1. Department of Physical Geography, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, PO Box 80115, 3508 TC Utrecht, The Netherlands
2. Flemish Institute for Technological Research (VITO), Unit Environmental Modelling, Boeretang 200, 2400 Mol, Belgium
3. Vrije Universiteit Brussel, Department of Hydrology and Hydraulic Engineering, Brussels, Belgium
4. UNESCO-IHE Institute for Water Education, Westvest 7, PO Box 3015, 2601 DA Delft, The Netherlands