JP2006120167A - Topographic data processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new topographic data processing method and a device therefor which can perform computer processing while maintaining reading/analysis accuracy of expert level which has been realized only by manual work conventionally. <P>SOLUTION: A valley head decision program makes a computer read, from a storage means, contour line data having information as a candidate for a valley head decided by the shape of a contour line and information on three-dimensional coordinates, if, for a candidate point of a valley head of the read contour line data, a coupling line segment is not generated toward the candidate point of a valley head whose elevation is lower by one rank, generates a coupling line segment sequentially downward, decide a valley head such that a start point of each line composed of the generated coupling line segments is decided as the valley head, and store or output the decision result. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention extracts various information for performing terrain classification on a computer by making maximum use of information (elevation and shape of terrain) contained in the contour line using the digitized contour lines. Or it is a program for calculating.
According to the present invention, it is possible to automatically perform operations (for example, extraction of a valley head and creation of a valley diagram) manually performed by an engineer using a contour map.
Information such as the valley head, valley line, and valley degree obtained by the present invention is useful for predicting the occurrence location and damage range of landslide disasters, and is particularly effective for disasters caused by heavy rain. The ridge line obtained by the present invention is important information about avalanche disaster. Furthermore, the slope type (FIG. 1), slope, slope orientation, valley order, and the like obtained by the present invention are basic data for grasping the features of topography.
Specifically, terrain classification information can be used to create hazard maps that have been developed by local governments in recent years to raise residents 'awareness of disaster prevention and support residents' evacuation activities during natural disasters. In recent years, environmental issues have been emphasized, and attention has often been paid to the natural environment of the region. Construction of visitor centers for introducing the natural environment has been promoted in various places. Terrain is a component of the natural environment and is deeply related to ecosystems (including vegetation). The output map of terrain information obtained by the present invention is a material suitable for display in a facility such as a visitor center. Furthermore, in the field of forestry (forestry), a highly accurate soil map is required, and a highly accurate terrain classification method is required. Also in this field, recently, a method using a computer is being sought. The present invention can meet this requirement by using highly accurate numerical contour data.

Topographic classification maps have traditionally been created manually, including photo interpretation, based on topographic maps (contour maps). For this reason, it takes a lot of labor and time to accurately interpret and analyze photographs and the like, and there is a problem that a huge cost is required. In addition, there were individual differences and oversights due to manual work by humans.
As a solution to this problem, a method has been developed in which terrain features, numerical terrain measurement, basin analysis, etc. are performed on a computer using elevation grid data covering the entire country of Japan, such as a numerical map 50 m mesh (elevation). . It is possible to automatically perform objective and wide-area terrain analysis in a short period of time automatically by using the same method using altitude grid data arranged uniformly. The elevation grid data is DEM (Digital Elevation Model) (numerical elevation model) most commonly used in Japan.
As a latest technique for obtaining a DEM, a typical technique is advancing the development of a method for obtaining position information (random point data) on the ground surface using a laser scanner or an artificial satellite. By using a laser scanner, it is possible to obtain high-density point data with an interval of 1 to 2 [m], but there is a problem in terms of cost when acquiring data over a wide area.
In addition, since the method of obtaining ground surface position information in the form of grid data from the beginning has not been put to practical use, various algorithms are used to create elevation grid data from numerical contour data and random point data. (Spline, kriging, idw, trend, TOPOGRID, etc.) have been developed. In order to create altitude grid data that reproduces the original terrain as accurately as possible, it is necessary to fully study the algorithm used and the value of the calculation condition set for each algorithm.
Since elevation grid data has a regular arrangement, once the DEM is converted to elevation grid data, 1) it is easy to calculate the difference between collapse and deposition from the difference in elevation grid data before and after the collapse. Yes, 2) Many methods have been developed and introduced for calculating gradients and slope orientations from elevation grid data. 3) Topographic statistical analysis methods using various grid data are also available in academic journals and books. Etc. That is, the altitude grid data is suitable for computer processing and can significantly improve the processing speed.

However, the above altitude grid data has different altitude values obtained from the acquired DEM depending on which algorithm or set value is used. Further, the result of the gradient calculated using the obtained elevation grid data varies depending on which calculation method is used. In addition, it is difficult to match terrain features obtained from altitude grid data using various algorithms with features obtained manually using conventional contour maps.
The digitized contour data is rarely used directly for the calculation of topographic features because of its irregular data arrangement, and is often used exclusively as the base data for obtaining elevation grid data. .

However, the present invention makes it possible to reproduce the means for obtaining the topographic features that have been performed manually by humans using the contour map by using the digitized contour line data.
In the present invention, calculation and determination of information regarding the shape of the slope are performed along the contour lines and the falling water lines obtained from the contour lines as in manual operations, and the method is one. Therefore, there are various methods such as calculation of various terrain information using altitude grid data, and the results obtained by the methods are not different. Also, before the spread of computers, various classification maps (landslides, geology, soil, collapse, active faults, etc.) based on contour lines have been created, which is valuable information. The results (output diagrams) of the present invention output based on contour line data are much easier to compare with these diagrams and photographs than with grid data. In addition, since the present invention includes a method for converting the resulting line data with attributes relating to terrain information into grid data, it can be combined with various types of grid data that are widely used as numerical data. Wide application range.
Until now, elevation grid data has often been created based on contour line data, and in that case, an error occurs due to the grid method. In addition, since the data is divided at equal intervals due to the grid formation, it is difficult to perform calculation in consideration of the boundary of slopes such as valley lines and ridge lines, and topographic features such as mountain peaks, depressions, and ridges. However, by using the contour line data as it is, it is possible to classify the slopes faithfully according to the information that the contour line has, and this is done by considering the valleys, ridges, peaks, depressions, ridges, etc. expressed by the contour lines. The classification by work can be reproduced.

The present invention has been made in view of the above-described conventional situation, and the object thereof is new terrain data that can be processed by a computer while maintaining the interpretation / analysis accuracy of an expert level that has been realized only by manual work. To provide a processing method and an apparatus thereof, specifically, to generate waterfall line data and steepest climb data from digitized contour line data, and to provide a computer-processable terrain classification program based on these data There is. These programs automate most parts of the topographic classification map creation work process, and dramatically increase the efficiency of the creation work.

The terrain data processing program for determining the valley head of the present invention and storing or outputting the determination result has the information on the valley head candidate determined by the contour line shape in the computer, and the contour line having the information of the three-dimensional coordinates A step of reading data from the storage means, and when the candidate points of the valleys of the read contour data are not generated for the candidate points of valleys whose elevation is one rank lower, A step of generating downward, and a step of determining a starting point of each line formed of the generated coupled line segments as a valley head.

[data structure]
The present invention performs various data processing based on contour line data.
First, the data structure of contour line data will be described.
FIG. 2A is an image diagram of contour line data. In this figure, the numbers in the squares of the contour lines indicate line numbers, and the numbers in the circles also indicate point numbers.
FIG. 2B shows the data structure, and the file is divided into an xy file for storing x-coordinate data and y-coordinate data, and a z-file for storing z-coordinate data. The line number, point number, and END symbol are stored.
The present invention is based on contour line data, a program for classifying horizontal sectional shapes, a program for generating falling water lines, and a program for generating steepest climbs as basic programs, and an application program for performing various applied data processing, It is composed of The present invention is a valley determination program among the application programs, and details will be described in paragraphs 0033 to 0047.

The horizontal section shape classification program includes a contour position determination subprogram for determining whether the selected contour line data is located on the left or right side of the adjacent contour line data, and the data points of the contour lines are on the ridge-type slope. It consists of a horizontal section shape determination subprogram that determines whether it is located on a valley slope or a straight slope. Details will be described later.

In addition, the steepest climb generation program performs data processing using the arrival point of the earliest climbing data generated earlier from the lower slope to the upper side as the starting point of the next most rapid climbing data to be generated. By repeating, each point of the most rapid climbing line data is started from an arbitrary point of all the line segment data of the contour line data, and an arbitrary point of all the line segment data of the adjacent high level contour lines is the arrival point. It generates and generates the steepest climb that climbs with a maximum inclination from the contour line to the adjacent higher contour line. This is also described in detail in paragraphs 0020-0031.

Furthermore, the waterfall line generation program is the reverse of the steepest climbing line generation program, from the upper side of the slope to the lower side, the arrival point of the previously generated waterfall line data, By repeating the data processing as the starting point, each waterfall line starts from an arbitrary point of all the line segment data of the contour line data and starts from an arbitrary point of all the line segment data of the adjacent lower contour lines. Line data is generated to generate a falling water line that descends with a maximum inclination from the contour line to the adjacent lower contour line. This is also described in detail in paragraphs 0050-0058.

Hereinafter, the horizontal section shape classification program will be described in detail with reference to FIGS.
In order to classify the horizontal cross-sectional shape of the slope, it is necessary to know whether an arbitrary contour line is bent toward a high contour line or a low contour line.
For this reason, first, it is necessary to determine on the left or right side of the contour line data M whether the adjacent contour line data having a low or high altitude exists.
Furthermore, since the horizontal cross-sectional shape of the slope is classified according to the shape of the contour line, the inflection point of the curve becomes the point that divides the horizontal cross-sectional shape.

[Horizontal sectional shape classification program]
The horizontal sectional shape classification program includes a step of selecting an arbitrary data point of the line data of the selected contour line data as a reference point for generating the shortest distance line, and a high or low contour line adjacent to the selected contour line data. Of the arbitrary data points of the minute data, a step of selecting an arbitrary data point existing within a predetermined radius from the reference point as a selection point, and calculating the distance between the selection point and the reference point, and the shortest distance A temporary line segment is selected using the selected point as a destination point candidate, a line segment that connects the starting point and the destination point candidate is selected, and a line segment that does not intersect the temporary line segment is selected. A step of determining that a contour line including a minute is a high or low contour line adjacent to the selected contour line, and each of contour line data determined to be a high or low contour line adjacent to the reference point. When a line extended to any point of the minute does not intersect the temporary line segment, a step of setting any point of each line segment of the contour line data as a tip point candidate for creating a waterfall line, and Determining a candidate closest to the reference point from among the candidates as a tip point; generating a shortest distance line from the reference point toward the tip point; and the previous data starting from the reference point Cross product of a vector with the same orientation as a vector with a point as an end point and an arbitrary size, and a vector with the same direction as a vector with the reference point as a start point and the end point as an end point and an arbitrary size And a vector having the same orientation as the vector starting from the reference point and ending at the end point, and an arbitrary size, and the same vector as the vector starting from the reference point and ending by the next data point Have direction and size Calculate the sign of the outer product with an arbitrary vector, and when the outer product of both vectors is positive, the tip point is located on the right side of the reference contour data, and when the outer product of both vectors is negative, the tip point Is determined to be located on the left side of the reference contour data, and the angle formed by the vector from the data point immediately before the reference point to the reference point and the vector from the reference point to the data point after the reference point is predetermined. If it is equal to or less than the value, it is determined that the slope is an isotropic slope, and if the angle exceeds a predetermined value, whether the tip point is located on the left or right side of the reference contour data is one of the reference points. The same direction as the vector starting from the previous data point and having the reference point as the end point, and the vector of any size, and the vector starting from the reference point and the next data point as the end point Have a large Depending on whether the sign of the outer product with any vector is positive or negative, the adjacent contour data adjacent to the reference contour data is located on the left or right side of the reference contour data, the left or right side is higher, the slope is linear or valley type Classifying the horizontal cross-sectional shape of the slope according to whether it is a ridge type or the ridge type, and repeatedly executing each of the steps until the reference point reaches one point before the end point of the selected contour line data. When the contour data reaches one point before the end point, the next contour line data is selected and the above steps are repeated to classify the horizontal cross section of the slope for all data points except the start point and end point of the contour line data. The classification data is stored, output, or transmitted.

This will be specifically described below.
[Contour position determination subprogram]
First, Check 1 for checking the positional relationship with the contour line data one rank lower will be described with reference to FIGS.
In step 101, the contour line data is read, and the jth data point of the contour line data M (line number i) is set to m _j , and before and after that, m _j−1 and m _{j + 1} . At this time, the counter value, count = 0.
Next, in step 103, the contour line data K located next to M at the reference point m _j of the reference contour line data M and having an elevation lower than M is searched.
First, it is examined whether the contour line data M is located on the left or right side of the contour line data K one rank lower, and then, it is examined whether the contour line data M is located on the left or right side of the contour line data H one rank higher. This will be specifically described below.

In step 104, a line with the shortest distance from the reference point m _j to the contour line data K is drawn, and the intersection of this line and K is set as k. If the point k does not exist, the position of k cannot be determined, and the process proceeds to step 117 (step 105).
Vectors from reference points m _j to m _{j + 1} , m _j−1 , and k are α, γ, and β, respectively (FIG. 5), and only the x and y coordinate values of the contour data are used (Z = 0). The outer products γ × β and β × α are calculated (step 106). When γ × β> 0 and β × α> 0, the point k is positioned on the right side of the contour line data M (step 108), and the right side of the contour line data M is low as shown in FIG. If γ × β <0 and β × α <0, the point k is located on the left side of the contour line data M, and the left side of the contour line data M is low (step 112). (Γ × β> 0 and β × α <0), or (γ × β <0 and β × α> 0), or γ × β = 0 or β × α = 0. At this time, the point k is a point that is not suitable for the determination, and therefore the process jumps to Step 117.

