A method and system for batch calculation of vertical development position of landslides in slope units

Abstract

This application discloses a batch calculation method and system for the vertical development location of landslides within slope units, relating to the field of landslide prediction and prevention. The method first acquires the digital elevation model and landslide surface vector data of the target study area, divides the target study area into several slope units, and spatially matches each landslide surface with its corresponding slope unit. Then, it performs batch calculations for multiple landslide surfaces: an initial slope direction line is generated based on the slope direction of the slope unit passing through the centroid of the landslide surface; the slope direction line of the slope unit is obtained by trimming the slope unit boundary, and the endpoint elevations are extracted to determine the top and bottom points; simultaneously, the landslide slope direction line is obtained by trimming the landslide surface boundary, and the endpoint elevations are extracted to determine the top and bottom points of the landslide; finally, the vertical development location of the landslide surface within its corresponding slope unit is calculated. This application significantly improves the efficiency of regional-scale analysis of the vertical development location of landslides and is suitable for large-scale, multi-landslide susceptibility assessment and disaster surveys.

Description

Technical Field

[0001] This application relates to the field of landslide prediction and prevention, and in particular to a batch calculation method and system for the vertical development location of landslides in a slope unit. Background Technology

[0002] Landslides are a common geological hazard in mountainous areas. The stress characteristics vary at different elevations within a slope, meaning that the location of a landslide is closely related to its vertical position on the slope. Understanding the spatial distribution patterns of landslides at a regional scale, especially their vertical development location within the slope, is crucial for landslide susceptibility assessment and disaster prevention.

[0003] Current research on landslide spatial distribution largely focuses on analyzing the statistical relationships between landslides and topographic factors such as elevation, slope, and aspect. However, factors like elevation and slope are absolute or global quantities and cannot reflect the relative vertical development location of a landslide within its slope unit. For example, two landslides at the same elevation may be located at the upper and lower parts of different slopes, respectively, exhibiting significant differences in stability and hazard levels, which current methods struggle to distinguish. Therefore, existing technologies cannot quantitatively characterize the vertical development location of landslides within a slope, limiting the precision of regional landslide susceptibility analysis.

[0004] Some studies attempt to qualitatively describe or classify slope position (such as dividing landslides into upper, middle and lower parts), but they mostly rely on subjective judgment based on human experience and lack standardized, batch-calculated quantitative methods, making it difficult to conduct cross-sectional comparisons and statistical modeling over a large area. Summary of the Invention

[0005] The purpose of this application is to provide a batch calculation method and system for the vertical development location of landslides in a slope unit, which solves the problem that the existing technology cannot quantitatively calculate the vertical development location of landslides within a slope unit in a batch and in a standardized manner. It relies more on absolute elevation or qualitative classification (upper / middle / lower part) and lacks quantitative indicators that can be compared laterally.

[0006] To achieve the above objectives, this application provides the following solution: Firstly, this application provides a batch calculation method for the vertical development location of landslides in a slope element, including: Obtain digital elevation models and landslide surface vector data for the target study area; Several slope elements are generated based on the digital elevation model; Spatial matching is performed between the vector data of each landslide surface and the slope unit in which it is located; For multiple landslide surfaces within the target study area, perform the following steps in batches: Based on the slope aspect of the slope unit where the landslide surface is located, an initial slope aspect line is generated through the centroid of the landslide surface; the length of the initial slope aspect line is sufficient to extend beyond the boundary of the slope unit. The initial slope direction line is trimmed using the boundary of the slope element to obtain the slope direction line of the slope element; the two endpoints of the slope direction line of the slope element are extracted, and the respective elevations of the two endpoints are extracted from the digital elevation model; the elevations of the two endpoints are compared, and the one with the larger elevation is taken as the top point of the slope element, and the one with the smaller elevation is taken as the bottom point of the slope element. Simultaneously, the initial slope direction line is trimmed using the boundary of the landslide surface to obtain the landslide slope direction line; the two endpoints of the landslide slope direction line are extracted, and the respective elevations of the two endpoints are extracted from the digital elevation model; the elevations of the two endpoints are compared, and the one with the larger elevation is taken as the top point of the landslide, and the one with the smaller elevation is taken as the bottom point of the landslide. Based on the extracted elevation, the vertical development position of the landslide surface within its corresponding slope unit is calculated, and represented as follows: The interval, where: ; .

[0007] Secondly, this application provides a batch calculation system for the vertical development location of landslides in a slope element, comprising: The data acquisition module is used to acquire digital elevation models and landslide surface vector data of the target study area; A slope element partitioning module is used to generate several slope elements based on the digital elevation model. The association module is used to spatially match each landslide surface vector data with the slope unit in which it is located; The slope direction line generation module is used to generate an initial slope direction line through the centroid of the landslide surface based on the slope direction of the slope unit where the landslide surface is located; the length of the initial slope direction line is sufficient to extend beyond the boundary of the slope unit. The trimming and endpoint extraction module is used to trim the initial slope direction line using the boundary of the slope unit to obtain the slope unit slope direction line; extract the two endpoints of the slope unit slope direction line and extract the respective elevations of the two endpoints from the digital elevation model; compare the elevations of the two endpoints, and take the one with the larger elevation as the top point of the slope unit and the one with the smaller elevation as the bottom point of the slope unit; simultaneously, the module trims the initial slope direction line using the boundary of the landslide surface to obtain the landslide slope direction line; extract the two endpoints of the landslide slope direction line and extract the respective elevations of the two endpoints from the digital elevation model; compare the elevations of the two endpoints, and take the one with the larger elevation as the top point of the landslide and the one with the smaller elevation as the bottom point of the landslide; The calculation module is used to calculate the vertical development position of the landslide surface within its corresponding slope unit based on the extracted elevation, represented as follows: The interval, where: ; .

