Using multi scale DEM datum, multi scale topographic index are extracted and mapped in the whole country and sample area in bess plateau, which prepare topographic datum basis for developing regional soil and water loss assessment model.

• （2）利用多尺度的DEM数据，提取了多尺度的水土流失地形指标，编制了全国及黄土高原典型样区的水土流失地形指标专题图件，为多尺度区域水土流失评价模型的建立准备了地形数据基础。