Next, check 2 for checking the positional relationship with the contour data one rank higher will be described.
The same processing as the check of the positional relationship with the contour data that is one rank lower, except that contour data that is located next to M and has an elevation higher than M is used (the contour data is H and the data point is h). I do. That is, in steps 117 to 129, it is checked whether the contour line data H is located on the left or right side of M.
The vector from the reference points m _j to h is set as β ′, and the outer products γ × β ′ and β ′ × α are calculated using only the x-coordinate and y-coordinate values of the contour data (Z = 0) (see FIG. 5).
When γ × β ′ <0 and β ′ × α <0, the point h is located on the left side of the contour line data M, and the left side of the contour line data M is higher as shown in FIG.
If γ × β ′> 0 and β ′ × α> 0, the point h is located on the right side of the contour line data M, and the right side of the contour line data M is higher.
(Γ × β ′> 0 and β ′ × α <0), or (γ × β ′ <0 and β ′ × α> 0), or γ × β ′ = 0 or β ′ When xα = 0, the point h is a point that is not suitable for the judgment, and the process jumps to step 130 to use the next data point m _{j + 1} .
In order to confirm the topological relationship between the contour line data M and the adjacent contour line data, the processes of the above check 1 and the above check 2 are performed three times while changing the reference points (m _j = m _{j + 1} , m _{j + 2} ,...). repeat. At this time, the number of checks is recorded as the value of the counter.

Thereafter, when the values of the contour line position data J [1], J [2], and J [3] obtained as a result of the three checks all match, the position information is stored in the data area of the contour line data. Export as an attribute for. If they do not match, if a certain number of data points can be secured before reaching the end point of the contour data, the above checks 1 and 2 are repeated from the beginning.

In this example, if a certain number of data points cannot be secured before reaching the end point of the contour data, the matching data are contour line position data J [1] and J [2] of the first and second counters. Retake the data in [3]. If the next data point is the end point of the contour line data, the values of the contour line position data J [1], J [2] and J [3] obtained as a result of the three checks match. The position information is written as an attribute to the contour line data file.
The content of the position information is 1 when the right side of the contour line is low or high on the left side, and 2 when the right side of the contour line is high or the left side is low.
In this specific example, the check is started from the second data point of each contour line data, and when the same positional relationship is recognized three times while changing the reference point, the positional relationship is accepted as positive, The check start data point and the number of executions are not particularly limited to this, and may be executed appropriately.

[Horizontal cross section judgment subprogram]
In step 161 of FIG. 21, the contour line data and the value of position information J of each contour line data, that is, 1 or 2, created by the contour line position determination subprogram are read.
In the next step 162, γ defining a straight slope is input. In this example, γ is 5 °.
In the next step 164, the data points _{m j} contour data M, when placing a vector directed from the data points _{m j} to the data points _{m j + 1} and alpha _j, all of the data points of the contour data M, alpha _j-1 and The angle θ _j formed by α _j and the outer product α _j−1 × α _j are calculated (see FIG. 7). However, calculation is not performed at the start point and end point of M.
If the sign of the outer product at the point m _{j + 1} is different from the sign of the outer product at the point m _j , the midpoint between the points m _j and m _{j + 1} is the inflection point, and the contour data M is a new data point. Add.

Next, at all data points of the original contour line data M, the horizontal sectional shape of the slope is determined.
When the contour line data H and K exist on both sides of the contour line data M, the elevations of the contour line data H, M, and K are defined as E _H , E _M , and E _K , respectively (E _H ≧ E _M ≧ E _K. , Except for E _H = E _M = E _K ). At this time, if α _j−1 × α _j <0, the line m _j−1 m _j m _{j + 1} protrudes to the left of the contour line data M (FIG. 7A). If α _j−1 × α _j > 0, the line m _j−1 m _j m _{j + 1} protrudes to the right side of the contour line data M (FIG. 7B).
If the outer product α _j−1 × α _j = 0, m _j−1 m _j m _{j + 1} is a straight line, and the angle θ _j between the vectors α _j−1 and α _j is equal to 0 ° (0 ° ≦ θ _j <180 °).
The horizontal sectional shape of the slope at the point m _j is classified as follows.
Case 1. α _j−1 × α _j = 0 (θ _j = 0 °): straight slope (step 166)
Case 2. α _j−1 × α _j <0 and the contour line data H (K) is located on the left (right) side of the contour line data M: Catchment (valley type) slope (FIG. 7A, step 169)
Case 3. α _j−1 × α _j <0 and the contour line data H (K) is located on the right (left) side of the contour line data M: Divergent (ridge type) slope (FIG. 7A, step 170)
Case 4. α _j−1 × α _j > 0 and the contour line data H (K) is located on the left (right) side of the contour line data M: Divergent (ridge type) slope (FIG. 7B, step 173)
Case 5. α _j−1 × α _j > 0 and the contour line data H (K) is located on the right (left) side of the contour line data M: Catchment slope (FIG. 7B, step 174)
Since it is rare in the calculation that θ _j = 0 °, it is necessary to give a width to γ that defines the straight slope. For this reason, in this example, γ is calculated as ± 5 °.
This is the end of the description of the horizontal sectional shape classification program, and then the steepest climbing program.
[Early Climbing Line Generation Program]

This program is a program for generating a steepest climb from a data point of arbitrary contour line data to the nearest data point among the contour line data one rank higher.
The present invention repeats the data processing using the arrival point of the previously generated steepest climbing data as the starting point of the steepest climbing data to be generated next, to the computer. Starting from an arbitrary point and starting from an arbitrary point of all the line segment data of adjacent high level contour lines, the individual steepest line segment data is generated, and from the contour line to the adjacent high level contour line A topographic data processing program that generates the steepest climb that climbs at the maximum slope.
The terrain data program is
A first step of selecting an arbitrary data point of line segment data of arbitrary contour line data as a starting point for generating the steepest climb;
A second data point selected as a selection point is an arbitrary data point preferentially selected from the arbitrary data points of the line data of the higher contour line adjacent to the selected contour line data. And the steps
The distance between the selected point and the starting point is calculated, and the selected point having the shortest distance is selected as a candidate for the destination, and a temporary line segment that is a contour line segment including any of the preferentially selected data points is selected. A line segment connecting the origin and the candidate for the arrival point is selected and does not intersect the temporary line segment, and the contour line including the arrival point of the selected line segment is adjacent to the selected contour line A third step of determining a high contour line;
When a line drawn to an arbitrary point of each line segment of the contour line data determined to be a high-level contour line adjacent to the starting point does not intersect the temporary line segment, the arbitrary point of each line segment of the contour line data is determined as the maximum. A fourth step that is a candidate for a destination for rapid climbing;
A fifth step of determining the candidate closest to the starting point among all the candidate reaching points as a reaching point;
And a sixth step of generating steepest climb line segment data from the starting point toward the reaching point,
On the computer,
As the starting point of the steepest line data to be generated next the determined arrival point, the second to sixth steps are sequentially repeated,
When it is determined that there is no candidate for the arrival point and the end point of the steepest climb is reached, an arbitrary data point is selected, and then the second jump is made between the first and second steps. Through the sixth step,
When it is determined that the selected arbitrary data point is the last data of the arbitrary contour line data, contour data that has not yet been used as a starting point is selected and the first and second steps are performed. The process is repeated when the second to sixth steps are repeatedly executed, and when it is determined that there is no contour data that is not used for the start point, the process is terminated. It is a topographic data processing program for generating the steepest climb that climbs at the maximum slope.

In this embodiment, rise_i [line number of contour data] [point number of contour data] =-1 (when there is an existing fastest climb, the fastest climb number for all the data points of the contour data) Rise_j [Contour line data line number] [Contour line data point number] = -1 (-10 if the most rapid line cannot be drawn from that point, or if there is an existing rapid line) The point is characterized in that it is given the attribute of (adding the point number of the established steepest line at that point) (step 203).
As a result, it is possible to determine whether or not the most rapid climbing data has already been generated or whether or not it has been impossible to generate the data.

This embodiment will be described with reference to the flowcharts of FIGS.
In step 201, the CPU reads all the contour line data, and in the next step 202, the contour line data whose line number is n is first M _n , the nnth data point of M _n is m _nn , and the steepest climb data to be created the steepest registered line number s, the steepest registered ray data the W _s, W _s ss th point of the w _ss, which is the steepest registered line number s of.
In step 203, the above-mentioned attributes are given to all data points of the contour line data.
Next, after sequentially setting 1 to n, s and nn to define the starting point m = m _nn , ss = 1 is set (steps 205 to 208).

As a characteristic part of this embodiment, in step 209, whether or not the attribute rise_i [n] [nn] of the data point of the fastest climb data is positive, and in step 210, the fastest climb data It is determined whether or not it was impossible to generate.
From these steps 209 and 210, it is determined whether or not the fastest climb data has already been generated.
At this time, if the fastest climb data starting from the data point m has already been generated, the process proceeds to steps 211 and 213 without newly generating the fastest climb data, and the points of the fastest climb data are generated. It is determined whether the number is 1 and whether m is the end point of _Mn . If it is not the end point, the next data point is selected (nn = nn + 1) (step 214) and the process goes to step 207. Return. If m is the end point of M _n, M _n is determined whether the line number maximum contour data, if M _n is not the contour line data of the maximum line number, selects the next contour data (n = n + 1) ( Step 216) and return to Step 206, and if _Mn is the contour line data with the largest line number, it is determined that there is no contour line data that is not used for the start point. The data generation process is terminated.

In step 210, it is determined whether or not the point number of the fastest climb data is -10. Although this attribute-10 will be described later, it has already been impossible to extend the fastest climb data from m, in other words, the data point is determined to be the end point of the fastest climb. Therefore, the processing proceeds to the next step 211 without generating the most rapid climbing line segment data starting from m.
When the point number of the fastest climb data is not −10, m is the generation point of the fastest climb data W (fastest climb number s). At this time, m is the ss-th point of W (initial value ss = 0) (actually, in step 208, m is the first point of W).

Next, in step 217, it is determined whether or not there is contour line data whose elevation is one rank higher than the contour line data M _n , and if not, it is determined that it is the end point of the steepest climb data. The attribute “−10” is assigned, and the process returns to step 211.
Next, in steps 217 to 218, when there is contour line data whose elevation is one rank higher than the contour line data M _n and the data point of the contour line data higher than M _n is within the radius R of the starting point m, the elevation is 1 Among all the data points of the contour data with higher rank, all data points existing within a predetermined radius R from the starting point m are selected, and flag 1 is set for all the selected data points (step 219).
In step 217, when there is no contour data whose elevation is one rank higher than the contour data M _n , and in step 218, when the data point of the contour data higher than M _n is not within the radius R of the starting point m, the starting point Is the end point of the fastest climb data, and the line segment of the fastest climb cannot be drawn upward from m. Therefore, the attribute of −10 is given to the data point, and the process returns to step 211.
In the present embodiment, the predetermined radius R can be set by an analyst using an input device.
The predetermined radius R is selected for the analysis target area, and is selected in consideration of the contour line density, the accuracy of the obtained data, and the like. In this embodiment where the mountain area is the target area, R = 150 m (6 mm on the 1: 25,000 topographic map). The choice of R is important because it affects the computation time.

The CPU calculates the distance of the origin m data points selected (step 220), whose distance is short selected point and data point t _1, the contour line data of the contour including the data points t ₁ and T Along with (Step 221), a contour data line segment including all data points existing within the radius R from the starting point m (a line segment connecting two consecutive data points on the same contour line data) is selected (Step 222). .
Next, using these selected contour line data (hereinafter referred to as “provisional line segment”), it is determined whether or not the contour data T having an elevation of one rank is adjacent to the selected contour data M _n. Investigate.
If t ₁ is a data point of contour line data adjacent to M _n , the line segment mt ₁ does not intersect any temporary line segment (FIG. 3, A).
However, if t ₁ is not a data point of the contour line data adjacent to M _n , the line segment mt ₁ intersects any of the above-described temporary line segments.
Therefore, when it is determined in step 223 that the line segment mt ₁ intersects the temporary line segment, the flag is deleted to remove t ₁ from the selected point (step 224), and there is another selected point. As long as (step 225), the process returns to step 221, the point closest to the starting point m is selected by calculation, and the process proceeds to steps 222 and 223 to repeat this process. If there is no other selection point in step 225, the process returns to step 211 in the above-described procedure.
At this time, if the contour line data whose elevation is one rank higher cannot be determined using all the selected points, the data point m is set as the end point of the steepest climb data.

On the other hand, when it is determined by calculation that the line segment mt ₁ does not intersect with the temporary line segment, the contour line data T is assumed to exist next to the contour line data M _n .
Let T = Q, t ₁ = q _j , where q _j is the jth data point of Q.
At this time, k = j and kk = j, and in order to check whether or not the data points before and after the data point q _j also intersect the temporary line segment,
min = j-5 (provided that min = 1 if j-5 <0),
max = j + 5 (where j + 5> [maximum value of Q point number], max = [maximum value of Q point number]) (step 226).
Next, the line segment (q _{j + 5} ... Q _j− between the starting point m and the data points q _j before and after the data point q _j of the adjacent contour data Q whose elevation is one rank higher (in this example, every five points before and after). ₅ ) is to check whether or not it intersects with the temporary line segment (steps 227 to 229 and 231 to 233). A candidate for w is set (step 230.234).
Further, from the starting point m, a perpendicular line is drawn to a straight line passing through q _{k + 1} and q _k and a straight line passing through q _kk-1 and q _kk to make the intersections p _k and p _kk (step 238.244), p _k , p _kk Is a candidate for the tip point w for creating the steepest climb on the line segments q _{k + 1} q _k , q _{kk + 1} q _kk , and the line segments of mp _k , mp _kk do not intersect the temporary line segment (Step 241.247).
Then, the point closest to the starting point m is selected from among all the candidates for the leading point as the leading point w for creating the steepest climb (see FIG. 4), and m and w are connected to generate the steepest climb. The fastest climb data is stored in the fastest climb data file (step 250.251).

