Method and device for automatically delimiting drainage basin control unit connected with administrative boundary

Abstract

The invention provides an automatic division method and device for a drainage basin control unit joining an administrative boundary, and relates to the field of drainage basin division, and the method comprises the steps: obtaining initial DEM data of a target region and administrative division planar vector data, constructing a buffer region according to the administrative division planar vector data, and cutting the initial DEM data according to the buffer region to obtain final DEM data; presetting an accumulated flow threshold value and a minimum watershed area of the target area, and constructing and optimizing a natural watershed vector surface according to the final DEM data, the accumulated flow threshold value and the minimum watershed area to obtain optimized natural watershed vector surface data; performing superposition and fitting degree calculation on the administrative division planar vector data and the optimized natural drainage basin vector surface data to obtain a preliminary drainage basin control unit; optimizing the initial drainage basin control unit according to the minimum drainage basin area to obtain a final drainage basin control unit; and performing field endowing on the final drainage basin control unit according to the administrative division planar vector data to obtain a delimiting result of the natural drainage basin and the administrative boundary.

Description

Technical Field

[0001] This invention relates to the field of watershed delineation, and more particularly to an automated method and apparatus for delineating watershed control units that connect administrative boundaries. Background Technology

[0002] Existing watershed delineation methods mainly fall into two categories. The first method is based on DEM data and a model builder to automate natural watershed delineation. The main processes include: a DEM preprocessing stage: using a dynamic value constraint algorithm to eliminate depressions in the DEM data; a hydrological analysis stage: using a single-flow-direction algorithm to calculate flow direction, generating a cumulative discharge matrix, and extracting river networks using adaptive thresholds to generate water systems of different densities; and a model builder delineation stage: using a model builder to perform concatenated depression filling, flow direction, discharge, and river network vectorization, ultimately achieving the delineation of natural watersheds. This method only delineates natural watersheds and does not address the connection between natural watersheds and administrative boundaries. It cannot achieve precise matching between township-level administrative units and natural watersheds, making the delineation results difficult to directly apply to administrative region-watershed management and unable to support the needs of refined watershed management.

[0003] The second method involves manually dividing township-level administrative units and hydrological units. The main process includes: a basic data preparation stage, where a 1:10,000 scale township administrative map is overlaid with a 30m resolution hydrological unit map, and a topological rule base is established to ensure data consistency; and a manual interpretation stage, where administrative units and hydrological units are manually identified while ensuring the integrity of the water system. This method relies on manual overlay analysis and repeated verification, resulting in low division efficiency, requiring multiple manual interventions, and lacking batch processing capability and automation. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an automated delineation method for watershed control units that connect administrative boundaries, comprising the following steps: Acquire the initial DEM data and administrative division isometric vector data of the target area, construct a buffer based on the administrative division isometric vector data, and crop the initial DEM data based on the buffer to obtain the final DEM data; The cumulative flow threshold and minimum watershed area of ​​the target area are preset. Based on the final DEM data, the cumulative flow threshold and minimum watershed area, the natural watershed vector surface is constructed and optimized to obtain optimized natural watershed vector surface data. By overlaying and calculating the fit of administrative division surface vector data and optimized natural watershed vector surface data, a preliminary watershed control unit is obtained; The preliminary watershed control unit is optimized based on the minimum watershed area to obtain the final watershed control unit; the final watershed control unit is then assigned fields based on the administrative division area vector data to obtain the delineation results of natural watersheds and administrative boundaries.

[0005] Optionally, a buffer can be constructed based on the administrative division isometric vector data, specifically including: Township boundary data is obtained from the administrative division area vector data. The minimum convex polygon of the township is obtained from the township boundary data through a fusion tool. The boundary of the minimum convex polygon of the township is extended outward to obtain a buffer zone.

