THE SURVEY STUDY ON THE LAND DESERTIFICATION IN THE ECOTONE OF SONGNEN PLAIN BASED ON RS AND GIS
遥感与GIS支持下的松嫩平原农牧交错区土地沙漠化调查研究

By taking LANDSAT TM images in 1986 and 2000 as the main information source, with the field survey, the status quo, degree and developing trend of the land desertification were interpreted and analyzed in the ecotone of Songnen Plain. The land desertification in the area had the trend of reversing, which can be embodied by the decreasing area, and the land desertification degree. From 1986 to 2000, the desertified land area decreased by 0.71×10 4hm 2/a in average, and the annual decrease rate is 0.8%. On the other hand, the trend of the degree of land desertification converted to less desertified. During the time period, the total area of light-degree desertified land, middle-degree desertified land and severe-degree desertified land decreased by 44.3%. But the area of slight-degree land desertification increased by 92.9% , indicating the great decrease of middle- to severe-degree desertified lands. We can say that the main trend of the land desertification in the area has been controlled. The problem of land desertification cannot be neglected because the degree of land desertification was still intensified in the specific part of the area. The human activities were the main driving force of the land desertification in the area. Land use and climatic variation are of significant influence too. The desertfied land was decline to the dry landing stead of mainly from the grassland before.