Further, in order to generate the steepest climb to the adjacent contour data on one rank, the contour data Q is replaced with M, the data point w is replaced with m (step 252), and ss is incremented by one. Proceeding to step 254, when m is not a data point of the contour line data, the process returns to step 217 to enter the process for generating the next steepest climb data.
On the other hand, when m is the data point m _ii of the contour line data M _i , it is determined whether rise_j [i] [ii] is −10 and rise_i [i] [ii] is −1. If there is, m is the end point, and if it is -1, the process returns to step 217 to enter the processing for generating the most rapid climbing data.
In step 256, when rise_i [i] [ii] is not −1, the fastest climb data passing through m _ii already exists. M _ii is the rise_j [i] [ii] th point of the rise_i [i] [ii] th steepest climb data (step 258).

At this time, the data from rise_j [i] [ii] + 1st point to the end point of the fastest climb data already generated from the data point m is connected to the fastest climb data W _s (step 258).
Next, at step 259, the ss-1th point from the start point of W (the ssth point is m) is examined.
The points that match the rr-th data point _{m rr} contour data _{M r} of the line number r is the contour line data points, rise_i [r] [rr] = W s line number, rise_j [r] [rr] = The attribute of point number in W _s is given.
If there is no w candidate in step 248, the process returns to step 211 after performing the process in step 266.
In step 256, when the line number of the steepest climbing data is -1, the steepest climbing data does not exist, so the process returns to step 217.
Further, in step 255, when the point number of the fastest climb data is -10, the process of steps 259 to 264 is performed with m as the end point of the fastest climb data W, and the process returns to step 213.

When the generation of the steepest climbing data from the last data point of the contour line data is completed, the steepest climbing data is generated from the first data point of the contour data one rank higher, and this processing is executed in sequence. When the contour data having the largest number is reached, the generation of the steepest climb data is terminated.

In the present embodiment, in step 203, rise_i [line number of contour data] [point number of contour data] = − 1 and rise_j [line number of contour data] [contour data] are added to all data points of the contour data. The point number] =-1 attribute is given, but this step can be omitted.
The flowchart of the program in this case is as shown in FIGS.

[Waterfall line generation program]
Next, the falling water line generation program will be described.
The program for generating the steepest climb from the data point of arbitrary contour line data to the data point climbing at the maximum slope of the contour line data one rank higher than the above On the contrary, a waterfall line is generated from a data point of arbitrary contour line data to a data point that falls at the maximum slope of the contour line data one rank below.
This program is actually used in the valley line generation program described later, and will be described in detail at that time.
The basic program of the present invention has been described above.
Next, various application programs will be described.
The application program includes a valley head determination program according to claim 1 (see paragraphs 0033 to 0047), a valley line generation program outside the gist (see paragraphs 0048 to 0058), a ridge line generation program outside the gist (see paragraphs 0059 to 0067), Grid for non-abstract valley degree calculation program (see paragraphs 0081-0090), out-of-summary valley order and slope vertical cross-section combination program (see paragraphs 0091-0111), and line data with non-abstract attributes It is a program (see paragraphs 0112 to 0132). Hereinafter, these application programs will be described in order.

[Determination program]
The valley line and ridge line are important information for grasping the shape of the entire mountain area. In particular, the valley head is the origin of erosion in the mountains, and is the top of the valley. The speed and direction of movement along the time of the valley is important for predicting the erosion and topographic change of the mountainous area and its speed.
In the present invention, a point corresponding to a valley head is selected from data points of numerical contour data by a procedure as close as possible to a traditional manual operation.
The valley head here means the top of the valley where the valley-shaped slope first appears in the mountains.

This will be described with reference to FIG.
This program first inputs and defines the angle to determine the upper limit angle that defines the valley slope.
Then, the horizontal sectional shape classification program already described in paragraphs 0012 to 0019 is executed to output horizontal sectional shape classification data.
Next, the horizontal section classification data is read to analyze the attribute of one unit line.

In this embodiment, by using one unit line classified as a valley slope by the horizontal sectional shape classification program, the valley head that is the starting point of the valley line is defined.
In this embodiment, when θ _j <5 °, the horizontal cross section at the data point m _j is treated as a straight slope.
As an item for defining the valley head, in this embodiment, the valley head is defined using the angle s ₁ Ps ₂ of the valley slope, but the width (D ₁ ) of the valley slope and the depth of the valley slope are defined. Of course, it may be defined using (L / D ₁ ) (see FIG. 10).

[1 unit line attribute analysis program]
This will be described with reference to FIG.
First, the output result of the horizontal section classification program, which is the basic program described above, is read, each contour line data is classified by horizontal section, and a line file is created for each unit line, with the classified lines as one unit. . The line number of the classified line is set to s (step 401).

Next, the read contour line data is M (line number i), the start point of M is m ₁ , the end point is m _n , and the jth point is m _j . At this time, the line number s = 1.
Then, M is determined whether the polygon (step 403), if the polygon is checked whether or not the flag of the start and end points of the data points are the same (step 404), and m ₁ be the same m the midpoint of the _n-1 to the start point of one unit (step 405), the _{m 1} if they are the same as a start point of one unit (step 406).
If it is determined in step 403 that the object is not a polygon, m ₁ is set as a starting point of one unit (step 407).

Next, the next point m _j is read to determine whether the read point is one point before the end point (step 409). If the read point is one point before the end point, is n = 3? determining, when the _n = 3, _m n (step 411) as an end point of a unit, the process proceeds to the subroutine Option1 (see FIG. 50) in the next step 412.
If n = 3 is not satisfied, it is checked whether or not the flag of the read point is the same as that of the previous point (step 413). If equal, the point immediately after the read point is set as an end point (step 414). If they are not equal, the midpoint of the read point and the previous point is set as the end point of one unit (step 416), and the process proceeds to the subroutine Option1.
In the above step 409, if the point read this time is not one point before the end point, it is checked whether the flag of the point read this time is the same as the flag of the point before one (step 420). The midpoint of this point is set as the end point of one unit (step 421), and the process proceeds to the subroutine Option1.

For the outline of the processing contents of the subroutine Option1, with reference to FIGS. 10, 11, and 50, the start point and the end point of one unit are determined in the above processing, so whether there is a predetermined valley depth or ridge protrusion thereafter? Judgment of whether or not, giving a valley-type or ridge-type attribute for a unit line with a predetermined valley depth or ridge protrusion, and giving a straight line attribute to the others .

First, it calculates a straight line distance D ₁ of the start and end points of one unit (step 431).
Then, a perpendicular line is dropped from each data point, except for start and end points on one unit line with respect to the straight line D _1, we obtain the respective perpendicular length, the longest ones L, data point that is the end point of the L (point number b) is determined (step 432). The data point with the point number b is set as the apex of the valley slope or the ridge slope.
Then, the length (s ₁ p) of the start point of one unit and the data point of the point number b (s ₁ p) and the length of the end point of one unit and the data point of the point number b (s ₂ p) are calculated, and the line segment s ₁ The angle ω of the valley-type slope or the ridge-type slope is calculated using p, line segment s ₂ p, and line segment D ₁ (step 433).
The angle is calculated using the following formula:

(Formula 1)

The horizontal cross-sectional shape is the same at all data points on one unit line excluding the start point and end point. Therefore, the attributes of straight line: 0, ridge type: 1, valley type: -1 are assigned to each unit line (step 434).
For each unit line, the xy coordinates are written together with the attribute of horizontal section (r) (step 435).
At this time, if the start point of one unit is the midpoint between two consecutive data points (m _j−1 and m _j ), the data is written from m _j . Similarly, when the end point of one unit is the midpoint between two consecutive data points (m _j−1 and m _j ), the contents of the file to be written up to m _j−1 are as shown in the table below. . Let this file be file_xyr1.

(1 in Table 1)

structure of file_xyr1 (2 in Table 1)
At this time, when the data point corresponds to the apex (point number b) of the valley slope where ω <a, r = −10, and when the data point is other than the apex on the valley slope, r = −1. r = 10 when the data point corresponds to the apex (point number b) of the ridge slope where ω <a, r = 1 when the data point is other than the apex on the ridge slope, and r otherwise. = 0 attribute is provided (step 435).
In addition, s and Z _s are also written in the line elevation file (Z _s is the elevation of one unit line of the horizontal section number s).
In the next step 436, s is incremented by 1 to return to the attribute analysis program of one unit.

At this time, when the subroutine Option1 is executed and returned in step 417 and step 422, the flag of the previous point is not equal when read this time, that is, the middle point of m _j−1 and m _j is changed. Since it is clear that it is a music point, the start point of the next unit is set as the midpoint between m _j−1 and m _j (steps 418 and 423).
Then, in step 418-1, it is checked whether flag [m ₁ ] = flag [m _n-1 ], and by either of them, the subroutine Option1 is executed again with the start point determined in step 404 as the end point (step 419). ). The above processing is repeated until M becomes the contour line data having the largest line number. When M becomes the contour line data having the largest line number, the process returns to the main routine.

[Tanigami decision program]
This will be described with reference to the flowchart of FIG.
In order to determine the valley point, first, the candidate is extracted (FIG. 11_1).
In order to find a data point to be a valley head, a process of drawing a line (hereinafter referred to as a “zigzag line”) connecting data points with r = −10 written to file_xyr1 by the attribute analysis program of one unit line described above is executed. .
First, file_xyr1 and its elevation file are read and rearranged in order from the highest contour line (step 441).
Next, the maximum length R of the zigzag line segment is determined (step 443).
All of the data points are given attributes such as fall_i (contour line number, contour data point number) =-1, and fall_j (contour line number, contour data point number) =-1. Line numbers n (1, 2, 3,..., N_end) are given to the contour line data in the order of reading. At this time, g = 0 is set (step 444).
Further, the contour line data of the line number n is M, and a point number nn (1, 2, 3,..., Nn_end) is given to each data point of M (step 445).
Then, the data point of the M point number nn is set to m (step 446).
In the next step 447, it is checked whether or not the attribute r of m is −10. If it is −10, the data point is a candidate for a valley head, and therefore, the process moves to step 448 and falls_i (n, nn)> 0. Judge whether.
Here, if fall_i (n, nn)> 0, the zigzag line number has already been set, and there is already a zigzag line passing through m, so a zigzag line starting from m is not generated. On the other hand, if fall_i (n, nn)> 0, it is determined whether fall_j (n, nn) is −10. If it is −10, an attempt is made to extend the zigzag line from m. Since it was possible, a zigzag line starting from m is not generated. When fall_j (n, nn) is not −10, g = g + 1 and m is the generation point of the zigzag line W (line number g). At this time, m is the gg-th point (gg = 1) of W (step 450).
Here, an attempt is made to extend the zigzag line W from m. At this time, the point number at W of m is gg.

Therefore, when there is contour data whose rank is one rank lower than M, among data points of contour data lower than M, if a data point having an attribute r of −10 exists within a radius R of m ( Step 453), the above point is set as a selection point of the valley head. A contour line segment including a data point existing within the radius R of m is selected as a temporary line segment (step 454).
In step 455, when there is a line segment that does not intersect the temporary line segment among the line segments (selected line segments) that connect m and the selected points, the long selected line segment that does not intersect the temporary line segment. The selection point having the smallest value is determined as the extension point w from m (step 456).
Then, the contour line data including w is replaced with M and w is replaced with m (step 457), and the process proceeds to the next step 458. However, m is a data point of point number jj of contour line data M of line number ii.
If fall_i (ii, jj) = − 1, the zigzag line point number gg is incremented by 1 (step 459), and the process returns to step 452.
Further, when not fall_i (ii, jj) = − 1, it is checked whether or not fall_j (ii, jj) = − 10 (step 460). If not 10, W is connected from the [fall_j (ii, jj) +1] th point of the zigzag line W ′ to the end point (step 462).
Next, the gg-1st point from the start point of W (the ggth point is m) is examined. For points that coincide with the data points (assuming t, point number bb) of the contour line data (assuming T, line number aa), fall_i (aa, bb) = g, fall_j (aa, bb) = After giving the attribute of point number in W (step 464), the process returns to step 467.

When it is determined No in Steps 452 and 453, the attribute of fall_i (n, nn) = − 10 is given, and m is treated as an end point of W (Step 471), and the process proceeds to Step 467. If the maximum point number assigned in step 445 has been reached, the point number nn is incremented by 1 and the flow returns to step 446.
When it is determined in step 467 that the point number has reached the maximum value, it is checked whether the line number assigned in step 469 has reached the maximum value. If not, the line number n is incremented by 1. Then, the process returns to step 445 and the above processing is repeatedly executed.
When the process proceeds and all processes are executed and it is determined Yes in step 469, the creation of the zigzag line is terminated, and the starting point of the created zigzag line is determined as the valley head (step 472).
As a final process, file_xyr1 is called again, and when the read (x, y) coordinates are equal to the (x, y) coordinates of the starting point of the created zigzag line, the attribute of r is set to −10, and the others When r is changed to r = 0, it is written in the same format as file_xyr1. This is designated as file_xyr2 (step 474).
As is clear from the above, file_xyr2 has only the value of attribute r changed compared to file_xyr1.
It is also possible to create a point file of only the data points at the valley head.

[Generate valley lines]
The valley line and ridge line are important information for grasping the shape of the entire mountain area. In particular, valley lines are indispensable information for classification of water systems, extraction of water system areas and calculation of valley density, etc. It is used in the extraction of lineament by rock structure.
The purpose of the present invention is to generate valley lines in a procedure as close to traditional manual work as possible. Is generated.
The valley line here means a falling water line that is generated only from the valley head and falls most steeply.
Accordingly, no falling water line is generated from data points other than the top of the valley which is the top of the valley. In this respect, it differs from the falling water line generated from all the data points of the contour line data.

