Information processing device, information processing method and program

Abstract

To more easily estimate a deposition range in the case that a landslide disaster occurs.SOLUTION: Provided is an information processing device including: a storage part for storing map data including altitude data showing a height of a ground surface; a reception part for receiving the specification of a runoff occurrence point indicating a point on a map at which sediment runoff occurs, a deposition depth indicating a height at which the soil is deposited at the point where the outflow occurs, and a deposition angle indicating an angle at which the soil is deposited; an estimation part for estimating a range where the soil is deposited on the map on the basis of a top, the deposition angle and the map data when the soil is deposited at the deposition angle with a position obtained by adding the deposition depth to a height direction of the point where the outflow occurs as the top; and an output part for outputting deposition range information representing the range where the soil is deposited.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an information processing device, an information processing method, and a program. [Background technology]

[0002] In recent years, landslides have occurred due to the occurrence of linear precipitation bands, etc., causing a lot of damage. Patent Document 1 discloses a landslide disaster prediction device that can predict landslides and issue landslide warnings even in areas where the communication environment is not well established. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-160537 A Summary of the Invention [Problem to be solved by the invention]

[0004] If it were possible to predict the extent of sediment accumulation in the event of a landslide, it would be useful for disaster prevention and insurance design. The extent of sediment accumulation varies greatly depending on the characteristics of the terrain, geology, water content, etc. Thus, in order to more accurately estimate the extent of sediment accumulation in the event of a landslide, it is necessary to perform simulations that take into account a large number of parameters.

[0005] Therefore, an object of the present invention is to provide a technique that enables easier estimation of the extent of accumulation in the event of a landslide. [Means for solving the problem]

[0006] An information processing device according to one embodiment of the present invention has a memory unit that stores map data including elevation data indicating the height of the ground surface, a reception unit that receives specification of a runoff occurrence point indicating the point on the map where a sediment runoff occurs, a deposition depth indicating the height at which the sediment will be deposited at the runoff occurrence point, and a deposition angle indicating the angle at which the sediment will be deposited, an estimation unit that estimates the range in which the sediment will be deposited on the map based on the apex, the deposition angle and the map data when the sediment is deposited at the deposition angle, with the position obtained by adding the deposition depth to the height direction of the runoff occurrence point as the apex, and an output unit that outputs deposition range information indicating the range in which the sediment will be deposited. Effect of the Invention

[0007] According to the present invention, it is possible to provide a technique that makes it possible to more easily estimate the extent of accumulation in the event of a landslide. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of the configuration of a disaster simulation system according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a diagram for explaining an overview of a method in which an information processing device simulates the accumulation range of a landslide disaster. [Diagram 3] FIG. 2 is a diagram illustrating an example of a hardware configuration of an information processing device. [Figure 4] FIG. 2 is a diagram illustrating an example of a functional block configuration of an information processing device. [Diagram 5] 13 is a flowchart showing an example of a processing procedure for estimating whether or not soil and sand will accumulate in surrounding meshes. [Figure 6] 11A and 11B are diagrams for explaining a specific example of a method for estimating an accumulation range. [Figure 7] 10 is a diagram for explaining a method for calculating an accumulation judgment angle and an accumulation surface height (accumulation depth). FIG. [Figure 8] FIG. 13 is a diagram for explaining an overview of Modification 1. [Figure 9]13 is a flowchart showing an example (variation 1) of a processing procedure for determining whether or not soil and sand will accumulate in a mesh. [Figure 10] FIG. 13 is a diagram for explaining a specific example (variation 1) of a method for estimating an accumulation range. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings, in which the same reference numerals denote the same or similar configurations.

[0010] <System configuration> 1 is a diagram showing an example of the configuration of a disaster simulation system 1 according to this embodiment. The disaster simulation system 1 has an information processing device 10 and one or more terminals 20. The information processing device 10 and the terminals 20 are connected via a wireless or wired communication network N and can communicate with each other.

[0011] The information processing device 10 simulates the area where sediment will accumulate when a landslide occurs (hereinafter, referred to as the "accumulated area").

[0012] The terminal 20 transmits various data input by the user to the information processing device 10, and displays the results of the simulation performed by the information processing device 10. The terminal 20 is a terminal operated by the user, and any terminal equipped with a communication function, such as a smartphone, a tablet terminal, a mobile phone, a personal computer (PC), or a notebook PC, can be used.

[0013] The information processing device 10 does not simulate the accumulation range of a landslide disaster using many parameters, but simulates the accumulation range of a landslide disaster using a simpler method. Specifically, the information processing device 10 estimates the accumulation range based on three parameters, namely, the point where the landslide occurs (hereinafter referred to as the "runoff occurrence point"), the height at which the landslide occurs at the runoff occurrence point (hereinafter referred to as the "accumulation depth"), and the angle at which the landslide accumulates (hereinafter referred to as the "accumulation angle"), and map data. The runoff occurrence point may be expressed by latitude and longitude. Note that the accumulation depth is the height at which the landslide accumulates, and may therefore be read as the "accumulation height".

