Assessment of the grassland degradation in the southeastern part of the source region of the Yellow River from 1994 to 2001.

The source region of the Yellow River is located in the middle east of the Tibetan Plateau in northwest China. The present study is based on two phases of satellite image data and field studies conducted from 1994 to 2001. The study area is the southeastern part of the source region of the Yellow River in China. The total land mass of study area is about 32,115 km 2 , out of which 26,802 km 2 is composed of grassland which accounts for 83.45% of total area. The extensive land utilization beyond its limits has led to the risk of environmental degradation. The ArcGIS 9.2 and Erdas 9.1 were used to convert data types and perform the overlay, image processing, reclassification and zonal statistic analysis. The experimental results revealed that the grassland degradation is the most important land cover change in the study area, which occupied 9% of the regions total area. Degradation rate was more on the sunny slopes. The degradation process was found to be more severe near the settlements and roads. The unsustainable human activities along with climate change were the main source of degradation in the study area since 1985. In order to mitigate the devastating rate of grassland degradation and to resolve these issues, the improvement of the level of education and rearing the number of livestock by keeping in view the carrying capacity of grassland can be effective to overcome grassland degradation process. Study of the degradation and rehabilitation of grassland in the region is important for the protection of eco-environment of the source region of Yellow River, even for the whole Qinghai-Tibetan Plateau in China.