Grain size characteristics of a degraded Tugai riparian forest landscape between Taklamakan and Kuruktagh deserts in the eastern Tarim Basin, northwest China

Grainsize is among the most important parameters in aeolian research as it controls the sediment mobilization and the mode of transport. Therefore, it is a critical parameter for instance in wind erosion modeling studies which are used to analyze sand and dust storms in the Tarim Basin, an important natural hazard in this region. Spatially explicit parameterization of grain size is difficult, as the texture of the topsoil is not homogeneous across a landscape. Thus, a geomorphological classification of a Tugai landscape in the eastern Tarim Basin is developed and a stratified analysis of the grain-size distributions and the corresponding threshold friction velocities is presented. The results show that transversal dunes have the coarsest sediment in this landscape, while vegetated patches within the alluvial plain of the Tarim River are characterized by the finest sediments. The other landform classes open space, channel, and nebkha have properties between these two landform types. It is concluded that the surface sediment of a Tugai landscape in the eastern Tarim Basin shows a considerable heterogeneity. The landform-based stratification for grain-size analysis is an appropriate solution for an assessment of sediment grains.