[0006] Optionally, the natural watershed vector surface is constructed and optimized based on the final DEM data, cumulative flow threshold, and minimum watershed area to obtain optimized natural watershed vector surface data, specifically including: Based on the final DEM data and cumulative flow thresholds, initial natural watershed vector surface data are generated using a hydrological analysis toolchain. All natural watersheds in the initial natural watershed vector surface data are obtained, the watershed area of ​​each natural watershed is calculated, and natural watersheds with watershed areas smaller than the minimum watershed area in the initial natural watershed vector surface data are removed by elimination tools to obtain the first stage natural watershed vector surface data. Each natural watershed in the first-stage natural watershed vector surface data is assigned a unique identifier using a letter sequence to obtain optimized natural watershed vector surface data.

[0007] Optionally, the administrative division isometric vector data and optimized natural watershed vector isometric data are overlaid and their fit is calculated to obtain a preliminary watershed control unit, specifically including: S11: Overlay the administrative division area vector data and the optimized natural watershed vector area data to obtain overlaid vector area data. Calculate the area of ​​all townships and the area of ​​all villages based on the overlaid vector area data. S12: Calculate the intersection area between all townships and natural watersheds, and the intersection area between all villages and natural watersheds based on the superimposed vector surface data; S13: Select township i from the overlay vector surface data; S14: Select the natural watershed x from the overlay vector surface data; S15: Select village j in township i, and calculate the intersection area between village j and natural watershed x. Area of ​​village j The percentage is used as the goodness of fit between village j and natural watershed x. ; The intersection area of ​​township i and natural watershed x Area of ​​township i The percentage, or the sum of the areas of intersection between all villages within township i and the natural watershed x. Area of ​​township i The percentage is used as the goodness of fit between township i and natural watershed x. ; in, , i is the township number, j is the village number, n is the total number of villages contained in township i, and x is the natural watershed number; S16: Repeat step S15 to calculate the goodness of fit between all villages in township i and natural watershed x, obtain the goodness of fit threshold, and calculate the goodness of fit satisfaction rate between township i and natural watershed x based on the goodness of fit between all villages in township i and natural watershed x, the goodness of fit threshold, and the total number of villages n in township i. ; S17: Based on the goodness of fit between township i and natural watershed x The goodness-of-fit rate between township i and natural watershed x The overall fit between township i and natural watershed x is calculated. ; S18: Repeat steps S14-S17 to calculate the comprehensive fit between township i and all natural watersheds, and take the natural watershed corresponding to the maximum comprehensive fit as the natural watershed to which township i belongs. S19: Repeat steps S13-S18 to obtain the superimposed vector surface data of the natural watersheds of all townships as the preliminary watershed control unit.

[0008] Optionally, the goodness-of-fit rate between township i and natural watershed x. The calculation process specifically includes: The percentage of villages within township i whose goodness of fit with natural watershed x exceeds the goodness-of-fit threshold, compared to the total number of villages n within township i, is taken as the goodness-of-fit satisfaction rate between township i and natural watershed x. .

[0009] Optional, the overall fit between town i and natural watershed x The calculation process specifically includes: Obtain the comprehensive fit coefficient W1 of the first township and the comprehensive fit coefficient W2 of the second township, where W1 + W2 = 100%; The comprehensive fit coefficient W1 of the first township and the fit between township i and the natural watershed x are calculated. Multiply them to obtain the first product, and then combine the comprehensive fit coefficient W2 of the second township with the fit rate of township i to the natural watershed x. Multiply the first and second products to obtain the second product. Add the first and second products to obtain the overall fit between township i and natural watershed x. .

[0010] Optionally, fields are assigned to the final watershed control unit based on the administrative division areal vector data to obtain the delineation results of natural watersheds and administrative boundaries, specifically including: The final watershed control unit obtains all townships included in the natural watershed and the area of ​​the natural watershed. The township field is obtained from the administrative division area vector data. The township field is assigned to all townships included in the natural watershed. The natural watershed and the area of ​​the natural watershed after assigning the township field are used as the delineation results of the natural watershed and the administrative boundary.

