关键词: 沙丘类型, 沙丘发育指数, 新月形沙丘, 垄间地, 塔克拉玛干沙漠

Abstract: There exist a large number of dunes in small size and simple shape on interdune corridors in the Taklimakan Desert, while the distribution and the spatial variation and cause of which are poorly studied so far. Based on Google Earth images and field surveys, this paper mainly discusses the cause of the distribution pattern and morphological characteristics of the dunes on interdune corridors in the Taklimakan Desert. The results are as follows: (1) There exist pie-shaped dunes, barchans, barchan chains and linear dunes on interdune corridors in the central of Taklimakan Desert. The density and coverage of barchans are the highest among the four types, while the pie-shaped dunes, widely distributed on all interdune corridors, rank only second to barchans. Barchan chains are mainly distributed in the leeward slope toe, but linear ones in the windward slope toe of complex sand ridges. (2) There is a distinct pattern of spatial distribution of the dunes in this area. The density and coverage of barchans in the dominant wind direction ranks in order of windward, leeward, central, whereas the length, width, basal area, coverage and wingspan decrease from the leeward slope toe of sand ridges to the middle of interdune corridors, but gradually increase from the middle of interdune corridors to the windward slope toe of sand ridges under similar conditions. It indicates that barchans first degrade and then recover on interdune corridors. (3) The spatial distribution and morphological differences of dunes are determined by the spatial variation of sand supply and wind force. In the leeward slope toe of sand ridges, the wind force is relatively slight and the sand source is rich, moreover, the dunes are distributed in high density and barchans maturely developed to great extent. From the leeward slope toe of sand ridges to the near windward slope toe, the airflow is hardly influenced by wind shadow of  complex sand ridges, thus the wind speed rises gradually and the sand supply decreases accordingly due to the coarse sand covered surface. Then there tend to be an imbalance of the sand flux, so barchans have a reverse evolution trend. From the middle of interdune corridors to the windward slope toe of sand ridges, the wind speed reduces due to the blocking of sand ridges. Besides, the sand is fine and the supply is relatively sufficient. In that case, the dune compounds are improved and dunes recovered.

Key words: dunes types, dune development index, crescent dune, Interdune corridor, Taklimakan Desert