A method for obtaining a hydrological station position based on a digital elevation model

Abstract

This invention provides a method for obtaining the location of hydrological stations based on a digital elevation model, belonging to the fields of hydrology, water resources, and geographic information technology. The method includes: generating an initial boundary centered on the hydrological stations through spatial distribution; extracting the river channel grid; obtaining the outlet points and their catchment areas; and performing spatial overlay analysis with the initial boundary. For incorrectly generated initial boundaries, the scope is expanded to generate extended boundaries. The catchment areas of the extended boundaries are then iteratively calculated to finally obtain the correct catchment areas and accurate coordinates of the hydrological stations. This invention solves the problem of insufficient spatial distribution information for hydrological stations and is of great significance for water resources information statistics.

Description

Technical Field

[0001] This invention belongs to the field of hydrology, water resources and geographic information technology, and in particular relates to a method for obtaining the location of hydrological stations based on digital elevation models. Background Technology

[0002] Spatial information from hydrological stations is crucial for hydrological model calculations. The accuracy of these stations directly determines the precision of the simulation and serves as a fundamental basis for water resources assessment and forecasting. Currently, published hydrological station information is often presented in tabular form, lacking direct spatial representation. Furthermore, the station coordinates provided in these tabular data are often not precise enough, leading to either the inability to generate catchment areas or inaccurately defined catchment area boundaries. In addition, some hydrological stations lack the vital attribute of catchment area. This is highly detrimental to hydrological simulation and water resources assessment. Summary of the Invention

[0003] To address the aforementioned shortcomings in existing technologies, this invention provides a method for obtaining the location of hydrological stations based on a digital elevation model, aiming to improve the accuracy of generating the spatial range of the catchment area of ​​hydrological stations by utilizing limited data.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] This solution provides a method for obtaining the location of hydrological stations based on a digital elevation model, including the following steps:

[0006] S1. Organize the hydrological station information in an Excel spreadsheet, spatially display its latitude and longitude information, and save it as a vector file;

[0007] S2. Filter hydrological stations based on whether they have catchment area attributes, and create initial boundary vector files for hydrological stations based on the filtering results;

[0008] S3. Based on the initial boundary vector file, extract the DEM data within the region and perform depression filling to obtain the flow direction and confluence accumulation, and set the confluence accumulation threshold to extract the river grid.

[0009] S4. Obtain the outlet point and its catchment area, and perform spatial overlay analysis with the initial boundary. Based on the analysis results, when the catchment area boundary coincides with the initial boundary, expand the range of the initial boundary to generate an extended boundary.

[0010] S5. Iteratively calculate the catchment area of ​​the expanded boundary and determine whether the expanded boundary and the catchment area boundary do not coincide at all. If so, the catchment area of ​​the hydrological station is obtained, and the location of the hydrological station is obtained. Otherwise, return to step S4.

[0011] The beneficial effects of this invention are as follows: This invention provides a method for accurately acquiring the location of hydrological stations and generating the spatial range of their catchment areas. Utilizing the ArcGIS platform, it uses hydrological station information and a digital elevation model to estimate the initial boundary and generate a river network. Then, based on the initial boundary, iteratively calculates the expanded catchment area, ultimately achieving accurate acquisition of hydrological station locations and accurate generation of the catchment area's spatial range. This avoids the inability to generate the catchment area's spatial range or the generation results being incorrect due to incomplete data, effectively improving the accuracy and efficiency of catchment area digitization and providing technical support for high-precision simulation of hydrological models.

[0012] Further, step S1 includes the following steps:

[0013] S101. In an Excel spreadsheet, organize the hydrological stations according to their attributes;

[0014] S102. Based on the data processing results and the latitude and longitude information of the hydrological stations, spatial distribution is performed by adding X and Y coordinate tools in the ArcGIS platform and saved as a vector point file.

[0015] The beneficial effect of the above-mentioned further scheme is that by spatially displaying latitude and longitude information, the two-dimensional information that cannot be displayed intuitively is transformed into vector point data with spatial coordinates, which can then be matched with other hydrological data, which is conducive to obtaining accurate hydrological station locations in the future.

