Localization Comparison on Dynamic Coupling Relationship Between Land Use Change and Soil Organic Matter at County Scale——A Case of Changwu County in Weihe Arid Plateau Region

Taking Changwu County in Shanxi Province as the study area,based on the land use spatial data between 1983 to 2008,the land use change range,transfer direction and spatial distribution characteristics which led to the evolution regularity of soil organic matter content were analyzed by using GIS spatial analytical method.The results showed that land use dynamic change in this period was remarkable,the areas of dry land,grass land and waste land decreased largely,but the areas of forest land and orchard increased greatly.Meanwhile,the transformation of land use change which resulted in the increase of soil organic matter at different degrees had become the driving force of soil organic matter content variation.Soil organic matter content increased respectively 6.6g/kg and 5.11g/kg after conversion from dry land to forest land and orchard,but the increment did not vary obviously after forest land was converted to dry land and grass land.The variation of soil organic matter content not only improved soil structure but also controlled the loss of water and soil,which provided the valuable information to guide land use change toward a proper direction