As shown in the flowchart of FIG. 44, the present invention reads valley head data obtained by executing a program for determining a valley using a part of a horizontal sectional shape classification program and an analysis program of one unit line, A program for generating a valley line using a part of the line generation program is executed to generate a valley line. (FIG. 44).

First, the file_xyr2 and its elevation file described above are read, and the waterfall line generation program subroutine shown in FIGS. 24 and 25 is entered to generate the waterfall line data only from the data point where r = −10, that is, the valley head. Thus, step 301 is skipped and processing is started from step 302.

[Waterfall line generation program]
At this stage, valley lines are generated.
In step 302, the CPU first sets contour line data having a line number n to M _n , the nnth data point of M _n to m _nn , the falling line number of the falling water line data to be created to s, and the falling water line number s. The falling line data is W _s , and the ssth point of W _s is w _ss .
In step 303, the r attribute is given to all data points of the contour line data. In other words, the line number n, the data points _{m nn} is the point number nn, fall_i [n] [nn ] = - 1, fall_j [n] [nn] = - 1 to.
In the next step 304, when a line segment of a falling water line is drawn downward from an arbitrary point a, a is set as the starting point m.
Next, 1 is sequentially set to n, s, and nn to define the starting point m = m _nn and then ss = 1 is set (steps 305 to 308).

As a characteristic part of the present embodiment, in step 309, whether or not the attribute fall_i [n] [nn] of the data point of the waterfall line data is positive, and in step 310, it is attempted to generate the waterfall line data. Determine whether it was impossible.
By these steps 309 and 310, it is determined whether or not the waterfall line data has already been generated.
At this time, if the waterfall line data starting from the data point m has already been generated, the process proceeds to steps 311 and 313 without newly generating the waterfall line data, and whether the point number of the waterfall line data is 1 or not. It is determined whether or not m is the end point of _Mn . If it is not the end point, the next data point is selected (nn = nn + 1) (step 314) and the process returns to step 307. If m is the end point of M _n, M _n is determined whether the line number maximum contour data, if M _n is not the contour line data of the maximum line number, selects the next contour data (n = n + 1) ( Step 316) and return to Step 306, and if M _n is the contour line data having the largest line number, the generation process of the falling water line data is terminated.

When the point number of the waterfall line data is not −10, m is the generation point of the waterfall line data W (waterfall line number s). At this time, m is the ssth point of W (step 308).

Next, in step 317, it is determined whether or not there is contour line data whose elevation is one rank lower than the contour line data _Mn . If not, it is determined that it is the end point of the waterfall line data. An attribute of −10 is assigned as the data point number, and the processing returns to step 311.
Next, in steps 317 to 318, when there is contour line data whose elevation is one rank lower than the contour line data M _n and the data point of the contour line data lower than M _n is within the radius R of the starting point m, the elevation is 1 Among all the data points of the contour data with low rank, all data points existing within a predetermined radius R from the starting point m are selected, and flag 1 is set for all the selected data points (step 319).
In step 317, when there is no contour data whose elevation is one rank lower than the contour data M _n , and in step 318, when the data point of contour data lower than M _n is not within the radius R of the starting point m, the starting point Is the end point of the waterfall line data, and the line segment of the waterfall line cannot be drawn downward from m. Therefore, the attribute of fall_j [n] [nn] = − 10 is given to the data point, and the process returns to step 311. .
In the present embodiment, the predetermined radius R can be set by an analyst using an input device.
The predetermined radius R is selected for the analysis target area, and is selected in consideration of the contour line density, the accuracy of the obtained data, and the like. In this embodiment where the mountain area is the target area, R = 150 m (6 mm on the 1: 25,000 topographic map). The choice of R is important because it affects the computation time.

The CPU calculates the distance of the origin m data points selected (step 320), whose distance is short selected point and data point t _1, the contour line data of the contour including the data points t ₁ and T In addition to (Step 321), a contour data line segment including all data points within the radius R from the starting point m (a line segment connecting two consecutive data points on the same contour line data) is selected (Step 322). .
Next, using the selected line segments of the contour line data (hereinafter referred to as “provisional line segments”), it is determined whether or not the contour line data T whose elevation is one rank lower is adjacent to the selected contour line data M _n. Investigate.
If t ₁ is a data point of contour line data adjacent to M _n , the line segment mt ₁ does not intersect any temporary line segment (FIG. 3, A).
However, if t ₁ is not a data point of the contour line data adjacent to M _n , the line segment mt ₁ intersects any of the above-described temporary line segments.
Therefore, when it is determined in step 323 that the line segment mt ₁ intersects the temporary line segment, t ₁ is removed from the selected points (step 224), and as long as there are other selected points (step 325), step Returning to 321, the point t ₂ closest to the starting point m next to t ₁ is selected, and the processing proceeds to steps 322 and 323 to repeat this processing. If there is no other selection point in step 325, the process returns to step 311 in the above-described procedure.
At this time, if the contour line data whose elevation is one rank lower cannot be determined even if all the selected points are used, the data point m is set as the end point of the falling water line data.

On the other hand, when it is determined that the line segment mt ₁ does not intersect with the temporary line segment, the contour line data T is assumed to exist next to the contour line data M _n .
Let T = Q, t ₁ = q _j , where q _j is the jth data point of Q.
At this time, k = j and kk = j, and in order to check whether or not the data points before and after the data point q _j also intersect the temporary line segment,
min = j-5 (provided that min = 1 if j-5 <0),
max = j + 5 (where j + 5> [maximum value of Q point number], max = [maximum value of Q point number]) (step 326).
Next, the line segment (q _{j + 5} ... Q _j−5 ) between the data point q _j before and after the starting point m and the data point q _j of the adjacent contour line data Q one rank lower (in this example, five before and after) Whether the line segment intersects with the line segment is checked (steps 327 to 329, 331 to 333), and the line segment between the starting point m and each data point does not intersect with the temporary line segment is set as a candidate for the tip point w of the falling water line creation ( Step 330.334).
Further, from the starting point _m, the intersections down the perpendicular line to the straight line passing through the straight line and _{q kk-1} and _{q kk} through the _{q k + 1} and _{q k p k,} and _{p kk} (step _{338.344), p} k, p _kk Is a candidate for the tip point w of the falling water line creation for those that are on the line segments q _{k + 1} q _k , q _{kk + 1} q _kk and the line segments of mp _k , mp _kk do not intersect the temporary line segment (step 341.347).
Then, the point closest to the starting point m is selected from all the candidates for the tip point w as the tip point w for creating the falling water line, and a falling water line is generated by connecting m and w. It is stored in the data file (step 350.351).

Further, in order to generate a falling line from the contour line data adjacent one rank below, the contour line data Q is replaced with M _n , the data point w is replaced with m (step 352), and ss is incremented by one. Proceeding to step 354, when m is not a data point of contour line data, the process returns to step 317 to enter the next waterfall line data generation process.
On the other hand, when m is the data point m _ii of the contour line data M _i , it is determined whether fall_j [i] [ii] is −10 or −1. If it is −10, m is the end point (step 365), and if it is -1, the process returns to step 317 and enters the process of generating the falling water line data.
In step 356, when fall_i [i] [ii] is not -1, waterfall line data passing through m _ii already exists. M _ii is the fall_j [i] [ii] th point of the fall_i [i] [ii] th falling water line data (step 358).

At this time, the fall line data Ws already generated from the data point m is connected to the fall line data W _s from the fall_j [i] [ii] + 1st point to the end point (step 358).
Next, in step 359, the ssth point from the start point of W (the [ss + 1] th point is m) is examined.
The points that match the rr-th data point _{m rr} contour data _{M r} of the line numbers r are the data points _{m rr, fall_i [r] [} rr] = W s line number, fall_j [r] [rr] = The point number at W _s is given.
If there is no w candidate at step 348, the process returns to step 311 after performing the process of step 366.
In step 356, when fall_i [i] [ii] of the waterfall line data is −1, since there is no waterfall line data, the process returns to step 317.
Furthermore, in step 355, when the point number of the waterfall line data is −10, it has already been impossible to extend the waterfall line data from m. Step 359 is processed.

Further, in order to generate a waterfall line from the contour line data adjacent to one rank below, the contour line data Q is replaced with M and the data point w is replaced with m (step 352), and the process returns to step 317 and returns to step 318. Step 353 is repeated until the end point of the waterfall line is reached.
When the end point of the waterfall line is reached, the process returns to step 311 again to continue generating waterfall line data from the next data point until the end point is reached.
When the generation of waterfall data from the last data point of the contour line data is completed, waterfall line data is generated from the first data point of the contour data one rank below, and this processing is sequentially executed, and the line number with the largest line number is When the contour data is reached, the generation of the falling water data is terminated.

[Ridge line generation program]
The steepest climb is important information for grasping the shape of the entire mountain area. In particular, it has been pointed out that the ridge line has a deep relationship with avalanches, and it is indispensable for disaster prevention by creating hazard maps of avalanches.
The object of the present invention is to generate a ridge line by a procedure that is as close to the traditional manual work as possible. A line is generated.
The ridge line here means the steepest climb that is generated only from the ridge lower end point and climbs with the steepest slope.
Accordingly, no ridge line is generated from data points other than the ridge bottom end point of the ridge which is the most protruding point. In this respect, it differs from the steepest climb generated from all data points of the contour line data.

This program (see FIG. 40) is defined by inputting a numerical value of the angle in order to determine an upper limit angle that prescribes a ridge-type slope.
Then, the above-described horizontal sectional shape classification program (see FIGS. 19 to 21) is executed to output horizontal sectional shape classification data.
Next, this horizontal section classification data is read and the attribute of one unit line (see FIG. 49) is analyzed.
A subprogram (see FIG. 27) for determining the ridge lower end point based on the data obtained by the analysis is executed, and then a subprogram for generating a ridge line is executed to generate a ridgeline.

In this embodiment, by using one unit line classified as a ridge-type slope by the horizontal sectional shape classification program, the ridge lower end point that is the starting point of the ridge line is defined.
In this embodiment, when θ _j <5 °, the horizontal cross section at the data point m _j is treated as a straight slope.
As an item for defining the ridge bottom point, in this embodiment, the ridge bottom point is defined by using the angle of the ridge slope (型 s ₁ ps ₂ ), but the width of the ridge slope (D ₁ ) And the depth of the ridge-type slope (L / D ₁ ), of course (FIG. 10_2).

[1 unit line attribute analysis program]
Since this program is the same as the attribute analysis program for one unit line of the valley line generation program already described in paragraphs 0036 to 0048, detailed description thereof will be omitted.

[Ridge bottom point determination program]
In order to find the data point that becomes the lower end point of the ridge, a line (hereinafter referred to as “zigzag line”) connecting the data points with r = 10 written to file_xyr1 by the attribute analysis program of one unit line described above is drawn.
This will be described with reference to FIG.
In order to determine the ridge bottom point, first, the candidate is extracted (FIG. 11_2).
First, file_xyr1 and its elevation file are read and rearranged in order from the contour line with the lowest elevation (step 441-2).
Next, the maximum length R of the zigzag line segment is determined (step 443-2).
All data points are given attributes of rise_i (line number of contour line data, point number of contour line data) = − 1 and rise_j (line number of contour line data, point number of contour line data) = − 1. Line numbers n (1, 2, 3,..., N_end) are given to the contour line data in the order of reading. At this time, g = 0 is set (step 444-2).
Further, the contour line data of the line number n is set to M, and a point number nn (1, 2, 3,..., Nn_end) is given to each data point of M (step 445-2).
Then, the data point of the M point number nn is set to m (step 446-2). In the next step 447-2, it is checked whether or not the attribute r of m is 10, and if it is 10, the data point is a candidate for the bottom edge of the ridge, so the process proceeds to step 448-2 and rise_i (n, nn). )> 0 is judged.
Here, if rise_i (n, nn)> 0, the zigzag line number has already been set, and there is already a zigzag line passing through m. Therefore, no zigzag line starting from m is generated. Conversely, if rise_i (n, nn)> 0 is not satisfied, it is determined whether rise_j (n, nn) is −10. If it is −10, an attempt is made to extend the zigzag line from m. Since it was possible, a zigzag line starting from m is not generated. When rise_j (n, nn) is not −10, g = g + 1 and m is the generation point of the zigzag line W (line number g). At this time, m is the gg-th point (gg = 1) of W (step 450-2). Here, an attempt is made to extend the zigzag line W from m.

Therefore, when there is contour data whose elevation is one rank higher than M, among data points of contour data higher than M, if a data point having attribute r is within radius R of m (step 453-2), and the above point is set as a selected point of the ridge lower end point. A contour line segment including a data point existing within the radius R of m is selected as a temporary line segment (step 454-2).
In step 455-2, when there is a line segment (selected line segment) connecting m and each selected point that does not intersect with the temporary line segment, among the selected line segments that do not intersect with the temporary line segment. The selection point having the minimum length is determined as the extension point w from m (step 456-2).
The contour data including w is replaced with M and w is replaced with m (step 457-2), and the process proceeds to the next step 458-2. However, m is a data point of point number jj of contour line data M of line number ii.
Here, if rise_i (ii, jj) = − 1, the zigzag line point number gg is incremented by 1 (step 459-2), and the processing returns to step 452-2.

When it is determined No in Steps 452-2 and 453-2, an attribute of rise_j (n, nn) = − 10 is given, and m is treated as an end point of W (Step 471-2). The process proceeds to step 467-2, where it is checked whether or not the maximum value of the point number assigned in step 445-2 has been reached. If not, the point number nn is incremented by 1 and the process returns to step 446-2. .
When it is determined in step 467-2 that the point number has reached the maximum value, it is checked whether or not the line number assigned in step 444-2 has reached the maximum value. Is incremented by 1, and the process returns to Step 445-2 to repeat the above processing.

