关键词: 起沙风, 输沙势, 起沙风玫瑰, 巴丹吉林沙漠

Abstract: Sand Mountains always accompany with lakes in some desert. Many beautiful lakes distribute in the hinterland of the Badain Jaran Desert of China. The height of Sand Mountain is about 500 m and the area of some lakes is in excess of 1 km2. Why lakes in desert are not buried by dune has attracted many scientists over world for centuries. The area of lakes is controlled not only by underground water but by environments of wind-blown sand between sand dunes and lakes. Specific heat， coefficient of thermal conductivity and reflectance ratio on the surface of lakes and sand mountains is different， which will change air temperature， vary field of press and then arise local circulation. Otherwise， timely alternative of the direction of sand-laden wind determines the balance of sand transport and affects the existence of lakes. This paper aims to reveal the effect of local circulation on sand transport between Sand Mountains and lakes. Based on the detailed wind data in the Dashazao Lake of the Badain Jaran Desert， sand-laden wind， drift potential and sand transport were investigated. Combined with the landscape of sand mountains and lakes， local circulation and dynamical environments in the Dashazao Lakes were illustrated. Drift potential around sand mountains is different and ranges from 25.58 VU to 45.01 VU，which belongs to a low-energy wind environment in this region. Frequency of sand-laden wind decreases from the periphery of sand dune to the lake’s centre. Resultant sand-drifting direction is SE in the western side of the Dashazao Lake， and SW in its eastern side. The direction of sand-landed wind in the center of lake is relative unidirectional and the resultant direction is SE. Local circulation is very obvious because of the pattern of sand mountains and lakes. Average wind speed in the center of the lake is little less than that around sand mountains. The eastern sand dune threatens the lakes less than the western side. A northeast-trend complex sand mountain just locates in the west side of the Dashazao Lake， and western wind passing the mountain would be decreased near the lake. Therefore， sand mountains will shelter the lakes because the lakes mostly locate in the lee of the mountains. The results of this paper are important for forecast of the trends of wind-blown sand environments near lakes surrounded by sand-mountains and for attempt to show regional ecological change in the hinterland of the Badain Jaran Desert.

Key words: sand-laden wind, drift potential, wind-blown rose, Badain Jaran Desert