Geomorphology of aeolian dunes in the western Sahara Desert

Abstract

Although the western Sahara Desert is dominated by aeolian dunes, research on the geomorphology of aeolian dunes throughout this region as a unit has been limited compared with other large deserts. In the present study, comprehensive research is conducted on the geomorphology of dunes in the western Sahara Desert based on aeolian parameters and dune growth mechanisms. We identified the controlling factors on the dune morphology and formation of superimposed dunes. The results suggest that the spatial patterns of dune morphology are closely correlated with the drift potential (DP) and dune orientation. A well-defined gradient of declining DP, resultant drift potential (RDP), and directional wind variability from north to south was found, indicating a gradual weakening trend in the DP along the sand flow path. Linear and transverse dunes are distributed on the central part of the desert. Barchan dunes are distributed on the western coastal areas and desert margins. Lastly, star dunes are distributed in the upwind on the northern desert margin. We concluded that the wind regime and sand availability directly impact the dune morphology in the western Sahara Desert by considering the growth mechanisms. This study provides valuable reference data on regional aeolian activities that can be used by subsequent regional aeolian geomorphology studies in the western Sahara Desert.