[0008] Thirdly, this application provides a computer device, including: 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 the batch calculation method for the vertical development position of landslides in the slope unit described in any one of the above-mentioned methods.

[0009] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the batch calculation method for the vertical development position of landslides in the slope unit described above.

[0010] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the batch calculation method for the vertical development position of landslides in the slope unit described above.

[0011] Compared with the prior art, this application discloses the following technical effects: This application provides a batch calculation method and system for the vertical development location of landslides in a slope element. An initial slope direction line is generated through the centroid of the landslide surface. This centroid effectively represents the overall spatial location of the landslide surface, ensuring the representativeness and stability of subsequent calculation results. By setting the length of the initial slope direction line sufficient to extend beyond the slope element boundary, it is guaranteed that two endpoints (one at the upper boundary and one at the lower boundary) will be obtained after slope element trimming. This avoids the problem of insufficient initial slope direction line length leading to the inability to obtain a complete slope element slope direction line or missing endpoints, thus improving the robustness of the method. The initial slope direction line is trimmed using the slope element boundary to obtain the complete span and top and bottom points of the slope element in the slope direction; simultaneously, the same initial slope direction line is trimmed using the landslide surface boundary to obtain the actual coverage area of ​​the landslide in the slope direction, as well as its top and bottom points. This double-cropping operation ensures that the top and bottom points of the landslide are located on the actual boundary of the landslide surface, rather than artificially selected single points or virtual points calculated based on the hydrological network. This truly reflects the spatial distribution characteristics of the landslide and improves the accuracy of the vertical development location calculation.

[0012] After extracting the two endpoints of the slope element's aspect line, the system automatically determines the higher elevation as the top point of the slope element and the lower elevation as the bottom point by comparing the elevations of the two endpoints. The same process is applied to the two endpoints of the landslide aspect line. This step avoids manual judgment or empirical assignment, ensuring the objectivity and repeatability of the calculation results, while also enabling the algorithm to adapt to uniform processing of different slope aspects (north slope, south slope). By calculating α = (landslide bottom elevation - slope element bottom elevation) / (slope element top elevation - slope element bottom elevation) and β = (landslide top elevation - slope element bottom elevation) / (slope element top elevation - slope element bottom elevation), the following values ​​are obtained: The interval (i.e., the two-parameter interval) uses the bottom of the slope unit as the reference and the slope unit height as the normalized denominator, eliminating the influence of differences in absolute elevation and topographic scale among different slope units. This makes the vertical development locations of landslides in different regions and on different slopes comparable, overcoming the shortcomings of existing technologies that use absolute elevation or qualitative classification (upper / middle / lower) and cannot make lateral comparisons. The entire process of the method in this application is completed automatically, without the need for manual measurement or visual interpretation, which greatly improves the efficiency of regional-scale analysis of the vertical development location of landslides and is suitable for large-scale susceptibility assessment and disaster surveys of multiple landslides. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is an application environment diagram of a batch calculation method for the vertical development location of landslides in a slope unit according to an embodiment of this application; Figure 2 A flowchart illustrating a batch calculation method for the vertical development location of landslides in a slope unit, provided as an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0015] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0016] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] This application provides a batch calculation method for the vertical development location of landslides in a slope element, which can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be set up independently, integrated into server 104, or placed in the cloud or on another server. Terminal 102 can send the target study area's Digital Elevation Model (DEM) data and landslide surface vector data to server 104. After receiving the above data, server 104 first generates several slope elements based on the DEM and spatially matches each landslide surface with its corresponding slope element. Then, for multiple landslide surfaces within the target study area, it performs the following batch operations: Based on the slope aspect of the slope element containing the landslide surface, it generates an initial slope aspect line through the centroid of the landslide surface, ensuring the initial slope aspect line extends sufficiently beyond the slope element boundary; it trims the initial slope aspect line with the slope element boundary to obtain the slope element slope aspect line, extracts its two endpoint elevations from the DEM, and compares them to determine the top and bottom points of the slope element; simultaneously, it trims the initial slope aspect line with the landslide surface boundary to obtain the landslide slope aspect line, extracts its two endpoint elevations from the DEM, and compares them to determine the top and bottom points of the landslide; it then calculates... The server 104 can feed back the calculated vertical development location of the landslide to the terminal 102. Furthermore, in some embodiments, this method can also be implemented by either the server 104 or the terminal 102 alone. For example, the terminal 102 can directly perform batch calculations on locally stored DEM data and landslide surface vector data, or the server 104 can retrieve the target study area data to be processed from the data storage system and perform the above calculations.

