Dust fall and biological soil crust distribution as indicators of the aeolian environment in China's Shapotou railway protective system

Jiaqiong Zhang ^a,b,c, Chunlai Zhang ^a,c, Xiaojie Ma ^a,c, Na Zhou^a,c, HuanzhiWang ^a,c, Patrick S. Rissler ^d

^a State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China;

^b State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China;

^c MOE Engineering Research Center of Desertification and Blown-sand Control, Beijing Normal University, Beijing 100875, China;

^d Department of Sociology, Anthropology & Social Work, Kansas State University, KS 66502, USA.

Abstract: Spatial and temporal distributions of dust fall along with the spatial variation of the biological crust were measured along a cross-section in China's Shapotou railway protective system. The variation of the aeolian environment was evident from the spatial variation of near-surface wind flow and both grain size and accumulation rate of dust fall. These varied greatly along the selected cross-section that extended from the mobile dune through the straw checkerboards and vegetation zone to the gravel platform of the railway. On the temporal scale, the dust fall concentrated from March through May. The grain-size composition changed monthly. These temporal changes were related to the wind-force variation and surface condition. The surface conditions along the cross-section were characterized by crust type, crust thickness, and ground (0–5 cm) compaction. Crust could only be found in a relatively stable environment. The distribution of dust fall and crust indicated the intensity of aeolian activity and the stability of the aeolian environment. Further improvement of the aeolian environment by natural processes or by human construction would promote additional dust fall and accelerate the development of the crust.

Keywords: Wind field; Biological soil crust; Dust; spatial and temporal distribution.