Effects of Land Use on Desertification in Typical Regions in the Horqin Sandy Land

Abstract

In this study,the composition and spatial change of land use structure and sandy land was evaluated using data derived from the TM images of Naiman Banner in Inner Mongolia obtained in 1975,1985,1995 and 2005 under the support of 3S.The results revealed that the study area was primarily comprised of cultivated and sandy land.Specifically,cultivated and sandy land occupied 40.33% and 40.14% of the total study area,respectively.Furthermore,the results revealed that woodland and cultivated land increased more than any other types of land,as indicated by increases from 22 828 hm2 and 207 493 hm2 to 121 375 hm2 and 331 442 hm2,respectively.Conversely,the meadow area was reduced from 120 751 hm2 to 13 299 hm2.Overall,these results indicate that some meadow and sandy land was transformed to cultivated land,and some cultivated land was transformed to woodland.In addition,sandy land occupied more than 40% of the total study area,and these areas were dominated by fixed dunes,which occupied more than 50% of the total sandy land area.However,over the study period,the sandy land area was reduced,and the desertification index decreased from 0.24 to 0.19,which indicates that desertification was reversed.Areas in which desertification was reversed reflect conversion of sandy land to cultivated land and woodland,whereas areas in which desertification was expanded reflect the conversion of meadows and cultivated land to sandy land.