1. Ph.D. Student, Dept. of Environmental Engineering, Technical Univ. of Denmark, Miljovej, Building 113, 2800 Kgs. Lyngby, Denmark; and Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Rd., Chaoyang District, Beijing 100101, P.R. China; and Sino-Danish Center for Education and Research, Niels Jensens Vej 2, 8000 Aarhus C, Denmark (corresponding author).
2. Ph.D. Student, Dept. of Environmental Engineering, Technical Univ. of Denmark, Miljovej, Building 113, 2800 Kgs. Lyngby, Denmark.
3. Professor, Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Rd., Chaoyang District, Beijing 100101, P.R. China.
4. Professor Emeritus, Dept. of Environmental Engineering, Technical Univ. of Denmark, Miljovej, Building 113, 2800 Kgs. Lyngby, Denmark.
5. Associate Professor, Dept. of Environmental Engineering, Technical Univ. of Denmark, Miljovej, Building 113, 2800 Kgs. Lyngby, Denmark.