A complex terrain parameterization representation method and terrain feature analysis method

Abstract

The present invention discloses a method for parameterized characterization of complex terrain, including obtaining coordinates of a to-be-studied area and determining the scope of the to-be-studied area; obtaining images and terrain data corresponding to the to-be-studied area in a database; performing visualization processing, integrating and preprocessing, and constructing a data set; for three-dimensional terrain, simplifying and obtaining a number of typical two-dimensional profiles through mathematical analysis processing; performing parameterized analysis processing on the two-dimensional profiles and obtaining analysis results; storing and classifying the terrain and completing the parameterized characterization of the terrain; the method of the present invention also includes a terrain feature analysis method of the method for parameterized characterization of complex terrain, including obtaining calculation parameters and constructing a parameter data set; obtaining data of the to-be-studied area and constructing a regional data set through data processing; obtaining correlations between data sets through regression analysis processing; completing feature analysis of the terrain; the reliability of the method of the present invention is improved and the objectivity is enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of geographic information systems and geomorphology, and specifically relates to a complex terrain parameterization characterization method and a terrain feature analysis method. Background Art

[0002] The terrain effect refers to the effect of terrain on seismic motion. When seismic waves pass through complex terrain, the height changes and geomorphic features of the terrain will affect the propagation and attenuation of seismic waves, thereby causing changes in seismic motion. In order to deeply understand the terrain effect, it is necessary to comprehensively apply geographic information system (GIS) technology, mathematical modeling and geomorphological theory. GIS technology is used to obtain and analyze terrain parameters, including terrain elevation, slope, and slope direction, thereby providing detailed terrain data; mathematical modeling can quantify and simulate complex terrain effects, and express the impact of terrain on seismic motion through mathematical methods. At the same time, geomorphological theory and methods study the relationship between terrain morphology and surface processes, and provide tools for quantifying and explaining terrain effects.

[0003] Simplifying terrain into a few sets of parameters can depict complex terrain effects and reduce data complexity. This comprehensive approach is widely used in scientific research, engineering and other fields. It provides researchers with a theoretical basis and practical methods to deeply understand the impact of terrain on various surface processes, including the propagation of seismic motion. By comprehensively applying these background technologies, it is possible to more comprehensively analyze terrain effects and reveal the characteristics and impacts of complex terrain effects, which is of great significance to scientific research, engineering and natural resource management.

[0004] In summary, current methods mostly focus on the impact of a single terrain parameter on ground motion, and have not yet fully considered the combined impact of multiple terrain parameters and geomorphic features. However, terrain effect is a complex issue that requires comprehensive consideration of multiple influencing factors. Summary of the invention

[0005] One of the purposes of the present invention is to provide a complex terrain parameterization characterization method with improved reliability and enhanced objectivity.

[0006] A second object of the present invention is to provide a terrain feature analysis method that includes the above-mentioned complex terrain parameterization characterization method.

[0007] The complex terrain parameterization method provided by the present invention comprises the following steps:

[0008] S1. Obtain the coordinates of the area to be studied and determine the scope of the study area;

[0009] S2. Using the coordinates of the area to be studied obtained in step S1, obtain the image and terrain data corresponding to the area to be studied in the database;

[0010] S3. Performing visualization processing on the image and terrain data obtained in step S2, and integrating and preprocessing the processed terrain data and the research area determined in step S1 to construct a data set;

[0011] S4. Based on the data set constructed in step S3, for the three-dimensional terrain, several typical two-dimensional profiles are simplified through mathematical analysis and processing;

[0012] S5. Perform parametric analysis on the two-dimensional profile obtained in step S4, obtain analysis results, and complete parametric characterization of the terrain;

[0013] The step S1 of obtaining the coordinates of the area to be studied and determining the scope of the study area specifically includes:

[0014] If the research object is a latitude and longitude point coordinate, then: take the point coordinate as the center, divide the research area according to the set size, analyze and process the newly generated research area, and then realize the analysis of the research object;

[0015] If the research object is regional coordinates, then: divide the research area according to the regional coordinates, and perform analysis on the divided research area;

[0016] The step S2 uses the coordinates of the area to be studied obtained in step S1 to obtain the image and terrain data corresponding to the area to be studied in the database, which specifically includes:

[0017] Determine the scope of the study area through the coordinates obtained in step S1, and then determine the data type required for the study area, including images, vector data, and digital elevation model (DEM) raster data;