When the process proceeds and all the processes are executed and it is determined Yes in step 469-2, the creation of the zigzag line is terminated, and the starting point of the created zigzag line is determined as the ridge lower end point (step 473-). 2).
As final processing, file_xyr1 is called again, and when the read (x, y) coordinates are equal to the (x, y) coordinates of the starting point of the created zigzag line, 10 is set as the attribute of r, and otherwise Change to r = 0 and write in the same format as file_xyr1. This is designated as file_xyr2 (step 474-2). As is clear from the above, file_xyr2 has only the value of attribute r changed compared to file_xyr1.
When the above processing is completed, the process returns to the main routine of the ridge line generation program.

[Early Climbing Line Generation Program]
Generate a ridge line.
First, the file_xyr2 and its elevation file are read, and in order to generate the ridge line data only from the data point where r = 10, that is, the ridge bottom point, the subroutine of the steepest ridge generation program (see FIG. 22) is entered. Step 201 is skipped, and processing is started from Step 202.
Since the subsequent processing contents are the same as those described in paragraphs 0022 to 0031, the description thereof is omitted.

When generating a line connecting contour line data of the same height in the buttocks or the like, the following processing is further performed.
The program described below assumes that the number of line segments connecting any two contour lines is one.
Execute the unit line attribute analysis program again. The option executed at this time is Option1 (see FIG. 50). At this time _{D 2} is not calculated. Further, since the inflection points are not written out, the number of read data points is equal to the number of data points to be written.
When the attribute analysis program for one unit line is finished, the process returns to the main routine and the same contour line generation program is executed.

[Same Contour Line Segment Generation Program]
This will be described with reference to FIGS.
First, the user inputs and determines the total length max_length of the contour line and the maximum length limit_length of the line segment to be combined.
Contour data whose total length is shorter than max_length and whose start point = end point is set as the start polygon, and a line segment connecting the contour lines having the same height as the start polygon is drawn. This line segment does not exceed the maximum length limit_length determined by the user.
Next, file_xyr is read, and line numbers i (1, 2, 3,...) Are given in the reading order. Let sum be the total number of contour lines. Further, the total number of contour line data points with line number i is set to P [i] (step 482).
Also, file_Z is read and the elevation of each contour line is set to Z [i] (step 483).
In the next step 484, when the line number is i for each contour line, (1) the attribute poly [i] = 1 is given to the contour line data where the starting point = ending point,
Otherwise, give the attribute poly [i] = 0,
(2) The total length is calculated, and the line number line_i [i] and the total length line_l [i] are saved and temporarily stored. Next, s = 1 and i = 1 are set (steps 485 to 486). In the next step 487, if poly [i] = 1, the total length is less than or equal to max_length, and the altitude is higher than 0, the line number (poly_i [s] = i) and the total length (poly_l [ s] = line_l [i]) is temporarily stored, s is incremented by 1, and the process proceeds to step 490 (steps 487 to 489).
On the other hand, if any of the conditions that poly [i] = 1 total length <max_length and elevation is above 0 is not satisfied in step 487, the process proceeds to step 490.
In step 490, it is determined whether or not the line number i is equal to the total number of contour line data sum. If not, the line number i is incremented by 1, and the process returns to step 487 to repeat the process.
On the other hand, when it is determined that the line number i is equal to the total number sum of contour line data, the total number p_num of start polygons is set to s, and the start polygon selection process is ended (step 492).

In the next step 493, poly_i [s] and poly_l [s] are rearranged in order of decreasing poly_l [s]. By this processing, poly_l [1] (contour line number poly_i [1]) becomes the start polygon with the shortest overall length, and poly_l [p_sum] (contour line number poly_i [p_sum]) becomes the start polygon with the longest overall length. .
Next, line_i [i] and line_l [i] are rearranged in order of increasing line_l [i].
By this processing, line_l [1] (the contour line number line_l [1]) becomes the contour line with the longest overall length, and line_l [sum] (the contour line number line_l [sum]) becomes the contour line with the shortest overall length (step 494). .

In the next step 495, a line segment connecting the starting polygon and the contour line is written.
The number of the line segment to be written is number = 0. Also, ii = 1 is set (step 496).
Next, the line number i of the contour line, which is the starting polygon for examining whether or not the line segment can be connected, is set to poly_i [ii] (step 497).
Further, after setting hh = 1, the line number h of the contour line for examining whether or not the line segment with the starting polygon (line number i) can be connected is set to line_i [hh] (steps 498 to 499).
Then, the altitude is 0, and it is examined whether or not the line segment between the start polygon and the start polygon can be connected. The contour line is not equal in elevation, and the line number between the start polygon and the start polygon (line number i) If any one of the three conditions of the contour line number h for examining whether or not the minutes can be satisfied is satisfied, when the contour line number hh is not equal to the total number sum of contour lines, hh is incremented by 1 (step 504), If equal, if the total number of start polygons has not been reached, the next start polygon is selected (step 506). When the total number of start polygons has been reached, the creation of the line segment is terminated (step 507) and the line segment is written ( Step 508).
At this time, writing to the output file is repeatedly executed from t = 1 to t = maximum line segment number to be written (cycle of steps 509 to 511). The format of the output data at this time is as shown in the following table.

(Table 2)
When the value of t reaches the maximum line segment number to be written, writing to the output file is stopped (step 511).

On the other hand, in steps 500 to 502, the elevation is 0, and it is examined whether or not the line segments of the start polygon and the start polygon can be connected. When the line number of the contour line for which it is considered whether or not the line segment can be connected to the line number is equal, if none of the three conditions is satisfied, the starting polygon (line number i) and the contour line (line number h) are ) To see if there is a line connecting. Then, a combination of data points connecting the two contour lines with the shortest distance is searched.

In step 514, tmp_j = -1, tmp_g = -1, ll = 100000 [m], and then j = 1. This j is the point number of the starting polygon (step 515). Then, it is determined whether or not the point j is a data point that is a ridge-type slope (r = 1). If Yes, g = 1 is set. g is a point number of a contour line h for examining whether or not a line segment with the starting polygon can be connected.
If the point g is a data point having a ridge slope (r = 1) (step 518), if poly [h] = 1 and g = p [h], the distance l between the point j and the point g is set. Calculate (step 520), and when ll is larger than l, tmp_j = j, tmp_g = g, and ll = l, and the process proceeds to step 523. On the other hand, when ll is smaller than 1, the process proceeds directly to step 523.
In step 523, if it is not the total number of point numbers of the contour line h for examining whether or not the line segment with the starting polygon can be connected, g is incremented by 1, and the process returns to step 518 to determine whether or not the line segment with the starting polygon can be connected. When the total number of point numbers of the contour line h to be examined is reached, the process proceeds to step 525. If the value of j has not reached the total number of points of the starting polygon, j is incremented by 1 (step 526), and the process returns to step 516.
In step 525, if the value of j has reached the total number of points of the starting polygon, the process proceeds to step 527, where it is checked whether tmp_j is -1, and if it is -1, the process returns to step 503 again.

On the other hand, when tmp_j is not −1 in step 527, j = tmp_j and g = tmp_g are set, and the point on h closest to point j is searched by executing the following steps.
In step 530, time = 1, tt = 0, x1 = x [i] [j], and y1 = y [i] [j]. Here, (x [i] [j], y [i] [j]) is the (x, y) coordinates of the data point of the point number j of the contour line of the line number i.
Next, at step 531, if the total number of point numbers of the contour line h for examining whether or not the line segment with the start polygon can be connected is 5 or less, the process proceeds to step 532 and start1 = 1 and end1 = P [h]. .
Further, when the total number of point numbers of h exceeds 5, when the point number is 1, start1 = 1, end1 = 3, and in the case of a polygon, further, times = 2, start2 = p [h] − 2, end2 = p [h] (step 536).
Further, when the point number is 2, start1 = 1, end1 = 4, and in the case of a polygon, further, times = 2, start2 = p [h] -1, end2 = p [h] (step 540). ).
When the point number is equal to the total number of point numbers, start1 = p [h] −3 and end1 = p [h] are set (step 542).
When the point number is equal to (total number of point numbers −1), start1 = p [h] −3, end1 = p [h], and in the case of a polygon, further, times = 2, start2 = 1, end2 = 2 (Step 546).
When the determinations in steps 531, 533, 537, 541, and 543 are all No, start1 = g−2 and end1 = g + 2 are set (step 547), and the process proceeds to step 548.
If the determinations in steps 531, 533, 537, 541, and 543 are Yes, the process proceeds to step 548 even after the next process is executed.

By the processing after step 548, a line segment between the point j and the data point from start1 to end1 on h is examined.
First, k = start1 is set (step 549).
In the next step 550, x2 = x [h] [k] and y2 = y [h] [k] are set.
By executing the following steps, it is checked whether or not the line segment tmp_segment having (x1, y1) and (x2, y2) as endpoints intersects the contour line. At this time, it is only necessary to examine the contour lines whose elevation is Z [i] and an elevation that is one rank lower than Z [i].
In step 552, it is determined whether or not the line segment tmp_segment having the end points at (x1, y1) and (x2, y2) intersects the contour line.
In the next step 553, with respect to the length l of tmp_segment, it is checked whether limit_length is 1 or more, and when it is 1, x2, y2, 1 are stored. Also, tt = tt + 1 tmp_x [tt] = x2, tmp_y [tt] = y2, tmp_l [tt] = l (step 554), the process proceeds to the next step 555, and it is determined whether k = end1. When it is determined No, k is incremented by 1, and the process returns to Step 550 to repeat the above processing.
If it is determined in step 552 that the line segment tmp_segment having (x1, y1) and (x2, y2) as endpoints intersects the contour line, the process proceeds to step 555 without saving the data.
In step 555, when the value of k reaches end1, with respect to each line segment from the contour data points start1 to end1 by a process after step 557, an intermediate point (line Also check n equal points (points where n is an integer).
At this time, the length of each of the n equally divided line segments is assumed to be longer than min_length. This min_length is determined by input by the user.
In step 559, the value of k is set to start1.
The length 12 of the contour line segment whose end points are (x [h] [k], y [h] [k]) and (x [h] [k + 1], y [h] [k + 1]) is min_length. When x2 or more, _n is determined as a quotient of 12 / min_length.
In the next step 562, Sign = 1 is set.
560, the length 12 of the contour line segment whose end points are x [h] [k], y [h] [k] and x [h] [k + 1], y [h] [k + 1] is min_length. When it is less than x2, it is checked whether or not the value of k is end1-1. If it is No, k is incremented by 1 (step 569) and the process returns to step 560.
Proceeding to step 563, the coordinates of x2 and y2 are calculated.

(Formula 2)

In the processing after the next step 564, it is checked whether or not the line segment tmp_segment having the end points at (x1, y1) and (x2, y2) intersects the contour line. It suffices to examine only the contour lines whose elevation is one rank lower than Z [i] and Z [i].
When the line segment tmp_segment having (x1, y1) and (x2, y2) as the end points intersects the contour line, it is checked whether sign = n−1. Increment and return to step 563 to repeat the above processing. When sign = n−1, the process proceeds to step 571 to determine whether or not the value of k is larger than endi−1. If the value of k is not equal to endi-1, k is incremented by 1, and the process jumps to S563.
When the value of k is equal to endi-1, it is determined whether or not times is 2. If it is 2, then start1 = start2, end1 = end2, and times = 1 are set (step 573), and then to step 548. Return. When times is not 2, it is determined whether or not tt is 0. When tt is 0, the process returns to step 503, and when tt is not 0, it is determined whether or not tt is 2 or more. If it is 2 or more, tmp_1 [tt] is rearranged together with tmp_x [tt] = x2 and tmp_y [tt] = y2 in ascending order (step 576), and the number is incremented by 1 in the next step 577 (step 577). .
In the next step 578, the following information is stored as a new line segment new_segment connecting the two contour lines.

(Table 3)

Next, it is checked whether new_segment intersects with the segment segment created so far.
In step 581, whether number is 1 or not is checked. If it is 1, the process returns to step 503, and if it is not 1, t is set to 1 (step 582), It is checked whether or not a line segment pre_segment [t] and new_segment intersecting with two_x [t], two_y [t]) as endpoints.
When these intersect, when final_l [t] is smaller than final [number], information of pre_segment [t] and new_segment is replaced (step 586), and the process proceeds to step 587, where number = number-1 and step 503 is set. Return to.
If final_l [t] is not smaller than final [number], the process jumps to step 587 to set number = number-1 and returns to step 503.
Furthermore, if the line segments pre_segment [t] and new_segment that end at (one_x [t], one-y [t]) and (two-x [t], two-y [t]) do not intersect, t When t is not equal to number-1, t is incremented by 1. When t is equal to number-1, the relationship between pre_segment [t] and new_segment is examined.
In step 591, t is set to 1. In the next step 592, it is determined whether or not pre_segment [t] has already been connected for two contour lines connected by new_segment.
If the result of determination is No, it is further determined whether one point of one of the contour lines (line numbers i and h) connected by new_segment is the end point of pre_segment [t]. (Step 593), the distance 13 between the two end points on M of new_segment and pre_segment [t] is calculated (step 594). As a result, when l3 does not exceed 1000, new_segment and pre_segment [t] are considered as vectors starting from one point on M, respectively, and an angle θ formed by the two vectors is calculated (step 596). After determining whether <45 ° and l3 <500, it is further determined whether final_l [t] <final_l [number] (steps 597 to 598). If both are Yes, pre_segment [t] and new_segment After the information is exchanged, the process of number = number-1 is performed (step 599), and the process returns to step 503. If the determination result in step 598 is No, the process of step 600 is performed and the process returns to step 503.
When the determination result in step 592 is Yes, if final_l [t] <final_l [number], the information of pre_segment [t] and new_segment is replaced, and then the process of number = number-1 is performed. Return to 503 (steps 601 to 603).
Furthermore, when the determination result of step 593 is No and the determination result of step 595 is Yes, the process returns to step 503.

