1. Institute of Agricultural Sciences, ETH, Zurich, Switzerland
2. Institute of Geography, University of Bern, Bern, Switzerland
3. College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Bejing, People’s Republic of China
4. Institute of Biogeochemistry and Pollutant Dynamics, ETH, Zurich, Switzerland
5. Department of Water Resources and Drinking Water, Eawag, Dubendorf, Switzerland