1AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New Zealand
2Department of Geography, Hydrology and Climate, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
3Hydrology and Quantitative Water Management Group, Wageningen University & Research, PO Box 47, 6700 AA Wageningen, the Netherlands
4Research and Innovation Centre Techniek, Ontwerpen en Informatica, Inholland University of Applied Sciences, Bergerweg 200, 1817 MN Alkmaar, the Netherlands
5Department of Geography, King's College London, Bush House, 30 Aldwych, London WC2B 4BG, United Kingdom
6Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650091, P. R. China
7Laboratoire des Radio-Isotopes, University of Antananarivo, BP 3383, Route d'Andraisoro, 101 Antananarivo, Madagascar
8Faculty of Geo-information and Earth Observation (ITC), University of Twente, Enschede, Hengelosestraat 99, 7514 AE Enschede, the Netherlands