[Calculation of valley order]
If the occurrence sites of the slope collapse are concentrated at a specific valley order n, the portion of the valley order n where the collapse has not yet occurred has a higher risk of collapse than others. Therefore, the valley order obtained along the valley line is important information for grasping the progress of erosion, the tendency of collapse, and the degree of danger. This program first executes a valley line generation program to generate a valley line, and then reads water system classification data obtained by executing a water system classification program for classifying the generated valley line for each water system. The order is calculated. Of course, a falling water line may be used (FIG. 45).

Since the valley line generation program has been described above, the water system classification program (FIG. 43) will be described in detail below.
As a premise, when the distance between the data points (end points) of two valley lines (falling line) data with the same altitude is within d [m] (default is 0.5 [m]), the two valley lines (falling line) ) Data will be merged.
The falling water line creation method of the present invention connects adjacent contour lines, and therefore, contour lines having different altitudes with straight lines.
Since there are only a few such parts as a whole, it is currently most practical to connect the disconnected parts manually.
Therefore, if there is an interrupted portion in the created waterfall line, the portion is manually connected to correct the waterfall data, and the corrected waterfall data is set as an analysis target.

[Water system classification program]
Regarding the water system, in the present invention, valley line (falling line) data that converge to the same end point is defined as the same water system.
Actually, when the plane distance of the end points of two valley lines (falling line) with the same altitude is within d [m], these two valley lines (falling line) converge to the same end point. Is processed.
In this embodiment, the default is d = 0.0 [m]. For example, if the original data is a contour line with a scale of 1: 25,000 and it is desired to make the end points separated by only 0.1 [mm] in the figure the same, d = 2.5 [m]. In the present invention, this d is input according to the purpose by an analyst.
In addition, when at least f or more valley lines (falling lines) have the same end point, these valley lines (falling lines) form a water system. This f is input according to the purpose by a person who analyzes using the present invention.
In step 611 of FIG. 43, the corrected valley line (falling line) data is read, and the attribute of water system number -1 is given to all valley line (falling line) data.
In the next step 612, k = 1 and s = 1 are set. In the next step 613, the end point of W _s is set as w, the altitude of the end point is the same as w from the valley line (falling line) data having a valley line (falling line) number larger than s, and the horizontal distance is d. Select the valley line (falling line) data that is within (determined by the user). When the total number of these valley lines (falling lines) is greater than or equal to f (step 614), a water system number k is given to each selected valley line (falling line) (step 615) (FIG. 12_1_B). When the total number is smaller than f, the attribute of the water system number −10 is given to each selected valley line (falling line) (step 616) (FIG. 12_1_A). If s is the maximum valley line (falling line) number (step 617), the process returns to the main routine. Otherwise, the valley line (falling line) number is incremented by 1 (step 618), and the attribute of W _s is-. If it is 10 (step 619), the process jumps to step 617. If the attribute of W _s is not −10, if the attribute of W _s > 0 in step 620, the process jumps to step 617 in the same manner. If not satisfied, +1 is given to the water system number, and the process jumps to step 613.
Through the above processing, the valley line (falling line) is classified for each water system.
In addition, by changing the color of the valley line (falling line) for each water system number (for example, 1, 2, 3,...), The classified water system is displayed and printed based on the valley line (falling line). It is possible to create a water map that is easy to understand visually.

Next, the valley order calculation program will be described with reference to FIGS.
First, valley data subjected to water system classification is read (step 631), and in the next step 632, α = altitude interval between contour lines (default is α = 10 [m]). Further, s = 1.
Thereafter, the valley order is calculated for each water system. Here, k = 1. This k is a water system number (1, 2, 3,..., K_end) assigned to each water system.
In the next step 634, the valley data having the water system number k is rearranged in descending order of the elevation of the starting point, and provisional numbers h (1, 2, 3,..., H_end) are given. The starting altitude of the valley line data _{W 1} of the temporary number 1 max_z, the elevation of the end point and min_z (Figure 13).
In this embodiment, the data used as the basis for calculating the valley order is a valley line, but it may be a falling water line.
When the g-th data point of the valley line data W _h of the temporary number h is set to w _{h, g} , the total number of data points of W _h is P [h]. The starting point of the line segment w _{h, g} w _{h, g + 1} is set as w _{h, g} and the tip point is set as w _{h, g + 1} .
In this _case, the altitude of _{w h, g is} greater than _{w h, g + 1} of the elevation.
First, 0 is given in advance to the valley orders of the line segments w _{h, 1} w _{h, 2} whose starting point is the starting point of the valley line data.

In step 636, E = max_Z, and in the next step, h = 1. Next, Count = 0 is set (step 638).
Next, it is determined whether or not the total number P [h] of data points of W _h is 0.
When the total number of data points of W _h is not 0, for the data points of W _h, a search is made for points where the elevation of the data points is equal to E in ascending order of the point numbers. Here, g = 1 is set.
Next, it is determined whether or not the altitude of [wh _{, g} ] is E (step 641). When [Elevation of w _{h, g} ] is E and Count is 0, i = h, j = g and line segments w _{i, j} w _{i, j + 1} are set as reference line segments. At this time, tmp = −1, count = 1, order = −1 (step 643), the process returns to step 647 to determine whether or not the temporary number h is the final number, and the process proceeds to the next step.

On the other hand, when [elevation of w _{h, g} ] is greater than E, it is determined whether or not w _{h, g + 1} is the end point of W _h (step 645). Return to.
When w _{h, g + 1} is the end point of W _h in step 645, when [elevation of w _{h, g} ] is smaller than E in step 644, and in step 649, the line segments w _{i, j} w _{i, j + 1} and the line segment If it is determined that w _{h, g} w _{h, g + 1} do not merge at w _{i, j + 1} , the process proceeds to step 647.
In step 647, it is determined whether or not the temporary number h is the final number. If it is not the final number, h is incremented by 1 (step 648), and the process returns to step 639.

If it is determined in step 649 that the line segments w _{i, j} w _{i, j + 1} and the line segments w _{h, g} w _{h, g + 1} meet at w _{i, j + 1} , the flow proceeds to step 650 to calculate the valley order. move on.
In step 650, h and g are stored, and P [h] = 0 is set. This is performed in order to avoid duplication of W _i and W _h downstream of w _{i, j + 1} (FIGS. 17 and 18).
In step 651, it is checked whether tmp is negative (see paragraph 0098 for the meaning of tmp). If negative, the valley order of the line segments w _{i, j} w _{i, j + 1} is the line segment w _h, When it is equal to the valley order of _g w _{h, g + 1} , in step 653, processing of tmp = 5, order = (valley order of w _{i, j} w _{i, j + 1} ) +1 is performed. When the valley order of the line segments w _{i, j} w _{i, j + 1} is larger than the valley order of the line segments w _{h, g} w _{h, g + 1} , in step 655, tmp = 1, order = (wi _{, j} w _{i , J + 1} valley degree).
Further, when the valley order of the line segments w _{i, j} w _{i, j + 1} is smaller than the valley order of the line segments w _{h, g} w _{h, g + 1} , in step 656, tmp = 10, order = (line segments w _{h, g} wh, valley order of _{h + 1} ).

When the above processing ends, the process returns to step 647.
In step 647, when the temporary number h is not the final number h_end, h is incremented by 1, and the process returns to step 639.
When the temporary number h is the final number h_end, the process proceeds to step 657. If order is a negative number, the valley number of the line segment w _{i, j + 1} w _{i, j + 2} is determined as the line segment w _{i, j} w _{i, If the} order is the same as the rank of _{j + 1} (step 658) and order is a number greater than or equal to 0, the rank of w _{i, j + 1} w _{i, j + 2} is set as the order number (step 659).

In step 651, when tmp is 0 or more, the subroutine of Option-v1 (FIG. 47) is entered.
This subroutine is executed when three or more valley line data merge at one point (see paragraph 0098 for the meaning of tmp).
In step 671, when the valley order of w _{i, j} w _{i, j + 1} is equal to the valley order of w _{h, g} w _{h, g + 1} and tmp = 1, tmp = 5 and order = (w _{i, j} w _{i, j + 1} trough order) +1 (step 672).
In step 671, when the valley order of w _{i, j} w _{i, j + 1} is not equal to the valley order of w _{h, g} w _{h, g + 1} or tmp = 1, w _{i, j} w _{i, j + 1} valley orders _{w h, g w h,} small it is judged whether or not than _{g + 1} of the valley degree. If the determination result is Yes, it is checked whether tmp is 1, 5, 10, 10 or 15 (steps 674, 676, 678, 683). When Yes in steps 674 and 676, tmp = 10, order = (Wh _{h, g h h, g + 1} valley order) is processed.
Also, when tmp = 10 in step 678 and the valley order of w _{h, g} w _{h, g + 1} is order in step 679, tmp = 15, order = valley order of w _{h, g} w _{h, g + 1 + 1} (Step 680).
And when _{w h, g w h, g} + 1 of the valley orders is not order in step _{679, w h, g w h} , valleys order of _{g + 1} it is determined whether the order is greater than the flow proceeds to step 681, larger if _{tmp = 10, order = w h} , g w h, carry out the _{g + 1} of the valley following the number of processing (step 682).
Further, in step 683, when it is _{tmp = 15, order = w h} , g w h, g + 1 valley orders, and the determination order (whether higher), when the Yes, tmp = 10, Order = w _{h, g} w _{h, g + 1} trough degree processing is performed (step 685). If No, the processing ends and the processing returns to step 647.

When the calculation for the valley number is completed, the calculation result is written in step 660.
In the next step 661, s is incremented by 1, and when i = h_end is not satisfied, h = i + 1 and count = 0 are set, and the process returns to step 639 again.
When i = h_end, if E> min_Z + α, E = E−α is processed (step 664), and the process returns to step 638.
When i = h_end, if E> min_Z + α, k = k_end is determined.
If k = k_end is not satisfied, k is incremented by 1 and the process returns to step 634 to execute processing for the data of the next water system number.
If the data of all water system numbers is processed, k = k_end, so the calculation is terminated.
[Combination of valley order and vertical section of slope]

This will be described with reference to FIGS.
For the falling water line data W _i , W _h , W _p , the j-th data point is set to w _{i, j} , the g-th data point is set to w _{h, g} , and the q-th data point is set to w _{p, q} . Also, the midpoints of w _{i, j} and w _{i, j + 1} , w _{h, g} and w _{h, g + 1} , w _{p, q} and w _{p, q + 1} are respectively represented by t _{i, j} , th _{h, g} , t _{p. , Q.} The vertical cross-sectional shape of the slope according to the present invention has two line segments with the data point of the falling water line data as the midpoint, that is, a line composed of three points as one unit. The points at both ends of a unit line are often the midpoints of the line segment of the waterfall line data (FIG. 15B)), but may also be the start point and the end point of the waterfall line data (FIG. 15A)). Further, when a plurality of waterfall line data merge at the same data point, the vertical sectional shape of one unit line having the merge point as the midpoint may be different (FIG. 15, B1) and B2)). Therefore, Drainage line data _{W i, W h, W p} is the data point _{w i,} when merging the _{j + 1, w i,} the slope of the vertical cross-sectional shape in the _{j + 1} and _{(w i,} line to the _{j + 1} midpoint), The only procedure is as follows.
First, the waterfall line generation program is executed to generate a waterfall line (step 701), and then the water system classification program is executed in the next step 702. Although the present Example calculated based on the falling water line data, valley line data may be sufficient.
Therefore, the water system classification data is read (step 702-2). Subsequently, it is determined by inputting whether or not to calculate a waterfall line that does not have a water system number, that is, does not form a water system (step 703).
When it is determined to perform the calculation for the falling water line having no water system number, the process proceeds to the Option-c subroutine. Since this subroutine is additional, this subroutine will be described later.

This program first calculates the valley order for each water system, and further classifies the vertical cross section. Therefore, this process will be described in detail.
First, in step 706, an elevation interval α between contour lines is defined. The default is α = 10 [m]. Here, s = 1 (because s appears in step 765), and k = 1. s is a data number, and k is a water system number (1, 2, 3,..., k_end) assigned to each water system.
In step 708, the waterfall line data of the water system number k is rearranged in descending order of the elevation of the starting point, and a temporary number h (1, 2, 3,..., H_end) is given. Further, the starting point elevation of the drainage line data _{W 1} of the temporary number 1 max_z, the elevation of the end point and min_z.
Next, the g-th data point of the waterfall line data W _h of the temporary number h is set to w _{h, g,} and the total number of data points of W _h is set to P [h]. The starting point of the line segment w _{h, g} w _{h, g + 1} is set to w _{h, g} and the tip point is set to w _{h, g + 1} . At this _time, there _{w h, g} of _{elevation> w h,} at an altitude of relationship of _{g + 1.}
Then _, the valley order of the line segments wh _{, 1} wh _{, 2} where the starting point is the start point of the falling water line data is set to 0. Next, E = max_Z, h = 1, and count = 0.

When the total number of data points of W _h is not 0, for the data points of W _h, a search is made for points where the elevation of the data points is equal to E in ascending order of the point numbers. Here, g = 1 is set (step 714).
Next, it is determined whether or not the altitude of _{wh, g} is E (step 715). When the elevation of w _{h, g} is E, if Count is 0, i = h, j = g, and line segments w _{i, j} w _{i, j + 1} are set as reference line segments. At this time, tmp = −1, count = 1, order = −1 (step 723), the process returns to step 719, and it is determined whether or not the temporary number h is the final number. When the determination result is No, the temporary number h is incremented by 1 and the process returns to step 713.