[0018] Determine data sources, including geographic databases, satellite image libraries, and weather station data;

[0019] Conduct data query and retrieval in geographic databases, and filter required data according to the scope and boundaries of the study area;

[0020] Use database query languages ​​or related tools to obtain data on the required study area, including images, vector data, and digital elevation model data;

[0021] Step S3 performs visualization processing on the image and terrain data obtained in step S2, and integrates and preprocesses the processed terrain data and the research area determined in step S1 to construct a data set, specifically including:

[0022] Through GIS software tools, the scope of the study area and the specific data of the study area are integrated and analyzed to generate a visualization image of the study area;

[0023] Perform regional point conversion analysis on the study area, select point density or point distance according to the resolution of DEM raster data, and then divide the study area into several points;

[0024] Through GIS software tools, visualization analysis and point processing are performed to obtain three-dimensional topographic maps and point data;

[0025] Based on the obtained point data, a data set is constructed in a predetermined format;

[0026] Provide data support for subsequent terrain parameterization through data sets;

[0027] The data set constructed in step S3 described in step S4 is simplified to obtain several typical two-dimensional profiles through mathematical analysis and processing for the three-dimensional terrain, specifically including:

[0028] The simplification process specifically includes:

[0029] Select the section, including the section at the line connecting the maximum elevation and the minimum elevation, and the diagonal section;

[0030] After simplifying the three-dimensional complex terrain into a cross section, the data points on the cross section are integrated;

[0031] Step S5 performs parameterized analysis on the two-dimensional profile obtained in step S4, obtains analysis results, and completes parameterized representation of the terrain, specifically including:

[0032] (5-1) General parameters:

[0033] Performing parameterized analysis on the two-dimensional profile obtained in step S4, selecting integrated profile point data for parameterized analysis; the selected parameters are conventional terrain parameters, including elevation, slope, and curvature;

[0034] Elevation: Select H i Indicates the altitude of each point;

[0035] Slope: It is the inverse tangent of the elevation difference between two points on the profile and the distance between the two points, expressed by the following formula:

[0036] H ci =arctan((H i -H i+1 ) / (X i -X i+1 ))

[0037] Among them, H ci Indicates the slope value of the i-th point, in degrees; H i Indicates the altitude value of the i-th point, in meters; H i+1Indicates the altitude value of the i+1th point, in meters; X i Indicates the horizontal azimuth value of the i-th point, in m; X i+1 Indicates the horizontal azimuth value of the i+1th point, in meters;

[0038] Curvature: It is the curvature characteristic of the surface at a point, which describes the degree of curvature of the surface at a point;

[0039] (5-2) Derived parameters:

[0040] (1) By averaging the elevation and slope in the study area, derived parameters including mean elevation and mean slope were obtained;

[0041] Average elevation: Take the average elevation of all points in the profile. The calculation formula is as follows:

[0042]

[0043] Among them, H a represents the average elevation in meters; n represents the number of points into which the study area is divided;

[0044] Average slope: Take the average slope of all points in the profile. The calculation formula is as follows:

[0045]

[0046] Among them, H d represents the average slope value; n represents the number of points into which the study area is divided;

[0047] Based on the average elevation and average slope, the terrain change trend of the study area is analyzed by studying the discreteness of elevation and slope;

[0048] Studying the discreteness of elevation and slope includes calculating the standard deviation and variance of elevation and slope respectively;

[0049] Elevation discreteness: Take the standard deviation of the elevations of all points in the profile, and the calculation formula is as follows:

[0050]

[0051] Slope Discreteness:

[0052]

[0053] (2) rate of change of elevation and slope;

[0054] Through the elevation change rate and slope change rate, the terrain change trend of the study area is obtained from the perspective of coordinate images;

[0055] (3) Custom parameters:

[0056] Customized parameters include profile saturation rate and profile special angle;

[0057] Profile saturation rate: The calculation formula is as follows:

[0058] Profile saturation rate = the integral area of ​​the profile area between the lowest point and the highest point / the area formed by the line between the lowest point and the highest point of the profile and the vertical line perpendicular to the X-axis between the lowest point and the highest point

[0059] The size of the profile saturation rate indicates the urgency of the profile trend;

[0060] Special angles of section: Special angles of section are divided into section angle X and section angle Y;

[0061] The section angle X represents the angle between the set straight line and the X axis; the section angle Y represents the angle between the set straight line and the Y axis;

[0062] The "set straight line" is the line between the lowest and highest points of the profile;

[0063] (5-3) Using the above analysis results, the terrain is stored and classified to complete the parametric representation of the terrain, including:

[0064] The analysis results are used to divide and store the terrain, and the terrain is classified using specifications to complete the parameterization of complex terrain.

