Method for processing dem water area based on planar vector data

Abstract

The application provides a method for processing DEM water area based on planar vector data, comprising the following steps: obtaining planar vector data of water area established by water area boundary line in a task area and grid DEM data of the task area; obtaining buffer planar vector data of the water area boundary line to the periphery of the shore boundary line; and adjusting overall elevation value of the grid DEM data of the water area according to the planar vector data of the water area. The method for processing DEM water area based on planar vector data provided by the application processes DEM based on planar vector data, and saves more labor cost and time cost and improves the processing efficiency of DEM water area in a computer-based batch processing mode of DEM, especially in a region with developed water system.

Description

Technical Field

[0001] This invention belongs to the field of geographic information data processing technology, specifically relating to a method for processing DEM water areas based on areal vector data. Background Technology

[0002] With the development and innovation of geographic information technology, geographic information data processing technology is also constantly being upgraded and improved. From the application of two-dimensional data to the display of 2.5-dimensional data, and then to the deployment of three-dimensional data, each step forward brings us closer to convenience, objectivity, and visualization. Therefore, more and more industries, enterprises, and governments are applying geographic information technology to their respective fields. Whether it's the creation of enterprise platform network data or the 3D effect display of government deployment platforms, terrain data, as fundamental data, serves various fields and is an indispensable part of these applications.

[0003] In the processing of DEM (Digital Elevation Model) data, due to the influence of water, it is difficult to obtain the true underwater topography; often, only the water surface elevation value is obtained. Therefore, in 3D data visualization, special processing of water areas is required to achieve the best 3D visual effect. Different processing software employs different methods for processing water areas in DEM data, but most methods rely on manual, screen-by-screen processing, which is inefficient. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for processing DEM water areas based on planar vector data, which can effectively solve the above-mentioned problems.

[0005] The technical solution adopted in this invention is as follows:

[0006] This invention provides a method for processing DEM water areas based on planar vector data, comprising the following steps:

[0007] S1, acquire the water area vector data established using the water area boundary line within the task area and the grid DEM data of the task area; wherein, the grid DEM data of the task area refers to: after the task area is gridded, the geographic coordinates of the center point of each grid and the corresponding DEM data are obtained; the task area includes water area and land area, wherein the grid DEM data of water area refers to the grid DEM data of the water surface; the grid DEM data of land area refers to the grid DEM data of the land surface;

[0008] S2, using the water boundary as the baseline reference image, extends the land area to the outer edge of the shoreline with the greatest distance, and obtains the water and land area vector data established from the outer edge of the shoreline;

[0009] Use the clipping tool to remove the area that overlaps with the water area vector data in the land and water area vector data, and obtain the buffer area vector data from the water area boundary to the outer edge of the shoreline;

[0010] S3. Based on the water area surface vector data, locate the water area grid DEM data in the grid DEM data of the task area, and adjust the overall elevation value of the water area grid DEM data to adjust the water area grid DEM data to the water bottom grid DEM data.

[0011] S4. Based on the buffer area vector data, locate the buffer area grid DEM data in the grid DEM data of the task area, and filter the buffer area grid DEM data to obtain the filtered buffer area grid DEM data, thereby achieving a smooth transition from land to water.

[0012] S5: Obtain the land area vector data outside the shoreline and locate the land area grid DEM data in the grid DEM data of the task area.

[0013] The grid DEM data of the land area, the grid DEM data of the filtered buffer area, and the grid DEM data of the bottom of the water area are combined to form the overall grid DEM data of the task area, thereby realizing the processing of the DEM data of the task area.

[0014] Preferably, in S1, the water area vector data is obtained using navigation data or large-scale high-precision basic geographic information data; the grid DEM data of the task area is downloaded from network resources.

[0015] Preferably, in S2, the baseline reference image is obtained from a network resource.

[0016] Preferably, S2 includes the following steps:

[0017] S201, Analyze the baseline reference image and water area vector data to obtain the maximum distance D from the water edge to the shoreline of different water areas, and determine the buffer distance value based on the standard that the buffer distance d satisfies d=D;

[0018] S202, based on the buffer distance value, a new water and land area surface layer is obtained, and the overlapping part with the water area surface vector data is erased to obtain the buffer area surface vector data from the water area edge line to the shore edge line.