[0014] In general, the deposition angle varies greatly depending on the moisture content, density, flow rate, and type of sand contained in the sediment. For example, the deposition angle of high moisture content sediment is smaller than that of low moisture content sediment. Therefore, in order to estimate the deposition range of the sediment more accurately, it is necessary to consider many characteristics such as the moisture content, density, flow rate, and type of sand contained in the sediment. On the other hand, the deposition angle can be predicted to some extent by analyzing landslides that have occurred in the same place in the past. Therefore, in this embodiment, these multiple characteristics are consolidated into a parameter called the deposition angle, making it possible to perform a simulation with fewer parameters without significantly compromising accuracy.

[0015] Fig. 2 is a diagram for explaining an outline of a method for simulating the accumulation range of a landslide disaster by the information processing device 10. Fig. 2A shows the disaster area as viewed from the horizontal direction, and Fig. 2B shows the disaster area as viewed from above.

[0016] In A of Fig. 2, angle f indicates the deposition angle. As shown in A of Fig. 2, the information processing device 10 estimates the extent to which the sediment will be deposited, assuming that the position obtained by adding deposition depth h in the height direction from the runoff occurrence point P is set as apex S and that the sediment will flow out at a deposition angle f. The sediment that flows out from apex S flows from top to bottom at a deposition angle f. Therefore, the information processing device 10 may draw a line segment from apex S at an inclination of deposition angle f, identify point T where the line segment intersects with the ground surface G by referring to map data, and estimate the range from the runoff occurrence point P to point T as the deposition range.

[0017] The information processing device 10 estimates a point T in a 360-degree direction centered on the vertex S. By connecting the numerous points T estimated in this way with lines, it is possible to estimate the accumulation range Z in the event that soil and sand flows out from the vertex S, as shown in B of FIG.

[0018] As described above, the present embodiment aims to easily estimate the accumulation range using three parameters, namely, the runoff occurrence point, the accumulation depth, and the accumulation angle. Therefore, in the present embodiment, the accumulation range of the sediment is estimated on the assumption that there is no limit to the amount of runoff sediment.

[0019] <Hardware configuration> FIG. 3 is a diagram showing an example of a hardware configuration of an information processing device 10. The information processing device 10 includes a processor 11 such as a central processing unit (CPU) or a graphical processing unit (GPU), a memory (for example, a random access memory (RAM) or a read only memory (ROM)), a storage device 12 such as a hard disk drive (HDD) and / or a solid state drive (SSD), a network interface (IF) 13 for wired or wireless communication, an input device 14 for receiving an input operation, and an output device 15 for outputting information. The input device 14 is, for example, a keyboard, a touch panel, a mouse, and / or a microphone. The output device 15 is, for example, a display, a touch panel, and / or a speaker. The information processing device 10 may be composed of one or more physical servers, or may be composed of a virtual server operating on a hypervisor, or may be composed of a cloud server.

[0020] <Function block configuration> FIG. 4 is a diagram showing an example of a functional block configuration of the information processing device 10. The information processing device 10 includes a storage unit 100, a reception unit 101, an estimation unit 102, and an output unit 103. The storage unit 100 can be realized by using a storage device 12 included in the information processing device 10. The reception unit 101, the estimation unit 102, and the output unit 103 can be realized by the processor 11 of the information processing device 10 executing a program stored in the storage device 12. The program can be stored in a storage medium. The storage medium storing the program may be a non-transitory computer readable medium. The non-transitory storage medium is not particularly limited, and may be, for example, a storage medium such as a Universal Serial Bus (USB) memory or a Compact Disc Read-Only Memory (CD-ROM).

[0021] The storage unit 100 stores map data including altitude data indicating the height of the earth's surface from sea level. The map data may be provided in an external server, and the information processing device 10 may acquire the map data from the external server and temporarily store it in the storage unit 100.

[0022] The reception unit 101 receives from the user a designation of a runoff occurrence point indicating a point on a map where a runoff of sediment occurs, a deposition depth indicating the height at which sediment will be deposited at the runoff occurrence point, and a deposition angle indicating the angle at which the sediment will be deposited. The runoff occurrence point may be designated by, for example, latitude and longitude. The range of deposition angles that can be designated may be a range exceeding 0 degrees and less than 90 degrees, or may be limited to a range of 2 degrees to 45 degrees based on past statistical data. The deposition depth and deposition angle may be automatically set based on past statistical data.

[0023] The estimation unit 102 estimates the range on the map where sediment will be deposited if it flows out from the apex, which is the position obtained by adding the accumulation depth in the vertical direction of the point where the runoff occurs, and is deposited at a deposition angle, based on the apex, the deposition angle, and map data.

[0024] In addition, the estimation unit 102 may estimate that when a line segment is drawn toward the ground surface at a deposition angle centered on the vertex, the range where the line segment intersects with the ground surface represented by the map data is the range on the map where sediment will be deposited. Furthermore, the estimation unit 102 may estimate that, when a line segment is drawn from the vertex toward the ground surface within a predetermined range centered on the vertex, sediment will be deposited in a direction from the vertex where the deposition judgment angle (depression angle) of the line segment with respect to the horizontal plane is equal to or greater than the deposition angle. Furthermore, the estimation unit 102 may estimate that sediment will not be deposited in a direction from the vertex where the deposition judgment angle of the line segment with respect to the horizontal plane is less than the deposition angle. The deposition judgment angle refers to a reference angle for determining whether or not sediment will be deposited.