[0011] The present invention also provides an automated delineation device for watershed control units connecting administrative boundaries, used to implement the aforementioned automated delineation method for watershed control units connecting administrative boundaries, the device comprising: The final DEM data acquisition module is used to acquire the initial DEM data and administrative division isometric vector data of the target area, construct a buffer based on the administrative division isometric vector data, and crop the initial DEM data based on the buffer to obtain the final DEM data. The module for acquiring optimized natural watershed vector surface data is used to preset the cumulative flow threshold and minimum watershed area of ​​the target area. Based on the final DEM data, the cumulative flow threshold and the minimum watershed area, the module constructs and optimizes the natural watershed vector surface to obtain optimized natural watershed vector surface data. The preliminary watershed control unit acquisition module is used to overlay and calculate the fitting degree of administrative division surface vector data and optimized natural watershed vector surface data to obtain the preliminary watershed control unit. The delineation result acquisition module is used to optimize the preliminary watershed control unit based on the minimum watershed area to obtain the final watershed control unit; and to assign fields to the final watershed control unit based on the administrative division isometric vector data to obtain the delineation results of natural watersheds and administrative boundaries.

[0012] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the aforementioned method for automatically delineating watershed control units that connect administrative boundaries.

[0013] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the aforementioned method for automatically delineating watershed control units that connect administrative boundaries.

[0014] The present invention has the following beneficial effects: 1. By overlaying administrative division surface vector data and optimized natural watershed vector surface data, calculating the fit, determining the natural watershed to which the township belongs, and optimizing the area, the final watershed control unit is generated. The final watershed control unit seamlessly connects the township administrative boundary with the natural watershed and can obtain all the townships included in each natural watershed as well as the area of ​​each natural watershed, thus providing high-precision results for the delineation of natural watersheds and administrative boundaries without the need for manual delineation; 2. By calculating the fitting degree between all villages within a township and the natural watershed, the fitting degree threshold, and the total number of villages included in the township, the fitting degree satisfaction rate between the township and the natural watershed is obtained. The comprehensive fitting degree between the township and the natural watershed is then calculated using the fitting degree between the township and the natural watershed and the fitting degree satisfaction rate. Finally, the natural watershed to which the township belongs is determined by the maximum comprehensive fitting degree. By considering the impact of the natural watershed on the village, the impact of the natural watershed on the township, and the impact of the village on the township in the process of determining the natural watershed, the accuracy of determining the natural watershed to which the township belongs is significantly improved. Attached Figure Description

[0015] Figure 1 This is a flowchart of a method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the buffer zone; Figure 3 This is a schematic diagram of superimposed vector surfaces; Figure 4 A flying map of townships and a schematic diagram of small-area townships; Figure 5 A schematic diagram showing the results of the delineation of natural watersheds and administrative boundaries; The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0016] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0017] Reference Figure 1 This invention provides an automated delineation method for watershed control units that connect administrative boundaries, comprising the following steps: Acquire the initial DEM data and administrative division isometric vector data of the target area, construct a buffer based on the administrative division isometric vector data, and crop the initial DEM data based on the buffer to obtain the final DEM data; In some embodiments, a buffer is constructed based on administrative division areal vector data, specifically including: Township boundary data is obtained from the administrative division area vector data. The minimum convex polygon of the township is obtained from the township boundary data through the fusion tool (the minimum convex polygon of the township is the polygon of the overall area boundary composed of all townships). The boundary of the minimum convex polygon of the township is extended outward to obtain a buffer zone.

[0018] In some embodiments, the administrative division polygon vector data includes "village" and "township" fields. The detailed steps for generating the minimum convex polygon of the township using ArcGIS ModelBuilder and expanding it into a buffer of a preset range are as follows: For example, if a mountainous area (containing 122 townships) is used as administrative division isometric vector data, after loading the administrative division isometric vector data, select "Data Management Tools > Features > Minimum Boundary Geometry" in the ArcToolbox of the model builder, set the input features to the township layer, the output feature class path, and select the geometry type "CONVEX_HULL" (convex hull) to generate the minimum convex polygon; Using the "Data Management Tools > Cartographic Generalization > Merge" tool in the Model Builder, input the convex polygon layer generated in the previous step, and uncheck the "Create Multi-Part Feature" option to ensure that adjacent polygons are merged into a single feature; Open the Model Builder's "Analysis Tools > Neighborhood Analysis > Buffer", input the blended convex polygon layer, set the buffer distance to 20 kilometers, select "kilometers" as the unit, and generate the buffer. The buffer is shown below. Figure 2 The blue area is shown in the image.

