塔克拉玛干沙漠腹地路面沙害的空间分布研究

塔克拉玛干沙漠腹地公路芦苇机械防沙体系失效后,在短时间内能够形成强度很大的路面沙害,严重影响交通。路面沙害的空间分布具有规律性:(1)沙垄区的路面沙害强度和发生频率均大于垄间地,而在沙垄次级地貌部位中,沙害强度垄顶>迎风坡>背风坡,但是沙害发生频率背风坡>垄顶>迎风坡;各地貌部位中沙害类型中都以路面积沙为主,沙丘前移压埋为辅。(2)在各种道路横断面中,路堑断面最易发生路面沙害,在各地貌区域都能够发生;零断面沙害发生频率其次,在垄间地比例最高;路堤断面沙害出现最少,只分布在垄间地。(3)道路与主风向大夹角路段的路面沙害发生频率和强度远大于小角度段,但是小角度之间的变化规律不明显。(4)地貌部位、道路断面和路风夹角3因素在空间上呈共轭分布。

Spatial Distribution of Sand Drift Disasters on Road Surface in the Hinterland of the Taklimakan Desert

Sand drift disasters occur frequently and intensively on road surface and impact transportation seriouslyafter the straw-breaks along the highway in the hinterland of the Taklimakan desert become ineffective. Sand driftdisasters on road surface have significant spatial distribution features: (1) Sand drift disasters on road surfaceoccur more intensively and frequently in the regions with dune-chains than that in the inter-dune-chain regions,their intensity on the top of dune-chains is higher than that on the windward slopes and leeward slopes, but theiroccurring frequency on the leeward slopes of dune-chains is higher than that on the top and windward slopes; sanddrift disasters on road surface are dominated by aeolian sand deposition accumulation and followed by mobiledune burying; (2) Sand drift disasters occur most frequently in cuttings; (3) Sand drift disasters occur morefrequently and intensively in the areas where the angles between the road alignment and the prevailing winddirection is large; (4) There is a spatial conjugate distribution between morphological positions, road transects andangles between the road alignment and the prevailing wind direction.