[0018] The terminal 102 can be, but is not limited to, various desktop computers, laptops, workstations, tablets, and other electronic devices with Geographic Information System (GIS) processing capabilities. The server 104 can be implemented using a standalone server, a cloud server, or a server cluster composed of multiple servers. The data storage system can be a local disk, NAS, cloud storage, or object storage, etc.

[0019] In one exemplary embodiment, such as Figure 2As shown, a batch calculation method for the vertical development location of landslides in a slope unit is provided. This method is executed by a computer device, specifically by a terminal or server alone, or by both a terminal and a server. In this embodiment, the method is applied to... Figure 1 Taking server 104 as an example, the explanation includes the following steps 201 to 208. Wherein: Step 201: Obtain the digital elevation model and landslide surface vector data of the target study area; Step 202: Generate several slope elements based on the digital elevation model; Step 203: Spatial matching of the vector data of each landslide surface with the slope unit in which it is located; For multiple landslide surfaces within the target study area, perform the following steps in batches: Step 204: Based on the slope aspect of the slope unit where the landslide surface is located, generate an initial slope aspect line through the centroid of the landslide surface; the length of the initial slope aspect line is sufficient to extend beyond the boundary of the slope unit. Step 205: Trim the initial slope direction line using the boundary of the slope unit to obtain the slope unit slope direction line; extract the two endpoints of the slope unit slope direction line and extract the respective elevations of the two endpoints from the digital elevation model; compare the elevations of the two endpoints, and take the one with the larger elevation as the top point of the slope unit and the one with the smaller elevation as the bottom point of the slope unit; simultaneously, trim the initial slope direction line using the boundary of the landslide surface to obtain the landslide slope direction line; extract the two endpoints of the landslide slope direction line and extract the respective elevations of the two endpoints from the digital elevation model; compare the elevations of the two endpoints, and take the one with the larger elevation as the top point of the landslide and the one with the smaller elevation as the bottom point of the landslide; Step 206: Based on the extracted elevation, calculate the vertical development position of the landslide surface within its corresponding slope unit, denoted as... The interval, where: ; .

[0020] The core concept of this application is to obtain the complete elevation span of the slope unit and the actual coverage area of ​​the landslide surface on the slope direction using the same baseline along the slope direction (i.e., the initial slope direction line). Then, the elevations of the top and bottom points of the landslide are normalized based on the total elevation difference of the slope unit to obtain a two-parameter interval. This interval uses the bottom of the slope unit as the reference zero point and the elevation difference of the slope unit as the normalized denominator, eliminating the influence of the differences in absolute elevation and elevation difference between different slope units. This makes the vertical development positions of landslides in different regions and on different slopes comparable, and can further characterize the relative vertical width occupied by the landslide in the slope direction through β-α.

[0021] To implement the batch calculation method for the vertical development location of landslides in a slope unit according to this application, the following steps are performed in batches: First, obtain the digital elevation model and landslide surface vector data of the target study area, generate several slope units, and spatially match each landslide surface with the slope unit it belongs to; then, for multiple landslide surfaces in the target study area, perform the following steps in batches: In step 204, an initial slope direction line is generated by passing through the centroid of the landslide surface. The length of the initial slope direction line is set to be sufficient to extend beyond the boundary of the slope element, ensuring that two endpoints are obtained after trimming (one located at the upper boundary of the slope element and one located at the lower boundary). This avoids the problem of not being able to obtain the complete slope direction line of the slope element or missing endpoints due to insufficient line length, thus improving the robustness of the method.

[0022] In step 205, the same initial slope aspect line is trimmed using both the slope unit boundary and the landslide surface boundary: on the one hand, the slope aspect line of the slope unit is obtained by trimming the slope unit boundary, thus obtaining the complete span of the slope unit and its top and bottom endpoints in the slope direction; on the other hand, the landslide aspect line is obtained by trimming the landslide surface boundary, thus obtaining the actual coverage area of ​​the landslide body in the slope direction and its top and bottom endpoints. This dual trimming operation ensures that the top and bottom points of the landslide are located on the actual boundary of the landslide surface, rather than artificially selected single points or virtual points calculated based on the hydrological network, truly reflecting the spatial distribution characteristics of the landslide and improving the accuracy of vertical development location calculation. After extracting the endpoints in step 205, the elevations of the two endpoints are extracted from the digital elevation model, automatically determining the larger elevation as the top point and the smaller elevation as the bottom point. This step avoids manual judgment or empirical assignment, ensuring the objectivity and repeatability of the calculation results, while enabling the algorithm to adapt to the uniform processing of different slope aspects (north slope, south slope).

[0023] Step 206 calculates The dual-parameter interval, with the bottom of the slope unit as the benchmark and the height of the slope unit as the normalized denominator, eliminates the influence of differences in absolute elevation and topographic scale between different slope units, making the vertical development location of landslides in different regions and on different slopes comparable. This overcomes the shortcomings of existing technologies that use absolute elevation or qualitative classification (upper / middle / lower) and cannot make horizontal comparisons.