[0019] Obtain initial DEM data with a resolution of 30 meters through geospatial data cloud. Then, crop out the DEM data within the buffer range (30-meter resolution) from the initial DEM data. Use the DEM data within the buffer range as the final DEM data to eliminate edge errors. Note that the range of the initial DEM data is larger than that of the final DEM data.

[0020] The cumulative flow threshold and minimum watershed area of ​​the target area are preset. Based on the final DEM data, the cumulative flow threshold and minimum watershed area, the natural watershed vector surface is constructed and optimized to obtain optimized natural watershed vector surface data. In some embodiments, the cumulative flow threshold is unitless and ranges from approximately 100,000 to 2,000,000. Generally, the smaller the value, the smaller the defined natural watershed area, depending on the size of the target area's townships. The unit for the minimum watershed area is square kilometers, determined based on the minimum value of the watershed control unit to be generated.

[0021] In some embodiments, the construction and optimization of natural watershed vector surfaces are performed based on the final DEM data, cumulative flow threshold, and minimum watershed area to obtain optimized natural watershed vector surface data, specifically including: Based on the final DEM data and cumulative flow thresholds, initial natural watershed vector surface data are generated using a hydrological analysis toolchain. In some embodiments, the process of generating initial natural watershed vector surface data using a hydrological analysis toolchain is as follows: (1) Depression filling: Use [Spatial Analyst tools > Hydrological analysis > Depression filling] to process the final DEM data, determine the depression filling threshold through the limit value (empty value will fill all depressions), and output a depression-free DEM; (2) Flow direction analysis: Input a DEM without depressions, use a single flow direction algorithm to calculate the water flow direction, and output a raster; (3) Accumulated flow calculation: The accumulated flow is calculated through [Hydrological Analysis > Flow]. (4) Use the grid calculator to set the cumulative flow threshold. The choice of the cumulative flow threshold directly affects the river network density (the smaller the value, the more tributaries). (5) Water catchment area generation: Use the [Capture Drainage Point] tool to correct the position and determine the outlet point; execute the [Watershed] tool, input the flow direction grid and the corrected outlet; output the watershed boundary in raster format; (6) Raster to polygon: Use [Conversion Tools > Raster to Polygon] to generate vector polygons, check "Simplify polygons" to optimize the geometry, set appropriate clustering tolerance to reduce redundant nodes, and finally output the initial natural watershed vector polygon data containing hierarchical attributes; All natural watersheds in the initial natural watershed vector surface data are obtained, the watershed area of ​​each natural watershed is calculated, and natural watersheds with watershed areas smaller than the minimum watershed area in the initial natural watershed vector surface data are removed by elimination tools to obtain the first stage natural watershed vector surface data. In some embodiments, fragmentation areas smaller than a set value (minimum catchment area, such as 500 km²) are eliminated; Each natural watershed in the first-stage natural watershed vector surface data is assigned a unique identifier using a letter sequence to obtain optimized natural watershed vector surface data.

[0022] In some embodiments, a unique identifier is assigned to the “basin” field of a natural watershed using a letter sequence (A, B, C, ..., AA, AB, AC).

[0023] By overlaying and calculating the fit of administrative division surface vector data and optimized natural watershed vector surface data, a preliminary watershed control unit is obtained; In some embodiments, administrative division areal vector data and optimized natural watershed vector areal data are overlaid and their fit is calculated to obtain a preliminary watershed control unit, specifically including: S11: Overlay the administrative division area vector data and the optimized natural watershed vector area data to obtain overlaid vector area data. Calculate the area of ​​all townships and the area of ​​all villages based on the overlaid vector area data. In some embodiments, superimposed vector surfaces such as Figure 3As shown, the thick lines represent the boundaries of natural watersheds, and the thin lines represent the boundaries of townships.

