Abstract:

The morphological change and migration of dunes contain the key information of regional aeolian environment and landform evolution， which is an important issue in aeolian geomorphology. In this paper， the rectangular dune networks and square dune networks in the southern edge of Tengger Desert are taken as an example， we used wind data and Google Earth satellite images to monitor the morphological changes of reticulate dunes from 2009 to 2020 and analyze their migration characteristics. The results showed that： （1）The prevailing wind direction in the southwest and southeast of Tengger Desert are northwest wind. The secondary wind direction in the distribution area of rectangular dune networks is southeast wind， and that of square dune networks is east wind and southeast. The wind regime features are belonging to low wind energy environment and intermediate wind direction variability. The wind energy environment in the southwest is stronger than that in the southeast. The wind power in the study area showed a decreasing trend in recent ten years. （2） The length and spacing of ridges of reticulate dunes are increasing， and the height of rectangular dune networks is increasing， while that of square dune networks is decreasing. The orientation of the primary ridge is shifted to the east， and the secondary ridge is shifted to the south， while the overall morphology of the dunes remains stable. （3） The average migration rate of rectangular dune networks is 1.57-1.71 m·a^-1， and that of square dune networks is 1.63-2.01 m·a^-1. The average migration direction of dunes is similar to the resultant drift direction. The volume of dune is the main reason affecting the difference of migration speed.

Key words: dune migration, reticulate dune, dune morphology evolution, wind regime, Tengger Desert