International Hydrological Programme of UNESCO Uncertainties in the ‘monitoring-conceptualisation- modelling’ sequence of catchment research 11th Conference of the Euromediterranean Network of Experimental and Representative Basins (ERB) Luxembourg, 20 – 22 September 2006 Convened by: Public Research Center – Gabriel Lippmann (Luxembourg) and ERB, UNESCO/IHP (NE FRIEND Project 5) PROCEEDINGS Edited by L. Pfister and L. Hoffmann IHP-VI ⏐Technical Documents in Hydrology ⏐ No. 81 UNESCO, Paris, 2007