[0024] In practical applications, for a very small number of landslide surfaces with special shapes (such as concave polygons or narrow, curved surfaces), their centroid may fall outside the landslide surface. In this case, if the initial slope line is directly generated from the centroid, the line may not pass through the interior of the landslide surface, affecting the effectiveness of subsequent trimming operations. To address this, a point inside the landslide surface closest to the centroid can be selected, or the geometric center of the landslide surface or an interior point on the main sliding axis can be used instead of the centroid to ensure that the initial slope line passes through the interior of the landslide surface. Those skilled in the art can adopt the above alternative solutions based on actual data to still achieve the technical effects of this application.

[0025] Furthermore, for completely flat areas (where the elevation difference between the top and bottom points of a slope element is zero), the denominator of the normalization formula is zero, and α and β are undefined. In actual batch calculations, a judgment condition can be set: if the elevation difference of a slope element is less than a preset threshold (e.g., 0.1 meters), then the landslide within that slope element is skipped, or a default value is directly assigned (e.g., α=0, β=1), and this is marked in the results to remind the user to check. All of the above processing methods do not depart from the core concept of this application and should be included within the scope of protection of this application.

[0026] Furthermore, the output of this application Both parameter intervals are dimensionless decimals. Regardless of whether the elevation difference of the slope unit is 50 meters or 500 meters, the landslide... The values ​​of both parameters strictly fall within the [0,1] interval, thus enabling direct statistical analysis and lateral comparison across study areas, terrain types, and slope units of different scales. This completely overcomes the shortcomings of existing technologies, which use absolute elevation to compare the vertical positions of landslides in different regions and rely heavily on subjective qualitative classification (upper / middle / lower) methods that cannot be precisely quantified. Furthermore, this... Intervals can serve as input feature variables for landslide susceptibility assessment models (such as logistic regression, random forest, support vector machine, etc.), and can also be further used to construct derived features, such as the relative vertical center position of the landslide (α+β) / 2 or the vertical coverage width of the landslide β-α. These features enable the model to capture the spatial distribution patterns of landslides more precisely, significantly improving the model's prediction accuracy and physical interpretability compared to using only traditional factors such as elevation and slope. If the study area has a multi-period time-series digital elevation model (which can be obtained by inversion based on time-series LiDAR or InSAR observation data), this method can also be extended to the dynamic evolution analysis of the vertical development location of landslides, by calculating the DEM of the same landslide at different periods. By observing the migration trend of its vertical development location within a certain range (e.g., the upward expansion of the rear edge of a landslide leading to an increase in the β value), a quantitative basis for landslide early warning can be provided.

[0027] Furthermore, the technical solution of this application is not limited to the above embodiments, and can be modified, extended, and combined in various ways according to actual needs. The initial slope aspect line generation point can be the centroid of the landslide surface, or a specific point along the main axis of the landslide. The representative slope aspect of the slope unit is not limited to the average of all grid slope aspects within the slope unit; it can also be the median, mode, or the plane normal projection direction fitted based on the slope unit boundary. When the slope unit has complex terrain and discrete slope aspect distribution, a weighted average or an alternative method based on the direction of the line connecting the highest and lowest points can be used. The length of the initial slope aspect line is not limited to a preset fixed value; it can be automatically calculated based on the actual span of the slope unit in the slope aspect. For example, the boundary of the slope unit can be extracted first, the maximum width along the slope aspect can be calculated, and then this width can be multiplied by a safety factor (e.g., 1.5 times) to obtain the length of the initial slope aspect line, or it can be dynamically extended to the shortest length that yields two complete endpoints after trimming.

[0028] Besides directly using GIS clipping and vertex-to-point tools, clipping and endpoint extraction can also be achieved through spatial queries, geometric intersections, or custom algorithms. For landslides with non-convex shapes (such as arcs or dumbbells), the initial slope direction line may intersect the landslide boundary at multiple points. In this case, the two outermost intersection points along the slope direction can be taken as the top and bottom points of the landslide to ensure that the actual coverage area of ​​the landslide is reflected. When the DEM resolution is low or contains local errors, the DEM can be interpolated or filtered before extracting endpoint elevations. Alternatively, high-precision data sources such as LiDAR point clouds can be used to replace traditional DEMs to improve the accuracy of elevation extraction. The calculated... If anomalies such as α < 0 or β > 1 occur within a given interval, outlier filtering rules can be set. For example, landslides with α < 0 can be forced to have α = 0, and landslides with β > 1 can be forced to have β = 1. Alternatively, the user can be prompted to manually check the corresponding landslide surface and slope unit boundary. The output... Intervals can be used as independent features and input into landslide susceptibility assessment models (such as logistic regression, random forest, support vector machine, etc.) along with traditional factors such as elevation, slope, aspect, lithology, and land use. Alternatively, derived features can be constructed, such as the relative vertical center position of the landslide (α+β) / 2 or the vertical coverage width of the landslide (β-α), to enrich the input information of the model.

[0029] The method presented in this application can be used not only for landslide surveys at the regional scale (tens to thousands of square kilometers) but also for detailed analysis at the local scale (single slope or watershed). It can be adapted to different research scopes and data accuracies simply by adjusting the DEM resolution and the runoff accumulation threshold for slope unit division. The method can be packaged as a standalone software module and integrated into common geographic information system platforms (such as ArcGIS, QGIS, and SuperMap), or deployed as a cloud service, web service, or offline desktop tool, supporting batch task scheduling and parallel computing. When the target study area has multiple time-series DEMs (which can be obtained by inversion from time-series LiDAR or InSAR observation data), the method can be extended to the dynamic evolution analysis of the vertical development location of landslides: by calculating the DEMs of the same landslide at different times... The migration trend of the vertical development location within a given interval is observed to provide a basis for landslide early warning. All variations and extensions mentioned above fall within the protection scope of this application; appropriate solutions should be selected based on actual needs during implementation. Any equivalent substitutions or modifications made by those skilled in the art based on the technical concept disclosed in this application should be included within the protection scope of the claims of this application.