[0025] The output unit 103 outputs accumulation range information indicating the range where sediment will accumulate to the terminal 20. The accumulation range information may be, for example, a map screen that displays the range where sediment will accumulate in different colors so that it can be identified.

[0026] <Processing Procedure> Next, a method in which the information processing device 10 simulates the accumulation range in the event of a landslide will be specifically described.

[0027] The information processing device 10 stores map data in which the earth's surface is divided into meshes, such as a digital elevation model (DEM) or a digital surface model (DSM), and the map data includes elevation data indicating the elevation of each mesh. That is, in this embodiment, the map data is expressed in meshes, and the elevation data included in the map data may be data indicating the elevation of the mesh. Furthermore, the elevation of the mesh may be synonymous with the height of the earth's surface from sea level.

[0028] The information processing device 10 simulates the accumulation range by estimating the extent to which sediment that has flowed out from the runoff occurrence point accumulates in each mesh. First, the estimation unit 102 of the information processing device 10 calculates an accumulation judgment angle for each of a plurality of second meshes that exist around the first mesh when the mesh in which sediment has accumulated is defined as the first mesh. Specifically, the estimation unit 102 defines a horizontal plane obtained by adding the accumulation depth to the elevation of the ground surface of the first mesh as the accumulation surface, and calculates the angle between the line connecting the center point of the accumulation surface of the first mesh and the center point of the ground surface of the second mesh and the ground surface of the second mesh as the accumulation judgment angle. Note that the first mesh also includes a mesh that corresponds to the runoff occurrence point. In addition, the "accumulation surface" means a surface on which sediment has accumulated in each mesh, and corresponds to a horizontal plane that exists at a position obtained by adding the elevation of the ground surface of the mesh to the accumulation depth of the mesh. Next, the estimation unit 102 estimates that sediment will accumulate in the second mesh if the accumulation judgment angle is equal to or greater than the accumulation angle. Furthermore, when the accumulation determination angle is less than the accumulation angle, the estimation unit 102 estimates that no earth or sand will accumulate in the second mesh.

[0029] In addition, when the estimation unit 102 estimates that soil and sand will accumulate in the second mesh, it calculates the point where a perpendicular line passing through the center point of the ground surface of the second mesh intersects with a line extended at a deposition angle from the center point of the deposition surface of the first mesh, and estimates that the horizontal plane including the point where the perpendicular line intersects is the deposition surface in the second mesh.

[0030] FIG. 5 is a flow chart showing an example of a processing procedure for estimating whether or not sediment will accumulate in surrounding meshes. In the following description, "mesh (with accumulation)" refers to a mesh where sediment is estimated to accumulate. "Mesh (no accumulation)" refers to a mesh where sediment is estimated not to accumulate. Note that mesh (with accumulation) also includes the mesh where the runoff occurred.

[0031] First, the information processing device 10 estimates whether all meshes around the mesh at the point where the spill occurred are meshes (with deposition) or meshes (without deposition) by executing the processing procedure of FIG. 5. Next, the information processing device 10 estimates whether a mesh (with deposition) or mesh (without deposition) is a mesh for which estimation has not been completed among all meshes around the mesh estimated to be a mesh (with deposition) by executing the processing procedure of FIG. 5. The information processing device 10 estimates the deposition range by repeating the processing procedure of steps S10 to S13 until all meshes around the mesh (with deposition) are estimated to be meshes (without deposition) or estimation has been completed for all meshes included in a predetermined maximum deposition range. This will be described in detail below.

[0032] In step S10, the estimation unit 102 calculates the accumulation judgment angle for each mesh that is present around the mesh (with accumulation) and is not estimated as having accumulation or not having accumulation and is within the maximum accumulation range. The calculation method of the accumulation judgment angle will be described later. The maximum accumulation range will be described later. It is set to the maximum accumulation range.

[0033] In step S11, the estimation unit 102 determines whether the accumulation determination angle is equal to or greater than the accumulation angle. If the accumulation determination angle is equal to or greater than the accumulation angle, the process proceeds to step S13, and if the accumulation determination angle is less than the accumulation angle, the process proceeds to step S12.

[0034] In step S12, the estimation unit 102 estimates that no sediment has accumulated in the mesh to be processed (i.e., the mesh is (no accumulation)). In addition, the estimation unit 102 assigns a flag indicating that the mesh in which no sediment has accumulated is estimated to be "mesh (no accumulation)".

[0035] In step S13, the estimation unit 102 estimates that sediment will accumulate in the mesh to be processed (i.e., it is a mesh (with accumulation)). Furthermore, the estimation unit 102 assigns a flag to the mesh in which sediment is estimated to accumulate, indicating that it has been estimated as a "mesh (with accumulation)". Next, the estimation unit 102 calculates the height of the accumulation surface (i.e., the accumulation depth) of the mesh (with accumulation). A method for calculating the height of the accumulation surface will be described later.