[0024] S12: Calculate the intersection area between all townships and natural watersheds, and the intersection area between all villages and natural watersheds based on the superimposed vector surface data; S13: Select township i from the overlay vector surface data; S14: Select the natural watershed x from the overlay vector surface data; S15: Select village j in township i, and calculate the intersection area between village j and natural watershed x. Area of ​​village j The percentage is used as the goodness of fit between village j and natural watershed x. ; In some embodiments, fit The calculation formula is as follows:

[0025] The intersection area of ​​township i and natural watershed x Area of ​​township i The percentage, or the sum of the areas of intersection between all villages within township i and the natural watershed x. Area of ​​township i The percentage is used as the goodness of fit between township i and natural watershed x. ; In some embodiments, fit The calculation formula is as follows: ,or

[0026] in, , i is the township number, j is the village number, n is the total number of villages contained in township i, and x is the natural watershed number; S16: Repeat step S15 to calculate the goodness of fit between all villages in township i and natural watershed x, obtain the goodness of fit threshold, and calculate the goodness of fit satisfaction rate between township i and natural watershed x based on the goodness of fit between all villages in township i and natural watershed x, the goodness of fit threshold, and the total number of villages n in township i. ; In some embodiments, the goodness-of-fit rate between township i and natural watershed x is... The calculation process specifically includes: The percentage of villages within township i whose goodness of fit with natural watershed x exceeds the goodness-of-fit threshold, compared to the total number of villages n within township i, is taken as the goodness-of-fit satisfaction rate between township i and natural watershed x. .

[0027] In some embodiments, the fit satisfaction rate The calculation formula is as follows:

[0028] Under theoretical conditions, there is at least 1 and at most x (the total number of natural basins) in one administrative village, and the goodness of fit , and there is only one maximum value. However, usually, the area of the natural basin is much larger than that of the administrative village. At this time, in most cases, one administrative village is included in the natural basin, or is divided by 2 natural basins, and the situation of being divided by 3 or more natural basins is relatively rare. Therefore, the goodness of fit The goodness-of-fit threshold can be set at 50%. That is, when 50% of the area of a certain administrative village is within one basin, it is determined that this village is an administrative village in this township that meets the goodness-of-fit threshold; S17: According to the goodness of fit between township i and natural basin x and the satisfaction rate of the goodness of fit between township i and natural basin x , calculate the comprehensive goodness of fit between township i and natural basin x ; In some embodiments, the calculation process of the comprehensive goodness of fit between township i and natural basin x specifically includes: Obtain the first township comprehensive goodness-of-fit coefficient W1 and the second township comprehensive goodness-of-fit coefficient W2, where W1 + W2 = 100%; Multiply the first township comprehensive goodness-of-fit coefficient W1 by the goodness of fit between township i and natural basin x to obtain the first product, multiply the second township comprehensive goodness-of-fit coefficient W2 by the satisfaction rate of the goodness of fit between township i and natural basin x to obtain the second product, and add the first product and the second product to obtain the comprehensive goodness of fit between township i and natural basin x .

[0029] In some embodiments, the calculation formula of the comprehensive goodness of fit is as follows: , or

