JP2013210600A - Debris flow flooding area high speed simulation method and debris flow flooding area high speed simulation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To integrally manage the respective simulation tools to visually and intelligibly display simulation of debris flow in a short time on an image of a GIS.SOLUTION: In a debris flow high speed simulation tool part 100 of a debris flow flooding area high speed simulation device 10, a meshing part 101 meshes LP data of a database 200 for LP data, and a binarization part 103 converts the meshed LP data into binary data. Then, a lowest river line automatic drawing part 150 performs overlap display of a primary mountain stream by a layering part 500, and a flooding simulation range setting part 110 generates a flooding simulation frame Wi on the basis of the downstream end P2. A specific range two-dimensional tomographic model calculation part 120 determines altitude data within a specific range by using the binary data corresponding to the flooding simulation frame Wi to be simulated by a debris flow flooding simulation result display tool 160.

Description

  The present invention relates to a debris inundation high-speed simulation method for simulating inundation in a plain portion of a debris flow flowing through a mountain stream using LP data.

  Electronic information processing technology has made great strides in both software and hardware. In recent years, a large amount of high-precision landform information measured by a laser profiler has been acquired by the Geospatial Information Authority of Japan, a directly controlled sabo office, and the like in the field of sabo. This high-accuracy terrain information is generally obtained by scanning a target with a laser beam at high speed using a laser profiler mounted on an aircraft, and using one or more points of data obtained from the obtained 2 m range data as LP data. It is generated based on LP data.

  However, there is no application for easily using high-precision terrain information based on LP data from the laser profiler.

  For this reason, this high-precision terrain information can only be handled by a special system or a special consultant company.

  Many simulation models have been proposed in the field of sabo, but high-precision terrain information is available because the application range is limited and an effective interface for data input / output is not implemented. Was rarely fully utilized.

  Therefore, there is a debris flow simulation tool as one tool in the field of sabo to solve such problems.

  This debris flow simulation tool is effective in predicting the scale of disasters and studying effective sabo structures. It implements an effective GUI (graphic user interface) and enables input / output with a mouse, as well as existing models. It is a user-friendly tool by integrating, integrating and improving

  On the other hand, during the Iwate Miyagi inland earthquake in June 2008, the effectiveness of the data measured by the laser profiler was confirmed in the investigation of many natural dams. This led to the development of precise and wide-ranging sabo data for sabo in the 2008/21 fiscal year, based on nationally standardized sabo areas and their surrounding areas.

  The three-dimensional terrain data (DEM: Digital Elevation Model) obtained from LP data has national standard and accuracy (JPJIS, within 1m x 1m), and about 15% (5% of the land area mainly in hilly and mountainous areas) It is expected to be widely used in future equipment management and sabo surveys.

"Kana Nakatani, Takashi Wada, Yoshifumi Satobuka, Takahisa Mizuyama: Development of general-purpose debris flow simulator with GUI, 4th Symposium on Sediment Disasters, p149-154, 2008"

JP 2009-251250 A JP 2008-84243 A

  However, when a conventional debris flow simulation tool is applied to another debris flow simulation system for real terrain, it is necessary to manually input and set high-precision terrain information.

  In addition, the conventional debris flow simulation tool is a software that allows a person in charge to create high-accuracy topographic information by manually inputting necessary data while looking at the topographic map, or software that can automatically read data for creating a topographic map However, these methods require complicated work.

  In addition, when necessary data is input using a generally available topographic map to reduce labor, the topographic map has a low accuracy, and thus a problem remains.

  In order to perform a more accurate simulation, it is essential to use detailed three-dimensional terrain data such as DEM.

  However, a special technique is required when extracting data of a required area from the DEM and converting the data into a format corresponding to the debris flow simulation tool.

  On the other hand, when inputting necessary data with high-accuracy terrain information using LP data, LP data has a huge capacity (for example, about 10 GB in one mountain stream), and simulation was performed using this LP data. In some cases, the simulation process takes a long time.

  That is, since development of simulation software that can easily use LP data has not progressed, high-precision terrain information using LP data is not sufficiently utilized.

  Therefore, even if the simulation is executed using the high-precision landform information measured with the LP data, it takes a very long time to obtain the simulation result because the LP data has a huge capacity.

  In addition, many work processes are required to manage and apply the simulation results, and there is no system environment in which these results can be integrated.

  That is, an inundation simulation apparatus that connects LP data and a map of GIS (Geographic Information Systems) and operates with a GUI (graphic user interface) has not been developed.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a debris flow inundation area high-speed simulation method capable of developing the inundation of the inundation simulation frame specified on the map on the GUI at high speed using LP data. And

