Measuring Sand Dune Dynamics in the Badain Jaran Desert, China, Using Multitemporal Landsat Imagery

The Badain Jaran Desert (BJD) and surrounding deserts are the main sources of sand and dust storms in Asia. However, for complex factors, the descriptions of the sand dune dynamics in the BJD and investigations on the contribution of the BJD to the formation of the Tengger Desert (TD) and the Ulan Buh Desert (UBD) are lacking. We evaluated the performance of the discrete Fourier transform method in achieving subpixel precision when measuring the displacements of sand dunes in the BJD and surrounding deserts. This method was applied to Landsat 5/8 and 7 scan-line-corrector (SLC)-off/8 image pairs, respectively. The results show that it is a robust method in desert conditions without ground control points. Nineteen scenes of Landsat 5/8 were tested for estimating the movements of the BJD and surrounding areas. We found that the sand dunes moved eastward during 2004-2016. However, the dunes' movements showed different patterns in different parts of the desert. In the western BJD, the dunes moved at an average speed of 1-3 myr(-1), while in the southern and middle parts of the BJD, the dunes' speed was about 0.1-1 myr(-1). The fastest displacements of dunes were located in the northeastern BJD, and the mean speed was about 12 myr(-1). The sand fluxes in the two corridors between the BJD and the TD and UBD were estimated. The annual total amount of sand transported from the BJD to the TD through the main corridor was about 0.95 million tonnes, while that from the BJD to the UBD was about 2.24 million tonnes. The estimations of dune displacements and sand transport based on Landsat images in this study are important for understanding the dynamics of the BJD and surrounding areas.