[0065] The method of the present invention also provides a feature analysis method including the above-mentioned complex terrain parameterization characterization method, comprising the following steps:

[0066] S11. Using a parametric characterization method based on terrain effects, obtain calculation parameters and construct a parameter data set;

[0067] S12. Obtain the data of the area to be studied, and construct a regional data set through data processing;

[0068] S13. Using the parameter data set constructed in step S11 and the regional data set constructed in step S12, the correlation between the data sets is obtained through regression analysis;

[0069] S14. Based on the correlation between the data sets obtained in step S13 and the visualization data obtained by the parametric characterization method based on the terrain effect, the characteristic analysis of the terrain is completed;

[0070] Step S13 uses the parameter data set constructed in step S11 and the regional data set constructed in step S12 to obtain the correlation between the data sets through regression analysis, specifically including:

[0071] Through regression analysis, a mathematical model is constructed to represent the relationship between the parameter data set and the regional data set;

[0072] Step S14, based on the correlation between the data sets obtained in step S13 and the visualization data obtained by the parametric characterization method based on the terrain effect, completes the feature analysis of the terrain, specifically including:

[0073] Based on the spectral characteristics of terrain data, the terrain spectrum is obtained by performing second-order derivative calculation on the relative distance.

[0074] According to the data graph, the terrain curvature and slope changes show fluctuation characteristics, and the fluctuation characteristics have a trend;

[0075] Trends include macro and micro levels:

[0076] 1) Macro part:

[0077] The curvature, elevation change rate and slope change rate under different terrain conditions show regularity;

[0078] Regularities include peak slope, peak elevation change rate, and peak curvature for different terrain types;

[0079] Terrain types include hills, mountains, and plateaus;

[0080] The region is divided into different terrain effect areas according to the values ​​of average elevation and average slope, and the terrain effect areas are related to administrative divisions;

[0081] 2) Microscopic part:

[0082] By studying the rate of change values ​​of specific profiles, the spectral relationship is obtained;

[0083] The locations of the peaks of different rates of change are correlated;

[0084] By fitting the data, the characteristics of the terrain spectrum are obtained; the positions of the peaks of different characteristic change rates on the terrain spectrum and the magnitude of the change rates at different positions under the terrain;

[0085] The terrain is parameterized and a terrain spectrum is generated by fitting the region with the data;

[0086] By analyzing the spectral characteristics of terrain data, we can understand terrain trends and characteristics, provide support for further terrain data applications, and complete terrain feature analysis;

[0087] The complex terrain parameterization characterization method provided by the present invention simplifies and compresses terrain information by converting complex terrain data into parameters; by using parameterization representation, it helps to understand and process complex terrain, reduces the complexity and redundancy of data, and extracts key features and morphological information of terrain; by selecting appropriate parameterization methods and indicators, it captures important features of terrain; the present invention also provides a feature analysis method including the complex terrain parameterization characterization method; the reliability and objectivity of the method of the present invention are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Figure 1 The figure is a schematic diagram of the method flow of the present invention.

[0089] Figure 2 Schematic diagram of local complex terrain grid division according to the method of the present invention.

[0090] Figure 3 The figure is a schematic diagram of three-dimensional visualization of complex terrain according to the method of the present invention.

[0091] Figure 4 This is a schematic diagram of a typical cross-section of the study area selected in the method of the present invention.

[0092] Figure 5 It is a schematic diagram of the slope at the analysis section in the method of the present invention.

[0093] Figure 6 It is a schematic diagram of the curvature at the analysis section in the method of the present invention.

[0094] Figure 7 It is a schematic diagram of the average elevation at the analysis section in the method of the present invention.

[0095] Figure 8 It is a schematic diagram of the elevation change rate at the analysis section in the method of the present invention.

[0096] Fig. 9 Schematic diagram of cross-section saturation rate in the method of the present invention.

[0097] Fig.10 It is a schematic diagram of special angles of the cross section in the method of the present invention.

[0098] Fig.11 The figure is a schematic diagram of the method flow of the characteristic analysis method in the method of the present invention.