The debris flow inundation area high-speed simulation method of the present invention stores geographical information of a region, reads a topographic map including a mountain stream area included in the geographical information, and displays it on a screen;
A debris flow information calculation tool for obtaining debris flow information flowing in the mountain stream area;
A database storing LP data including three-dimensional coordinates in a text format obtained by irradiating the area with a laser;
First storage means for storing mesh data in which LP data having a constant interval among the LP data is connected to each other and meshed;
Preparing a second storage means for storing the specified range two-dimensional terrain model;
Computer
The local LP data is read from the database, meshed by connecting them at regular intervals, and the text-format LP data forming the vertices of each mesh is associated with the mesh as the mesh data, and Storing in one storage means;
Designating the meshes of the first storage means in order, and for each designation, binary-converting the textual Z coordinate of the data of each vertex of the mesh;
Specifying the top and bottom ends of the mountain stream area of the topographic map, obtaining a streamline between the top and bottom edges and displaying the top of the topographic map in an overlapping manner;
With the lower end of the mountain stream line as a reference, a step of displaying a frame of an area preset from the lower end as an inundation simulation frame overlaid on the topographic map,
Retrieving the mesh having the two-dimensional coordinates of the lower end on the topographic map from the first storage means, and defining the position of the two-dimensional coordinates of the lower end in the retrieved mesh;
The position of the lower end projected on the mesh is set as a reference position, and the inundation simulation frame is defined on the mesh group of the first storage means from this reference position, and the mesh mass in the inundation simulation frame is used for LP data. A process defined as a simulation area;
Obtaining an average value of binary data of each Z coordinate assigned to each vertex of the mesh of the LP data simulation region, and setting this as elevation data of the mesh of the LP data simulation region;
Each time elevation data per mesh in the LP data simulation area is obtained, the mesh two-dimensional coordinates, the mesh size, and the elevation data are associated with each other, and this is used as the specified range two-dimensional terrain model. Storing in the storage means;
The debris flow information calculation tool unit obtains debris flow information flowing through the mountain basin per fixed time, and the calculation result is sequentially from the mesh corresponding to the lower end of the specified range two-dimensional terrain model of the second storage means. The gist is to perform the step of reflecting the results and displaying the results by color.

The debris flow inundation area high-speed simulation device of the present invention stores geographical information of a region, reads a topographic map including a mountain stream area included in the geographical information, and displays it on a screen;
A debris flow information calculation tool for obtaining debris flow information flowing in the mountain stream area;
A database storing LP data including three-dimensional coordinates in a text format obtained by irradiating the area with a laser;
First storage means for storing mesh data in which LP data having a constant interval among the LP data is connected to each other and meshed;
The text that reads the LP data of the region from the database and connects them at regular intervals to form a vertex of each of the meshes by reading the LP data of the region from the database and second storage means for storing the specified range two-dimensional terrain model Means for associating LP data in the form as mesh data with the mesh and storing it in the first storage means;
Means for sequentially specifying the meshes of the first storage means, and for each designation, means for binary-converting the Z coordinate in the text format of the data of each vertex of the mesh;
Means for designating the upper and lower ends of the mountain stream area of the topographic map, obtaining a streamline between the upper and lower ends and displaying the streamline on the topographic map;
Means for displaying the frame of the area set in advance from the lower end as a flood simulation frame on the topographic map based on the lower end of the mountain stream line;
Means for searching the mesh having the two-dimensional coordinates of the lower end on the topographic map from the first storage means, and defining the position of the two-dimensional coordinates of the lower end in the searched mesh;
The position of the lower end projected on the mesh is set as a reference position, and the inundation simulation frame is defined on the mesh group of the first storage means from this reference position, and the mesh mass in the inundation simulation frame is used for LP data. Means to define as a simulation area;
Means for obtaining an average value of binary data of each Z coordinate assigned to each vertex of the mesh of the LP data simulation region, and making this an altitude data of the mesh of the LP data simulation region;
Each time elevation data per mesh in the LP data simulation area is obtained, the mesh two-dimensional coordinates, the mesh size, and the elevation data are associated with each other, and this is used as the specified range two-dimensional terrain model. Means for storing in the storage means;
The debris flow information calculation tool unit obtains debris flow information flowing through the mountain basin per fixed time, and the calculation result is sequentially from the mesh corresponding to the lower end of the specified range two-dimensional terrain model of the second storage means. The gist of the invention is that it includes means for reflecting the results and displaying the results by color.

  As described above, according to the present invention, text-format LP data is connected at regular intervals to form a mesh, and the Z coordinate of each vertex of the mesh is converted into binary data.

  Then, on the contour map displayed on the screen, a stream line is automatically generated between the designated upstream end and downstream end, and an inundation simulation frame is generated based on the downstream end.

  Next, the cluster of meshes corresponding to the flood simulation frame is searched, and each vertex in the searched mesh blocks is converted into binary data, and the average value of these binary data is used as the elevation data per mesh. The specified range two-dimensional terrain model is generated by assigning the elevation data to the mesh.

  For each mesh of the specified range two-dimensional terrain model, a simulation is performed when debris flow information flowing through a streamline flows, and the result is displayed in units of meshes.