[0036] The above-described processing procedure will now be described with a concrete example.

[0037] FIG. 6 is a diagram for explaining a specific example of a method for estimating an accumulation range. The circles shown in A to E in FIG. 6 indicate the maximum accumulation range. The maximum accumulation range may be determined in advance, for example, based on statistical data of past landslides. The maximum accumulation range may also be defined as the maximum number of meshes in which sediment is estimated to accumulate. The maximum accumulation range may also be determined based on the topography. For example, it may be a range excluding the sea, or a range excluding places where the mesh elevation is negative.

[0038] First, as shown in A of Fig. 6, it is assumed that a sediment runoff has occurred in mesh 4d. The estimation unit 102 estimates whether each of the eight meshes around mesh 4d is a mesh (with deposition) or a mesh (without deposition) by executing the processing procedure of Fig. 5. Here, as shown in B of Fig. 6, it is assumed that meshes 3c to 3e and 4e are estimated to be meshes (with deposition), and meshes 4c, 5c to 5e are estimated to be meshes (without deposition).

[0039] Next, as shown in Fig. 6C, for meshes 3b, 4b, 2b-2f, and 3f-5f that exist around meshes 3c-3e and 4e, have not been estimated as having or not having deposition, and have at least a part included in the maximum deposition range, the estimation unit 102 estimates whether they are meshes (with deposition) or meshes (with deposition) by executing the processing procedure of Fig. 5. Here, it is assumed that meshes 2b-2f and 3f-5f are estimated to be meshes (with deposition), and meshes 3b and 4b are estimated to be meshes (without deposition).

[0040] Next, as shown in D of Fig. 6, for the meshes 2a, 3a, 1b-1f, 2g-5g, and 6e-6g that are present around the meshes 2b-2f and 3f-5f and that have not been estimated as having or not having deposition, and that are at least partially included in the maximum deposition range, the estimation unit 102 estimates whether they are meshes (with deposition) or meshes (with deposition) by executing the processing procedure of Fig. 5. Here, it is assumed that the meshes 1b-1e are estimated to be meshes (with deposition), and the remaining meshes are estimated to be meshes (without deposition).

[0041] Next, the estimation unit 102 ends the process because there are no meshes that are present around the meshes 1b to 1e and that have not been estimated as having or not having deposition, and that are at least partially included in the maximum deposition range. By performing the process in this manner, the range of meshes (with deposition) can be estimated, as shown in E of FIG. 6.

[0042] FIG. 7 is a diagram for explaining a method for calculating the accumulation judgment angle and the height of the accumulation surface (accumulation depth). FIG. 7 is a diagram when the mesh is viewed from the vertical direction. In FIG. 7, it is assumed that mesh 2x is the mesh at the point where the runoff occurred. First, the estimation unit 102 calculates a point T2x by adding accumulation depth H2 in the height direction to center point B2x of the ground surface of mesh 2x, as shown in FIG. 7A. Note that since mesh 2x is the mesh at the point where the runoff occurred, accumulation depth H2 is a value designated by the user.

[0043] Next, the estimation unit 102 calculates the pile-up judgment angle a1 between the mesh 2x and the mesh 3x adjacent to the mesh 2x. The pile-up judgment angle is the angle a1 of the line segment connecting the center point T2x of the pile-up surface of the mesh 2x and the center point B3x of the ground surface of the mesh 3x with respect to the horizontal plane, as shown in A of FIG. 7. As described in step S11 of FIG. 6, when the pile-up judgment angle is equal to or larger than the pile-up angle, it is estimated that the soil and sand will flow out and pile up in the mesh that is equal to or larger than the pile-up angle. In the example of A of FIG. 7, the pile-up judgment angle a1 is equal to or larger than the pile-up angle.

[0044] Here, as shown in A of Fig. 7, the deposition surface of mesh 2x means a horizontal plane obtained by adding deposition depth H2 to the height of the ground surface of mesh 2x. Since the height of the ground surface of a mesh is an elevation value, the height of the deposition surface of mesh 2x can also be said to be the value obtained by adding deposition depth H2 to the elevation value of mesh 2x.

[0045] Next, the estimation unit 102 calculates the deposition surface of the mesh 3x. As shown in B of Fig. 7, in the case of the mesh 3x, when a line segment is drawn from the center point T2x of the deposition surface of the mesh 2x at the deposition judgment angle f, the horizontal plane including the point T3x where the line segment intersects with a perpendicular line from the center point B3x of the ground surface of the mesh 3x becomes the deposition surface of the mesh 3x. The deposition depth of the mesh 3x becomes the height H3 from the ground surface of the mesh 3x to the deposition surface.

