Based On Topography, High-quality Dem

With the dovolopmont of computer and technology of Geographic Information System, Digital Elevation Model, as a basic data of Geographic Information System in the geography area, plays more and more of important role. It has numerous applying foreground and potential. The quality of Digital Elevation Model is the first factor in determining using value.In this paper, the author discusses the theories and methods on making high quality Digital Elevation Model based on terrain feature from digital contour line. Firstly, the conception, expression methods and development situation of Digital Elevation Model are introduced, the study contents and the study emphases are put forward accordingly. On the basis of summarizing previous work, the author makes the study and experiment on distilling terrain line by using principle and method of Mathematical Morphology. In order to improving modeling efficiency and model fidelity, the author studies the modeling methods and improving measure on constructing TIN considering limitation of terrain character. The author introduces arithmetic from Triangulated Irregular Network to Regular Square Grid DEM because the latter apply abroad than the former in fact.At last the paper summarizes research productions and development direction.