The analysis of relief amplitude in Qinghai Province based on GIS

The relief amplitude is an important indicator in digital geomorphologic mapping, the evaluation of soil erosion sensitivity. Based on the DEM data (100m resolution), the relief amplitude of Qinghai was calculated by spatial statistical tool of GIS. By using the method of window analysis and the mean of change-point, the optimum statistical unit and relief amplitude of Qinghai Province was calculated. The result shows, the optimum statistical unit of Qinghai is 1km² and is same with the 5 districts of soil and water conservation in Qinghai; classifying the relief amplitude of Qinghai by 2 methods, the result shows the relief amplitude can be divided into 6 grades.