Regional climate change scenarios in the Brazilian Pantanal watershed

In the Brazilian Pantanal, hydrometeorological conditions exhibit a large interannual variability. This variability includes the seasonality of floods and droughts which can be related to land surface processes and to El Nino/La Nina. Based on regional climate change projections derived from the Eta-HadGEM2 ES models with 20 km latitude-longitude resolution for the RCP8.5 for 2071-2100, it is expected that there will be an annual mean warming of up to or above 5-7 degrees C and a 30% reduction in rainfall by the end of the 21st century. As a consequence of higher temperatures and reduced rainfall, an increased water deficit would be expected, particularly in the central and eastern parts of the basin during spring and summer, which could affect the pulse of the Paraguay River. While the changes projected by the Eta-HadGEM2 ES are consistent with the changes produced by the CMIP5 models for the same scenario and time slice, we can affirm that changes in the hydrology of the Pantanal are uncertain, because in a comparison of CMIP5 and Eta-HadGEM2 ES model projections, some show increases in rainfall and in the discharges of the Paraguay Basin, while others show reductions.