On the other _hand, when _{w h,} elevation _g is higher than _{E, w h, g + 1} is determined whether the end point of the _{W h} (step 717), returns to step 715 and increments the data number g to be the end point .
When w _{h, g + 1} is the end point of W _h in step 717, when the altitude of w _{h, g} is lower than E in step 716, and in step 724, w _{i, j} w _{i, j + 1} and w _{h, g} w _{h , G + 1} go to step 719 when it is determined that w _{i, j + 1} do not merge.
In step 719, it is determined whether or not the temporary number h is the final number. If the temporary number h is not the final number, the temporary number h is incremented by 1 (step 720), and the process returns to step 713.

If it is determined in step 724 that the line segments w _{i, j} w _{i, j + 1} and the line segments w _{h, g} w _{h, g + 1} merge at w _{i, j + 1} , the process proceeds to step 725 to calculate the valley order. move on. In step 725, h and g are stored.
In step 726, it is checked whether tmp is negative, and if it is a negative number, the valley order of the line segments w _{i, j} w _{i, j + 1} is equal to the valley order of the line segments w _{h, g} w _{h, g + 1.} If equal, in step 728, processing of tmp = 5, order = (valley of line segments w _{i, j} w _{i, j + 1} ) +1 is performed.
When the valley order of the line segments w _{i, j} w _{i, j + 1} is larger than the valley order of the line segments w _{h, g} w _{h, g + 1} , in step 730, tmp = 1, order = (line segments w _{i, j} wi _{, j + 1} valley order).
Further, when the valley order of the line segments w _{i, j} w _{i, j + 1} is smaller than the valley order of the line segments w _{h, g} w _{h, g + 1} , in step 731 tmp = 10, order = (line segments w _{h, g} wh, valley order of _{g + 1} ).

When the above processing ends, the process returns to step 719.
If the temporary number h is not the final number h_end in step 719, h is incremented by 1 and the processing returns to step 713, and the above processing is repeated until the temporary number h reaches the final number.
Further, when the temporary number h reaches the final number h_end, it is determined whether Count is 0 or not. If it is determined in step 721 that Count is 0, the process proceeds to step 790. If the altitude is the altitude just before the end point, the altitude at the start point of the falling water line data is lowered by 1, and the process returns to step 713.
On the other hand, in step 790, if the altitude is not the elevation just before the end point, and the water system number k is not the final one, the water system number is incremented by 1 and the process returns to step 708 to start data processing for the next water system number. Further, when the water system number k is the last one, the processing is finished for all the objects, so this processing is finished.

In step 726, if tmp is greater than or equal to 0, in step 732, the valley order of the line segments w _{i, j} w _{i, j + 1} is equal to the valley order of the line segments w _{h, g} w _{h, g + 1} , and tmp = When it is 1, tmp = 5 and order = (valley of line segments w _{i, j} w _{i, j + 1} ) +1 (step 733).
In step 732, if the valley order of the line segments w _{i, j} w _{i, j + 1} is not equal to the valley order of the line segments w _{h, g} w _{h, g + 1} or tmp = 1, the line segment w _{i , J} w _{i, j + 1} is determined as to whether or not the valley order of the line segments w _{h, g} w _{h, g + 1} is smaller.
If the determination result is Yes, it is checked whether tmp is 1, 5, 10, 10 or 15 (steps 735, 736, 738, 743), and when tmp is 1 or 5 in steps 735 and 736, tmp = 10, order = (line _{w h, g w h, g} + 1 valley orders) process is (step 737).
Further, when tmp = 10 in step 738 and the valley degree of the line segment w _{h, g} w _{h, g + 1} is order in step 739, tmp = 15, order = line segment w _{h, g} w _{h, g + 1} The process of the valley order of +1 is performed (step 740).
Then, the segment _w h at step _{739, g w h,} when the valleys order of _{g + 1} is not order, the segment _w h proceeds to step _{741, g w h,} valleys order of _{g + 1} is whether order greater than If it is determined that the value is larger, the order of the order = the line segments w _{h, g} w _{h, g + 1} is processed (step 742).
Further, in step 743, when tmp = 15, it is determined that the valley degree of the line segment w _{h, g} w _{h, g + 1} ≧ order, and when Yes, tmp = 10, order = line segment w _{h, g} Processing of the valley order of wh _{, g + 1} is performed (step 745), and the process returns to step 719. Also, if the determination of the valley number of the line segments w _{h, g} w _{h, g + 1} in step 744 ≧ order or No, the process ends and the process returns to step 719.

Here, the meaning of the value of tmp is summarized.
tmp = 1: Only the line segment w _{i, j} w _{i, j + 1} has the maximum valley order.
tmp = 5: The line segments w _{i, j} w _{i, j + 1} and the other line segment (s) w _{h, g} w _{h, g + 1} have the maximum valley order.
tmp = 10: A single line segment w _{h, g} w _{h, g + 1} (≠ line segment w _{i, j} w _{i, j + 1} ) has the maximum valley order.
tmp = 15: A plurality of line segments w _{h, g} w _{h, g + 1} (≠ line segments w _{i, j} w _{i, j + 1} ) have the maximum valley order.

When the calculation of the valley order for the falling water line data belonging to one water system is completed, a determination of Yes is made in step 719, and the process proceeds to step 721 to determine whether Count is 0 or not. When Count is determined to be 0, the process proceeds to step 790, and when it is not 0, the process proceeds to step 746.
In step 746, it is determined whether order is negative.
When it is determined to be negative, the value of the valley degree of the line segment w _{i, j + 1} w _{i, j + 2} is set as the value of the valley degree of the line segment w _{i, j} w _{i, j + 1} .
If it is not determined to be negative, the value of order is the value of the valley order of the line segments w _{i, j + 1} w _{i, j + 2} .

Next, in step 749 and step 750, when order is negative or tmp is 1, ii = i and jj = j are set.
When tmp is 10 in step 752, the line segment having the maximum valley degree among the line segments wh _{, gwh , g + 1} (where h ≠ i) joined at the data points wi _{, j + 1} . Let ii = h and jj = g using (h, g).
If none of the above three steps applies, the line segments w _{i, j} w _{i, j + 1} and the line segments w _{h, g} w _{h, g + 1} have the same valley degree, Since they are equal, the line segments wh _, gw _{h, g + 1} and the line segments wh _{, g + 1} wh _{, g + 2} are on the horizontal plane in order to investigate which falling water line will flow linearly. The formed angle δ _{h, g + 1} (≦ 180 °) is calculated (FIG. 16B). However, this h includes i, and this g includes j.
Accordingly, the angle δ _{h, g + 1} (≦ 180 °) formed by the line segment w _{i, j} w _{i, j + 1} and the line segment w _{i, j + 1} w _{i, j + 2} on the horizontal plane is also calculated. Then, among the calculated [delta] _{h, g + 1,} for a maximum [delta] _{h, g + 1} of the h and g, ii = h, put a jj = g. That is, priority is given to the one that flows linearly as the reference line segment.

Here, the data structure and the calculation method of the attribute and the attribute will be described.

(Table 4)


Gradient θ _{ii, jj} : tan θ _{ii, jj} = α / l _{ii, jj} Calculated valley order v _{ii, jj-1} : w _{ii, jj-1} Determines the valley degree vertical section of w _{ii, jj} τ _{ii, jj} = 180 ° + θ _{ii, jj−1} −θ _{ii, jj}
The angle δ _{ii, jj} on the horizontal plane is obtained from the horizontal plane distance ll between l _{ii, jj−1} , l _{ii, jj} , w _{ii, jj−1} and w _{ii, jj + 1} by the following calculation.

(Formula 3)

The attributes to be written in the attribute file for the middle point, the data point, and the middle point data m _{ii, jj−1} w _{ii, jj} m _{ii, jj + 1 from} the top are as follows.
(1) Line number: s (corresponds to s in the xy file)
(2) Elevation of midpoint: z _{ii, jj}
(3) Water system number: k
(4) Gradient of line segment upstream of w _{ii, jj} : θ _{ii, jj-1}
(5) Gradient of the line segment downstream of w _{ii, jj} : θ _{ii, jj}
(6) Angle in horizontal plane at w _{ii, jj} : δ _{ii, jj}
(7) Angle for dividing the vertical sectional shape: τ _{ii, jj}
(8) Valley degree v _{ii, jj-1} : As seen from the valley degree of the line segment w _{ii, jj-1} w _{ii, jj} , for example, the valley order is a line segment of one falling line data, and therefore two data Although it has one attribute for a point, for example, the angle that determines the vertical cross-section has one attribute for two consecutive waterfall line segments, and thus three data points.
For this reason, the waterfall line data excluding the first and last ones typically writes out the data points in step 807 as shown in the table below.

(Formula 4)
The attributes to be written are as shown in the table below.

(Table 5)

By executing the following processing, processing for writing data to the xy file attribute file is executed for all line segments.
The (x, y, z) coordinates of w _{ii, jj} are respectively (x _ii, j j y _ii, j j, z _ii, j j), _and the (x, y, z) coordinates of _{wh , g} are respectively (x _h, j _g , yh _{, g} , zh _{, g} ) (step 755).
Then, the segment _{w ii, jj w ii,} besides _{jj + 1, w i,} is determined whether or not the line segment to the tip point of the _{j + 1} exists (step 756), if present, a line segment _{w ii, jj} w _ii, except _{jj + 1, w i,} a plurality of line segments with the tip point _{j + 1 w h, g w} h, and _{g + 1} (step 757).

Through the processing from step 758 to step 766, all of the data acquired by the processing so far is written to a file.
First, in step 759 and step 761, it is determined whether the data point number is 1 or 2 or otherwise.
If the data point number is 1, writing is performed in step 760, and if the data point number is 2, writing is performed in step 762.
If the data point number is neither 1 nor 2, writing is performed in step 763.
In step 764, the total number P [h] of W _h data points is set to zero. This is a process that is performed to eliminate overlapping waterfall line data in subsequent processes.
With the above processing, the writing of the xy coordinate data and attribute data of all the falling water line data is finished.

Next, the line segment w _{ii, jj} w _{ii, jj + 1} is written.
It is checked whether the data point number is 1 or 2 and two before the total number of data points P [ii] of W _ii , and the data is written in accordance with the respective conditions (steps 768 to 778), and the data number s +1 and go to step 789.
On the other hand, when there is no line segment with w _{ii, jj + 1} as a tip point other than w _{ii, jj} w _{ii, jj + 1 at} step 756, the process proceeds to step 780 to determine whether the data point number is 1 or not. If it is 1, the process proceeds to Step 789.
If the data point number is other than 1, the data point number is 2, the total number of data points is 3, the data number is 2, and the data number is one before the total number of data points. Depending on whether or not, data is written in four formats (steps 781 to 787).
Thereafter, the data point number s is incremented by 1, and the process proceeds to Step 789.

In step 789, it is determined whether or not the line number of the reference line has reached the total number of temporary numbers.
If not reached, h = i + 1 and count = 0, and the process returns to step 713.
When it is determined that the line number of the reference line has reached the total number of temporary numbers, when E> min_Z + α, the altitude is lowered by one rank (E = E−α) and the process returns to step 713 and thereafter. Execute the process.
Further, when E> min_Z + α is not satisfied, if the end of the water system number has not been reached, the process proceeds to the process for the next water system (step 794).
Here, when the end of the water system number is reached, since the processing has been completed for all the water systems, the execution of the program is terminated.

Here, the subroutine Option_c (FIG. 48) will be described again. Next, an attribute of valley degree 0 is given to all the lines of the falling water line G (step 796).
When there is drainage line data _{W ii} the exported non G (1 in step _797), jj th _{w ii} data points _{(jj = 1,2,3, ...) w} ii, and _jj. At this time, jj = 1 is set (step 797-2).
In the next step 798, when the data number jj is not 1, jj = 2 and P [ii] = 3, or jj = 2 and jj = P [ii] −1 are satisfied. In this case, steps 801, 804, and 808 are executed to write out data.
Also, although this is the most common, step 807 is executed.
Then, after executing Step 801 and Step 808, s is incremented by 1 at Step 802, and the process returns to 1 of Step 797 to repeat the subsequent processing.
After executing Steps 804 and 807, s is incremented by 1 at Step 805, jj is incremented by 1 at Step 799, and the routine returns to Step 798 to repeat the subsequent processing.
As a result of repeating the above processing, it is determined in step 797 1 that all the G waterfall line data w _ii have been written out, the processing is terminated, and the processing returns to the main routine to enter the processing from step 706 onward. .

[Contour line attribute data gridding program 1]
The present invention relates to a program used when a variety of attribute data (line segments) calculated based on contour line data is gridded.
In general, the number-of-values statistical analysis method often uses grid data having a regular, grid-like arrangement. Many data such as vegetation data and geological data have been prepared as grid data.
On the other hand, it is difficult to use line data and (random) point data having various information in combination with the grid data as they are.
Therefore, the present invention intends to expand the range of utilization by making the obtained line segment data having terrain attributes into a grid and linking with various grid data.
The line segment data used for grid formation always has information on the plane position coordinates of the start point and end point of the line segment, and has one or more attributes such as gradient and slope direction.
And, for example, the slope, slope direction and valley degree are calculated simultaneously from the line data of the falling water line, 1) the line number, 2) the x coordinate of the starting point of the line segment, 3) the y coordinate of the starting point of the line segment, 4) Create a file in which the x coordinate of the end point of the line segment, 5) the y coordinate of the end point of the line segment, 6) water system number, 7) gradient, 8) slope direction, and 9) valley degree are written for each line segment. , You may read only the attributes as needed.
When creating gradient grid data, a file in which only the above 2) to 5) and 7) are written may be created.
In any case, formation of line segment data used for creating grid data can be variously considered. Moreover, it is possible to create grid data based on not only the falling water line but also the steepest climb line, valley line, ridge line, and point data with attributes.