[0099] Fig.12 Schematic diagram of regression analysis in the method of the present invention.

[0100] Fig.13 Schematic diagram of topographic spectroscopy in the method of the present invention. DETAILED DESCRIPTION

[0101] like Figure 1The method flow chart of the method of the present invention is shown as follows: The complex terrain parameterization characterization method provided by the present invention comprises the following steps:

[0102] S1. Obtain the coordinates of the area to be studied and determine the scope of the study area; specifically including:

[0103] If the research object is a latitude and longitude point coordinate, then: take the point coordinate as the center, divide the research area according to the set size, analyze and process the newly generated research area, and then realize the analysis of the research object;

[0104] In the method of the present invention, a research area of ​​500m×500m was chosen to be created;

[0105] If the research object is regional coordinates, then: divide the research area according to the regional coordinates, and perform analysis and processing on the divided research area;

[0106] In the method of the present invention, the Chichi earthquake observatory in Taiwan is selected;

[0107] S2. Using the coordinates of the area to be studied obtained in step S1, obtain the image and terrain data corresponding to the area to be studied in the database; specifically including:

[0108] Determine the scope of the study area through the coordinates obtained in step S1, and then determine the data type required for the study area, including images, vector data, and digital elevation model (DEM) raster data;

[0109] Determine data sources, including geographic databases, satellite image libraries, and weather station data;

[0110] Conduct data query and retrieval in geographic databases, and filter required data according to the scope and boundaries of the study area;

[0111] Use database query languages ​​or related tools to obtain data on the required study area, including images, vector data, and digital elevation model data;

[0112] S3. Visualize the image and terrain data obtained in step S2, and integrate and preprocess the processed terrain data and the research area determined in step S1 to construct a data set; specifically, the following steps are included:

[0113] Through GIS software tools, the scope of the study area and the specific data of the study area are integrated and analyzed to generate a visualization image of the study area;

[0114] Perform regional point conversion analysis on the study area, select point density or point distance according to the resolution of DEM raster data, and then divide the study area into several points;

[0115] The resolution of DEM grid data is usually divided into 30M, 20M, and 12.5M. In the method of the present invention, the resolution of DEM grid data is set to 30M, and the study area is correspondingly divided into a number of points with a point distance of 30M.

[0116] Through GIS software tools, visualization analysis and point processing are performed to obtain three-dimensional terrain maps and point data; Figure 2 The schematic diagram of the local complex terrain grid division of the method of the present invention is shown as follows: Figure 3 Shown is a schematic diagram of three-dimensional visualization of complex terrain by the method of the present invention;

[0117] Based on the obtained point data, a data set is constructed in a predetermined format;

[0118] Provide data support for subsequent terrain parameterization through data sets;

[0119] S4. Based on the data set constructed in step S3, for the three-dimensional terrain, a number of typical two-dimensional profiles are simplified through mathematical analysis and processing; specifically, the following are included:

[0120] The simplification process specifically includes:

[0121] Select the section, including the section at the line connecting the maximum elevation and the minimum elevation, and the diagonal section;

[0122] After simplifying the three-dimensional complex terrain into a cross section, the data points on the cross section are integrated;

[0123] like Figure 4 Shown is a schematic diagram of a typical cross section of a selected research area in the method of the present invention;

[0124] S5. Performing parametric analysis on the two-dimensional profile obtained in step S4, obtaining analysis results, and completing parametric characterization of the terrain; specifically including:

[0125] (5-1) General parameters:

[0126] Performing parameterized analysis on the two-dimensional profile obtained in step S4, selecting the integrated profile point data for parameterized analysis; the selected parameters are conventional terrain parameters, including elevation, slope, and curvature;

[0127] Elevation: Select H i Indicates the altitude of each point;

[0128] Slope: It is the inverse tangent of the elevation difference between two points in the profile and the distance between the two points, such as Figure 5 The figure shows the schematic diagram of the slope at the analysis section in the method of the present invention, which is expressed by the following formula:

[0129] Hci =arctan((H i -H i+1 ) / (X i -X i+1 ))

[0130] Among them, H ci Indicates the slope value of the i-th point, in degrees; H i Indicates the altitude value of the i-th point, in meters; H i+1 Indicates the altitude value of the i+1th point, in meters; X i Indicates the horizontal azimuth value of the i-th point, in m; X i+1 Indicates the horizontal azimuth value of the i+1th point, in meters;

