1. Geo-Systems Centre (CVRM-IST); Technical University of Lisbon; 1049-001 Lisbon Portugal
2. Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas; 04120 Almería Spain
3. Department of Geo-Engineering/International Centre for Groundwater Hydrology (FCIHS); Technical University of Catalonia (UPC); 08034 Barcelona Spain
4. Royal Academy of Sciences of Spain (RAC); 28004 Madrid Spain