We inter-compare four hydrological models in terms of their surface water response simulations and their ability to capture the particular features of humid Mediterranean climates. We selected the Maule River basin (central Chile), in particular the Longaví basin as the paradigm of humid Mediterranean climate to run the study. The area is under intensive irrigated agricultural exploitation, which jeopardizes groundwater recharge and may be further pressurized by precipitation changes due to global warming. The Longaví basin in the south of the Maule, was studied and its hydrological cycle was simulated using four simulation tools: GR4J, HBV-light, HEC-HMS and WEAP, hence including lumped as well as a semi-distributed approaches. For model performance assessment, the Longaví was sub-divided into three zones with comparable characteristics in terms of climate, physical soil properties and altitude classes. Daily hydro-meteorological forcing time series were provided by official institutions of Chile for the 1979 to 2015 period. The individual model efficiency was evaluated through usual deterministic performance indicators. The models exhibit different strengths in terms of hydrologic response simulations. The results obtained with GR4J, HEC-HMS and WEAP perform better during southern hemisphere Winter between June and October, while HBV-light produces stronger results during the November to May Summer season. The more heavily parameterized WEAP model tends to better represent the stream flow variability observed during the rainy season with respect to the dry season.

We inter-compare four hydrological models in terms of their surface water response simulations and their ability to capture the particular features of humid Mediterranean climates. We selected the Maule River basin (central Chile), in particular the Longaví basin as the paradigm of humid Mediterranean climate to run the study. The area is under intensive irrigated agricultural exploitation, which jeopardizes groundwater recharge and may be further pressurized by precipitation changes due to global warming. The Longaví in the south of the Maule, was studied using four simulation tools: HBV-light, GR4J, HEC-HMS and WEAP, hence including conceptual as well as a semi-distributed approaches. For model performance assessment, the Longaví was sub-divided into three zones with comparable characteristics in terms of climate, physical soil properties and altitude classes. Daily hydro-meteorological forcing time series were provided by official institutions of Chile for the 1979 to 2015 period. The individual model efficiency was evaluated through usual deterministic performance indicators. The models exhibit different strengths in terms of hydrologic response simulations. The results obtained with GR4J, HEC-HMS and WEAP perform better during southern hemisphere Winter between June and October, while HBV-light produces stronger results during the November to May Summer season. The more heavily parameterized WEAP model tends to better represent the stream flow variability observed during the rainy season with respect to the dry season. The actual irrigation water demand for the selected study region is matter of further research and will be acknowledged in a sequel paper.