[0030] In another exemplary embodiment of this application, the method further includes adding an HPDID field to the landslide surface, adding an XPDYID field to the slope unit, and achieving batch parallel processing of multiple landslides through field inheritance and association.

[0031] For example, download a 30m resolution DEM of the target study area from the geospatial data cloud platform and name it "Study Area DEM.tif". Obtain landslide surface vector data within the target study area through remote sensing interpretation and name it "Landslide Surface.shp". After step 201, check whether the projection coordinate system (e.g., Gauss-Kruger projection) of the DEM and the landslide surface vector data is consistent. If not, use the projection conversion tool in the GIS software to unify them to the same coordinate system. Add an HPI field to "Landslide Surface.shp" to store the landslide number, and use the field calculator to assign sequential values ​​to the HPI field. Execute step 202 to generate slope units, name them "Slope Unit Surface.shp", add an XPDYID field to "Slope Unit Surface.shp", and use the field calculator to assign sequential values ​​to realize the slope unit numbering. In step 203, associate the HPI field and XPDYID field through spatial matching, thereby establishing a field inheritance relationship for subsequent batch processing.

[0032] In another exemplary embodiment of this application, positive and negative topographic sub-basins are extracted based on a digital elevation model, and the two are spatially combined to generate several slope units, specifically including steps 301 to 303, wherein: Step 301: Based on the acquired DEM, extract the positive terrain sub-watershed; Step 302: Construct an inverse DEM using a raster calculator and extract negative topographic sub-basins; Step 303: Spatially combine the positive and negative topographic sub-basins using a combination tool to generate slope units.

[0033] Specifically, the study area DEM.tif is loaded, and the depression filling tool is used to fill depressions, generating a depression-filled DEM.tif; the flow direction tool is used to calculate the flow direction, generating a flow direction.tif; the flow rate tool is used to calculate the cumulative runoff, generating a flow rate.tif; the cumulative runoff threshold is set using the raster calculator (e.g., 5000, 10000, the threshold that best matches the actual river network is selected after testing), generating a river network.tif; river linking and watershed extraction are performed sequentially, generating a watershed.tif; the watershed.tif is converted to a polygon feature using the raster to polygon tool, obtaining a positive topographic sub-watershed, which is saved as a positive topographic sub-watershed polygon.shp. The raster calculator is then used, and "constant - study area DEM.tif" (the constant is the maximum elevation of the target study area plus 1000) is input to generate a reverse DEM; the above depression filling, flow direction, flow rate, river network, river linking, watershed, and raster to polygon operations are repeated on the reverse DEM to obtain a negative topographic sub-watershed, which is saved as a negative topographic sub-watershed polygon.shp. Using a joint tool, the positive and negative topographic sub-watershed surfaces (.shp) are spatially joined to generate initial slope units. Optionally, small, fragmented patches with excessively small areas or unreasonable shapes are removed from the initial slope units, and the boundaries are adjusted by combining topographic shadow maps and remote sensing imagery to ensure consistency with the actual slope, ridge, and valley orientations, generating a slope unit surface (.shp). Using a surface-to-raster tool, with the XPDYID field as the assignment field, a slope unit number (.tif) is generated.

[0034] Furthermore, using the feature-to-point tool, the landslide surface .shp file is converted to a landslide centroid, named landslide point .shp, and inherits the HPDY field. Using the multi-value extraction to point tool, with landslide point .shp as the input point feature and slope cell number .tif as the input raster, and setting the output field name to XPDYID, the slope cell number where the landslide is located is assigned to the landslide point, completing the spatial matching between each landslide surface vector data and its corresponding slope cell.

[0035] Load the study area DEM.tif and use the aspect tool to generate the target study area aspect.tif. Using the zoning statistics tool, with the slope unit surface.shp as the zoning calculation basis, XPDYID as the classification field, and the target study area aspect.tif as the assignment raster, calculate the average aspect of all grids within each slope unit as the representative aspect of that slope unit, generating the slope unit aspect.tif. Using the multi-value extraction to point tool, associate the landslide point.shp with the slope unit aspect.tif to obtain the aspect value of each landslide-containing slope unit, storing it in the POXIANG field. Add X, Y, Length, XCQ, YCQ, XCZ, and YCZ fields to the landslide point.shp. Use computational geometry tools to calculate the X and Y coordinates of the points and write them into the corresponding X and Y fields. Assign the Length field a length sufficient to cover the maximum slope aspect span of the target study area, such as 2000 meters (in actual use, this can be dynamically adjusted according to the slope element size to ensure it is greater than the maximum slope aspect length of the slope element). Calculate the start and end coordinates using the following formula: XCQ=X+sin(POXIANG / 180 π) Length / 2 YCQ=Y+cos(POXIANG / 180 π) Length / 2 XCZ=X-sin(POXIANG / 180 π) Length / 2 YCZ=Y-cos(POXIANG / 180 π) Length / 2 Using the XY conversion tool, with XCQ and YCQ as the starting coordinates, XCZ and YCZ as the ending coordinates, and HPI as the reserved field, an initial slope aspect line (.shp) is generated. This initial slope aspect line (.shp) passes through the centroid inside the landslide surface and extends beyond the boundary of the slope element at both ends.

