关键词: 塔里木河下游, 沙质荒漠化, 演变规律, 控制途径

Abstract: Desertification is the result of interaction between human being and fragile eco-environment.It is also the consequence of the contradiction between human being and land.The water amount in Qiala station at the lower reaches of Tarim River is reduced from 14.80×10⁸ m³ in 1950s to 2.38×10⁸m³ in 1990s,which causes the reduction of underground water table and the degradation of vegetation.Meanwhile,under the influences of extreme raising living stock,reclaiming wasteland and cutting off firewood,sandy desertification developes seriously in the lower reaches area,whose degree is becoming strongly and strongly from upper section to lower section and from the middle to both sides of the Green Corridor on macro pattern.Mapping with remote sensing information of 1959,1983,1992 and 1996,the result shows that the annual mean growth rate of sandy desertification area is 0.24 percent from 1950s to 1990s.With area increasing the degree is strengthened.At the same time,a series of changes in natural landscape have occurred.The result of trend analyses with models of GM(1,1),non linear regression and multi-factor regression reveals that environment problems predominated by land desertification are quite out-standing.In order to solve the problem of water resources in ecology,production and life in the lower reaches area,it should be available to plan scientifically,use water resources rationally and control river courses in the upper and middle reaches of Tarim River.In addition to recover natural vegetation and prevent sandy desertification from expanding between Qieganlike and Alagan,monitoring sandy desertification changes by RS and GIS as well as increasing ecological water amount are very important.Meanwhile,in order to protect the Green Corridor and safeguard the No.218 national highway in the lower reaches of Tarim River area,some engineering measurements should be adopted.

Key words: the lower reaches of Tarim River, sandy desertification, evolution pattern, controlling approaches