Abstract: Sand component is an important material basis for regional surface desertification. The typical intermittent salt lake in the southwest of Hulun Lake was selected as the research object. Through field survey and measurement, particle size composition and grain size parameters of stratified samples 0-10cm layers in ten sites from the water margin to the lakeside zone in the southwest of the typical playa were measured. After analyzing the particle size distribution, the paper discussed the characteristics of grain size and erodibility. The results indicated that the sediments were sandy loam and aeolian sandy soil and the lakeside zone was a potential source of wind erosion and dust release. There were spatial heterogeneity of particle size composition in the lakeside. The majority of soil particle size was occupied by silt and fine sand which were the main grain grades of sediments showing spatial changes from the water margin to the lakeside zone. The grain size frequency curve of sediments showed the change from a three-peak to a double-peak dominated by fine sand grains from the water margin to the lakeside zone. The rough phenomenon of the surface particle size has been shown obvious from the edge of the lake to the lakeside in the study area. Wind transport and wind erosion were the main reasons for sediment particle size changing on the surface. Affected by the main wind direction, there exists a trend of expansion along the main wind direction at the playas lakesides in the southwest of Hulun Lake in recent years. The desertification of the playas lakesides intensifies, showing a trend of connected slices, which may become a new wind erosion area in Hulunbeier Sandy Land. Therefore, the phenomenon of wind erosion and desertification and the area expansion in the playa lakesides should be paid attention to.

Key words: intermittent salt lake, lakeside zone, grain size characteristics, erodibility