Abstract: Based on the high resolution DOM/DEM obtained by UAV low-altitude photogrammetry, a typical sandy grass shoal area near Cha Heze town, Yuyang District, Yulin is regarded as the study area. Terrain factors (slope, relief, surface roughness and profile curvature), patch shape index and vegetation coverage of the dune are extracted, and the evaluation system is constructed. The stability of sand dunes in the region is evaluated by using GIS spatial analysis function. The results show that:(1) With convenient and efficient characteristics, UAV aerial survey can establish high precision terrain data and realize extraction of terrain feature of small scale sand dune. (2) Under the dual functions of artificial aerial seeding and slow erosion of wind-blown sand, this region has already reflected unique geomorphological characteristic of relatively stable wind-sand grass area.

Key words: high resolution, terrain parameters, dune stability