[0019] Preferably, in S3, adjusting the overall elevation value of the grid DEM data of the water area specifically involves: determining the overall elevation adjustment value based on the width of the water area; subtracting the overall elevation adjustment value from each grid DEM data of the water area to obtain the adjusted grid DEM data.

[0020] Preferably, in S4, the filtering process includes median filtering and mean filtering;

[0021] The median filtering process involves replacing the value of a pixel in a data image or digital sequence with the median value of all pixels in its neighborhood, making the surrounding pixel values ​​closer to the true value, thereby eliminating isolated noise points.

[0022] The mean filtering process replaces the pixel values ​​in the original image with the mean value.

[0023] The method for processing DEM water areas based on planar vector data provided by this invention has the following advantages:

[0024] This invention provides a method for processing DEM water bodies based on planar vector data. This method, which uses planar vector data to process DEMs in batches primarily with computers, is particularly useful in areas with well-developed water systems. It saves significant labor and time costs and improves the efficiency of DEM water body processing. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating a method for processing DEM water areas based on planar vector data, as provided by the present invention. Detailed Implementation

[0026] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the invention.

[0027] This invention provides a method for processing DEM water bodies based on planar vector data. This method, which uses planar vector data to process DEMs in batches primarily with computers, is particularly useful in areas with well-developed water systems. It saves significant labor and time costs and improves the efficiency of DEM water body processing.

[0028] Specifically, this invention provides a method for processing DEM (Digital Elevation Model) water areas based on isometric vector data, belonging to the field of geographic information data processing technology. This method acquires isometric data of water areas established using water area boundaries within the task area; extends this isometric data to the outermost edge of the shoreline, obtaining a buffer zone from the water area to the shore, thus obtaining buffer zone data; adjusts the overall elevation value within the DEM water area based on the isometric data; and filters the DEM water area to the shoreline using the buffer zone data, finally obtaining the edited DEM data. This invention achieves a shift from primarily manual to computer-based processing in the editing of DEM water areas. This method saves time and labor costs in the special processing of terrain undulations in the visual display of 3D data in the geographic information field.

[0029] refer to Figure 1 This invention provides a method for processing DEM water areas based on planar vector data, comprising the following steps:

[0030] S1, acquire the water area vector data established using the water area boundary line within the task area and the grid DEM data of the task area; wherein, the grid DEM data of the task area refers to: after the task area is gridded, the geographic coordinates of the center point of each grid and the corresponding DEM data are obtained; the task area includes water area and land area, wherein the grid DEM data of water area refers to the grid DEM data of the water surface; the grid DEM data of land area refers to the grid DEM data of the land surface;

[0031] In this step, the water area vector data is obtained using navigation data or large-scale high-precision basic geographic information data; the grid DEM data of the task area is downloaded from online resources.

[0032] S2 uses the water boundary line as the baseline reference image to extend to the outer edge of the shoreline with the greatest distance, and obtains the water and land area vector data established from the outer edge of the shoreline; the baseline reference image is obtained from online resources.

[0033] Use the clipping tool to remove the area that overlaps with the water area vector data in the land and water area vector data, and obtain the buffer area vector data from the water area boundary to the outer edge of the shoreline;

[0034] S2 includes the following steps:

[0035] S201, Analyze the baseline reference image and water area vector data to obtain the maximum distance D from the water edge to the shoreline of different water areas, and determine the buffer distance value based on the standard that the buffer distance d satisfies d=D;

[0036] S202, based on the buffer distance value, a new water and land area surface layer is obtained, and the overlapping part with the water area surface vector data is erased to obtain the buffer area surface vector data from the water area edge line to the shore edge line.

[0037] S3. Based on the water area surface vector data, locate the water area grid DEM data in the grid DEM data of the task area, and adjust the overall elevation value of the water area grid DEM data to adjust the water area grid DEM data to the water bottom grid DEM data.

[0038] In this step, the overall elevation value of the grid DEM data of the water area is adjusted. Specifically, the overall elevation adjustment value is determined based on the width of the water area; the overall elevation adjustment value is subtracted from each grid DEM data of the water area to obtain the adjusted grid DEM data.

