Research On Geomorphology Analysis Based On DEM

Digital Elevation Model is basic data of terrain analysis by GIS. Terrain factors such as slope, aspect, elevation, surface roughness, and so on, can be extracted by utilizing DEM based on GIS. The main content of Geomorphology research is terrain analysis, it includes such as height slice analysis, slope analysis, gully density analysis and so on. During terrain analysis, height slice analysis can reflect surface form of relief, slope is an important factor of relief, it is a key factor to impact on the water δ soil loss .Gully density can be used to indicate local climate , geology and geomorphology. It has an important meaning for surveying waterδ soil loss and sustaining waterδ soil .Surface rolling, surface incision, surface coarseness, and so on, can reflect change of rolling and indicate degree of erosion of surface. So, it has a very important meaning to research character and rule of terrain information distributing.Taking two samples in Ningzhen as examples, by combining the raster data of DEM, Geology and land use in research regions, the method extracting Geomorphology information of different Geology stratum was got by reference others' scientific research and my own prophase research, mean elevation of different Geology stratum, mean slope of different Geology stratum, gully density of different Geology stratum, and so on, were finished calculating by GIS. Here DEM data were produced by digitizing the contour line. Geology data were got from geology map. Raster data of land use were generated by changing the 1:250000 vector data of Jiangsu land use. Then, correlation and illustration and comparison were used to analyze terrain data of different Geology stratum, some conclusions were drawn as follows:First, Terrain factors of others' Geographical element can be extracted quickly and conveniently based on DEM by GIS.Second, To some degree, terrain information extracted from DEM can reflect Geomorphology of Geology formation, so it can be used to judge Geology formation secondly.