[0131] Curvature: It is the curvature characteristic of the earth's surface at a point, describing the degree of curvature of the earth's surface at a point; Figure 6 Shown is a schematic diagram of the curvature at the analysis section in the method of the present invention;

[0132] (5-2) Derived parameters:

[0133] (1) By averaging the elevation and slope in the study area, derived parameters including mean elevation and mean slope were obtained;

[0134] Average elevation: Take the average of the elevations of all points in the profile, such as Figure 7 The figure shows the average elevation of the analyzed section in the method of the present invention. The calculation formula is as follows:

[0135]

[0136] Among them, H a represents the average elevation in meters; n represents the number of points into which the study area is divided;

[0137] Average slope: Take the average slope of all points in the profile. The calculation formula is as follows:

[0138]

[0139] Among them, H d represents the average slope value; n represents the number of points into which the study area is divided;

[0140] Based on the average elevation and average slope, the terrain change trend of the study area is analyzed by studying the discreteness of elevation and slope;

[0141] Studying the discreteness of elevation and slope includes calculating the standard deviation and variance of elevation and slope respectively;

[0142] Elevation discreteness: Take the standard deviation of the elevations of all points in the profile, and the calculation formula is as follows:

[0143]

[0144] Slope Discreteness:

[0145]

[0146] (2) rate of change of elevation and slope;

[0147] Through the elevation change rate and slope change rate, the terrain change trend of the study area can be obtained from the perspective of coordinate images; Figure 8 Shown is a schematic diagram of the elevation change rate at the analysis section in the method of the present invention;

[0148] (3) Custom parameters:

[0149] Customized parameters include profile saturation rate and profile special angle;

[0150] Profile saturation rate: Fig. 9 The figure shows a schematic diagram of the profile saturation rate in the method of the present invention, and the calculation formula is as follows:

[0151] Profile saturation rate = the integral area of ​​the profile area between the lowest point and the highest point / the area formed by the line between the lowest point and the highest point of the profile and the vertical line perpendicular to the X-axis between the lowest point and the highest point

[0152] The size of the profile saturation rate indicates the urgency of the profile trend;

[0153] Special angles of section: Fig.10 It is a schematic diagram of the special angle of the cross section in the method of the present invention, and the special angle of the cross section is divided into the cross section angle X and the cross section angle Y;

[0154] The section angle X represents the angle between the set straight line and the X axis; the section angle Y represents the angle between the set straight line and the Y axis;

[0155] The "set straight line" is the line between the lowest and highest points of the profile;

[0156] (5-3) Using the above analysis results, the terrain is stored and classified to complete the parametric representation of the terrain, including:

[0157] The analysis results are used to divide and store the terrain, and the terrain is classified using specifications to complete the parameterization of complex terrain.

[0158] like Fig.11The figure shows a method flow diagram of the feature analysis method in the method of the present invention: The method of the present invention also provides a feature analysis method including the above-mentioned complex terrain parameterization characterization method, including the following steps:

[0159] S11. Using a parametric characterization method based on terrain effects, obtain calculation parameters and construct a parameter data set;

[0160] S12. Obtain the data of the area to be studied, and construct a regional data set through data processing;

[0161] S13. Using the parameter data set constructed in step S11 and the regional data set constructed in step S12, the correlation between the data sets is obtained through regression analysis; specifically, the following steps are included:

[0162] Through regression analysis, a mathematical model is constructed to represent the relationship between the parameter data set and the regional data set;

[0163] In the method of the present invention, three parameters, namely, the average elevation within 500 m, the standard deviation of elevation, and the standard deviation of slope, are selected to construct a parameter data set, and the parameters are used to reflect the changes and undulations of the terrain, so as to provide an understanding of the terrain effect; seismic data of the Chichi main shock are collected from the Taiwan Seismic Observatory, and data processing is performed to construct a regional data set; taking the peak acceleration (PGA) as an example, the correlation between PGA and Vs30 (shear wave velocity) and fault distance is eliminated; through the above processing method, the regional data set can more accurately reflect the relationship between seismic motion and terrain effect; through the arrangement and analysis of the parameter data set and the regional data set, the terrain effect can be comprehensively understood, and the potential correlation between seismic motion and terrain can be revealed;

[0164] By performing regression analysis on parameter data sets and regional data sets, a mathematical model is established to reveal and quantify the relationship between data sets;

[0165] like Fig.12 Shown is a schematic diagram of regression analysis in the method of the present invention: Fig.12 The correlation between the datasets is shown in Fig.12 , the trend and correlation between the parameter data set and the regional data set can be obtained from a visualization perspective; although the correlation between them is weak, it shows to some extent that there is a certain correlation between terrain parameters and ground motion data;

[0166] S14. Based on the correlation between the data sets obtained in step S13 and the visualization data obtained by the parametric characterization method based on the terrain effect, the characteristic analysis of the terrain is completed; specifically including:

[0167] Based on the spectral characteristics of terrain data, the terrain spectrum is obtained by performing second-order derivative calculation on the relative distance.