[0046] Next, the estimation unit 102 calculates the pile-up judgment angle a2 between the mesh 3x and the mesh 4x adjacent to the mesh 3x, as shown in C of FIG. Here, the pile-up judgment angle a2 is assumed to be equal to or greater than the pile-up angle. Next, as shown in D of FIG. 7, the estimation unit 102 determines that when a line segment is drawn from the center of the pile-up surface of the mesh 3x at the pile-up judgment angle f, the horizontal plane including the point T4x where the line segment intersects with a perpendicular line from the center point B4x of the ground surface of the mesh 4x becomes the pile-up surface of the mesh 4x. In addition, the pile-up depth of the mesh 4 becomes the height H4 from the ground surface of the mesh 4x to the pile-up surface.

[0047] Next, the estimation unit 102 calculates the pile-up judgment angle a3 between the mesh 4x and the mesh 5x adjacent to the mesh 4x, as shown in E of Fig. 7. Here, the pile-up judgment angle a3 is a negative value, so the pile-up judgment angle a3 is less than the pile-up angle. Therefore, the estimation unit 102 estimates that no soil will flow from the mesh 4x to the mesh 5x.

[0048] (Variation 1) When sediment flows in a landslide disaster, if there is a direction in which the elevation suddenly drops in the surroundings (for example, a valley), it is assumed that the sediment will flow in that direction. Therefore, the information processing device 10 may estimate that the sediment will flow only in the direction with the largest elevation difference when the direction in which the sediment will flow is one in which the elevation difference is greater than or equal to the threshold value because the accumulation judgment angle is greater than or equal to the accumulation angle. On the other hand, if there is no direction in which the elevation difference is greater than or equal to the threshold value among the directions in which the sediment will flow, the information processing device 10 may estimate that the sediment will flow in all directions in which the accumulation judgment angle is greater than or equal to the accumulation angle. Note that the setting angle of the "threshold" is arbitrary, but it is desirable to set it to a relatively large value. The receiving unit 101 may receive a threshold value designation from the user. In this case, the receiving unit 101 may receive a designation of the threshold value when the value of the threshold value designated by the user is greater than a predetermined angle. Alternatively, the threshold value may be set to a fixed value in advance.

[0049] FIG. 8 is a diagram for explaining an outline of the first modification. A in FIG. 8 shows the disaster area viewed from the horizontal direction, and B in FIG. 8 shows the disaster area viewed from above. When a line segment is drawn from the runoff occurrence point P along the ground surface of a predetermined range M centered on the runoff occurrence point P to a ground surface point that is an end of the predetermined range M, the estimation unit 102 may estimate that, for a first line segment K at which an angle r (hereinafter referred to as "ground surface inclination") that is a depression angle of the line segment with respect to the horizontal plane is maximum, if the ground surface inclination r is equal to or greater than a threshold value, and if the accumulation judgment angle g of a second line segment L drawn from the vertex S toward the ground surface point N of the first line segment K with respect to the horizontal plane is equal to or greater than an accumulation angle, sediment will accumulate from the runoff occurrence point P in a direction of a predetermined range centered on the direction of a line segment K' obtained by projecting the first line segment K onto a horizontal plane (that is, in a direction of ±j degrees from the direction of the line segment K' shown in B in FIG. 8), and sediment will not accumulate in any direction other than the direction of the predetermined range.

[0050] More specifically, the estimation unit 102 calculates the ground surface inclination between the line connecting the center point of the ground surface of the first mesh and the center point of the ground surface of the second mesh and the ground surface of the second mesh for each of a plurality of second meshes existing around the first mesh, in the case where the mesh in which the sediment is deposited, including the mesh corresponding to the runoff occurrence point, is the first mesh. Next, the estimation unit 102 calculates the deposition judgment angle between the line connecting the center point of the deposition surface of the first mesh and the center point of the ground surface of the second mesh and the ground surface of the second mesh. Next, when the ground surface inclination angle having the largest angle among the ground surface inclination angles of each of the plurality of second meshes is equal to or larger than a threshold value, the estimation unit 102 may estimate that sediment will be deposited in the second mesh that has the maximum ground surface inclination and whose deposition judgment angle is equal to or larger than the deposition angle. In addition, the estimation unit 102 may estimate that sediment will not be deposited in the second mesh that does not have the maximum ground surface inclination or the second mesh whose deposition judgment angle is smaller than the deposition angle.

[0051] In addition, the estimation unit 102 may estimate that when the ground surface inclination r of the first line segment K relative to the horizontal plane is less than a threshold value, sediment will accumulate from the vertex S in a direction where the accumulation judgment angle g is greater than or equal to the accumulation angle, and that no sediment will accumulate in a direction where the accumulation judgment angle g is less than the accumulation angle.

[0052] More specifically, when the maximum ground surface slope, which is the largest angle among the ground surface slopes of each of the multiple second meshes, is less than a threshold value, the estimation unit 102 may estimate that sediment will accumulate in the second meshes among the multiple second meshes whose accumulation judgment angle is equal to or greater than the accumulation angle, and may estimate that sediment will not accumulate in the second meshes whose accumulation judgment angle is less than the accumulation angle.

[0053] FIG. 9 is a flowchart showing an example (variation 1) of a processing procedure for determining whether or not soil and sand will accumulate in a mesh.

