Abstract: The phenomenon of symbiotic dunes is a hotspot in the aeolian geomorphology field. Nevertheless, there is still lack of further study. In this paper, based on Google Earth satellite imagery, the wind regime and the development environment of the symbiotic area of barchan dunes and linear dunes in Sahara Desert was deeply discussed to explore the possible reasons for the formation of symbiotic dunes. The results showed that there are 17 symbiotic dune areas in Sahara Desert, which is the largest distribution area of symbiotic dunes in the world. Although morphological parameters have a certain correlation both in regional and individual dune, it does not express as well as in theory, which indicating that the factors affecting symbiotic dunes are complex. In low, medium and high wind energy environment and all wind direction variability can develop symbiotic dunes, but they are mainly formed in low wind energy environment, medium wind direction variability and bimodal wind with an acute angle. Single direction of threshold wind is a significant condition for the formation of symbiotic dunes. The direction of drift potential is basically the same as that of the sand dune. Additionally, wind conditions, obstacles such as mountains, coasts and other factors also play an important role in the formation of symbiotic dunes. In the future, the field survey and numerical simulation should be combined to further interpretation the formation of symbiotic dunes. This will improve our understanding in the formation mechanism of symbiotic dunes, and enrich the formation and evolution theory of aeolian landform.

Key words: barchan dune, linear dune, symbiotic dune, development environment