[0030] where the default values of W1 and W2 can be taken as 50% respectively, and can be adjusted according to actual needs. When w1 > w2, the basin control unit focuses on the integrity of the natural basin for township merger. When w1 < w2, the basin control unit focuses on the concentration of administrative villages for township merger; S18: Repeat steps S14 - S17, calculate the comprehensive goodness of fit between township i and all natural basins, and take the natural basin corresponding to the maximum comprehensive goodness of fit as the natural basin to which township i belongs; In some embodiments, also under theoretical conditions, a township has at least one and at most x (total number of natural watersheds) goodness of fit. Unlike administrative villages, townships have only one maximum value. Due to their larger area, a township may intersect with three or more natural watersheds. Therefore, the determination of the natural watershed to which a township belongs should not rely solely on the goodness of fit. Instead of making a judgment, we use a comprehensive fit. Determine the natural watershed to which the township belongs. That is, the natural watershed to which the township belongs is the one with the highest comprehensive fit value, i.e., max( The corresponding watershed; S19: Repeat steps S13-S18 to obtain the superimposed vector surface data of the natural watersheds of all townships as the preliminary watershed control unit.

[0031] The preliminary watershed control unit is optimized based on the minimum watershed area to obtain the final watershed control unit; the final watershed control unit is then assigned fields based on the administrative division area vector data to obtain the delineation results of natural watersheds and administrative boundaries.

[0032] In some embodiments, the actual management of administrative boundaries involves numerous flying map patches and small-area townships. Therefore, the preliminary watershed control units formed by merging townships also contain flying map patches and small-area townships. A schematic diagram of these flying map patches and small-area townships is shown below. Figure 4 As shown, "Wutai Forest Farm" is a fly-map patch within the red area below. The areas of "Xianju Township," "Wangdian Town," and "Anfusi Town" are smaller than the minimum watershed area, and therefore need to be removed. These fly-map patches and small-area towns need to be processed. By removing fly-map patches and small-area towns smaller than the minimum watershed area from the initial watershed control unit, the final watershed control unit can be obtained, ensuring that the final watershed control unit conforms to the natural watershed pattern.

[0033] In some embodiments, fields are assigned to the final watershed control unit based on administrative division areal vector data to obtain the delineation results of natural watersheds and administrative boundaries, specifically including: The final watershed control unit obtains all townships included in the natural watershed and the area of ​​the natural watershed. The township field is obtained from the administrative division area vector data. The township field is assigned to all townships included in the natural watershed. The natural watershed and the area of ​​the natural watershed after assigning the township field are used as the delineation results of the natural watershed and the administrative boundary.

[0034] In some embodiments, the delineation results of natural watersheds and administrative boundaries are as follows: Figure 5As shown, 122 townships are divided into 16 natural watersheds, and the natural watersheds with township fields and their areas are output as a table for display.

[0035] The present invention also provides an automated delineation device for watershed control units connecting administrative boundaries, used to implement the aforementioned automated delineation method for watershed control units connecting administrative boundaries, the device comprising: The final DEM data acquisition module is used to acquire the initial DEM data and administrative division isometric vector data of the target area, construct a buffer based on the administrative division isometric vector data, and crop the initial DEM data based on the buffer to obtain the final DEM data. The module for acquiring optimized natural watershed vector surface data is used to preset the cumulative flow threshold and minimum watershed area of ​​the target area. Based on the final DEM data, the cumulative flow threshold and the minimum watershed area, the module constructs and optimizes the natural watershed vector surface to obtain optimized natural watershed vector surface data. The preliminary watershed control unit acquisition module is used to overlay and calculate the fitting degree of administrative division surface vector data and optimized natural watershed vector surface data to obtain the preliminary watershed control unit. The delineation result acquisition module is used to optimize the preliminary watershed control unit based on the minimum watershed area to obtain the final watershed control unit; and to assign fields to the final watershed control unit based on the administrative division isometric vector data to obtain the delineation results of natural watersheds and administrative boundaries.

[0036] This application provides an electronic device, including a processor and a memory; the memory stores a computer program, wherein the computer program, when executed by the processor, implements the automated delineation method for watershed control units that connect administrative boundaries according to any of the above schemes.

[0037] Specifically, the processor may include, for example, a general-purpose microprocessor, an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor may also include onboard memory for caching purposes. The processor may be a single processing unit or multiple processing units for performing different actions of the method flow according to embodiments of this application.