If the unit is two line segments of the falling water line, such as the vertical cross section of the slope, it is divided into two line segments.
The line segment divided into two has the same attribute, although the start point and end point (x, y) coordinates are different.

In the case of a horizontal cross section of a slope classified along a contour line, it is written for each contour line segment.
(Example)
1) Line number 2) x-coordinate of start point of line segment 3) y-coordinate of start point of line segment 4) x-coordinate of end point of line segment 5) y-coordinate of end point of line segment 6) Type of horizontal sectional shape (1: Ridge type, -1: valley type, 0: other than that)

First, the creation range for creating grid data is determined. The following two methods are given as examples.
Method 1) The maximum value and minimum value (min_x, max_x, min_y, max_y) of (x, y) coordinates are determined manually by looking at the drawings and the like.
Method 2) The line segment data that is the basis of the grid data is read, and the maximum value and minimum value (min_x, max_x, min_y, max_y) of the (x, y) coordinates are determined from the start point and end point of these line segment data. . However, it should be noted that the range of distributed data is not always rectangular.
Next, the grid interval d of the grid data to be created is determined.
Furthermore, the position of the grid point is determined (the center or the point where the four corners are off).
Note that the grid data is actually expressed not as dots but as spread cells.

(Table 6)

When various types of grid data are calculated using altitude grid data that has been frequently used in the past, the calculation is performed as shown in the figure below.

(Table 7)
For example, when it is desired to calculate the gradient at the grid point g _{i, j} , the gradient of g _{i, j} cannot be calculated using only the elevation of g _{i, j} .
For this reason, it is also necessary to use the altitudes of grid points around g _{i, j} .
Therefore, since the calculation range is widened, the calculation result tends to be gentle.
On the other hand, in the present invention, line segment data calculated up to the attribute is created, and only data existing within the calculation range is used.
The feature is that the value in the grid is obtained.
Conventionally, various types of grid data such as gradients are usually created from elevation grid data.

(Table 8)

Hereinafter, an embodiment in which the attribute is a gradient will be described in detail.
This will be described with reference to FIGS.
First, the line segment data to be used and the priority order are determined.
This priority is patterned, and the pattern is
pattern1 [Priority 1: Falling Line Data, Priority 2: Fastest Climbing Data]
pattern2 [Priority 1: Most rapid climbing data, Priority 2: Falling water data]
pattern3 [Priority 1: Downstream data, Priority 2: None]
pattern4 [Priority 1: Most rapid climbing data, Priority 2: None]
There are four types.
Next, a range for creating grid data is determined.
At this time, min_x, max_x, min_y, and max_y are input. In addition to the manual input method, line segment data that is the basis of the grid data is read, and (min_x, max_x) is selected from the start point and end point of these line segment data. , Min_y, max_y) is automatically obtained by calculation. However, it should be noted that the range of distributed data is not always rectangular.

Then, the user determines d by inputting the grid interval d. As a result, the calculation range r is determined. The calculation range r is defined by a radius r centered on the grid in this embodiment. The default of r is d / √2, but can be changed by the user. When determining r, it is necessary to consider the accuracy of the data on which the grid is formed. Further, the position (x, y) and the total number (num_x, num_y) of each grid are determined by inputting the grid interval d.
Subsequently, the data of the priority order 1 is read, the line segment number is s, and the total number of line segments is sum_s (step 814).
In the next step 815, if it is determined that the pattern input and determined by the user is pattern = 1 or pattern = 2, the data of the priority order 2 is continuously read, the line segment number is ss, and the total number of line segments Is sum_ss.
Then, the row value j = 1 of the grid point, the column value i = 1, and the line segment number s = 1 are set (step 817).
In the subsequent processing, the value at the grid point g _{i, j} is calculated using the data of the priority order 1. At this time, the stored data number n = 0.
Then, the start point of the line segment with the line number s is set to p ₁ = (x ₁ , y ₁ ), and the end point is set to p ₂ = (x ₂ , y ₂ ).

In steps 820, 821, 822, 824, and 825, the start point and end point of the line segment are both outside the range of one grid, or the straight line T passing through the grid center g _{i, j} and the start point p ₁ and end point p ₂ If it is determined that the distance between the intersection point T (hereinafter simply referred to as “intersection point”) between the perpendicular line drawn from the grid center g _{i, j} and T exceeds the calculation range r, the process proceeds to step 826 and the line segment number is determined. If the total number of line segments has not reached the total number of line segments, the line segment number s is incremented by 1 and steps 819 to 825 are executed again. As a result of the execution, if it is determined No in steps 820, 821, 822, 824 and 825, in steps 828, 830 and 832,
a) The distance between the grid center and the intersection does not exceed the calculation range r, and the intersection is a point on the line segment p ₁ p ₂ (step 828).
b) The distance between the grid center and the end point is shorter than or equal to the distance between the grid center and the start point, and the distance between the grid center and the end point does not exceed the calculation range r (step 830).
c) When the distance between the grid center and the start point is shorter than the distance between the grid center and the end point, and the distance between the grid center and the start point does not exceed the calculation range r (step 832), The line segment number s and their distance l are stored (step 833-2), n is incremented by 1 (step 833-3), and the process returns to step 826.
If the line segment number s does not reach the total number of line segments sum_s when none of the above a) to c) applies, s is incremented by 1, and the process returns to step 819.

If it is determined in step 835 that there is a stored data number n (n> 0), if there is an instruction by input to generate gradient grid data using the nearest line segment data, in step 837 The stored n line segments are rearranged in order from the smallest distance l, and then the gradient value of the line segment having the smallest distance l is written as the gradient value at the grid point g _{i, j} (step 838). .
On the other hand, in step 836, when there is no instruction to create gradient grid data using the nearest line segment data, the average value of the gradients of n line segments is determined as the gradient at grid points g _{i, j.} Is written out as the value of (step 840).

On the other hand, when the priority level 1 data does not exist within the calculation range r of the grid point, “Yes” is determined in Step 835. If the user has selected “pattern 1” or “pattern 2”, “Yes” is determined in Step 841. Accordingly, the process proceeds to step 847, and the value at the grid point g _{i, j} is calculated using the data of the priority order 2.
Since the processing content from step 848 to step 870 is the same as the processing from step 819 to step 840 already described, description thereof will be omitted.
Note that step 841 is unique for processing data of priority 2.
If the priority level 2 data exists within the calculation range of the grid point as a result of executing the above processing and the priority level 2 data is processed, the process returns to step 843 after executing steps 865 to 869. , Continue processing.
If n = 0 in step 835 and the selected pattern is neither pattern = 1 nor pattern = 2, since there is no value at grid point gi _{, j} , −9999 is written ( Step 842).

Thereafter, in step 843, when the grid point column i has not yet reached the total number num_x, the process proceeds to the next grid point column (step 845), and returns to step 818 to repeat this cycle.
As a result, when it is determined in step 843 that the grid point column i has reached the total number num_x, the process advances to the next row of grid points (step 846), and returns to step 818 to increment the grid point column by one. When it is executed and the processing of the last grid point is finally finished, it is determined Yes in step 844, and the processing for grid formation is finished.

[Contour attribute data gridding program 2]
This program is characterized in that the data used in the previous grid point processing is not used in the subsequent processing, and the other points are the same as in the grid program 1.
Therefore, only the feature points will be described with reference to FIGS.
In step 874, the attribute used = -1 is given to all line segment data.
In step 894, when the line segment number s and the distance l are stored, the used value is also stored.
This used value is used when it is determined that all n line segments are used = 1, that is, all the line segment data has already been used as data at the previous data point. Since there is no possible data, the same processing as program 1 is performed (steps 903 and 907).
In the opposite determination, the same processing as in program 1 is performed using only the line segment with used = −1, but at this time, used = 1 is assigned to the line segment used for the calculation. (Steps 905, 909).

On the other hand, for priority level 2 data, it is assumed that this data is rarely used, and if there is no priority level 1 data, the number of priority level 2 data is also low. Since it is assumed, the attribute used = −1 is not given.

As mentioned above, although the calculation program of the gradient and the slope direction has not been described, it will be described again here.
Referring to FIG. 39, first, n line data are read in ascending order of line numbers. Line number i (1,2, ..., n) the line data of the _{W i.} Let s = 1.
_Let the j-th data point of W _{i be} w _{i, j} . The total number of data points of W _i and m. Then, j = 1 is set.
In step _{955, w i, j} and _{w i,} a line segment and a _{j + 1} end point _{w i, j w i,} for _{j + 1,} when computing the gradient θ and slope aspect _{[delta], w i,} the three-dimensional coordinates of the _j Let (x _{i, j} , y _{i, j} , z _{i, j} ), the three-dimensional coordinates of w _{i, j + 1 be} (x _{i, j + 1} , y _{i, j + 1} , z _{i, j + 1} ).
The slope gradient θ and the slope direction δ are calculated by the following [formula A] and [formula B], respectively (steps 956 to 957).
Also, the slope direction δ is counterclockwise and the east is 0 [°], and the altitude (z _{i, j} and z _{i, j + 1} ) is lower than _{wi, j} and w _{i, j + 1} . The three-dimensional coordinates are (x ₁ , y ₁ , z ₁ ), and the higher three-dimensional coordinates are (x ₂ , y ₂ , z ₂ ).
1) x ₁ −x ₂ ≧ 0 and y ₁ −y ₂ ≧ 0 → δ = a [°]
2) x ₁ −x ₂ <0 and y ₁ −y ₂ ≧ 0 → δ = 180−a [°]
3) x ₁ −x ₂ <0 and y ₁ −y ₂ <0 → δ = 180 + a [°]
4) x ₁ −x ₂ ≧ 0 and y ₁ −y ₂ <0 → δ = 360−a [°]

(Formula A)


(Formula B)

In step _{958, w i, j} and _{w i, j + 1} coordinates and the like gradient θ and slope aspect [delta], written in a form depending on the purpose. At this time, the line segment number is s.
In the next step 960, if the data number j does not reach the total number m, j is incremented by 1 and the next data is calculated and the total number of the line data is processed (step 962). (Step 963).
When all the data has been processed, the calculation is terminated.

In the present invention, the line segment data calculated up to the attribute is read and converted into grid data using only the data existing within the calculation range, so that the value in the grid is obtained.
In addition, the user can select whether to generate gradient grid data using the nearest line segment data or to generate gradient grid data using the average value of the gradients of n line segments. Depending on the nature of the specific output, it can be used properly.
Furthermore, when there are a plurality of basic data of the same type, various data can be used alone or in combination, and can be flexibly handled according to the purpose.

It is a classification figure of the shape of a slope (changed Dikau (1990)). L, straight line; V, convex; C, concave. The thick lines divide these shapes into three groups. (1) Both straight lines; (2) One is straight and the other is curved; (3) Both are curved Shows contour data structure and format. An example of an error when finding the decision and the point q _j of the point q _j. (A) t ₁ is closest to m among the selected points, the contour line data T is positioned next to the contour line data M, and the temporary line segment mt ₁ does not intersect any contour line. t ₄ and _{t 5} is not a selected point. B1) The temporary line segment mt ₁ intersects the contour line data M. This error often occurs where the contour data M is bent. A procedure for searching for a candidate for the point w will be described. This represents the relationship between contour line data M and H (or K) next to M. Points to classify the horizontal cross-sectional shape of the slope. The horizontal sectional shape of the slope obtained by the outer product of successive vectors is shown. Shows the data format of the falling water data and the steepest data. Shows falling water data and steepest climb data. The angle of valley slope and the angle of ridge slope: ω. Indicates a search for the bottom of a valley head or ridge. Indicates the assignment of the water system number. Indicates the order of calculation of the valley order. The combination along the falling water line data is shown. Indicates a unit of vertical cross section. A procedure for determining a single vertical cross-sectional shape of a slope at an arbitrary data point will be described. Indicates deletion of overlapping line segments. The merging of the falling water (fastest climb) data at the data points w _{i, j + 1} is shown. Horizontal section program (part 1) flow chart Horizontal section program (part 2) flow chart Flow chart for determining the horizontal cross section of the slope of each data point Flow chart for generating the fastest climb (part 1) Flow chart for generating the fastest climb (part 2) Flow line generation (part 1) flow chart Flow line generation (part 2) flow chart Program flowchart of Tanigami determination Ridge bottom point determination program flowchart Flow chart of creating the same contour line connecting line segment (Part 1) Flow chart for creating the same contour line connecting line segment (Part 2) Flow chart for creating the same contour line connecting line segment (Part 3) Combination program of valley order and vertical section (part 1) flow chart Combination program of valley order and vertical section (part 2) flow chart Combination program of valley order and vertical section (part 3) flow chart Combination program of valley order and vertical section (part 4) flow chart Attribute grid data creation 1 (part 1) flowchart Attribute grid data creation 1 (part 2) flowchart Attribute grid data creation 2 (part 1) flowchart Attribute grid data creation 2 (part 2) flowchart Gradient and slope orientation calculation flowchart Ridge line generation program flowchart Fastest climb generation (reference) (part 1) flow chart Fastest climb generation (reference) (part 2) flow chart Water system classification program flowchart Valley line generation program flowchart Overall flow chart for valley order calculation Valley degree calculation flowchart Option_v1 flowchart Option_c flowchart Single unit line attribute analysis program flowchart Option1 flowchart

Claims (1)

On the computer,
Having information as a valley candidate determined by the shape of the contour line, and reading the contour line data having the information of the three-dimensional coordinates from the storage means;
When the candidate point of the valley head of the read contour line data is not generated as a connecting line segment toward the candidate point of the valley head whose elevation is one rank lower, generating a connecting line segment sequentially downward;
Determining the start point of each line consisting of the generated coupled line segment as a trough;
A terrain data processing program for determining a trough including the above and storing or outputting the determination result.