1. College of Geography and Environmental Science, Northwest Normal University, Lanzhou, Gansu 730070, China
2. Key Laboratory of Resource Environment and Sustainable Development of Oasis, Lanzhou, Gansu 730070, China
3. Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
4. State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China