EGS-AGU-EUG Joint Assembly Nice, France, 6 - 11 April 2003 Session HS3 - Parameter estimation and uncertainty assessment in hydrological modelling: New approaches and future directions Calibration of a conjunctive surface- groundwater simulation model using multiple responses A. Efstratiadis, D. Koutsoyiannis, E. Rozos & I. Nalbantis Department of Water Resources National Technical University of Athens