[0036] Using the clipping tool, with the initial slope aspect line (.shp) as the input feature and the slope unit surface (.shp) as the clipping feature, perform spatial clipping, retaining line segments within the slope unit boundary to generate a slope unit slope aspect line (.shp), which inherits the HPI field. Using the feature vertex-to-point tool, input the slope unit slope aspect line (.shp) to obtain two endpoints, naming them slope unit slope aspect line endpoints (.shp). Using the multi-value extraction to point tool, extract the elevations of the two endpoints of each landslide slope aspect line from the study area DEM (.tif) and store them in the corresponding fields. Compare the elevations of the two endpoints, marking the one with the larger elevation as the top point of the slope unit and the one with the smaller elevation as the bottom point of the slope unit.

[0037] Simultaneously, the clipping tool is invoked, using the initial slope aspect line (.shp) as the input feature and the landslide surface (.shp) as the clipping feature. Spatial clipping is performed, retaining line segments within the landslide surface boundary to generate a landslide aspect line (.shp), inheriting the HPI field. The feature vertex-to-point tool is invoked, inputting the landslide aspect line (.shp) to obtain two endpoints, named landslide aspect line endpoints (.shp). The multi-value extraction to point tool is used to extract the elevations of the two endpoints of each slope unit's aspect line from the study area's DEM (.tif) and store them in fields. The elevations of the two endpoints are compared, with the larger elevation marked as the landslide top point and the smaller elevation marked as the landslide bottom point.

[0038] In the above-described trimming and endpoint extraction steps, the elevations of the two ends of the slope element's aspect line (where the higher one is the slope element's top elevation XPMax and the lower one is the slope element's bottom elevation XPMin) and the elevations of the two ends of the landslide aspect line (where the higher one is the landslide's top elevation HPMax and the lower one is the landslide's bottom elevation HPMin) have been extracted. These elevations are then stored in association using the HPDIP field.

[0039] By associating the values ​​using the HPID field, the obtained XPMax, XPMin, HPMax, and HPMin are merged into a single table according to HPID, and the slope element height is calculated. landslide height Then calculate separately and For each landslide, a pair is obtained. value, This indicates the relative vertical coverage of a landslide within a slope unit, from bottom to top.

[0040] In another exemplary embodiment of this application, after completing the above calculation steps, the method may further include batch processing implementation: For all landslide surfaces within the target study area, the following batch steps are performed sequentially for each landslide surface through the inheritance and association of landslide surface identifiers and slope unit identifiers: Based on the slope aspect of the slope unit to which the landslide surface is located, an initial slope aspect line is generated through the centroid of the landslide surface; the slope unit slope aspect line and the landslide slope aspect line are obtained by trimming the slope unit boundary and the landslide surface boundary respectively, the endpoints are extracted and the endpoint elevations are extracted from the digital elevation model, and the top and bottom points of the slope unit and the top and bottom points of the landslide are determined; calculations are performed. The interval. Parallel processing can also be used to improve efficiency, enabling batch calculation of multiple landslides, and finally outputting the values ​​of all landslides. Data sets of intervals.

[0041] For example, a model builder can be created in GIS software or a Python script can be written to iterate through each record in the landslide surface vector data and execute the above batch steps sequentially. The field calculator can then be used to calculate α and β in batches, and the results can be written into the corresponding fields of the landslide surface attribute table to complete the batch calculation of all vertical development locations of landslides at the regional scale.

[0042] This application also provides an application scenario that uses the batch calculation method for the vertical development location of landslides in a slope element, as described above. Taking a target study area as an example, the DEM resolution is 30m, and there are a total of 152 landslide surface vector data. Specifically: Step 401: Obtain the DEM data of the target study area (named Study Area DEM.tif) and the landslide surface vector data (named Landslide Surface.shp), and unify them to the UTM projection coordinate system.

[0043] Step 402: Use ArcGIS's Fill tool to fill depressions in the DEM, generating a filled DEM.tif; execute FlowDirection to generate a flow direction.tif; calculate the flow accumulation using Flow Accumulation to generate a flow rate.tif. Set a threshold of 8000 to extract the river network, and generate a positive topographic sub-basin via Stream Link and Watershed. Construct a reverse DEM (with the constant set to the maximum elevation of the target study area plus 1000), and repeat the above operations to obtain a negative topographic sub-basin. Spatially combine the positive and negative topographic sub-basins to generate a slope unit surface.shp. Add an XPDYID field to the slope unit surface.shp, and use the field calculator to assign values ​​sequentially to number the slope units. Then use the surface-to-raster tool to generate a slope unit number.tif.