  For this reason, even if LP data is used, a desired simulation result can be obtained in a resolution of LP data in a short time.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the debris flow inundation area | region high speed simulation apparatus 10 of this Embodiment. It is explanatory drawing of meshed LP data. It is explanatory drawing explaining the setting of a primary mountain stream. It is explanatory drawing explaining the setting of the flooding range. It is a flowchart explaining the production | generation process of the designated range two-dimensional terrain model WMi of this Embodiment. It is a flowchart explaining the detail of FIG. It is explanatory drawing explaining a designated range two-dimensional terrain model. It is a flowchart explaining operation | movement of the debris flow inundation area high-speed simulation apparatus using "HyperKANAKO" of this Embodiment. It is explanatory drawing explaining the setting of the dam with respect to a mountain stream line. It is explanatory drawing explaining the cross section of a mountain stream. It is explanatory drawing explaining the longitudinal cross-sectional view for setting a sedimentation gradient. It is a display figure of the sedimentation area by this Embodiment. It is explanatory drawing explaining the display of the simulation result on a GIS image (map image). It is explanatory drawing explaining the display of a simulation result on a bird's-eye view. It is explanatory drawing when the mesh size of a two-dimensional terrain model is 10 m. It is explanatory drawing at the time of setting the mesh size of a two-dimensional terrain model to 20m. It is explanatory drawing of the example of a display according to the flood simulation result according to the altitude data of the designated range two-dimensional terrain model WMi.

  The debris flow inundation area high-speed simulation device of this embodiment is an integrated system for simply and accurately executing a debris flow simulation tool using LP data.

  The debris flow inundation area high-speed simulation device is based on a GUI-compatible debris flow simulation tool program that can continuously calculate one-dimensional and two-dimensional riverbed fluctuation calculations, revising memory management methods and calculation processing algorithms, and greatly increasing simulation time. It has been improved so that it can be flexibly adapted to the mesh size of high-precision terrain information based on LP data.

  Furthermore, by using GIS, consideration is given to initial terrain condition setting and visualization of results.

  This debris flow flooding area high-speed simulation device can easily set high-precision topographic information, and can quickly obtain reasonable analysis results.

  For this reason, it is a very effective tool for debris flow inundation / deposition prediction or sabo planning. This tool is referred to as a debris flow high-speed simulation tool unit in the present embodiment.

  Further, the LP data is more specifically the three-dimensional coordinates (Xi, Yi, Zi) of the object obtained by irradiating the target area with a laser at intervals of several centimeters using a laser profiler from an aircraft equipped with GPS, IMU, etc. This is text data having reflection intensity and the like.

  In addition, one feature of the debris flow high-speed simulation tool part is an improvement in operability and visibility through cooperation with GIS.

  GIS is an optimal tool for easily indicating an object having a geographical index with a map as a background and displaying the object in an easy-to-understand manner.

  The debris flow high-speed simulation tool part can easily set LP data on GIS when creating two-dimensional terrain data using one-dimensional mountain stream lines.

  In addition, since LP data that is a source of high-precision terrain information has three-dimensional coordinates in a plane rectangular coordinate system, two-dimensional coordinates (also referred to as plane coordinates) are added to the high-precision terrain information together with elevation data. .

  Furthermore, geographical information is added to the high-precision terrain information in the world file format.

  By using this world file, the debris flow high-speed simulation tool unit can add the three-dimensional coordinates of LP data to the topographic map.

  In addition, the simulation results in the inundation simulation frame are output as a series of numerical values for each mesh of high-precision topographic information (hereinafter also referred to as topographic data). It is possible to simultaneously output time-series images having geographical information color-coded according to depth. For this reason, the result can be confirmed on the GIS immediately after the end of the simulation calculation.

  In addition, it is possible to overlay other topographical maps, such as sabo base maps, and easily check which buildings are flooded.

  Furthermore, the debris flow high-speed simulation tool unit can perform time-series three-dimensional display by superimposing the simulation result image on the bird's eye view display function possessed by GIS.

  The aforementioned GIS is a function provided in a system called Sabo · D-MAC (not shown). This system can centrally manage a variety of digitized sabo related information using "geographical location information" as an index, so office staff can call and use information on their desktop computers. Intranet type system.

The basic function of Sabo / D-MAC is a cooperative search function for maps, databases, folders, etc.
(1) Monitoring / Observation Data Management System (2) Business Progress Management System (3) This is an extended system to which a 3D data analysis system can be added as an option.

  This section describes the three-dimensional data analysis function closely related to the debris flow high-speed simulation tool.

3D data analysis function
1) Vertical cross section display function of arbitrary survey line 2) Bird's eye view display function of arbitrary range 3) Lowest riverbed (vertical section) search function 4) Sediment area display and sediment volume calculation function by arbitrary sediment gradient.

  The three-dimensional data used here uses LP data used in the simulation and TIN (Triangulated Irregular Network: digital data expressing the ground surface as a set of triangles) created with a sabo base map.

  The LADOF (Landslide Dam Overflow Flood) model that assumes the setting of mountain streams to which simulation is applied and the results are visualized, or the overflow of a natural dam described later, is a numerical simulation model for overflow erosion of a natural dam.

  The hydrograph calculation using the LADOF model is executed by utilizing these three-dimensional analysis functions.

  The configuration of the debris flow flooding area high-speed simulation device of the present embodiment will be described below with reference to FIG.

  The following embodiments show examples of apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is described in the claims. Various modifications can be made within the technical scope. It should be noted that the drawings are schematic and the configuration of the apparatus and system is different from the actual one.

  FIG. 1 is a schematic configuration diagram of a debris flow flood zone high speed simulation apparatus 10 according to the present embodiment.