[0016] Furthermore, step S2 includes the following steps:

[0017] S201. In an Excel spreadsheet, use the filter tool to filter hydrological stations based on whether the catchment area has a valid value, dividing them into hydrological stations with area and hydrological stations without area.

[0018] S202. Based on the screening results, select hydrological stations with areas. Using the hydrological station as the center and X as the radius, create an initial boundary vector file for the hydrological station with area in the ArcGIS platform using the create polygon tool. Area 站点 Indicates the area of ​​the hydrological station;

[0019] S203. Based on the screening results, select hydrological stations without area, estimate the initial boundary range according to their location in the watershed, and create the initial boundary vector file of the hydrological station without area in the ArcGIS platform using the surface creation tool.

[0020] The beneficial effect of the above-mentioned further scheme is that by providing two methods for creating initial boundaries for hydrological stations with and without area, it is conducive to the widespread application of this method.

[0021] Furthermore, step S3 includes the following steps:

[0022] S301. Based on the initial boundary vector file, extract the DEM data within the area using the ArcGIS platform to obtain DEM raster data;

[0023] S302. Based on the DEM raster data, use the depression filling tool in the ArcGIS platform's hydrological analysis to perform depression filling processing and obtain depression-free DEM raster data.

[0024] S303. Based on the DEM raster data without depressions, use the flow direction tool in the ArcGIS platform's hydrological analysis to calculate the flow direction grid and obtain the flow direction raster data of the initial boundary.

[0025] S304. Based on the flow direction raster data, use the flow tool in the ArcGIS platform's hydrological analysis to calculate the cumulative flow at each grid point, and obtain the raster data of the initial boundary's cumulative flow.

[0026] S305. Based on the cumulative runoff raster data and the cumulative runoff threshold, extract the river grid using the raster calculation tool on the ArcGIS platform.

[0027] The beneficial effects of the above-mentioned further scheme are: by using the initial vector boundary to clip the digital elevation model data for routine hydrological analysis, the consistency of ranges among various data is ensured, which is conducive to obtaining accurate hydrological station locations in the future.

[0028] Furthermore, the expression for extracting the river channel grid in step S305 is as follows:

[0029] River=Acc>T

[0030] T = Area 边界 ×10%

[0031] Where River represents the river channel raster matrix, Acc represents the cumulative runoff raster data, T represents the cumulative runoff threshold, and Area represents the area. 边界 Represents the area of ​​the boundary.

[0032] The beneficial effects of the above-mentioned further scheme are: it provides a calculation method for extracting river channel grids, and provides a basis for calculating the shortest Euclidean distance from hydrological stations to river channels.

[0033] Furthermore, step S4 includes the following steps:

[0034] S401. Using the near tool of the ArcGIS platform, obtain the outlet point, wherein the outlet point is the point with the shortest Euclidean distance from the hydrological station to the river channel.

[0035] S402. Based on the outflow point and the raster data of the cumulative runoff, use the watershed tool in the ArcGIS platform to generate the catchment area of ​​the outflow point;

[0036] S403. Based on the water collection area of ​​the outlet point, perform spatial overlay analysis with the initial boundary;

[0037] S404. Based on the analysis results, determine whether the catchment area boundary does not coincide with the initial boundary at all. If so, the complete catchment area of ​​the hydrological station is obtained, and proceed to step S5. Otherwise, any boundary coincides, and proceed to step S405.

[0038] S405. In the ArcGIS platform, use the buffer tool to expand the initial boundary range, generate the expanded boundary, increase the expanded distance, and proceed to step S5.

[0039] The beneficial effects of the above-mentioned further scheme are: by iteratively calculating the shortest Euclidean distance from the hydrological station to the river channel, the results are closer to the actual situation, avoiding errors caused by insufficient decimal places in latitude and longitude coordinates, and significantly improving the accuracy and efficiency of hydrological station location.

[0040] Furthermore, the expression for the increased distance is as follows:

[0041] R = (X + i × 5)

[0042] Where R represents the expansion distance, X represents the initial boundary radius, and i represents the expansion number.

