关键词: 蚀积强度, 积沙形态, 组合间距, 尼龙阻沙网

Abstract: As one of the most effective sand-controlling measures，nylon net windbreak has an excellent sand-blocking capability，has been applied to lots of transportation projects in desert areas of China. In a practical application，especially in drifting desert，two or more pieces of nylon net windbreaks were always settled together，however，few studies on its best combinatorial space between two pieces of windbreaks has rarely been reported so far. The paper conducted a sand-controlling experiment of two nylon-net-windbreaks combination with different space length treatments，which were 2 times （2H），5 times （5H），10 times （10H），and 15 times （15H） as broad as windbreak’s height on an inter-dune corridor in the hinterland of the Taklimakan Desert，Xinjiang，China. The landforms and erosion-deposition around all nylon-net windbreak combinations were investigated dynamically in a wind season. The results indicate that the intensities of erosion-deposition around the windbreak combinations were distributed in a clear spatial pattern including one sand-depositing region around windbreaks，two deflation regions in its windward and leeward neighborhoods，and one temporary deflation region between the two windbreaks. A sand ridge with similar height like windbreak was formed in the sand-depositing region; in the windward part of the first windbreak，the thickness of sand deposition increased exponentially with the horizontal distance to windbreak shortening; in the leeward part of the windbreaks，the thickness of sand deposition decreased with the horizontal distance to windbreak increasing，whose relation can be formulated as a standard quadratic function. The profiles of sand deposition cross section of 2H and 5H showed as single apex with a shape of Chinese character of ‘几’ in the middle and later period of wind season；But the profiles of sand deposition cross section of 10H and 15H showed as double peaks with a shape of English character of ‘M’ in the middle and later period of wind season. The smaller the windbreaks combination spacing，the more concentrated the distribution of sand deposition，the form is tall，the higher the body of sand deposition，conversely，the more dispersed and lower; the sort of the roughness，average grade，sand deposition volume per unit area，ratio between area and profile length of sand deposition was 2H，5H，10H，15H in descending order. The volume of sand deposition tends to decrease with increase of windbreaks combination spacing with a descending sort of 5H，2H，15H，10H. So the combination mode of 5H has the optimal effect of sand control.

Key words: erosion-deposition intensity, morphological feature of sand deposition, combinatorial space, nylon net windbreak