1. Key Laboratory of Western China's Environmental Systems (Ministry of Education); College of Earth and Environmental Sciences; Lanzhou University; 222 Tianshui South Road Lanzhou 730000 China
2. Key Laboratory of Wetland Ecology and Environment; Northeast Institute of Geography and Agroecology; Chinese Academy of Sciences; 4888 Shengbei Road Changchun 130102 China
3. University of Chinese Academy of Sciences; Beijing 100049 China
4. Research Center of Wetland Resources Protection and Industrial Development Engineering of Gansu Province; College of Geography and Environmental Science; Northwest Normal University; 967 Anning East Road Lanzhou 730070 China