1. Department of Earth, Ocean and Atmospheric Science; Florida State University; Tallahassee Florida USA
2. Department of Land, Air and Water Resources; University of California; Davis California USA
3. Groupe de Recerche en Sciences Exactes et Naturelles (GRSEN/DGRST); Ministere de la Recherche Scientifique; Brazzaville Republic of Congo
4. Department of Soil Physics and Hydrology; Congo Atomic Energy Commission; Kinshasa XI Democratic Republic of Congo
5. Department of Environmental Systems Science; Swiss Federal Institute of Technology, ETH Zurich; Zurich Switzerland