塔克拉玛干沙漠西北边缘的风沙环境与沙漠演变

The Environment of Wind-Sand and The Evolution of Desert in the Northwest Edge Region of Taklamakan Desert

在实地考察和遥感判读的基础上 ,本文分析了塔克拉玛干沙漠西北边缘风沙地貌发育的自然地理条件 ,探讨了区域风沙地貌类型及其分布规律 ,以及风沙活动特征与沙丘移动规律、风沙地貌的发育与演变过程。本区主要发育新月形沙丘及复合新月形沙丘链、复合型纵向沙垄、鱼鳞状沙丘群 ,沙丘的形态组合与分布规律、发育过程和运动状态受区域风向变化和自然地理条件的综合影响。研究区风沙主要来源于各大河流搬运的沉积物 ,在干燥气候条件下由风力吹扬、搬运再堆积“就地起沙”形成现代风沙地貌。综合分析各种地质记录表明 ,本区域沙漠是中更新世以来形成的 。

This paper analyses natural terms of the formation of wind-sand landforms,and discusses the law of type and distribution of the wind-sand landforms,the characters of the wind-sand action,the law of dune moving,and the process of the wind-sand landforms forming and evolving in the region.There are barchan dunes,complex barchan-chains,complex dune-chains,scale-dunes,pyramid-dunes in the region.The changes of wind direction and nature terms in the region are influence on the figure,distribution,formation of the dune.The authors believe that the sand formed by wind in the region comes from sediments carried by rivers.Sediments are blew,carried,and settled again by the wind.Finally,they become sand formed by the wind.Showed by the geological record,the desert started in the middle Pleistocene.In the history,large-scale desert formed gradually.