[0038] Memory can be any medium capable of containing, storing, transmitting, propagating, or transmitting instructions. For example, memory can include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, instruments, or propagation media. Specific examples of memory include: magnetic storage devices such as magnetic tape or hard disk drives (HDDs); optical storage devices such as optical discs (CD-ROMs); and also random access memory (RAM) or flash memory; and / or wired / wireless communication links.

[0039] This application also provides a computer-readable medium storing a computer program that, when executed by a processor, implements the automated delineation method for watershed control units connecting administrative boundaries, as described above. This computer-readable medium may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into that device / apparatus / system. The aforementioned computer-readable medium carries one or more programs, which, when executed, implement the methods described in the embodiments of this application.

[0040] According to embodiments of this application, a computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media can also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wired, optical fiber, radio frequency signals, etc., or any suitable combination thereof.

[0041] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments and / or claims of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application. Therefore, the scope of this application should not be limited to the above embodiments, but should be defined not only by the appended claims, but also by their equivalents. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for automatically delineating watershed control units that connect administrative boundaries, characterized in that, Including the following steps: Acquire the initial DEM data and administrative division isometric vector data of the target area, construct a buffer based on the administrative division isometric vector data, and crop the initial DEM data based on the buffer to obtain the final DEM data; The cumulative flow threshold and minimum watershed area of ​​the target area are preset. Based on the final DEM data, the cumulative flow threshold and minimum watershed area, the natural watershed vector surface is constructed and optimized to obtain optimized natural watershed vector surface data. By overlaying and calculating the fit of administrative division surface vector data and optimized natural watershed vector surface data, a preliminary watershed control unit is obtained; The preliminary watershed control unit is optimized based on the minimum watershed area to obtain the final watershed control unit; the final watershed control unit is then assigned fields based on the administrative division area vector data to obtain the delineation results of natural watersheds and administrative boundaries.

2. The method for automatically delineating watershed control units connecting administrative boundaries according to claim 1, characterized in that, A buffer is constructed based on the administrative division areal vector data, specifically including: Township boundary data is obtained from the administrative division area vector data. The minimum convex polygon of the township is obtained from the township boundary data through a fusion tool. The boundary of the minimum convex polygon of the township is extended outward to obtain a buffer zone.

3. The method for automatically delineating watershed control units connecting administrative boundaries according to claim 1, characterized in that, Based on the final DEM data, cumulative flow threshold, and minimum watershed area, the natural watershed vector surface is constructed and optimized to obtain optimized natural watershed vector surface data, specifically including: Based on the final DEM data and cumulative flow thresholds, initial natural watershed vector surface data are generated using a hydrological analysis toolchain. All natural watersheds are obtained from the initial natural watershed vector surface data. The watershed area of ​​each natural watershed is calculated. Natural watersheds with watershed areas smaller than the minimum watershed area in the initial natural watershed vector surface data are removed by elimination tools to obtain the first stage natural watershed vector surface data. Each natural watershed in the first-stage natural watershed vector surface data is assigned a unique identifier using a letter sequence to obtain optimized natural watershed vector surface data.

