RS/ GIS-based Study on the Dynamic Land Use Change in the Source Areas of the Yangtze River and Yellow River

The source area of the Yangtze River and Yellow River is an important region of water conserving and of high-cold biodiversity in China, and is also a sensitive region of ecological change. In this paper, the temporal and spatial change of land use types in the source area of the Yangtze River and Yellow River during the period of 1986～2000 is researched based on the TM/ETM satellite RS data with GIS methods. The results show that the areas of forestlands, wetlands, grasslands and modern glaciers were reduced in these 15 years, but the areas of the lands used for construction, lands under cultivation and unused lands were significantly enlarged, and the degree of synthetic land use was reduced. The dynamic land use change is mainly characterized by that the grasslands and wetlands were transformed as the unused lands and grasslands respectively, and the unused lands were conversely transformed as the grasslands. The change of geographical location of land use was higher than the change of the areas of land use types. It is considered that the land use change in the study area is mainly caused by climate change and human activities.