selected.

[0097] This application can realize the intelligent collaborative selection of massive artificial river network geographical entities under complex conditions such as different data sources, different geographical environments, and different mapping purposes, taking into account both the semantic information and spatial distribution of geographical entities, as well as automated calculation and human-computer collaborative operations. It can better maintain the overall river network characteristics and can well control the local density comparison after selection. In actual production, it can adapt to the intelligent processing of artificial river network geospatial data with different data sources, different geographical environments, and different mapping purposes.

[0098] It can also significantly improve the production efficiency of geographic entity data reduction, improve the construction efficiency and quality of multi-scale spatial databases, enhance the public welfare map service capabilities, and widely support the production of various map products, geographic information application services, natural resource management, and government emergency surveying and mapping support work.

[0099] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 5 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store geographic entity data of the artificial river network to be selected. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for selecting geographic entities for an artificial river network is implemented.

[0100] Those skilled in the art will understand that Figure 5 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0101] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0102] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0103] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0104] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0105] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0106] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0107] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for selecting geographical entities for artificial river networks, characterized in that: The method for selecting geographical entities for artificial river networks comprises: Acquire geographic entity data of the artificial river network to be selected; the geographic entity data includes location information, geometric information, semantic information and connection relationship of each entity constituting the artificial river network to be selected; According to the geographic entity data of the artificial river network to be selected, each entity edge constituting the artificial river network entity is used as an internal half-edge and an external half-edge to construct a planar directed graph of the artificial river network to be selected; wherein the internal half-edge and the external half-edge are in opposite directions; the planar directed graph includes a vertex and a directed edge set; the vertex represents an end point of the edge of the artificial river network entity to be selected, and the directed edge represents an internal half-edge or an external half-edge of the artificial river network entity to be selected; Extracting a facet set of the planar directed graph of the artificial river network to be selected, and respectively determining all the half-edges constituting each facet to obtain a half-edge information set of each facet; the facet represents a closed area surrounded by half-edges inside a plurality of entities; Calculate the area of ​​each patch, and calculate the half-edge divided area of ​​each internal half-edge in the patch according to the ratio of the length of each internal half-edge in the half-edge information set of each patch; The half-edge information sets of all facets are input into the Stroke model to obtain a continuous line segment set, and the total length and total divided area of ​​each continuous line segment in the continuous line segment set are calculated according to the half-edge divided area; the Stroke model is used to divide the adjacent internal half-edges connected head to tail into a continuous line segment according to the semantic information and geometric information of the half-edge information sets of all facets; Determine the locking state of each continuous line segment in the continuous line segment set according to the total length and the total divided area of ​​each continuous line segment; A preset number of continuous line segments are selected based on the locking state and the total divided area of ​​each continuous line segment, and unselected continuous line segments are marked as discarded to obtain the geographical entity selection result of the artificial river network to be selected.

2. The method for selecting geographical entities for artificial river networks according to claim 1, characterized in that: The calculation formula for the half-divided area is: ； ； in, Indicates i The first j The area is divided into two halves of the inner half. Indicates i The first j The inner half, Indicates i The first j The half length of the inner half, Indicates i The sum of the lengths of all inner half-edges of a face, Indicates i The total area of ​​the patches, n Indicates i The total number of vertices in a patch, k =1,2,..., n , indicating the i The first k Vertices, and Respectively represent i The first k The horizontal and vertical coordinates of the vertices, and Respectively represent i The first k +1 The horizontal and vertical coordinates of the vertex.

3. The method for selecting geographical entities for artificial river networks according to claim 1, characterized in that: The preset selection quantity is determined based on the square root law, and the formula is: ； in, Indicates the preset number of selected continuous line segments. N represents the total number of continuous line segments, m The denominator of the original image scale of the artificial river network to be selected. It represents the target scale denominator after the artificial river network is selected. x Indicates the selection level.

4. The method for selecting geographical entities for artificial river networks according to claim 1, characterized in that: Based on the locking state and total divided area of ​​each continuous line segment, a preset number of continuous line segments are selected, and the unselected continuous line segments are marked as discarded, and the selection results of the geographical entities of the artificial river network to be selected are obtained, which specifically include: Sort the total area divided by each continuous line segment from small to large to obtain a set of areas divided by continuous line segments; Determine whether the current continuous line segment in the continuous line segment divided area set meets a preset determination condition, and obtain a determination result; the preset determination condition includes that the continuous line segment is in a locked state or the continuous line segment contains an external half edge; If the judgment result is yes, the current continuous line segment is selected; If the judgment result is no, the current continuous line segment is marked as a discarded state, and the adjacent facets of each inner half edge of the current continuous line segment are merged to update the planar directed graph of the artificial river network to be selected; based on the updated planar directed graph of the artificial river network to be selected, the continuous line segment associated with the merged facet is marked as a locked state and added to the continuous line segment set; The next continuous line segment in the continuous line segment divided area set is used as the current continuous line segment, and the step of "determining whether the current continuous line segment in the continuous line segment divided area set meets the preset judgment condition and obtaining the judgment result" is returned until the preset selection quantity is met, and the geographical entity selection result of the artificial river network to be selected is obtained.

