Characterization of land cover types in Xilin River Basion using multi—temporal Landsat images

This study conducted computer-aided image analysis of land use and land cover in Xilin River Basin ,Inner Mongolia,using 4 sets of Landsat TM/ETM images acquired on July 31,1987,August 11,1991,September 27,1997 and May 23,2000,respectively,Primarity,17 sub-class land cover types were recognized ,including nine grassland types at community level: F.sibiricum steppe, S.baicalensis steppe,A.chinensis forbs steppe.A.chinensis bunchgrass steppe,A.chinensis Ar.frigida steppe,S.grandis A.chinensis steppe,S.grandis bunchgrass steppe,S.krylavii steppe, Ar.frigida steppe and eight non-grassland types:active cropland,harvested cropland,urban area, wetland,desertified land ,saline and aalkaline land,cloud ,water body clound shadow.To eliminate the classification error exsting among different sub-types of the same gross type ,the 17 sub-class land cover types were groped into five gross types:meadow grassland,tmeperate grassland ,desert grassland,cropland and non-grassland,The overall callssifcation accuracy of the five land cover types was 81.0% for 1987,81.7%for 1991,80.1% for 1997 and 78.2% for 2000.