Abstract:

Aeolian-fluvial interaction is an important geomorphic process in arid and semi-arid areas. The interaction between wind and water power is causal and promoting and has significant spatio-temporal variation characteristics. Under its action， a unique landform landscape， riparian dune， is formed， which is different from the dune landform formed by a single wind accumulation. Taking Wudinghe River Basin in Mu Us Sandy Land as a research area， based on remote sensing image interpretation and other methods， the dynamic geomorphological changes of the interaction between river channels and dunes are studied. The results show that： （1） The vegetation coverage in the Wudinghe River Basin in the Mu Us Sandy Land has recovered well during 1990-2020， and the riparian dunes have gradually solidified， showing the transformation from mobile dunes to semi-fixed dunes and from semi-fixed dunes to fixed dunes. （2） The river channel affects the continuity of the distribution of sand dunes， which makes them fragmented， and also blocks the movement of sand dunes and the transmission of some coarse particle size sand. （3） The geomorphologic pattern of riparian dunes in typical reaches is distributed in a band centered on the river channel， and moving dunes， semi-fixed dunes and fixed dunes are successively distributed along the distance from the river channel. The angle between wind direction and river direction affects the form and distribution of riparian dunes by influencing the mode and intensity of aeolian-fluvial interaction. （4） Riparian dune geomorphic system and river hydrological system maintain a dynamic equilibrium state through the water supply relationship， but excessive human activities may break their thresholds， resulting in increased desertification degree and deterioration of river hydrological conditions.

Key words: aeolian-fluvial interaction, riparian dunes, Mu Us Sandy Land, Wuding River