[0044] Step 403: Convert the landslide surface .shp file to the landslide centroid, save it as landslide point .shp, add an HPI field and assign values ​​sequentially. Use the multi-value extraction to point tool to assign the slope element number from the slope element number .tif file to the landslide point, thus achieving spatial matching between the landslide surface and the slope element.

[0045] Step 404: Calculate the slope aspect based on the study area DEM.tif file. Obtain the slope aspect of each slope unit through partitioned statistics and associate it with the landslide point. Add X, Y, and Length fields to the landslide point, assigning a Length value of 3000m (this length is tested to be greater than the maximum slope aspect span of all slope units). Calculate the start and end coordinates of the initial slope aspect line according to the slope aspect value and formula, and generate the initial slope aspect line.shp using the XY conversion tool. This initial slope aspect line passes through the centroid of the landslide surface and extends beyond the boundary of the slope unit at both ends.

[0046] Step 405: Taking the initial slope line L as an example. Use the Clip tool to clip L with the slope unit boundary to obtain line segment AB; extract the coordinates of points A and B, and obtain the elevations ZA and ZB from the DEM using Extract Multi Values ​​to Points. If ZA > ZB, then A is the top point of the slope unit and B is the bottom point. Similarly, clip L with the landslide surface boundary to obtain line segment CD, extract the elevations of points C and D, and determine C as the top point of the landslide and D as the bottom point of the landslide by comparing the elevations (if ZC > ZD, then C is the top point and D is the bottom point; otherwise, it depends on the actual terrain). For each landslide, perform the above double clipping and endpoint elevation comparison operation.

[0047] Step 406: Store the elevations of the top point of the slope element XPMax, the bottom point of the slope element XPMin, the top point of the landslide HPMax, and the bottom point of the landslide HPMin obtained in Step 405 by associating them through the HPD field.

[0048] Step 407: Calculate the value of each landslide using the formulas α=(HPMin-XPMin) / (XPMax-XPMin) and β=(HPMax-XPMin) / (XPMax-XPMin). Intervals. For example, a landslide calculated with α=0.32 and β=0.68 indicates that the bottom of the landslide is located at 32% of the slope unit from the bottom up, and the top is located at 68%, meaning the landslide mainly occupies the middle and lower part of the slope. This applies to all 152 landslides. The calculation results are output in batches and used as new quantitative characteristic factors in subsequent landslide susceptibility analysis.

[0049] Furthermore, for all 152 landslides Statistical analysis of the calculation results revealed that the mean value of the landslide base parameter α was 0.26, and the standard deviation was 0.15; the mean value of the landslide top parameter β was 0.71, and the standard deviation was 0.18. This indicates that in this study area, landslides mostly develop in the lower to middle parts of slopes. The calculated α and β were used as new features, along with traditional topographic factors (elevation, slope, aspect), and input into a random forest model for landslide susceptibility assessment. The results showed that introducing these features... After feature enhancement, the model's AUC (Area Under the Curve) value increased from 0.82 to 0.89, and the spatial agreement between the landslide susceptibility zoning map and the actual landslide distribution was significantly improved, demonstrating the practical value of the parameters provided in this application.

[0050] It should be noted that the ArcGIS software and specific tools (such as depression filling and flow direction analysis) used in the above examples are only for illustrating one specific implementation of the method in this application, and are not intended to limit the implementation path of the technical solution in this application. Those skilled in the art can fully implement this application based on the core steps disclosed herein: generating an initial line passing through the landslide centroid based on slope aspect → trimming slope aspect segments using slope unit boundaries and landslide surface boundaries respectively → extracting the endpoints of the segments and comparing elevations to determine the top and bottom points → calculating the normalized (α,β) interval, using other software with spatial analysis functions (such as QGIS, SuperMap) or independently writing computer programs (such as using Python to call the GDAL library for raster and vector analysis). Any equivalent substitutions or variations that do not depart from the inventive concept of this application should be included within the scope of protection of this application.

[0051] Based on the same inventive concept, this application also provides a system for implementing the batch calculation method for the vertical development location of landslides in a slope unit as described above. The solution provided by this system is similar to the solution described in the above method; therefore, the specific limitations in one or more system embodiments provided below can be found in the limitations of the method described above, and will not be repeated here.

[0052] In one exemplary embodiment, a batch calculation system for the vertical development location of landslides in a slope unit is provided, comprising: The data acquisition module is used to acquire digital elevation models and landslide surface vector data of the target study area; A slope element partitioning module is used to generate several slope elements based on the digital elevation model. The association module is used to spatially match each landslide surface vector data with the slope unit in which it is located; The slope direction line generation module is used to generate an initial slope direction line through the centroid of the landslide surface based on the slope direction of the slope unit where the landslide surface is located; the length of the initial slope direction line is sufficient to extend beyond the boundary of the slope unit. The trimming and endpoint extraction module is used to trim the initial slope direction line using the boundary of the slope unit to obtain the slope unit slope direction line; extract the two endpoints of the slope unit slope direction line and extract the respective elevations of the two endpoints from the digital elevation model; compare the elevations of the two endpoints, and take the one with the larger elevation as the top point of the slope unit and the one with the smaller elevation as the bottom point of the slope unit; simultaneously, the module trims the initial slope direction line using the boundary of the landslide surface to obtain the landslide slope direction line; extract the two endpoints of the landslide slope direction line and extract the respective elevations of the two endpoints from the digital elevation model; compare the elevations of the two endpoints, and take the one with the larger elevation as the top point of the landslide and the one with the smaller elevation as the bottom point of the landslide; The calculation module is used to calculate the vertical development position of the landslide surface within its corresponding slope unit based on the extracted elevation, represented as follows: The interval, where: ; .