[0054] In step S20, the estimation unit 102 calculates the accumulation judgment angle for each mesh among the meshes surrounding the mesh (with accumulation) that have not been estimated as having accumulation or not having accumulation and are within the maximum accumulation range. The calculation method of the accumulation judgment angle may be the same as the method described using FIG. 7. Next, the estimation unit 102 calculates the ground surface inclination for each mesh. As shown in A of FIG. 7, the ground surface inclination is the angle b1 of the line segment connecting the center point B2x of the ground surface of the mesh 2x and the center point B3x of the ground surface of the mesh 3x with respect to the horizontal plane. Also, in the example of B of FIG. 7, it is the angle b2 of the line segment connecting the center point B3x of the ground surface of the mesh 3x and the center point B4x of the ground surface of the mesh 4x with respect to the horizontal plane. Returning to FIG. 9, the description will be continued.

[0055] In step S21, the estimation unit 102 selects a mesh having the maximum ground surface slope from among the ground surface slopes of the meshes.

[0056] In step S22, the estimation unit 102 determines whether the maximum ground slope is equal to or greater than a threshold value. If the maximum ground slope is equal to or greater than the threshold value, the process proceeds to step S23. If the maximum ground slope is less than the threshold value, the process proceeds to step S24.

[0057] In step S23, the estimation unit 102 estimates that sediment will be deposited only in meshes where the maximum ground surface inclination is equal to or greater than the threshold value and the deposition judgment angle is equal to or greater than the deposition angle. The estimation unit 102 also estimates that sediment will not be deposited in meshes other than those surrounding the mesh (where deposition is present) where the deposition judgment angle is equal to or greater than the deposition angle and the maximum deposition judgment angle is equal to or greater than the threshold value. The estimation unit 102 also calculates the deposition depth for the meshes where it is estimated that sediment will be deposited. The method of calculating the deposition depth may be the same as that described with reference to FIG. 7.

[0058] In step S24, the estimation unit 102 estimates that, among the meshes surrounding the mesh (with accumulation), sediment will be accumulated in all meshes whose accumulation judgment angle is equal to or greater than the accumulation angle. Also, among the meshes surrounding the mesh (with accumulation), the estimation unit 102 estimates that sediment will not be accumulated in meshes whose accumulation judgment angle is less than the accumulation angle. Also, the estimation unit 102 calculates the accumulation depth for meshes in which sediment is estimated to be accumulated. The processing procedure of step S24 is the same as the processing procedure of steps S11 to S13 in FIG. 5.

[0059] 10 is a diagram for explaining a specific example (variation 1) of a method for estimating an accumulation range. Circles indicated by A to E in FIG. 10 indicate the maximum accumulation range.

[0060] First, as shown in A of FIG. 10, it is assumed that a sediment runoff has occurred in mesh 4d. The estimation unit 102 estimates whether each of the eight meshes surrounding mesh 4d is a mesh (with deposition) or a mesh (without deposition) by executing the processing procedure of FIG. 9. Here, mesh 5d is assumed to be a mesh whose maximum ground surface slope is equal to or greater than a threshold value and whose deposition judgment angle is equal to or greater than the deposition angle. In this case, as shown in B of FIG. 10, only mesh 5d is estimated to be a mesh (with deposition), and the other meshes are estimated to be meshes (without deposition).

[0061] Next, as shown in C of Fig. 10, the estimation unit 102 executes the processing procedure of Fig. 9 for meshes 6c to 6e that are present around mesh 5d, have not been estimated as having or not having deposition, and have at least a part included in the maximum deposition range, to estimate whether they are meshes (with deposition) or meshes (with deposition). Here, it is assumed that mesh 6d is a mesh whose maximum ground surface inclination is equal to or greater than a threshold value and whose deposition judgment angle is equal to or greater than the deposition angle. In this case, as shown in C of Fig. 10, only mesh 6d is estimated to be a mesh (with deposition), and meshes 6c and 6e are estimated to be meshes (without deposition).

[0062] Next, as shown in D of FIG. 10, the estimation unit 102 estimates whether the meshes 7c to 7e, which are present around the mesh 6d and have not been estimated as having or not having deposition, and which are at least partially included in the maximum deposition range, are meshes (with deposition) or meshes (with deposition) by executing the processing procedure of FIG. 9. Here, it is assumed that the mesh 7d is the mesh with the maximum ground surface inclination, but the maximum ground surface inclination is less than a threshold value. It is also assumed that the deposition judgment angles of the meshes 7c and 7d are equal to or greater than the deposition angle, but the deposition judgment angle of the mesh 7e is less than the deposition angle. In this case, as shown in D of FIG. 10, the meshes 7c and 7d are estimated to be meshes (with deposition), and the mesh 7e is estimated to be a mesh (without deposition).

[0063] Next, as shown in E of FIG. 10, the estimation unit 102 executes the processing procedure of FIG. 9 for meshes 6b and 7b that are present in the vicinity of meshes 7c and 7d, have not been estimated as having or not having deposition, and have at least a part included in the maximum deposition range, to estimate whether they are meshes (with deposition) or meshes (with deposition). Here, mesh 7b is the mesh with the maximum ground surface slope, but the maximum ground surface slope is assumed to be less than a threshold value. Also, the deposition judgment angle of meshes 6b and 7b is assumed to be less than the deposition angle. In this case, as shown in E of FIG. 10, meshes 6b and 7b are estimated to be meshes (without deposition).