  As shown in FIG. 1, the debris flow flood zone high-speed simulation apparatus 10 includes a display unit 30, a mouse 20, a debris flow high-speed simulation tool unit 100, an LP data database 200 storing LP data, and a geographic information database 300. A database 400 storing a sabo base map for each prefecture or region, a GIS layering unit 500, a debris flow information calculation tool unit 600, a GUI unit 140 (graphic user interface unit), and a minimum riverbed line automatic drawing unit 150, etc., and create a specified range 2D terrain model to be described later by binary conversion of LP data Z coordinate in the flood simulation frame (also called 2D terrain data) specified on the GIS contour map. Simulation of inundation according to elevation data for each mesh Down the results to display different colors.

  The debris flow information calculation tool unit 600 has a function of displaying a vertical and horizontal cross-sectional view of an arbitrary side line, a bird's eye view display function of an arbitrary range, a search function for a lowest riverbed line (longitudinal), a sedimentation area display and a sedimentation amount calculation by arbitrary sediment purchase. Includes functions etc.

  The LP data database 200 stores LP data (DEM: intervals of several centimeters) having three-dimensional coordinates (Xi, Yi, Zi) and reflection intensity of an object in a text format.

  The geographic information database 300 stores contour maps, road maps, river maps, dwelling maps, orthoimages, etc. of the target area.

  These are vector format or raster format. In the case of a raster format, a text format world file is associated.

  The GIS layering unit 500 (hereinafter simply referred to as the layering unit 500) displays the data stored in the geographic information database 300 or each memory on the display unit 30 in an overlapping manner.

  Also, the GIS layering unit 500 causes the display unit 30 to display the images created by the debris flow information calculation tool unit 600 in a superimposed manner.

  As shown in FIG. 1, the debris flow high-speed simulation tool unit 100 includes a meshing unit 101, a binarization unit 103, an inundation simulation range setting unit 110, a specified range two-dimensional terrain model calculation unit 120, a debris inundation simulation result display tool 160, and the like. Have It also has various memories.

  These are programs executed by a ROM, RAM, CPU, etc., and the programming language is VB. By converting from NET to C ++, higher speed is realized.

  This makes it possible to perform a detailed analysis using the LP data in the inundation simulation frame.

And by using C ++,
(1) Dynamic memory allocation and memory operation (2) Speeding up of array access by pointer (3) New class creation function (4) It is possible to use an existing image processing library.

(Dynamic memory allocation and memory manipulation)
C ++ has a function that can dynamically secure a memory (array) as necessary during program execution, and can flexibly cope with the number of meshes of two-dimensional terrain data by using this function. Further, in general simulation programs, data copying between arrays frequently occurs, but C ++ has a high-speed function for copying between memories and can realize high-speed processing.

(Acceleration of array access by pointer)
By using the point function of C ++, it is possible to access an arbitrary position of the array at high speed.

(New class creation function)
C ++ has a function to create a new class (a mechanism for adding a new function to a language) as necessary. The simulation process (program) of this embodiment creates a specified range two-dimensional terrain model WMi. Therefore, a huge file access class and a matrix processing class are used.

(Use of existing image processing library)
The simulation processing of this embodiment has already published a high-speed library for reading and creating PNG format so that the processing results can be confirmed in time series. It is possible to create a high-speed program with little.

<Description of each part>
The meshing unit 101 stores all the LP data in the area designated from the LP data database 200 in the memory 102a. The memory 102a is defined by a plane rectangular coordinate system.

  Then, based on the origin of the memory 102a as a reference, a mesh group in which LP data is connected at a constant interval is generated in the memory 102a based on the input resolution (1 m or 2.5 m..., Arbitrary) (see FIG. 2). . In the present embodiment, it is assumed that the distance is 1 m.

  If the resolution is 2.5 m, a 2.5 m mesh Li is created. Along with the creation of the mesh Li, a world file including the mesh number, the ordinate and abscissa of the mesh Li, the size (1 m) of the mesh Li, and the like is generated in the memory 102b.

  When a mesh group of LP data is generated in the memory 102a by the meshing unit 101, the binarizing unit 103 performs binary conversion on the Z coordinate in the text format that forms each vertex of the mesh Li (also referred to as a grid) (4 bytes). ), This binary data Lpbi is stored in the memory 106 in association with the mesh number. That is, a binary Z coordinate is assigned to each vertex of the mesh Li.

  Note that the binary conversion of the present embodiment is for conversion into an image file format, and the file format is a file format such as TIFF, BMP, JPEG, or PNG. In this embodiment, it is a PNG file.

  In the case of a PNG file, the Z coordinate binary-converted is embedded in the field in which the color value is embedded.

  When the setting of the primary stream line is instructed on the topographic map displayed on the screen of the display unit 30 and the upstream end P1 and the downstream end P2 are instructed, the lowest riverbed automatic drawing unit 150 is for the primary stream. A memory 162 (defining a plane rectangular coordinate system) is generated.

  Then, the primary mountain stream line up to both of these end points is obtained and stored in the primary mountain stream memory 162, and this is superimposed on the layering unit 500 (see FIG. 3).