[0043] The beneficial effect of the above-mentioned further scheme is that it provides a method for calculating the extended distance, thus providing a basis for expanding the boundary. Attached Figure Description

[0044] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0045] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0046] Example

[0047] like Figure 1 As shown, this invention provides a method for obtaining the location of hydrological stations based on a digital elevation model, the implementation of which is as follows:

[0048] S1. Organize hydrological station information in an Excel spreadsheet, spatially display its latitude and longitude information, and save it as a vector file. The method is as follows:

[0049] S101. In an Excel spreadsheet, organize the hydrological stations according to their attributes;

[0050] S102. Based on the data processing results and the latitude and longitude information of the hydrological stations, spatial distribution is performed by adding X and Y coordinate tools in the ArcGIS platform and saved as a vector point file.

[0051] In this embodiment, the data is organized in Excel according to five attributes: station number, station name, longitude, latitude, and catchment area. Based on the longitude and latitude information, the data is spatially displayed using the X and Y coordinate addition tool in ArcGIS and saved as a vector point file.

[0052] S2. Hydrological stations are filtered based on whether they have catchment area attributes, and initial boundary vector files for the hydrological stations are created based on the filtering results. The implementation method is as follows:

[0053] S201. In an Excel spreadsheet, use the filter tool to filter hydrological stations based on whether the catchment area has a valid value, dividing them into hydrological stations with area and hydrological stations without area.

[0054] S202. Based on the screening results, select hydrological stations with areas. Using the hydrological station as the center and X as the radius, create an initial boundary vector file for the hydrological station with area in the ArcGIS platform using the create polygon tool. Area 站点 Indicates the area of ​​the hydrological station;

[0055] S203. Based on the screening results, select hydrological stations without area, estimate the initial boundary range according to their location in the watershed, and create the initial boundary vector file of the hydrological station without area in the ArcGIS platform using the surface creation tool.

[0056] In this embodiment, in Excel, a filter tool is used to filter hydrological stations based on whether the catchment area has a valid value, categorizing them into hydrological stations with area and those without. Based on the filtering results, hydrological stations with area are selected, and a circle is drawn with the hydrological station as the center. In ArcGIS, the initial boundary vector file for hydrological stations with area is created using the Create Polygon tool. Based on the filtering results, hydrological stations without area are selected, and their initial boundary range is estimated according to their location in the watershed. The initial boundary vector file for hydrological stations without area is then created in ArcGIS using the Create Polygon tool.

[0057] S3. Based on the initial boundary vector file, extract the DEM data within the region and perform depression filling to obtain the flow direction and runoff accumulation. Set the runoff accumulation threshold to extract the river channel grid. The implementation method is as follows:

[0058] S301. Based on the initial boundary vector file, extract the DEM data within the area using the ArcGIS platform to obtain DEM raster data;

[0059] S302. Based on the DEM raster data, use the depression filling tool in the ArcGIS platform's hydrological analysis to perform depression filling processing and obtain depression-free DEM raster data.

[0060] S303. Based on the DEM raster data without depressions, use the flow direction tool in the ArcGIS platform's hydrological analysis to calculate the flow direction grid and obtain the flow direction raster data of the initial boundary.

[0061] S304. Based on the flow direction raster data, use the flow tool in the ArcGIS platform's hydrological analysis to calculate the cumulative flow at each grid point, and obtain the raster data of the initial boundary's cumulative flow.

[0062] S305. Based on the cumulative runoff raster data and the cumulative runoff threshold, extract the river grid using the raster calculation tool on the ArcGIS platform.

[0063] In this embodiment, based on the boundary file obtained in S2, DEM data within the region is extracted using the ArcGIS platform to obtain DEM raster data. Based on the DEM raster data, the depression filling tool in ArcGIS hydrological analysis is used to fill depressions, resulting in depression-free DEM raster data. Based on the depression-free DEM raster data, the flow direction tool in ArcGIS hydrological analysis is used to calculate the flow direction grid, obtaining the initial boundary flow direction raster data. Based on the flow direction raster data, the flow rate tool in ArcGIS hydrological analysis is used to calculate the cumulative runoff at each grid point, obtaining the initial boundary runoff cumulative runoff raster data. Based on the runoff cumulative runoff raster data, the river channel raster is extracted using ArcGIS's raster calculator tool, with the specific formula as follows:

[0064] River=Acc>T

[0065] T = Area 边界 ×10%

[0066] In the formula, River represents the river raster matrix, Acc represents the cumulative runoff raster data, T represents the cumulative runoff threshold, and Area represents the cumulative runoff threshold. 边界 Represents the area of ​​the boundary.