[0064] Next, since all meshes existing around the mesh (with deposition) are estimated to be meshes (without deposition), the estimation unit 102 ends the process. By performing the process in this manner, it is possible to estimate the range of the mesh (with deposition), as shown in E of FIG.

[0065] (Variation 2) The map data may include data indicating the positions of buildings and data indicating the attributes of each building (for example, data indicating whether the building is made of wood or reinforced concrete). The estimation unit 102 may estimate the damage caused by the landslide disaster by combining the estimated accumulation range, data indicating the positions of each building, and data indicating the attributes of each building. For example, it may be estimated that the damage is large in an area where the proportion of wooden buildings in the accumulation range of landslide is equal to or greater than a predetermined proportion, and that the damage is small in an area where the proportion of wooden buildings in the accumulation range of landslide is less than a predetermined proportion. This makes it possible to simulate the damage caused by the landslide disaster. The estimation unit 102 may also obtain data indicating the height of buildings and use it to estimate the damage.

[0066] (Variation 3) When outputting accumulation range information showing the range where sediment is accumulated to the terminal 20, the information processing device 10 may display the accumulation depth for each mesh in a distinguishable manner. For example, the accumulation depth may be divided into a number of stages, and the accumulation range information may be displayed on the terminal 20 as a risk map by color-coding the stages such that the mesh with the deepest accumulation depth is red and the mesh with the shallowest accumulation depth is blue. This makes it possible to easily distinguish between areas with deep accumulation depth and areas with shallow accumulation depth due to a landslide disaster.

[0067] (Variation 4) The reception unit 101 may receive a plurality of runoff occurrence points from the user. Furthermore, when the estimation unit 102 receives a plurality of runoff occurrence points, the estimation unit 102 may calculate the deposition depth of each mesh by executing the processing procedure shown in Fig. 5 or Fig. 9 for each runoff occurrence point. Furthermore, the estimation unit 102 may add up the deposition depth of each mesh calculated for each runoff occurrence point for each mesh, and estimate the deepest deposition depth as the deposition depth of that mesh.

[0068] For example, if the point where the runoff occurred is A, the sediment depth in mesh X is calculated to be 10m, and if the point where the runoff occurred is B, the sediment depth in mesh X is calculated to be 30m. In this case, the sediment depth in mesh X is estimated to be 30m. This makes it possible to more appropriately calculate the sediment depth for each mesh even when a landslide occurs over a wide area.

[0069] <Summary> According to the embodiment described above, the information processing device 10 estimates the accumulation range based on three parameters, namely, the runoff occurrence point, accumulation depth, and accumulation angle, and map data. This makes it possible to provide a technology that enables the accumulation range to be more easily estimated in the event of a landslide disaster.

[0070] The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The flow charts, sequences, elements included in the embodiments, and their arrangements, materials, conditions, shapes, sizes, etc. are not limited to those illustrated, and can be changed as appropriate. In addition, configurations shown in different embodiments can be partially replaced or combined with each other. [Explanation of symbols]

[0071] 1 Disaster simulation system, 10 Information processing device, 11 Processor, 12 Storage device, 13 Network IF, 14 Input device, 15 Output device, 20 Terminal, 100 Storage unit, 101 Reception unit, 102 Estimation unit, 103 Output unit

Claims

1. A storage unit that stores map data including elevation data indicating the height of the earth's surface; a reception unit that receives designation of a runoff occurrence point indicating a point on a map where a runoff of sediment occurs, a deposition depth indicating a height at which the sediment will be deposited at the runoff occurrence point, and a deposition angle indicating an angle at which the sediment will be deposited; an estimation unit that estimates an area on a map where the sediment will be deposited when the sediment is deposited at the deposition angle, based on a position obtained by adding the deposition depth in a height direction of the runoff occurrence point, as an apex, on the basis of the apex, the deposition angle, and the map data; an output unit that outputs accumulation range information indicating an area where the soil and sand are accumulated; An information processing device having the above configuration.

2. the estimation unit estimates that, when a line segment is drawn from the vertex toward the ground surface at the deposition angle, a range where the line segment intersects with the ground surface represented by the map data is a range on the map where the sediment will be deposited. The information processing device according to claim 1 .

3. When a line segment is drawn from the vertex toward a predetermined range on the ground surface centered on the vertex, It is estimated that the soil and sand are deposited in a direction from the vertex where the deposition judgment angle of the line segment with respect to the horizontal plane is equal to or greater than the deposition angle, and that the soil and sand are not deposited in a direction from the vertex where the deposition judgment angle is less than the deposition angle. The information processing device according to claim 1 .

