Center of Basin Resources and Environment Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China;
Graduate School Chinese Academy of Sciences Beijing 100049 China;
Key Laboratory of Western China's Environmental Systems Ministry of Education of China College of Resources and Environment Lanzhou University Lanzhou 730000 China;
Research Institute of Petroleum Exploration and Development PetroChina Qinghai Oilfield Company Dunhuang Gansu 736202 China;