Hydrological modelling of the Iberá Wetlands in southeastern South America

• VIC 4.1.2 model is calibrated for the first time over a wetland in South America.
• The streamflow, lagoon level and evaporation are successfully represented.
• Model sensitivity to temperature and precipitation conditions is studied.
• Results show a strong dependence on the precipitation field.
• The model captures the delay in streamflow caused by the Wetlands.

SummaryThe Iberá Wetlands are one of the largest inland freshwater ecosystems in the world hosting several unique flora and fauna species. They are located in northeastern Argentina, a region in southeastern South America that experienced large positive precipitation trends during the last decades. The aim of this paper is to calibrate and evaluate a hydrological model on the Iberá basin in order to quantify the hydrologic impacts of potential regional temperature and precipitation variations in the context of climate change as a result of anthropogenic greenhouse gas emissions. For this purpose, a version of the Variable Infiltration Capacity (VIC) hydrological model, accounting for the presence of lakes and Wetlands, was applied for the first time to the Iberá basin. Results show that the model can successfully simulate the main features of the system dynamics, including the daily mean streamflow of the Corriente River, the daily level of the Iberá Lake and the daily lake evaporation. Inclusion of the lake and Wetlands module improved the streamflow simulations. Sensitivity tests of the Iberá basin hydrology were performed by varying regional temperature and rainfall conditions according to the outputs of a set of climate models for three different time slices during the 21st century. These tests showed a strong dependence of the basin hydrology on the precipitation changes rather on the temperature ones.