[0067] S4. Obtain the outlet point and its catchment area, and perform spatial overlay analysis with the initial boundary. Based on the analysis results, when the catchment area boundary coincides with the initial boundary in any way, expand the range of the initial boundary to generate an extended boundary. The implementation method is as follows:

[0068] S401. Using the near tool of the ArcGIS platform, obtain the outlet point, wherein the outlet point is the point with the shortest Euclidean distance from the hydrological station to the river channel.

[0069] S402. Based on the outflow point and the raster data of the cumulative runoff, use the watershed tool in the ArcGIS platform to generate the catchment area of ​​the outflow point;

[0070] S403. Based on the water collection area of ​​the outlet point, perform spatial overlay analysis with the initial boundary;

[0071] S404. Based on the analysis results, determine whether the catchment area boundary does not coincide with the initial boundary at all. If so, the complete catchment area of ​​the hydrological station is obtained, and proceed to step S5. Otherwise, any boundary coincides, and proceed to step S405.

[0072] S405. In the ArcGIS platform, use the buffer tool to expand the initial boundary range, generate the expanded boundary, increase the expanded distance, and proceed to step S5.

[0073] In this embodiment, the outlet point, i.e., the shortest Euclidean distance from the hydrological station to the river channel, is obtained using ArcGIS's near tool. Based on the runoff accumulation raster data and the outlet point, the catchment area of ​​the outlet point is generated using ArcGIS's watershed tool. Based on the catchment area of ​​the outlet point, spatial overlay analysis is performed with the initial boundary. If the catchment area boundary does not coincide with the initial boundary at all, it means that the complete catchment area of ​​the hydrological station has been obtained. If any boundary coincides, it means that the initial boundary range is too small and needs to be expanded. The initial boundary range is expanded using ArcGIS's buffer tool by an expansion distance of (X+i×5)km, where X is the initial boundary radius and i is the expansion number. The catchment area of ​​the expanded boundary is iteratively calculated, and it is determined whether the expanded boundary and the catchment area boundary do not coincide at all. If they do, the catchment area of ​​the hydrological station is obtained, and the location of the hydrological station is obtained. Otherwise, the process returns to step S4.

[0074] S5. Iteratively calculate the catchment area of ​​the expanded boundary and determine whether the expanded boundary and the catchment area boundary do not coincide at all. If so, the catchment area of ​​the hydrological station is obtained, and the location of the hydrological station is obtained. Otherwise, return to step S4.

[0075] In this embodiment, step S4 is repeated to iteratively calculate the catchment area of ​​the expanded boundary until the expanded boundary and the catchment area boundary do not overlap at all, thus obtaining the catchment area of ​​the hydrological station; based on obtaining the catchment area of ​​the hydrological station, step S401 is repeated to obtain the precise location of the hydrological station.

[0076] This invention utilizes the ArcGIS platform, employing hydrological station information and digital elevation models to estimate initial boundaries and generate river networks. It then iteratively calculates the catchment areas of expanded boundaries based on these initial boundaries, ultimately achieving accurate acquisition of hydrological station locations and precise generation of catchment area spatial extent. This avoids the inability to generate catchment area spatial extent or incorrect generation results due to incomplete data, effectively improving the accuracy and efficiency of catchment area digitization and providing technical support for high-precision simulation of hydrological models.

