One decade of multiobjective calibration approaches in hydrological modelling: A review

ions at multiple sites (Efstratiadis et al., 2008). Distributed schemes are founded on small-scale physics, which, in theory, allows for getting all parameter values from field data, thus avoiding calibration effort. However, the lack of extended field measurements when dealing with real systems, in addition to scale-compatibility problems, leads to an intermediate strategy, aiming to optimize a small portion of parameters, while the rest of them are approximated on the basis of known properties of the basin (e.g. Refsgaard, 1997; Muleta & Nicklow, 2005). On the other hand, semi-distributed models are by nature conceptual, thus involving much more free variables to calibrate, if compared to analogous schemes with lumped or semi-lumped parameterization (Ajami et al., 2004). In the case of complex models with many parameters, multiobjective calibration provides a favourable framework for preserving parsimony and thus reducing uncertainty. This presupposes the