Assessing the impact of climate change scenarios on water resources in southern Brazil

Abstract

The SWAT hydrological model was applied to analyse the impacts of climate changes on the flow and sediment production regimes in the Concórdia River drainage basin, in southern Brazil. Climate scenarios A2 and B2 of the IPCC were used to simulate basin behaviour over the period 2071–2100 and to compare it with that in the baseline period (1961–1990). Runoff and sediment yield calculated on a monthly basis in the calibration period gave Nash-Sutcliffe coefficients of 0.82 and 0.83, respectively, showing good model fit. Comparison of simulations for scenarios A2 and B2 with the baseline showed a reduction in flow of 39.2% and 41.2%, respectively. Analysis of daily values and extreme events suggested that flood peaks could reach more extreme values in the future, especially under Scenario A2. Time series of rainfall do not show significant departures from basin mean values, although Scenario B2 and, in particular, Scenario A2, show greater maximum values. Sediment production follows the same pattern as basin streamflow. Editor Z.W. Kundzewicz Citation Perazzoli, M., Pinheiro, A., and Kaufmann, V., 2013. Assessing the impact of climate change scenarios on water resources in southern Brazil. Hydrological Sciences Journal, 58 (1), 1–11.