[0168] like Fig.13 The topographic spectrum diagram in the method of the present invention is shown as follows: Fig.13 It can be concluded that the changes in terrain curvature and slope show fluctuation characteristics, and the fluctuation characteristics have trends;

[0169] Trends include macro and micro levels:

[0170] 1) Macro part:

[0171] The curvature, elevation change rate and slope change rate under different terrain conditions show regularity;

[0172] Regularities include peak slope, peak elevation change rate, and peak curvature for different terrain types;

[0173] Terrain types include hills, mountains, and plateaus;

[0174] The region is divided into different terrain effect areas according to the values ​​of average elevation and average slope, and the terrain effect areas are related to administrative divisions;

[0175] In the method of the present invention, the southwest region is selected as an example, and the basis for regional division is understood in the form of a chart:

[0176] Table 1. Parameterized analysis of terrain in the southwest region

[0177] Southwest Region Mountain hills Plains plateau Average elevation AB AB AB AB Average slope AB AB AB AB Elevation change rate AB AB AB AB Slope change rate AB AB AB AB Curvature AB AB AB AB

[0178] The interval range in the chart is represented by "AB", which indicates the terrain characteristics within the regional range; by observing the values ​​of the average elevation, average slope, elevation change rate and slope change rate of different regions, the regions with similar terrain effects are divided; the division of terrain effect regions needs to be based on the needs of research and analysis, combined with actual geographical characteristics; the specific regional division will vary depending on the research purpose and data availability; such regional division helps to understand the regularity of terrain changes and the differences in terrain characteristics in different regions;

[0179] 2) Microscopic part:

[0180] By studying the rate of change values ​​of specific profiles, the spectral relationship is obtained;

[0181] The locations of the peaks of different rates of change are correlated;

[0182] By fitting the data, the characteristics of the terrain spectrum are obtained; the positions of the peaks of different characteristic change rates on the terrain spectrum and the magnitude of the change rates at different positions under the terrain;

[0183] The terrain is parameterized and a terrain spectrum is generated by fitting the region with the data;

[0184] By analyzing the spectral characteristics of terrain data, we can understand terrain trends and characteristics, provide support for further terrain data applications, and complete terrain feature analysis;

[0185] In the method of the present invention, the southwest region is selected as an example, and the concept of terrain spectrum and the "frequent segments" where the extreme values ​​of various terrain parameters may appear are understood in the form of charts:

[0186] Table 2 Extreme value intervals of terrain parameterization in the southwest region

[0187]

[0188] In the chart, the terrain spectrum is divided into different frequency bands, usually represented by Roman numerals; each frequency band represents the peak value of the rate of change within a specific frequency range in a certain area of ​​the terrain; by studying the peak values ​​of the rate of change in different frequency bands in the terrain spectrum, we can understand the changing characteristics of the surface morphology and infer the possible terrain development process; the above analysis method can provide information on the evolution of surface morphology and geological processes in geomorphology, geography and earth sciences; for the terrain spectrum in the southwest region, more detailed surface morphological characteristics can be obtained by studying the peak values ​​of the rate of change in different frequency bands.

