1. a Department of Geography , University of Namur , Namur , Belgium
2. b Department of Natural Resources Management, Faculty of Agronomy , University of Parakou , Parakou , Benin
3. c Environmental Sciences and Management Department , University of Liège , Arlon , Belgium
4. d LISA, UMR CNRS 7583, Universités Paris Diderot et Paris-Est Créteil, IPSL , Créteil , France
5. e IRD/UJF-Grenoble 1, LTHE UMR 5564, Représentation IRD , Sénégal