  The flood simulation range setting unit 110 generates the memory 165 (planar rectangular coordinate system) in accordance with the setting of the downstream end P2 of the display unit 30.

  Next, a 1 km × 1 km square frame (referred to as an inundation simulation frame Wi) is generated in the memory 165 (planar rectangular coordinate system) with the downstream end P2 as a reference, and this is superimposed and displayed by the layering unit 500 (FIG. 4).

  In addition, when the downstream end P2 is designated, the flood simulation range setting unit 110 generates the memory 113 and reads the position (Xi, Yi) on the map corresponding to the downstream end P2 into the memory 113. In the present embodiment, the position (X, Y) of the downstream end P2 stored in the memory 113 is referred to as a reference position P2a.

  The designated range two-dimensional terrain model calculation unit 120 reads the reference position P2a (downstream end P2) and the flood simulation frame Wi (for example, 1 km × 1 km or 1 km × 2 km ··) stored in the memory 113.

  Then, based on the world file in the memory 102b, the reference position Pa2 (downstream end P2) is projected onto the mesh Li in the memory 102a, this projection position is set as the projection reference position PQ2, and the flood simulation frame Wi is defined from the projection reference position PQ2. It is defined in the memory 102a. Next, the cluster of meshes Li in the inundation simulation frame Wi is read into the memory 106 as the LP data simulation area LWi.

  Furthermore, the designated range two-dimensional terrain model calculation unit 120 sequentially defines positions LBi (X, Y) in each mesh Li at intervals of 1 m from the projection reference position PQ2 of the LP data simulation area LWi in the memory 106.

  Then, a minimum two-dimensional coordinate (Ximin, Yimax) and a maximum two-dimensional coordinate (Ximax, Yimax) of each mesh Li are connected by a straight line TLi to form a triangle in each mesh Li, and assigned to each vertex of this triangle. The average value of the Z coordinates (binary data) is obtained.

  This is referred to as altitude data Hi in the mesh Li of the LP data simulation area LWi.

  Next, data in which the mesh number, the two-dimensional coordinates (X, Y) of the mesh Li, the size of the mesh Li, and the elevation data Hi are associated with each other is stored in the memory 130 as the designated range two-dimensional landform model WMi.

  That is, the designated range two-dimensional terrain model WMi is defined in the world file because the two-dimensional coordinates are assigned. This world file is preferably stored in the memory 131 in association with the mesh number.

  The debris inundation simulation result display tool 160 is based on an instruction input via the GUI unit 140, and includes a debris flow information calculation tool unit 600 (an arbitrary side line vertical / horizontal cross-sectional view display function, an arbitrary range bird's-eye view display function, a minimum riverbed line ( Vertical search) Activating a search function, a sediment area display by arbitrary sediment purchase and a sediment amount calculation function, etc., and storing these analysis results in the memory 163 (163a, 163b,...) Is displayed in an overlapping manner.

  Further, the data reflecting the analysis result is stored in the memory 164 in the designated range two-dimensional terrain model WMi in the memory 130 as necessary.

<Description of operation>
FIG. 5 is a flowchart for explaining a generation process of the designated range two-dimensional terrain model WMi of the designated range two-dimensional terrain model calculation unit 120 according to the present embodiment. FIG. 6 is a supplementary explanatory diagram of FIG.

  In the first embodiment, it is assumed that the Z coordinate of LP data has already been binary converted by the binarization unit 103 and stored in the memory 106.

  Further, in the topographic map displayed on the screen, the upstream end P1 and the downstream end P2 are designated and the primary streamline is drawn by the lowest riverbed automatic drawing unit 150.

  When the downstream end P2 is set on the map of the screen of the display unit 30, the inundation simulation range setting unit 110 displays the inundation simulation frame Wi on the screen map on the basis of the downstream end P2 (S1: FIG. 4).

  Next, the flood simulation range setting unit 110 generates the memory 113 in accordance with the designation of the downstream end P2, and stores the position (Xi, Yi) on the map of the downstream end P2 in the memory 113 (S2).

  Next, when the downstream end P2 is stored in the memory 113, the designated range two-dimensional terrain model calculation unit 120 reads the position (Xi, Yi) of the downstream end P2 and projects it on the mesh group of the memory 102a (S3). ).

  Then, the flood simulation frame Wi is defined in the mesh group of the memory 102a with reference to the projection reference position PQ2 (S4).

  Next, the cluster of meshes Li in the flood simulation frame Wi of the memory 102a is read out to the memory 106 (S5). In the present embodiment, the cluster of meshes read to the memory 106 is referred to as an LP data simulation area LWi.

  Next, the designated range two-dimensional terrain model calculation unit 120 sequentially defines positions LBi (Xi, Yi) in each mesh at intervals of 1 m from the projection reference position PQ2 of the LP data simulation area LWi in the memory 106 (S6). .

  Then, the mesh Li of the LP data simulation region LWi having this position LBi (including the projection reference position PQ2) is sequentially designated (S7).

  Next, the binary data Lpb1, Lpb2, and Lpb3 at the three vertices are averaged for each designated mesh Li to obtain the elevation data Hi in the mesh Li (S8).

