论文部分内容阅读
为了探讨防沙工程对现代风沙地貌的影响,通过在塔中地区的野外实地沙面蚀积测量,分析了塔里木沙漠公路防护林影响下地表形态变化的类型、分布和强度.研究发现:(1)在防沙体系内部以风积地貌为主,形成了小尺度的灌丛积沙堆,中尺度的片状积沙和较大尺度的垄状积沙体.在防沙体系内的林间也一定程度地形成了风蚀地貌,但在垄间地一般难以大规模发育,而在地形起伏的沙垄区的次级沙丘迎风坡中部,则可较大规模地发育;(2)在防沙体系的上风侧,阻沙林带及其形成的垄状积沙体使垄间的低矮流动沙丘在移动过程中发生形态和走向变化.阻沙林带垄状积沙体迎风坡形成稳定积沙坡面,但前移沙丘可造成其短时间的破坏,而后逐渐恢复成稳定坡面;(3)在防沙体系下风侧沙面,可形成较大范围的风蚀,在垄间地形成风蚀凹地,在地形起伏区沙丘被风蚀削平,地形起伏度降低.因此,防沙林带对上风侧风沙流具有巨大的消能截沙作用,到下风侧随着风力的逐渐恢复,风沙流逐渐趋于不饱和,造成沙面风蚀.
In order to investigate the effect of sand control project on modern wind sand landform, the type, distribution and intensity of surface morphological changes under the influence of Tarim Desert Highway Shelterbelt were analyzed by field sand surface erosivity measurements in Tazhong area.It was found that: (1) Within the sand control system, the main features of aeolian landforms are the formation of small-scale shrubs, mesoscale sheet-shaped sediments and larger-scale ridge-shaped sand bodies. The formation of wind erosion landscape to some extent, but generally difficult to large-scale development in the ridge land, and in the undulating sand dune area of the secondary sand dune windward slope in the middle, you can scale development; (2) in the sand control system , The sand-blocking zone and the ridge-shaped sand bodies formed by them changed the shape and direction of low-flow dune in the ridge during the moving process. , But the forward dunes can cause short-term damage and then gradually return to a stable slope. (3) Wind-induced sand erosion on the windward side of the sand control system can form a wide range of wind erosion, Undulating sand dunes are eclipsed by wind erosion and relief of terrain Low. Thus, a windbreak with great energy dissipation effect on the upwind side sectional sand sand flow to the leeward side of the wind with the gradual recovery, becoming more unsaturated sand flow, causing wind erosion sand.