黄河上游玛曲地区风沙地貌的类型及其分布  

Type and distribution of aeolian goemorphology at Marqu Region of Upstream Yellow River

作　　者：刘虎俊[1,2] 徐先英[2] 王继和[2] 李毅[1] 唐进年[2] 柴成武[2] 纪永福[2] 李发明[2] 魏怀东[2] 

机构地区：[1]甘肃农业大学,甘肃兰州730070 [2]甘肃省荒漠化防治重点实验室甘肃省治沙研究所,甘肃兰州730070

出　　处：《干旱区地理》2012年第3期348-357,共10页Arid Land Geography

基　　金：甘肃省技术研究与开发专项计划项目(0805TCYH030);国家自然科学基金项目(31060080)资助

摘　　要：玛曲草原是著名的高原牧场,也是黄河上游重要的水源涵养地,通过卫星影像分析和实地观测数据,对其风沙地貌进行分类,以期为沙化草地治理提供参考。玛曲沙化草地的风沙地貌可分为4级17类。横向沙丘(新月形沙丘)主要分布在河岸和黄河的一级或二级阶地上,单个的新月形沙丘最大高度可达12 m,64%的新月形沙丘迎风坡走向与当地起沙风向一致。分布在古河道或古三角洲的流动和半流动纵向沙丘(沙垄)高度小于3 m,51%的沙垄走向与当地起沙风向相同。低山上的沙垄和沙片出现在山顶或其阳坡,地形过渡带形成风蚀坎。风蚀洼地与固定和半固定沙地伴生,60%左右的风蚀洼地横切面为不规则椭圆和马蹄形;其深度与长轴呈正比例函数关系。古(现代)沉积物提供了丰富的沙源,大风、冻融、土层的岩性差异、脆弱的植被、人类过渡干扰和微地形促成了玛曲草地沙化和风沙地貌分异。通过对风沙地貌分类、分析,提出了以保护草皮免受破坏,为防止玛曲草地沙化的主要措施。The Marqu with rangeland area of 8.57×107 hm2 is hailed as the first pasture of Asia.At present,the desertificated area is 0.6% of the total area of the Marqu county whith 7 136.77 hm2 of desertificated land and 3 600 hm2 of potential rangeland sandification,and has been expanding by the effect of climate change and people action.A field measure on eolian lanform will give reference to control the desertificated grassland of Marqu.In July and August of 2008,we investigated the grassland of Marqu county referrenced satellite image,and measured the eolian lanform,such as sand dunes and sandy blowouts and so on at plains and hills by GPS,compass and other instruments.The surveyed result shown as follows: the eolian lanform of Marqu might be classified in 17 classes or 4 grades by reference standards of dynamic factors,dynamic bed surfaces,activity and shape of sand dunes.The desertificated grassland centralized at terrace of Yellow River and middle or lower reaches of streams in Marqu,and there were also sandy grasslands on many of hills at Marqu.The sand dune was higher at first and second terraces of Yellow River than that of dunes at others places,and the highest sand dune was 12 m with the SSE direction of 64% of barchan dunes.Another place where many moving sand dunes distributed was the remaining delta including Yellow River and its branches.Most of shift and semi-shift sandy ridges with 3 m height hold the remaining delta,and prevail direction of sand ridges was NNW of 51 % of line ridge.At top of hill or adret,the line ridge and sand sheet usually was found,and distributed at the transition of landforms.The sandy grassland blowout and eolian bank were fund at fixed and semi-fixed sandy land and the transition zone between sandy land and grassland.The shapes of sandy blowout were roundness,oval,arch and horseshoe,while 60% of sandy blowouts,which connected with fixed or semi-fixed sandy dunes,were oval and horseshoe.It was direct proportional function as Y=0.49x-0.11(R2=0.899,and Y is depth,x is macro axis o

关 键 词：玛曲 风沙地貌 类型 分布 黄河上游 

分 类 号：P931.3[天文地球—自然地理学]