  A method for obtaining the elevation data Hi will be described with reference to FIG. FIG. 6A shows a mesh group and the like in the LP data simulation area LWi of the memory 106. Note that m and n assigned to the vertices of the mesh mean coordinates (X, Y) indicated by the world file in the memory 102b.

  FIG. 6A shows the projection reference position PQ2 in the LP data simulation area LWi of the memory 106. FIG.

  Then, as shown in FIG. 6A, in each mesh Li including the frame line of the LP data simulation region LWi, a straight line TLi connecting the minimum coordinate (Ximin, Yimi) and the maximum coordinate (Ximax, Yimax) is formed. Define (referred to as A step).

  Next, the mesh Li in which the projection reference position PQ2 in the LP data simulation area LWi is defined is designated (referred to as B step).

  Next, the projection reference position PQ2 is set as a position LBi, and the position LBi is sequentially defined for each mesh at an interval of 1 m from the position LBi (referred to as C step).

  Next, every time the position LBi is defined in the mesh, binary data Lpb1, Lpb2, and Lpb3, which are Z coordinates assigned to the three vertices of this mesh, are read and averaged (using a weighting coefficient). As shown in (b), the elevation data Hi is determined (referred to as D step).

  Note that the elevation data Hi shown in FIG. 6B indicates that the average values of the binary data Lpb1, Lpb2, and Lpb3 assigned to the three vertices are assigned within the triangle.

  Next, as shown in FIG. 5, the designated range two-dimensional terrain model calculation unit 120 uses these mesh numbers, world file two-dimensional coordinates (X, Y), elevation data Hi, and the like as the designated range two-dimensional. It is stored in the memory 130 as data of the terrain model WMi (S9).

  Therefore, the designated range two-dimensional terrain model WMi as shown in FIG. 7 is generated in the memory 130.

  That is, as shown in FIG. 7, since only the elevation data (Hi) is assigned to each mesh of the designated range two-dimensional terrain model WMi, the processing speed is increased when a debris flow flood simulation is performed. Is very early. The processing is completed within a few minutes in the 1 km × 1 km flooding range.

  Operation of the debris flow inundation area high-speed simulation apparatus of the present embodiment in which the debris flow inundation simulation result display tool and the debris flow information calculation tool unit 600 are activated using the specified range two-dimensional terrain model WMi generated as described above. Will be described.

  FIG. 8 is a flowchart for explaining the operation of the debris flow flooded area high-speed simulation apparatus of this embodiment.

  As shown in FIG. 8, the mouse 20 is operated to set the analysis target mountain stream on the GIS image (map) (S31).

  This analysis target stream setting is also called one-dimensional stream line setting.

  The one-dimensional mountain stream line is set by specifying the upper and lower ends of the mountain stream on the map and using the minimum river line automatic drawing function (see FIG. 3).

  That is, in the map displayed on the screen of the display unit 30 (a map including contour lines), the upstream end P1 and the downstream end P2 are set with the mouse 20, and the one-dimensional mountain stream is drawn by the lowest riverbed line automatic drawing unit 150. Draw a line.

  Specifically, when an upper end and a lower end are designated, the lowest riverbed line automatic drawing unit 150 automatically searches for the lowest coordinate on a circle having a radius of 5 m centering on the reference coordinate. By performing this process recursively, the lowest riverbed line (longitudinal) of the mountain stream is searched and drawn.

  The structure and observation points on the one-dimensional mountain stream line can be similarly set on the GIS image.

  In addition, when inundation simulation for natural dams, etc. is performed, the position and height of natural dams, etc. are set, and the hydrograph based on the calculation of the amount of stored water and the LADOF model is displayed on the screen (S32, S33, S34).

  The hydrograph setting by the LADOF model described above has a mechanism in which the debris flow high-speed simulation tool unit 100 of the present embodiment creates a parameter file necessary for calculation using an Excel or text editor.

  For this reason, the debris flood simulation result display tool 160 can be used by reflecting externally calculated data, for example, hydrograph data calculated by the LADOF model, to the specified range two-dimensional terrain model WMi. With such a combination, debris flow simulation due to overflow of a natural dam can be carried out easily and with high accuracy.

  The LADOF model is a one-dimensional calculation model based on a two-layer flow model in which a fluidized bed is divided into two layers as a method for analyzing a transition process from a debris flow to a sweeping collective flow. Based on the idea that the side erosion rate equation is proportional to the first power of the flow velocity, it is a model that introduces the side erosion rate equation into the two-layer flow model and calculates the overflow and breakup process of a natural dam.

  The LADOF model calculation requires data such as the topographic model, inundation area, and inundation volume, but Sabo D-MAC has a function to automatically calculate the inundation quantity and inundation area by giving the scale of the natural dam. Have. By cooperating with these functions, hydrographs and sediment concentrations at arbitrary points associated with natural dam failures are calculated.

  The downstream end of the flood simulation frame Wi (also referred to as a two-dimensional terrain range) corresponding to the range (100 m × 100 m, 20 m × 200 m, 500 m × 500 m, 1 km × 1 km...) To which the flood simulation range setting unit 110 is input. Setting is based on P2 (S35: see FIG. 4).

