The Model And Application Of Landslide Digital Elevation Model (DEM)

In landslide study, landslide terrain is described by 2-D geologic plan, 2-D topographic map or simple 3-D model and kinds of physical model, which not only takes lots of time and is not precise, but also is not easy to observe, analyze and reply, is difficult to grasp space distribution and complex terrain shape, so leads to many inconveniences and serious restriction in landslide research. As the application of digital elevation model (DEM), the above problems will be solved totally. Landslide DEM is one of the most effective methods to reproduce rapidly and analyze synthetically the 3-D information of landslide, which will greatly prompt the development of landslide and bring to the enormous benefits for the society, the economy and ecosystem system.Firstly, the paper briefly introduces the development and present condition of landslide research and the meanings, characteristic, description method and the development and present condition of DEM. Secondly, the data-gain and data structure of DEM are mainly introduced. The data-gain includes data collection, data pretreatment and the error treatment. The data structures of DEM have five kinds of structure, including dispersed point, regular network, triangle irregular network, counter and mixing structure. Thirdly, the build, interpolation and application of DEM are introduced. The modeling methods of DEM include Regular Network model (GRID), Triangle Irregular Network (TIN), mixing model (GRID-TIN), etc. The interpolations of DEM include integration interpolation, block interpolation and point-by-point interpolation. DEM is basically applied in drawing counter, creating profile, drawing hill-shading map and terrain analysis etc. The conception, progress and present condition of hill-shading and the characteristics of hill-shading based on DEM are summarized. The principle, method and process of drawing hill-shading map based on DEM are introduced in detail. In conclusion, take Zhafangping Landslide in Reservoir area of Three Gorges for instance, the process of modeling landslide DEM based on landslide topographic map and the method of creating landslide profile and hill-shading map by landslide DEM are expatiated in detail. After the landslide topographic map is pretreated and assigned elevation by GIS software ARC/INFO, the Regular Network DEM based on delaunay triangular network of Zhafangping Landslide in Reservoir area of Three Gorges is modeled and the profile and hill-shading map of the landslide are drawn. The application of DEM in landslide research advances the automatization anddigitization level of landslide research, improves landslide research condition greatly and saves research money and time.