Dynamic monitoring and change analysis of Gyaring Lake and Ngoring Lake of recent 30 years based on remote sensing method

The Ngoring Lake and Gyaring Lake,two largest lakes at the upper reaches of the Yellow River,play an important role in the runoff and environment of the riverhead area of the Yellow River.The thesis used four-phase remote sensing images(MSS/TM/ETM+/CBERS,1976-2006) to monitor water surface changes and extract water spreading range information of the two lakes in recent 30 years.The changes of Gyaring Lake and Ngoring Lake were attributed to the synthetic actions such as climate change,human activities,geologic structure evolution,etc.