  The inundation simulation frame Wi is set according to the number of vertical and horizontal meshes and mesh size, and the size of the frame is changed accordingly. To change further, the mouse 20 is used to move the frame up and down or left and right. It is possible to set the range.

  Moreover, as shown in FIG. 9, the position of the observation point, which is the position of a structure such as a dam dam, is input (S36, S37). Then, the debris flood simulation result display tool 160 creates a streamline (also referred to as the lowest riverbed line) and a simulation one-dimensional terrain model (not shown) (S38).

  When the observation point indicates the dam so as to cross the lowest river bed line as shown in FIG. 9, the debris flood simulation result display tool 160 displays a cross-sectional view of this dam as shown in FIG.

  When the person in charge inputs the height of the dam, the dam shown by the red line in FIG. 10 is set, and a model in which the coordinates of the intersection between the dam and the topographic section is calculated is created in one of the memories 163a,.

  Next, the debris flood simulation result display tool 160 displays a vertical cross-sectional view for setting the sediment gradient shown in FIG. 11 from the set dam height and the lowest riverbed line. By setting an arbitrary sedimentation slope, the intersection coordinates of the sedimentation slope line and the lowest riverbed line are calculated. Furthermore, the formula of the sedimentation surface is calculated from the coordinates of the both ends of the dam shaft and the sediment end coordinates.

  As a result, the sedimentation area and the amount of sedimentation can be calculated. For example, the sedimentation area and the amount of sedimentation are calculated by using the sedimentation surface formula calculated by setting the sedimentation gradient and LP data.

  The sedimentation area is determined by calculating the altitude data on the sedimentary surface in the plane coordinates from the lattice point coordinates of the LP data and the formula of the sedimentation surface, and comparing it with the elevation data based on the LP data. To display the result (see FIG. 12).

  Using this function, the following analysis is possible. FIG. 12 shows a raster image. The geographic information database 300 stores the raster image world file in association with each other.

  Next, the specified range two-dimensional terrain model WMi is created from the LP data (S40).

  That is, the specified range two-dimensional terrain model calculation unit 120 meshes the LP data in the text format, binary converts the Z coordinate of each vertex of the mesh to obtain the elevation data of each mesh, and assigns the elevation data Hi. The specified range two-dimensional terrain model WMi is generated.

  Next, introductory data for simulation is created and stored in the memory 166 (S41).

  When the execution button is pressed after the above steps are completed, the debris flood simulation result display tool 160 uses the simulation introduction data in the memory 166 to execute a debris flow flood simulation (S42).

  Next, an image of the simulation calculation result is generated in the memory 163 (S43), and the layering unit 500 displays this image in an overlapping manner (S44). The simulation results are displayed three-dimensionally for each time (S45), and the calculation results at this time are stored and managed in a memory (not shown), and displayed as necessary (S46).

  FIG. 13 shows the display of the simulation result in the specified range. The amount of debris accumulated can be understood according to the color value.

  If you want to change parameters such as hydrographs and soil constants, use a special Excel sheet. The simulation result is output as image data together with numerical data at a specified time interval. Since the image data has geographical coordinates, it can be displayed on the GIS.

  In addition, three-dimensional (bird's-eye view) display using the Sabo · D-MAC function is also possible. The output status of the result is shown in FIG.

  The simulation results assuming the overflow of a natural dam are shown below (FIGS. 15 and 16).

  FIG. 15 is an inundation assumed area diagram when the mesh size of the two-dimensional terrain model is 10 m, and FIG. 16 is an inundation area diagram when the mesh size is 20 m. Both figures perform calculations for 1.500 seconds with the same calculation parameters, but the larger the mesh size, the faster the flow velocity and the wider the expected flood area. In this case, FIG. 16 reflects the actual situation.

  FIG. 17 shows an example in which the flood simulation result corresponding to the altitude data of the designated range two-dimensional terrain model WMi is displayed by color without displaying a map.

  That is, when each step of FIG. 8 is performed, the Z coordinate value of each vertex of the mesh created using the LP data of the inundation simulation frame Wi by the mouse is binary-transformed, and the average value of these is converted into the altitude of the mesh. Since the data is Hi, the processing can be completed in a short time.

  Therefore, it is possible to examine the planned scale and layout plan of the sabo dam, calculate various quantities when a large-scale disaster occurs (during the formation of a natural dam), and maintain and manage the existing sabo dam (asset management).

DESCRIPTION OF SYMBOLS 10 Debris flow inundation area high speed simulation apparatus 30 Display part 100 Debris flow high speed simulation system 101 Meshing part 103 Binaryization part 110 Inundation simulation range setting part 120 Designated range 2D terrain model calculation part 150 Minimum riverbed line automatic drawing part 160 Debris inundation simulation result Display tool 200 LP data database 500 Layering unit 600 Various analysis tool units

Claims (8)

