Projeções climáticas regionalizadas para a América do Sul com ênfase nos impactos hidrometeorológicos na Bacia do Rio Grande – região Sudeste do Brasil

Abstract

This work evaluates the projections for the 21st century of temperature and rainfall generated by RegCM4 regional climate model and MIROC global climate modelto South America under IPCC climate scenarios B1 and A1B. The rainfall projections were inserted in SMAP, a rainfall-runoff hydrological model, to provide scenarios of inflows in the Água Vermelha Hydroelectric Plant, located in the Rio Grande basin, between 2011 and 2100. Initially, atmospheric and hydrological models werevalidated under present climate conditions and compared toobserved values. Models wereable to simulate the main observed patterns overSouth America. A bias removal technique was employed and wasessential to decrease errors related to rainfall. Temperature projections indicate a gradual elevation in temperature throughout this century. In terms of rainfall, the trend noticed wasa reduction in north and central parts of South America, including the Rio Grande basin, and an increasing rainfall in the southern areas. These rainfall scenarios were inserted into the SMAP model to generate inflow scenarios for the 21stcentury. Projections indicate reductions in inflows of the order between-20 and-30% when using the regional model and 5 to-15%when using the global model.