节点文献
西藏土地风沙化问题的研究
STUDY ON THE WIND-SAND IMPAC1ED LANDS IN TIBET AUTONOMOUS REGION
【摘要】 西藏地区风沙土地主要分布于山地之间的盆地和河谷区的河漫滩、河岸阶地和山口处的冲洪积扇与山地上。自藏东南至藏西北大体处于三大自然带,讨论了不同自然带风沙化土地类型和特点及其差异。据考察,该区现代土地风沙化状况分布格局是由自然因素引起的自然过程和人为因素引起的人为加速过程组成。所以,未来发展趋势主要取决于两种因素决定的结果。
【Abstract】 Tibet area,Wind-sand impacted lands Abstact The whd-sand impacted lands in Tibet Autonomous Region are maimly distribrted in the inter-mountain basuin and on river beaches ,river terraces and on alluvial-deluvial fans and hillslopes at mountain pass in river valley,Thete are three natural belts from the sortheast to the nothwest of Tibet and there are remarkable differences in wind-sand impacted lands patternsand their characteristics in each belt.The southeast part of Tibet belongs to sub-humid forest- meadow steppe beIt in Alpine temperate-sub-tropical zone and its surface is mainly composedof vegetated and semi-fixed dunes.The south part of Tibet is located in the semi-arid steppe ofalpine temperate zone and semi-fixed,semi-shifting and partially mobile dunes are the mainduneforms,The north and the northwest parts of Tibet are situated in the arid desert and ex-tremely arid desert of alpine temperatr-frigid zone and mobile dunes occupy the dominant per-centage of duneforms,and there are some existence of a few vegetated semi-fixed dunes andbush vegetated sand mounds along river courses,lake shores and in the low-lying areas withhigh underground water table. It is concluded on the basis of the field invvestigation and the studyin recent years that the contemporary wind-sand impacted lands and their distributive situationin Tibet are related to the physical process caused by natural factors and to the human accelerativeprocess caused by human factors,Consequently,the developmentaI trend of wind-sand impactedlands in future in Tibet Region will be determind by the impacts of natural factors and humanfactors in coming years.
- 【文献出处】 地理研究 ,GEOGRAPHICAL RESEARCH , 编辑部邮箱 ,1994年01期
- 【分类号】S424
- 【被引频次】8
- 【下载频次】113