Establishment and application of DEM for loess slope land based on GIS

The paper established a digital elevation model (DEM) of loess slope land under different tillage conditions on the micro-scale, and DEM spatial characteristic was analyzed. The results showed that micro-DEM model established by the method of inverse distance weighted interpolation could correctly reproduce the surface morphology of sloping land. Derived micro-slope and micro-aspect values could be taken as important factors in studying spatial difference of soil erosion. Micro-slope distribution characteristics and tillage measures were closely related. As for artificial hoe and contour measures, grid statistic figures of micro-slope increased at initial then decreased with increasing of micro-slope, while grid statistic figures of micro-slope increased with increasing of micro-slope under the measures of artificial dig. Grid statistic figures of micro-aspect had obviously differences among measures of contour, artificial hoe and artificial dig, and slope had a significant effect on the distribution of micro-aspect. Surface erosion calculated using the micro-DEM could reflect the size of slope surface erosion. This study not only provides data information for the study of soil erosion process under the micro-topographic condition, but also lies the foundation of further study in the mechanism of soil erosion under the micro-topographic condition.