[0053] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 3 As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs in the non-volatile storage media to run. The database stores the digital elevation model and landslide surface vector data of the target study area, as well as intermediate and result data generated during the calculation process. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a batch calculation method for the vertical development location of landslides in slope units.

[0054] Those skilled in the art will understand that Figure 3The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0055] In one exemplary embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0056] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0057] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0058] 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, data stored, data displayed, 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 the relevant data must comply with relevant regulations.

[0059] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, databases, or other media 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), magnetic 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 can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0060] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0061] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0062] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A batch calculation method for the vertical development location of landslides in a slope element, comprising: Obtain digital elevation models and landslide surface vector data for the target study area; Several slope elements are generated based on the digital elevation model; Spatial matching is performed between the vector data of each landslide surface and the slope unit in which it is located; For multiple landslide surfaces within the target study area, perform the following steps in batches: Based on the slope aspect of the slope unit where the landslide surface is located, an initial slope aspect line is generated through the centroid of the landslide surface; the length of the initial slope aspect line is sufficient to extend beyond the boundary of the slope unit. Using the vector boundary of the slope unit as the clipping element, the portion of the initial slope direction line located inside the slope unit is taken as the slope unit slope direction line; the two endpoints of the slope unit slope direction line are extracted, and the respective elevations of the two endpoints are extracted from the digital elevation model; the elevations of the two endpoints are compared, and the one with the larger elevation is taken as the top point of the slope unit, and the one with the smaller elevation is taken as the bottom point of the slope unit. At the same time, using the landslide surface vector data as a clipping element, the portion of the initial slope aspect line located inside the landslide surface is taken as the landslide slope aspect line; Extract the two endpoints of the landslide slope line, and extract the respective elevations of the two endpoints from the digital elevation model; Compare the elevations of the two endpoints, and take the one with the larger elevation as the top point of the landslide and the one with the smaller elevation as the bottom point of the landslide. Based on the extracted elevation, the vertical development position of the landslide surface within its corresponding slope unit is calculated, and represented as follows: The interval, where: ； 。 2. The batch calculation method for the vertical development location of landslides in a slope unit according to claim 1, characterized in that, The generation of several slope units specifically includes: extracting positive and negative topographic sub-basins based on a digital elevation model, spatially combining the two, and generating several slope units.

3. The method for batch calculation of the vertical development location of landslides in a slope unit according to claim 1, characterized in that, Also includes: Each landslide surface is assigned a landslide surface identifier, each slope unit is assigned a slope unit identifier, and an association relationship is established between the landslide surface identifier and the slope unit identifier to achieve parallel processing of multiple landslide surfaces.

4. The method for batch calculation of the vertical development location of landslides in a slope unit according to claim 1, characterized in that, The top and bottom points of the slope element are determined based on the two intersections of the slope element's slope direction line and the slope element's boundary.

5. The method for batch calculation of the vertical development location of landslides in a slope unit according to claim 1, characterized in that, The top and bottom points of the landslide are the two intersections of the landslide slope line and the boundary of the landslide surface.

6. A batch calculation system for the vertical development location of landslides in a slope unit, characterized in that, include: The data acquisition module is used to acquire digital elevation models and landslide surface vector data of the target study area; A slope element partitioning module is used to generate several slope elements based on the digital elevation model. The association module is used to spatially match each landslide surface vector data with the slope unit in which it is located; The slope direction line generation module is used to generate an initial slope direction line through the centroid of the landslide surface based on the slope direction of the slope unit where the landslide surface is located; the length of the initial slope direction line is sufficient to extend beyond the boundary of the slope unit. The trimming and endpoint extraction module is used to use the vector boundary of the slope unit as a trimming element to take the portion of the initial slope direction line located inside the slope unit as the slope unit slope direction line; extract the two endpoints of the slope unit slope direction line and extract the respective elevations of the two endpoints from the digital elevation model; compare the elevations of the two endpoints and take the one with the larger elevation as the top point of the slope unit and the one with the smaller elevation as the bottom point of the slope unit; simultaneously, using the landslide surface vector data as a trimming element, the portion of the initial slope direction line located inside the landslide surface is taken as the landslide slope direction line; extract the two endpoints of the landslide slope direction line and extract the respective elevations of the two endpoints from the digital elevation model. Compare the elevations of the two endpoints, and take the one with the larger elevation as the top point of the landslide and the one with the smaller elevation as the bottom point of the landslide. The calculation module is used to calculate the vertical development position of the landslide surface within its corresponding slope unit based on the extracted elevation, represented as follows: The interval, where: ； 。 7. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the steps of a batch calculation method for the vertical development location of landslides in a slope unit according to any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the batch calculation method for the vertical development location of landslides in the slope unit according to any one of claims 1-5.

9. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the batch calculation method for the vertical development location of landslides in the slope unit according to any one of claims 1-5.

Images