4. The map data is expressed in a mesh format, The height of the ground surface in the elevation data represents an elevation of the ground surface of the mesh, The estimation unit, when a mesh in which the sediment has accumulated is defined as a first mesh, including a mesh corresponding to the runoff occurrence point, estimates, for each of a plurality of second meshes existing around the first mesh, a horizontal plane obtained by adding the elevation of the ground surface of the first mesh to the deposition depth is defined as a deposition surface, and if a deposition judgment angle between a line connecting the center point of the deposition surface of the first mesh and the center point of the ground surface of the second mesh and the ground surface of the second mesh is equal to or greater than the deposition angle, it is estimated that the soil and sand will be deposited in the second mesh; When the accumulation judgment angle is less than the accumulation angle, it is estimated that the soil and sand will not accumulate in the second mesh. The information processing device according to claim 1 .

5. When the estimation unit estimates that the soil and sand will accumulate in the second mesh, Calculating a point where a perpendicular line passing through a center point of the ground surface of the second mesh intersects with a line extending from the center point of the deposition surface of the first mesh at the deposition angle; A horizontal plane including a point where the horizontal plane intersects with the perpendicular line is estimated to be a deposition surface in the second mesh. The information processing device according to claim 4.

6. When the estimation unit draws a line segment from the runoff occurrence point along a ground surface of a predetermined range centered on the runoff occurrence point to a ground surface point that is an end of the predetermined range, For a first line segment at which the ground surface slope, which is the angle of the line segment with respect to the horizontal plane, is maximum, if the ground surface slope is equal to or greater than a threshold value and the accumulation judgment angle of a second line segment drawn from the vertex toward the ground point of the first line segment with respect to the horizontal plane is equal to or greater than the accumulation angle, it is estimated that the sediment will accumulate in a predetermined range of directions centered on the direction of the line segment obtained by projecting the first line segment onto a horizontal plane from the runoff occurrence point, and that the sediment will not accumulate in any direction other than the predetermined range of directions; When the ground surface inclination of the first line segment is less than the threshold value, it is estimated that the soil and sand are deposited in a direction from the vertex where the deposition judgment angle is equal to or greater than the deposition angle, and that the soil and sand are not deposited in a direction from the vertex where the deposition judgment angle is less than the deposition angle. The information processing device according to claim 1 .

7. The map data is expressed in a mesh format, The height of the ground surface in the elevation data represents an elevation of the ground surface of the mesh, The estimation unit, when a mesh in which the sediment has accumulated is defined as a first mesh, including a mesh corresponding to the runoff occurrence point, estimates, for each of a plurality of second meshes existing around the first mesh, Calculating a ground surface gradient between a line connecting a center point of the ground surface of the first mesh and a center point of the ground surface of the second mesh and the ground surface of the second mesh; a horizontal plane obtained by adding the deposition depth to the elevation of the ground surface of the first mesh is defined as a deposition surface, and a deposition determination angle is calculated between a line connecting the center point of the deposition surface of the first mesh and the center point of the ground surface of the second mesh and the ground surface of the second mesh; When the maximum ground surface slope, which is the largest angle among the ground surface slopes of each of the plurality of second meshes, is equal to or larger than a threshold value, It is estimated that the soil and sand will be deposited in a second mesh having the maximum ground surface slope and the deposition judgment angle being equal to or larger than the deposition angle; It is estimated that the soil will not be deposited in a second mesh that does not have the maximum ground surface slope or in a second mesh in which the deposition judgment angle is less than the deposition angle. The information processing device according to claim 1 .

8. The estimation unit is When the maximum ground surface slope, which is the largest angle among the ground surface slopes of each of the plurality of second meshes, is less than a threshold value, It is estimated that the sediment will be deposited in a second mesh among the plurality of second meshes, in which the deposition judgment angle is equal to or greater than the deposition angle, and it is estimated that the sediment will not be deposited in a second mesh in which the deposition judgment angle is less than the deposition angle. The information processing device according to claim 7.

9. storing map data including elevation data indicating the height of the earth's surface in a storage unit; receiving a designation of a runoff occurrence point indicating a point on a map where a runoff of sediment occurs, a deposition depth indicating a height at which the sediment will be deposited at the runoff occurrence point, and a deposition angle indicating an angle at which the sediment will be deposited; a step of estimating, based on a position obtained by adding the accumulation depth in a height direction of the runoff occurrence point to a vertex, an area on a map in which the sediment will be accumulated when the sediment is accumulated at the accumulation angle, based on the vertex, the accumulation angle, and the map data; outputting accumulation range information indicating an area where the sediment is accumulated; An information processing method executed by an information processing device, comprising:

10. storing map data including elevation data indicating the height of the earth's surface in a storage unit; receiving a designation of a runoff occurrence point indicating a point on a map where a runoff of sediment occurs, a deposition depth indicating a height at which the sediment will be deposited at the runoff occurrence point, and a deposition angle indicating an angle at which the sediment will be deposited; a step of estimating, based on a position obtained by adding the accumulation depth in a height direction of the runoff occurrence point to a vertex, an area on a map in which the sediment will be accumulated when the sediment is accumulated at the accumulation angle, based on the vertex, the accumulation angle, and the map data; outputting accumulation range information indicating an area where the sediment is accumulated; A program that causes a computer to execute the following.

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