1. Department of Environmental and Geographical Science; University of Cape Town; Rondebosch South Africa
2. Centre National de la Recherche Scientifique, UMR 5554; Institut des Sciences de l'Evolution-Montpellier; Université Montpellier; Montpellier France
3. Department of Physical Geography; Institute of Geography; Friedrich Schiller University Jena; Jena Germany
4. Institute of Earth Surface Dynamics, Geopolis; University of Lausanne, Quartier UNIL-Mouline; Bâtiment Géopolis CH-1015 Lausanne Switzerland
5. School of Geographic Sciences; East China Normal University; Shanghai PR China