4. The method for automatically delineating watershed control units connecting administrative boundaries according to claim 1, characterized in that, By overlaying and calculating the goodness of fit of administrative division areal vector data and optimized natural watershed vector areal data, a preliminary watershed control unit is obtained, which specifically includes: S11: Overlay the administrative division area vector data and the optimized natural watershed vector area data to obtain overlaid vector area data. Calculate the area of ​​all townships and the area of ​​all villages based on the overlaid vector area data. S12: Calculate the intersection area between all townships and natural watersheds, and the intersection area between all villages and natural watersheds based on the superimposed vector surface data; S13: Select township i from the overlay vector surface data; S14: Select the natural watershed x from the overlay vector surface data; S15: Select village j in township i, and calculate the intersection area between village j and natural watershed x. Area of ​​village j The percentage is used as the goodness of fit between village j and natural watershed x. ; The intersection area of ​​township i and natural watershed x Area of ​​township i The percentage, or the sum of the areas of intersection between all villages within township i and the natural watershed x. Area of ​​township i The percentage is used as the goodness of fit between township i and natural watershed x. ; in, , i is the township number, j is the village number, n is the total number of villages contained in township i, and x is the natural watershed number; S16: Repeat step S15 to calculate the goodness of fit between all villages in township i and natural watershed x, obtain the goodness of fit threshold, and calculate the goodness of fit satisfaction rate between township i and natural watershed x based on the goodness of fit between all villages in township i and natural watershed x, the goodness of fit threshold, and the total number of villages n in township i. ; S17: Based on the goodness of fit between township i and natural watershed x The goodness-of-fit rate between township i and natural watershed x The overall fit between township i and natural watershed x is calculated. ; S18: Repeat steps S14-S17 to calculate the comprehensive fit between township i and all natural watersheds, and take the natural watershed corresponding to the maximum comprehensive fit as the natural watershed to which township i belongs. S19: Repeat steps S13-S18 to obtain the superimposed vector surface data of the natural watersheds of all townships as the preliminary watershed control unit.

5. The method for automatically delineating watershed control units connecting administrative boundaries according to claim 4, characterized in that, The goodness-of-fit rate between township i and natural watershed x The calculation process specifically includes: The percentage of villages within township i whose goodness of fit with natural watershed x exceeds the goodness-of-fit threshold, compared to the total number of villages n within township i, is taken as the goodness-of-fit satisfaction rate between township i and natural watershed x. .

6. The method for automatically delineating watershed control units connecting administrative boundaries according to claim 4, characterized in that, The overall fit between township i and natural watershed x The calculation process specifically includes: Obtain the comprehensive fit coefficient W1 of the first township and the comprehensive fit coefficient W2 of the second township, where W1 + W2 = 100%; The comprehensive fit coefficient W1 of the first township and the fit between township i and the natural watershed x are calculated. Multiply them to obtain the first product, and then combine the comprehensive fit coefficient W2 of the second township with the fit rate of township i to the natural watershed x. Multiply the first and second products to obtain the second product. Add the first and second products to obtain the overall fit between township i and natural watershed x. .

7. The method for automatically delineating watershed control units connecting administrative boundaries according to claim 1, characterized in that, Based on the administrative division isometric vector data, fields are assigned to the final watershed control unit to obtain the delineation results of natural watersheds and administrative boundaries, specifically including: The final watershed control unit obtains all townships included in the natural watershed and the area of ​​the natural watershed. The township field is obtained from the administrative division area vector data. The township field is assigned to all townships included in the natural watershed. The natural watershed and the area of ​​the natural watershed after assigning the township field are used as the delineation results of the natural watershed and the administrative boundary.

8. An automated delineation device for watershed control units connecting administrative boundaries, used to implement the automated delineation method for watershed control units connecting administrative boundaries as described in any one of claims 1 to 7, characterized in that, The device includes: The final DEM data acquisition module is used to acquire the initial DEM data and administrative division isometric vector data of the target area, construct a buffer based on the administrative division isometric vector data, and crop the initial DEM data based on the buffer to obtain the final DEM data. The module for acquiring optimized natural watershed vector surface data is used to preset the cumulative flow threshold and minimum watershed area of ​​the target area. Based on the final DEM data, the cumulative flow threshold and the minimum watershed area, the module constructs and optimizes the natural watershed vector surface to obtain optimized natural watershed vector surface data. The preliminary watershed control unit acquisition module is used to overlay and calculate the fitting degree of administrative division surface vector data and optimized natural watershed vector surface data to obtain the preliminary watershed control unit. The delineation result acquisition module is used to optimize the preliminary watershed control unit based on the minimum watershed area to obtain the final watershed control unit; and to assign fields to the final watershed control unit based on the administrative division isometric vector data to obtain the delineation results of natural watersheds and administrative boundaries.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the automated delineation method for watershed control units that connect administrative boundaries as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the automated delineation method for watershed control units that connect administrative boundaries as described in any one of claims 1 to 7.

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