5. The method for selecting geographical entities for artificial river networks according to claim 1, characterized in that: According to the geographic entity data of the artificial river network to be selected, each entity edge constituting the artificial river network entity is used as an internal half-edge and an external half-edge to construct a planar directed graph of the artificial river network to be selected, and then the following is included: Initialization selection is performed on the planar directed graph of the artificial river network to be selected; the initialization selection includes deleting isolated artificial river sections and suspended artificial river sections that are less than a preset length index.

6. The method for selecting geographical entities for artificial river networks according to claim 1, characterized in that: Based on the locking state and the total divided area of ​​each continuous line segment, a preset number of continuous line segments are selected, and the unselected continuous line segments are marked as discarded, so as to obtain the geographical entity selection result of the artificial river network to be selected, and then the following is also included: Manual adjustment is performed on the geographical entity selection result of the artificial river network to be selected to obtain the geographical entity adjustment result; the manual adjustment operation includes: marking as a discard state or a selection state; The continuous line segments marked as discarded in the geographic entity adjustment result are deleted to obtain the final selection result of the geographic entity of the artificial river network to be selected.

7. The method for selecting geographical entities for artificial river networks according to claim 1, characterized in that: The method for determining the locking state is: If a continuous line segment meets any of the following preset conditions, the continuous line segment is determined to be locked; the preset conditions include that the continuous line segment is a key entity, the continuous line segment is associated with a natural river or lake, the continuous line segment has a name, the selection level of the continuous line segment is 2, the total length of the continuous line segment is greater than 20 mm and the correlation is greater than 5, and the total area of ​​the continuous line segment is greater than 80 cm 2 .

8. A geographical entity selection device for artificial river network, characterized in that: The device for selecting geographical entities for artificial river networks is applied to the method for selecting geographical entities for artificial river networks according to any one of claims 1 to 7, and the device for selecting geographical entities for artificial river networks comprises: A data acquisition module is used to acquire geographic entity data of the artificial river network to be selected; the geographic entity data includes location information, geometric information, semantic information and connection relationship of each entity constituting the artificial river network to be selected; A directed graph construction module is used to construct a planar directed graph of the artificial river network to be selected based on the geographic entity data of the artificial river network to be selected, taking each entity edge constituting the artificial river network entity as an internal half-edge and an external half-edge; wherein the internal half-edge and the external half-edge are in opposite directions; the planar directed graph includes a vertex and a directed edge set; the vertex represents an end point of the edge of the artificial river network entity to be selected, and the directed edge represents an internal half-edge or an external half-edge of the artificial river network entity to be selected; A patch and half-edge information extraction module is used to extract a patch set of the planar directed graph of the artificial river network to be selected, and respectively determine all the half-edges constituting each patch to obtain a half-edge information set of each patch; the patch represents a closed area surrounded by half-edges inside a plurality of entities; A half-edge partition area calculation module is used to calculate the area of ​​each patch, and calculate the half-edge partition area of ​​each internal half-edge in the patch according to the ratio of the length of each internal half-edge in the half-edge information set of each patch; A continuous line segment acquisition module is used to input the half-edge information sets of all face patches into the Stroke model to obtain a continuous line segment set, and calculate the total length and total divided area of ​​each continuous line segment in the continuous line segment set according to the half-edge divided area; the Stroke model is used to divide the adjacent internal half-edges connected head to tail into a continuous line segment according to the semantic information and geometric information of the half-edge information sets of all face patches; A locking state calculation module, used for determining the locking state of each continuous line segment in the continuous line segment set according to the total length and the total divided area of ​​each continuous line segment; The geographic entity selection module is used to select a preset number of continuous line segments based on the locking state and total divided area of ​​each continuous line segment, and mark the unselected continuous line segments as discarded to obtain the geographic entity selection results of the artificial river network to be selected.

9. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for selecting geographic entities for an artificial river network as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for selecting geographical entities for an artificial river network as described in any one of claims 1 to 7 is implemented.

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