[0039] S4. Based on the buffer area vector data, locate the buffer area grid DEM data in the grid DEM data of the task area, and filter the buffer area grid DEM data to obtain the filtered buffer area grid DEM data, thereby achieving a smooth transition from land to water.

[0040] In this step, the filtering process includes median filtering and mean filtering.

[0041] The median filtering process involves replacing the value of a pixel in a data image or digital sequence with the median value of all pixels in its neighborhood, making the surrounding pixel values ​​closer to the true value, thereby eliminating isolated noise points.

[0042] The mean filtering process replaces the pixel values ​​in the original image with the mean value.

[0043] S5: Obtain the land area vector data outside the shoreline and locate the land area grid DEM data in the grid DEM data of the task area.

[0044] The grid DEM data of the land area, the grid DEM data of the filtered buffer area, and the grid DEM data of the bottom of the water area are combined to form the overall grid DEM data of the task area, thereby realizing the processing of the DEM data of the task area.

[0045] In summary, the present invention provides a method for processing DEM water bodies based on planar vector data. This method, which uses planar vector data to process DEMs in batches primarily with computers, is particularly useful in areas with well-developed water systems. It saves significant labor and time costs and improves the efficiency of DEM water body processing.

[0046] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for processing DEM water areas based on planar vector data, characterized in that, Includes the following steps: S1, acquire the water area vector data established using the water area boundary line within the task area and the grid DEM data of the task area; wherein, the grid DEM data of the task area refers to: after the task area is gridded, the geographic coordinates of the center point of each grid and the corresponding DEM data are obtained; the task area includes water area and land area, wherein the grid DEM data of water area refers to the grid DEM data of the water surface; the grid DEM data of land area refers to the grid DEM data of the land surface; S2, using the water boundary as the baseline reference image, extends the land area to the outer edge of the shoreline with the greatest distance, and obtains the water and land area vector data established from the outer edge of the shoreline; Use the clipping tool to remove the area that overlaps with the water area vector data in the land and water area vector data, and obtain the buffer area vector data from the water area boundary to the outer edge of the shoreline; S2 includes the following steps: S201, Analyze the baseline reference image and water area vector data to obtain the maximum distance D from the water edge to the shoreline of different water areas, and determine the buffer distance value based on the standard that the buffer distance d satisfies d=D; S202, based on the buffer distance value, a new water and land area surface layer is obtained, and the overlapping part with the water area surface vector data is erased to obtain the buffer area surface vector data from the water area edge line to the shore edge line. S3. Based on the water area surface vector data, locate the water area grid DEM data in the grid DEM data of the task area, and adjust the overall elevation value of the water area grid DEM data to adjust the water area grid DEM data to the water bottom grid DEM data. The overall elevation value of the grid DEM data of the water area is adjusted as follows: the overall elevation adjustment value is determined based on the width of the water area; the overall elevation adjustment value is subtracted from each grid DEM data of the water area to obtain the adjusted grid DEM data. S4. Based on the buffer area vector data, locate the buffer area grid DEM data in the grid DEM data of the task area, and filter the buffer area grid DEM data to obtain the filtered buffer area grid DEM data, thereby achieving a smooth transition from land to water. S5: Obtain the land area vector data outside the shoreline and locate the land area grid DEM data in the grid DEM data of the task area. The grid DEM data of the land area, the grid DEM data of the filtered buffer area, and the grid DEM data of the bottom of the water area are combined to form the overall grid DEM data of the task area, thereby realizing the processing of the DEM data of the task area.

2. The method for processing DEM water areas based on planar vector data according to claim 1, characterized in that, In S1, the water area vector data is obtained using navigation data or large-scale high-precision basic geographic information data; the grid DEM data of the task area is downloaded from network resources.

3. The method for processing DEM water areas based on planar vector data according to claim 1, characterized in that, In S2, the baseline reference image is obtained from network resources.

4. The method for processing DEM water areas based on planar vector data according to claim 1, characterized in that, In S4, the filtering process includes median filtering and mean filtering; The median filtering process involves replacing the value of a pixel in a data image or digital sequence with the median value of all pixels in its neighborhood, making the surrounding pixel values ​​closer to the true value, thereby eliminating isolated noise points. The mean filtering process replaces the pixel values ​​in the original image with the mean value.

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