A GIS unit that stores geographical information of a region, reads a topographic map including a mountain region included in the geographical information, and displays it on a screen;
A debris flow information calculation tool for obtaining debris flow information flowing in the mountain stream area;
A database storing LP data including three-dimensional coordinates in a text format obtained by irradiating the area with a laser;
First storage means for storing mesh data in which LP data having a constant interval among the LP data is connected to each other and meshed;
Preparing a second storage means for storing the specified range two-dimensional terrain model;
Computer
The local LP data is read from the database, meshed by connecting them at regular intervals, and the text-format LP data forming the vertices of each mesh is associated with the mesh as the mesh data, and Storing in one storage means;
Designating the meshes of the first storage means in order, and for each designation, binary-converting the textual Z coordinate of the data of each vertex of the mesh;
Specifying the top and bottom ends of the mountain stream area of the topographic map, obtaining a streamline between the top and bottom edges and displaying the top of the topographic map in an overlapping manner;
With the lower end of the mountain stream line as a reference, a step of displaying a frame of an area preset from the lower end as an inundation simulation frame overlaid on the topographic map,
Retrieving the mesh having the two-dimensional coordinates of the lower end on the topographic map from the first storage means, and defining the position of the two-dimensional coordinates of the lower end in the retrieved mesh;
The position of the lower end projected on the mesh is set as a reference position, and the inundation simulation frame is defined on the mesh group of the first storage means from this reference position, and the mesh mass in the inundation simulation frame is used for LP data. A process defined as a simulation area;
Obtaining an average value of binary data of each Z coordinate assigned to each vertex of the mesh of the LP data simulation region, and setting this as elevation data of the mesh of the LP data simulation region;
Each time elevation data per mesh in the LP data simulation area is obtained, the mesh two-dimensional coordinates, the mesh size, and the elevation data are associated with each other, and this is used as the specified range two-dimensional terrain model. Storing in the storage means;
The debris flow information calculation tool unit obtains debris flow information flowing through the mountain basin per fixed time, and the calculation result is sequentially from the mesh corresponding to the lower end of the specified range two-dimensional terrain model of the second storage means. A debris flow inundation area high-speed simulation method characterized by performing a step of reflecting and displaying the result by color. The display by color is
The debris flow flood area high-speed simulation method according to claim 1, wherein the degree of flooding is displayed by color based on the altitude data of the mesh of the specified range two-dimensional terrain model.   3. The debris flow inundation area high-speed simulation method according to claim 1, wherein the vertices of the searched mesh are vertices facing each other of the mesh. The computer is
The debris flow flood zone high-speed simulation according to any one of claims 1 to 3, wherein a step of reading out a sabo base map included in the geographical information from the GIS unit and displaying it on the topographic map is performed. Method. A GIS unit that stores geographical information of a region, reads a topographic map including a mountain region included in the geographical information, and displays it on a screen;
A debris flow information calculation tool for obtaining debris flow information flowing in the mountain stream area;
A database storing LP data including three-dimensional coordinates in a text format obtained by irradiating the area with a laser;
First storage means for storing mesh data in which LP data having a constant interval among the LP data is connected to each other and meshed;
The text that reads the LP data of the region from the database and connects them at regular intervals to form a vertex of each of the meshes by reading the LP data of the region from the database and second storage means for storing the specified range two-dimensional terrain model Means for associating LP data in the form as mesh data with the mesh and storing it in the first storage means;
Means for sequentially specifying the meshes of the first storage means, and for each designation, means for binary-converting the Z coordinate in the text format of the data of each vertex of the mesh;
Means for designating the upper and lower ends of the mountain stream area of the topographic map, obtaining a streamline between the upper and lower ends and displaying the streamline on the topographic map;
Means for displaying the frame of the area set in advance from the lower end as a flood simulation frame on the topographic map based on the lower end of the mountain stream line;
Means for searching the mesh having the two-dimensional coordinates of the lower end on the topographic map from the first storage means, and defining the position of the two-dimensional coordinates of the lower end in the searched mesh;
The position of the lower end projected on the mesh is set as a reference position, and the inundation simulation frame is defined on the mesh group of the first storage means from this reference position, and the mesh mass in the inundation simulation frame is used for LP data. Means to define as a simulation area;
Means for obtaining an average value of binary data of each Z coordinate assigned to each vertex of the mesh of the LP data simulation region, and making this an altitude data of the mesh of the LP data simulation region;
Each time elevation data per mesh in the LP data simulation area is obtained, the mesh two-dimensional coordinates, the mesh size, and the elevation data are associated with each other, and this is used as the specified range two-dimensional terrain model. Means for storing in the storage means;
The debris flow information calculation tool unit obtains debris flow information flowing through the mountain basin per fixed time, and the calculation result is sequentially from the mesh corresponding to the lower end of the specified range two-dimensional terrain model of the second storage means. A debris flow inundation area high-speed simulation device comprising means for reflecting and displaying the result by color. The display by color is
6. The debris flow flood zone high-speed simulation apparatus according to claim 5, wherein the degree of flooding is displayed by color based on the altitude data of the mesh of the specified range two-dimensional terrain model.   7. The debris flow flood zone high-speed simulation apparatus according to claim 5, wherein each vertex of the searched mesh is a vertex of any one of the meshes opposed to each other. The debris flow flood zone high-speed simulation according to any one of claims 5 to 7, further comprising means for reading out a sabo base map included in the geographical information from the GIS unit and displaying it on the topographic map. apparatus.