Abstract: Nebkhas are one of main geomorphology, which are widely distributed in arid region. At present, nebkhas geomorphology patterns and its environmental significance in the sandy desert, agriculture land and oasis had been well researched. However, there are little research on the nebkha dunes in the gobi desert. The nebkhas in the gobi desert can be used as one of index for dust emission and sand fixing capacity. Therefore, the unmanned aerial vehicle and tilt camera were used to measure nebhka dunes morphology and sand fixing capacity in the gobi desert. (1) The research shows the nebkha dunes have an obvious spatial distribution patterns that almost all nebkha dunes are distributed on both sides of the gullies and low-lying areas. (2) The morphology of nebkha dunes on the gobi desert is similar as sandy desert, oasis and agriculture land, but the height, length, width, area and volume are smaller. Moreover, there is a clear correlation between the parameters. (3) The cumulative frequency curve of the sediments in the inner and over nebkha dunes shows a distinct three-stage: suspended component (particle size <63 μm), saltation component (63-500 μm) and creep component (>500 μm). The particle size range of the saltation components (50-700 μm) is significantly different from previous studies, which reflects the difference of sand supply and sediment transport type. Silt and clay is about 5% in the inner and over the nebkha dunes, which indicats it is come from dust emission in the Gobi desert. (4) According to the content of the silt and clay, we can derive that the dust emission quantity of single nebkha in the gobi desert is 0.05-0.08 m³, and sand fixing capability can reach to 18.71 m³.

Key words: unmanned aerial vehicle, gobi desert, nebkha dune, morphology, dust