| Slope is the basic data for the agriculture, forestry, hydrologic research and other activities of national economy. With the implementation of great exploitation and ecological environmental restoration in west region of China, it is necessary to beat out the accuracy of the slope data derived from DEM (Digital Elevation Model) in different spatial scale. From the viewpoint of geography and practical application, three typical test areas are chosen to represent the topographic features of Loess Plateau. Applying GIS, mathematical statistics and comparative laws as a basic research methodology and 1∶10000 DEM as a criterion, a research on the error simulation and the rectify method in deriving slope gradient from 1∶50000 DEM was made. An atlas of slope-correction was set up to rectify the statistical values of slope in different topographic areas of Loess Plateau, which would be of great importance in enacting referential standards in the fields of both applicable accuracy and suitable conditions of different kinds of DEM. The future work is also discussed and prospected. |