基于DEM数据的巴丹吉林沙漠沙丘分布规律及其形态参数

The morphologic characteristics of dunes are one of the important contents in the study of aeolian sand landform. Because of the excellent three-dimensional topographic expression ability, the digital elevation model (DEM) has been widely applied in the study of dune morphology. However, due to the constraints of traffic conditions and research methods, studies on dune morphology in the Badain Jaran Desert mostly focus on compound transverse dunes at the southeast margin of the desert. There is a lack of systematic cognition of the morphological characteristics and distribution of different dunes in the desert, but the study of morphologic characteristics of all the dunes in the desert is an important part of the study of formation and evolution of regional aeolian sand landform. In this paper, all the independent dunes in the Badain Jaran Desert are taken as the research object. DEM data and a new algorithm were used to systematically study the morphological characteristics and distribution of two types of dunes in the desert. The results show that there are about 6 033 independent dunes in the desert, with the height ranging from 9m to 433 m. There are 53 dunes whose height over 350m. Among them, there are 7star dunes with a maximum height 373 m and 46 transverse dunes with a maximum height 433 m. There are 602 sample dunes selected to analyze their morphological parameter. The linear correlations between the height and equivalent sand thickness of transverse dunes indicate that the height of transverse dunes is still increasing, and the logarithmic function relation between equivalent sand thickness and the height of star dunes shows that the height growth of star dunes is slowing down. The main axis of the two types of dunes is mostly perpendicular to the dominant wind direction of the desert, NW-SE. The threshold wind direction of transverse dunes is single, and transverse dunes’ orientation is mainly NE-SW and NNE-SSW. The threshold wind direction of star dunes is complex, and there are several secondary dune axe directions of star dunes.

Keywords： digital elevation model ; Badain Jaran Desert ; dune morphological parameter ; transverse dunes ; star dunes