摘要
In this paper, based on a new Geographic Information System (GIS) grid-based three-dimensional (3D) deterministic model and taken the slope unit as the study object, the landslide hazard is mapped by the index of the 3D safety factor. Compared with the one-dimensional (1D) model of infinite slope, which is now widely used for deterministic model based landslide hazard assessment in GIS, the GIS grid-based 3D model is more acceptable and is more adaptable for three-dimensional landslide. Assuming the initial slip as the lower part of an ellipsoid, the 3D critical slip surface in the 3D slope stability analysis is obtained by means of a minimization of the 3D safety factor using the Monte Carlo random simulation. Using a hydraulic model tool for the watershed analysis in GIS, an automatic process has been developed for identifying the slope unit from digital elevation model (DEM) data. Compared with the grid-based landslide hazard mapping method, the slope unit possesses clear topographical meaning, so its results are more credible. All the calculations are implemented by a computational program, 3DSlopeGIS, in which a GIS component is used for fulfilling the GIS spatial analysis function, and all the data for the 3D slope safety factor calculation are in the form of GIS data (the vector and the grid layers). Because of all these merits of the GIS-based 3D landslide hazard mapping method, the complex algorithms and iteration procedures of the 3D problem can also be perfectly implemented.
In this paper, based on a new Geographic Information System (GIS) grid-basedthree-dimensional (3D) deterministic model and taken the slope unit as the study object, thelandslide hazard is mapped by the index of the 3D safety factor. Compared with the one-dimensional(1D) model of infinite slope, which is now widely used for deterministic model based landslidehazard assessment in GIS, the GIS grid-based 3D model is more acceptable and is more adaptable forthree-dimensional landslide. Assuming the initial slip as the lower part of an ellipsoid, the 3Dcritical slip surface in the 3D slope stability analysis is obtained by means of a minimization ofthe 3D safety factor using the Monte Carlo random simulation. Using a hydraulic model tool for thewatershed analysis in GIS, an automatic process has been developed for identifying the slope unitfrom digital elevation model (DEM) data. Compared with the grid-based landslide hazard mappingmethod, the slope unit possesses clear topographical meaning, so its results are more credible. Allthe calculations are implemented by a computational program, 3DSlopeGIS, in which a GIS component isused for fulfilling the GIS spatial analysis function, and all the data for the 3D slope safetyfactor calculation are in the form of GIS data (the vector and the grid layers). Because of allthese merits of the GIS-based 3D landslide hazard mapping method, the complex algorithms anditeration procedures of the 3D problem can also be perfectly implemented.
基金
Under the auspices of Research Institute of Software Engineering(RISE)of Japan(No.01-004).