Claims

1. A complex terrain parameterization characterization method, comprising the following steps: S1. Obtain the coordinates of the area to be studied and determine the scope of the study area; S2. Using the coordinates of the area to be studied obtained in step S1, obtain the image and terrain data corresponding to the area to be studied in the database; S3. Performing visualization processing on the image and terrain data obtained in step S2, and integrating and preprocessing the processed terrain data and the research area determined in step S1 to construct a data set; S4. Based on the data set constructed in step S3, for the three-dimensional terrain, several typical two-dimensional profiles are simplified through mathematical analysis and processing; S5. Perform parametric analysis on the two-dimensional profile obtained in step S4, obtain analysis results, and complete parametric characterization of the terrain; In the specific implementation, the two-dimensional profile obtained in step S4 is subjected to parametric analysis, and the integrated profile point data is selected for parametric analysis, and the selected parameters are conventional terrain parameters, including elevation, slope, and curvature; By taking the average of the elevation and slope in the study area, the derived parameters, including the average elevation and average slope, are obtained; based on the average elevation and average slope, the discreteness of the elevation and slope is studied to analyze and obtain the terrain change trend of the study area; the discreteness of the elevation and slope is studied, including calculating the standard deviation and variance of the elevation and slope respectively; through the elevation change rate and slope change rate, the terrain change trend of the study area is obtained from the perspective of the coordinate image; Calculate custom parameters, including profile saturation rate and profile special angle; Profile saturation rate = integrated area of ​​the profile area between the lowest point and the highest point / area formed by the line between the lowest point and the highest point of the profile and the vertical line perpendicular to the X-axis between the lowest point and the highest point; The special angles of the section are divided into section angle X and section angle Y. Section angle X represents the angle between the set straight line and the X axis. Section angle Y represents the angle between the set straight line and the Y axis. The "set straight line" is the line between the lowest point and the highest point of the section. The analysis results are used to divide and store the terrain, and the terrain is classified using specifications to complete the parameterization of complex terrain.

2. A complex terrain parameterization method according to claim 1, characterized in that The step S1 of obtaining the coordinates of the area to be studied and determining the scope of the study area specifically includes: If the research object is a latitude and longitude point coordinate, then: take the point coordinate as the center, divide the research area according to the set size, analyze and process the newly generated research area, and then realize the analysis of the research object; If the research object is regional coordinates, then: divide the research area according to the regional coordinates, and perform analysis and processing on the divided research area.

3. A complex terrain parameterization method according to claim 2, characterized in that The step S2 uses the coordinates of the area to be studied obtained in step S1 to obtain the image and terrain data corresponding to the area to be studied in the database, which specifically includes: Determine the scope of the study area through the coordinates obtained in step S1, and then determine the data type required for the study area, including images, vector data, and DEM raster data; Determine data sources, including geographic databases, satellite image libraries, and weather station data; Conduct data query and retrieval in geographic databases, and filter required data according to the scope and boundaries of the study area; Use database query language or related tools to obtain the data of the required study area, including images, vector data, and digital elevation model data.

4. A complex terrain parameterization method according to claim 3, characterized in that Step S3 performs visualization processing on the image and terrain data obtained in step S2, and integrates and preprocesses the processed terrain data and the research area determined in step S1 to construct a data set, specifically including: Through GIS software tools, the scope of the study area and the specific data of the study area are integrated and analyzed to generate a visualization image of the study area; Perform regional point conversion analysis on the study area, select point density or point distance according to the resolution of DEM raster data, and then divide the study area into several points; Through GIS software tools, visualization analysis and point processing are performed to obtain three-dimensional topographic maps and point data; Based on the obtained point data, a data set is constructed in a predetermined format; The dataset provides data support for subsequent terrain parameterization.

5. A complex terrain parameterization method according to claim 4, characterized in that The data set constructed based on step S3 in step S4 is simplified to obtain several typical two-dimensional profiles through mathematical analysis and processing for the three-dimensional terrain, specifically including: The simplification process specifically includes: Select the section, including the section at the line connecting the maximum elevation and the minimum elevation, and the diagonal section; After simplifying the three-dimensional complex terrain into a cross-section, the data points on the cross-section surface are integrated.