Claims

1. A method for obtaining the location of hydrological stations based on a digital elevation model, characterized in that, Includes the following steps: S1. Organize the hydrological station information in an Excel spreadsheet, spatially display its latitude and longitude information, and save it as a vector file; S2. Filter hydrological stations based on whether they have catchment area attributes, and create initial boundary vector files for hydrological stations based on the filtering results; Step S2 includes the following steps: S201. In an Excel spreadsheet, use the filter tool to filter hydrological stations based on whether the catchment area has a valid value, dividing them into hydrological stations with area and hydrological stations without area. S202. Based on the screening results, select hydrological stations with areas. Using the hydrological station as the center and X as the radius, create an initial boundary vector file for the hydrological station with area in the ArcGIS platform using the create polygon tool. , Indicates the area of ​​the hydrological station; S203. Based on the screening results, select hydrological stations without area, estimate the initial boundary range according to their location in the watershed, and create the initial boundary vector file of the hydrological station without area in the ArcGIS platform using the surface creation tool. S3. Based on the initial boundary vector file, extract the DEM data within the region and perform depression filling to obtain the flow direction and confluence accumulation, and set the confluence accumulation threshold to extract the river grid. S4. Obtain the outlet point and its catchment area, and perform spatial overlay analysis with the initial boundary. Based on the analysis results, when the catchment area boundary coincides with the initial boundary, expand the range of the initial boundary to generate an extended boundary. S5. Iteratively calculate the catchment area of ​​the expanded boundary and determine whether the expanded boundary and the catchment area boundary do not coincide at all. If so, the catchment area of ​​the hydrological station is obtained, and the location of the hydrological station is obtained. Otherwise, return to step S4.

2. The method for obtaining the location of hydrological stations based on a digital elevation model according to claim 1, characterized in that, Step S1 includes the following steps: S101. In an Excel spreadsheet, organize the hydrological stations according to their attributes; S102. Based on the data processing results and the latitude and longitude information of the hydrological stations, spatial distribution is performed by adding X and Y coordinate tools in the ArcGIS platform and saved as a vector point file.

3. The method for obtaining the location of hydrological stations based on a digital elevation model according to claim 1, characterized in that, Step S3 includes the following steps: S301. Based on the initial boundary vector file, extract the DEM data within the area using the ArcGIS platform to obtain DEM raster data; S302. Based on the DEM raster data, use the depression filling tool in the ArcGIS platform's hydrological analysis to perform depression filling processing and obtain depression-free DEM raster data. S303. Based on the DEM raster data without depressions, use the flow direction tool in the ArcGIS platform's hydrological analysis to calculate the flow direction grid and obtain the flow direction raster data of the initial boundary. S304. Based on the flow direction raster data, use the flow tool in the ArcGIS platform's hydrological analysis to calculate the cumulative flow at each grid point, and obtain the raster data of the initial boundary's cumulative flow. S305. Based on the cumulative runoff raster data and the cumulative runoff threshold, extract the river grid using the raster calculation tool on the ArcGIS platform.

4. The method for obtaining the location of hydrological stations based on a digital elevation model according to claim 3, characterized in that, The expression for extracting the river grid in step S305 is as follows: in, Represents the river channel raster matrix. Represents raster data of cumulative confluence. Indicates the cumulative flow threshold. Represents the area of ​​the boundary.

5. The method for obtaining the location of hydrological stations based on a digital elevation model according to claim 4, characterized in that, Step S4 includes the following steps: S401. Using the near tool of the ArcGIS platform, obtain the outlet point, wherein the outlet point is the point with the shortest Euclidean distance from the hydrological station to the river channel. S402. Based on the outflow point and the raster data of the cumulative runoff, use the watershed tool in the ArcGIS platform to generate the catchment area of ​​the outflow point; S403. Based on the water collection area of ​​the outlet point, perform spatial overlay analysis with the initial boundary; S404. Based on the analysis results, determine whether the catchment area boundary does not coincide with the initial boundary at all. If so, the complete catchment area of ​​the hydrological station is obtained, and proceed to step S5. Otherwise, any boundary coincides, and proceed to step S405. S405. In the ArcGIS platform, use the buffer tool to expand the initial boundary range, generate the expanded boundary, increase the expanded distance, and proceed to step S5.

6. The method for obtaining the location of hydrological stations based on a digital elevation model according to claim 5, characterized in that, The expression for the increased distance is as follows: in, Indicates increasing the distance. Indicates the initial boundary radius. Indicates the number of times.

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