Soil erosion effect of land use structure in Longchuanjiang catchments in Yunnan province

With the aid of the spatial analyzing technology, three periods land use data of the Longchuanjiang catchments have been obtained. Raster-conversion and cartographic algebraic operation were conducted of the land coverage data, using a complex method integrating GIS spatial analysis with traditional statistical analysis, to create a new GRID database. Based on the database, the effect of land use structure on environmental erosion in Longchuanjiang catchments was studied. The results as follows: ① The transferring among cultivated land, forestland and grassland is the main process of the catchments, including the constructed area increased drastically; ② Land coverage transforming from cultivated land towards forestland or grassland favors decrease in environmental erosion intensity, whereas the reverse transformation aggravates environmental erosion; ③ The eco-environment quality has been improved since 2000.