6. A complex terrain parameterization method according to claim 5, characterized in that Step S5 performs parameterized analysis on the two-dimensional profile obtained in step S4, obtains analysis results, and completes parameterized representation of the terrain, specifically including: (5-1) General parameters: Performing parameterized analysis on the two-dimensional profile obtained in step S4, selecting the integrated profile point data for parameterized analysis, and selecting conventional terrain parameters, including elevation, slope, and curvature; Elevation: Select H i Indicates the altitude of each point; Slope: It is the inverse tangent of the elevation difference between two points on the profile and the distance between the two points, expressed by the following formula: H ci =arctan((H i -H i+1 ) / (X i -X i+1 )) Among them, H ci Indicates the slope value of the i-th point, in degrees; H i Indicates the altitude value of the i-th point, in meters; H i+1 Indicates the altitude value of the i+1th point, in meters; X i Indicates the horizontal azimuth value of the i-th point, in m; X i+1 Indicates the horizontal azimuth value of the i+1th point, in meters; Curvature: It is the curvature characteristic of the surface at a point, which describes the degree of curvature of the surface at a point; (5-2) Derived parameters: (1) By averaging the elevation and slope in the study area, derived parameters including mean elevation and mean slope were obtained; Average elevation: Take the average elevation of all points in the profile. The calculation formula is as follows: Among them, H a represents the average elevation in meters; n represents the number of points into which the study area is divided; Average slope: Take the average slope of all points in the profile. The calculation formula is as follows: Among them, H d represents the average slope value; n represents the number of points into which the study area is divided; Based on the average elevation and average slope, the terrain change trend of the study area is analyzed by studying the discreteness of elevation and slope; Studying the discreteness of elevation and slope includes calculating the standard deviation and variance of elevation and slope respectively; Elevation discreteness: Take the standard deviation of the elevations of all points in the profile, and the calculation formula is as follows: Slope Discreteness: (2) rate of change of elevation and slope; Through the elevation change rate and slope change rate, the terrain change trend of the study area is obtained from the perspective of coordinate images; (3) Custom parameters: Customized parameters include profile saturation rate and profile special angle; Profile saturation rate: The calculation formula is as follows: Profile saturation rate = the integral area of ​​the profile area between the lowest point and the highest point / the area formed by the line between the lowest point and the highest point of the profile and the vertical line perpendicular to the X-axis between the lowest point and the highest point The size of the profile saturation rate indicates the urgency of the profile trend; Special angles of section: Special angles of section are divided into section angle X and section angle Y; The section angle X represents the angle between the set straight line and the X axis; the section angle Y represents the angle between the set straight line and the Y axis; "Set straight line" is the line between the lowest and highest points of the profile; (5-3) Using the above analysis results, the terrain is stored and classified to complete the parametric representation of the terrain, including: The analysis results are used to divide and store the terrain, and the terrain is classified using specifications to complete the parameterization of complex terrain.

7. A terrain feature analysis method comprising a complex terrain parameterization characterization method according to any one of claims 1 to 6, comprising the following steps: S11. Using a parametric characterization method based on terrain effects, obtain calculation parameters and construct a parameter data set; S12. Obtain the data of the area to be studied, and construct a regional data set through data processing; S13. Using the parameter data set constructed in step S11 and the regional data set constructed in step S12, the correlation between the data sets is obtained through regression analysis; S14. Based on the correlation between the data sets obtained in step S13 and the visualization data obtained by the parametric characterization method based on the terrain effect, the characteristic analysis of the terrain is completed.

8. The terrain feature analysis method of the complex terrain parameterization characterization method according to claim 7 is characterized in that Step S13 uses the parameter data set constructed in step S11 and the regional data set constructed in step S12 to obtain the correlation between the data sets through regression analysis, specifically including: Through regression analysis, a mathematical model is constructed to represent the relationship between the parameter data set and the regional data set.

9. The terrain feature analysis method of the complex terrain parameterization characterization method according to claim 8, characterized in that Step S14, based on the correlation between the data sets obtained in step S13 and the visualization data obtained by the parametric characterization method based on the terrain effect, completes the feature analysis of the terrain, specifically including: Based on the spectral characteristics of terrain data, the terrain spectrum is obtained by performing second-order derivative calculation on the relative distance. According to the data graph, the terrain curvature and slope changes show fluctuation characteristics, and the fluctuation characteristics have a trend; Trends include macro and micro levels: 1) Macro part: The curvature, elevation change rate and slope change rate under different terrain conditions show regularity; Regularities include peak slope, peak elevation change rate, and peak curvature for different terrain types; Terrain types include hills, mountains, and plateaus; The region is divided into different terrain effect areas according to the values ​​of average elevation and average slope, and the terrain effect areas are related to administrative divisions; 2) Microscopic part: By studying the rate of change values ​​of specific profiles, the spectral relationship is obtained; The locations of the peaks of different rates of change are correlated; By fitting the data, the characteristics of the terrain spectrum are obtained; the positions of the peaks of different characteristic change rates on the terrain spectrum and the magnitude of the change rates at different positions under the terrain; The terrain is parameterized and a terrain spectrum is generated by fitting the region with the data; By analyzing the spectral characteristics of terrain data, we can understand terrain trends and characteristics, provide support for further terrain data applications, and complete the characteristic analysis of terrain.

Images