Analysis On The Land Use Change In Middle And Lower Reaches Of Yarkant River Basin

Land use is changed by the influences of natural factor and social factor of humanity.Land use change is one of the main reasons of global environment change.Yarkant River Basin lies in southwest of Xinjiang,which the ecological environment deteriorated because of excessive human productive activity.Therefore a series of issues have appeared such as decrease of water in middle and lower reaches,forest degradation,and soil salinization and so on.At the same time,great changes of land use have taken place in study area.The study on the land use change in middle and lower reaches of Yarkant River Basin have important significance to enhance the prctection of soil resource in this area,prevent the unreasonable develop and use activity,improve ecological environment.This thesis supported by spatial analysis method of geographic information system(GIS) and statistical method,use of TM of 1990,1999 and 2008 in Yarkant River Basin.Analysis on land use transition change,land use change range,land ues change degree,land use change tendency,the main factors and so on.The conclusions are attained as following:(1)Ayalysis on land use change processThe main change of land use occourred in farmland,grassland,forest,residential land,wetland and salinate fileds.From 1990 to 1999,the area of grassland to farmland is 104080hm2, the area of farmland to other forest is 10621hm2, the area of forest to farmland is 5017hm2, the area of sandland to farmland is 4129hm2 the area of farmand to residential is 1292hm2 and so on;from 1999 to 2008, the area of grassland to farmland is 73423hm2, the area of farmland to other forest is 14303hm2, the area of forest to farmland is 10038hm2, the area of sandland to salinate fileds is 1225hm2, the area of farmland to residential is 1611hm2.(2) Ayalysis on land use change tendencyFrom the features of the range,speed of the area`s land use quantity ,revealed the tendency of its land use.farmland,other forest,,bottomaind,residential are all increased,and forest,shurbland,high coverage grassland,middle coverage grassland,low coverage grassland,river,sandland,swamp are all decreased.(3) Ayalysis on the main factor of land use changeBased on the analysis on land use change process and tendency in study area,analysis on the main factor in land use change from natural factor,population factor,social economic factor and policy factor.The result shows: the land ues change in this area is the result of nature factor and human activities,and the most important factors are the high speed of population for human and the environment of policy.