Grassland resources degradation of the loess plateau based on remote sensing and GIS

The Loess Plateau region, surrounded by the Taihang Mountains to the east, the Qilian Mountains to the west, the Ordos Plateau to the north and the Qinling Mountains to the south, is dispersed over seven provinces with a total area of about 623,700 km2 and a population of 85 million people. One third of the plateau area is grassland, which covers transition from the southeast monsoon region to the arid, semi-arid region of Northwest China. With visual interpretation and automatic classification method, the grassland distribution of two years based on analysis of 1987 and 2000 TM images was obtained. In order to improve the ecological environment of China´s western region, significant areas of the dry land must be reforested and regrassed. GIS has been identified as a useful tool to find the areas where dessicated land on the Loess Plateau region can be reforested or regressed. The result of overlay analysis and area statistical analysis by GIS has shown how the grassland has been transformed on the Loess Plateau over the past 20 years. The existing grassland resources on the Loess Plateau region covered with the vast grassland have already lost their primary feature, the soil erosion area now occupying 54.3% of the total plateau area. The southeast of the plateau has been torn to pieces, and severe soil erosion has occurred on the central plateau. Even more significantly, the northwestern region is experiencing a significant devastation by windy activity and desertification. In order to protect and rehabilitate the ecological environment of the Loess Plateau, seven recommendations are made.