The hydrology of the Iberá wetlands in Argentina as depicted by observed data and regional climate models

MONTROULL, N.; SAURRAL, R.; CAMILLONI, I.

Foz do Iguazu

Conferencia; 2010 Meeting of the Americas; 2010

Most of La Plata basin and central-eastern Argentina has become increasingly vulnerable to floods and droughts with important social, economic and environmental consequences. The main objective of this work is to analyze the impacts of climate change in the region of the Esteros del Ibera (Fig.1), one of the most important wetlands of the world in terms of its high level of conservation and biodiversity. A detailed knowledge of the hydrological variability in the region as a consequence of climate variability and change will be an important tool for the development of adaptation strategies for the conservation of the region. For this purpose, the VIC hydrological model was adjusted for the Corriente River basin and the ability of this model to estimate the Corriente River streamflows downstream of the Iberá wetlands was evaluated. The monthly mean and the interannual variability of the streamflow is well represented by the VIC model, although this model has been found to perform better in basins with pronounced topography and high runoff ratios than in basins with flat topography and low runoff ratios, like the Corriente River basin.In addition, four regional climate models (RCM) were used as input data for the hydrological model and their ability to represent the present climate in the study region was evaluated. The RCM considered in this work were: RCA3 (CIMA-Rossby Center/SMHI), REMO (MPI-M), PROMES (UCLM) and LMDZ (LMD). We found that models have still some limitations to simulate some features of the regional climate and these errors can affect hydrological simulations considerably. These results indicate that it is essential the use of an unbiasing scheme for RCM outputs in order to correct systematic errors before using the variables provided by regional climate models as input to hydrological models. This work highlights some of the uncertainties associated with the use of regional climate models for hydrological impact studies.