1. School of Environmental Science and Engineering, Guangzhou University, and Key Laboratory of Waters Safety & Protection in the Pearl River Delta, Ministry of Education, Guangzhou 510006, China
2. Earth Observatory of Singapore and Asian School of the Environment, Nanyang Technological University, Singapore 639798
3. Faculty of Technological Sciences, Department of Ecoscience, Aarhus University, Roskilde DK-4000, Denmark
4. Laboratory of Soil- and Groundwater-Management, Institute of Foundation Engineering, Water- and Waste-Management, School of Architecture and Civil Engineering, University of Wuppertal, Wuppertal 42285, Germany