Climate Change Impacts on Water Resources of the Largest Hydropower Plant Reservoir in Southeast Brazil

Carlos R Mello,Lívia A Alvarenga,Jorge A Guzman,Marcelo R Viola,Nayara P A Vieira,Samuel Beskow

doi:10.3390/w13111560

Abstract

Approximately 70% of all the electric energy produced in Brazil comes from hydropower plants. In this context, the Grande River Basin (GRB) stands out in Brazil. Some studies have been carried out to investigate the impacts of climate change in tropical regions to support water resources’ management and planning. This study aims to project the changes in the runoff that feed the Furnas Hydropower Plant (FHP) reservoir (GRB-Furnas basin), the largest and most important facility in Southeast Brazil. The lavras simulation of hydrology model (LASH) was used to project the impacts on runoff and hydrological droughts over the century in GRB-Furnas. The regional climate models (RCMs) Eta-HadGEM-ES, Eta-MIROC5, and Eta-CanESM2 forced the LASH model from 2007 to 2099, taking the representative concentration pathways (RCPs) 4.5 and 8.5. LASH simulated the runoff adequately for the baseline period (1961–2005) using the RCMs’ outputs. A noticeable reduction in precipitation was identified in the wet season, especially in the 2007–2040 period for RCP4.5 and in the 2071–2099 period for RCP8.5. As a result, a significant reduction in the runoff, mainly in the baseflow, and an increase in droughts’ severity were projected throughout the XXI Century, which may compromise the water security to the FHP reservoir.

Highlights

The availability of water resources is determined by the complex interaction of natural and human-driven processes occurring along the critical zone
The water resource of the Grande River Basin (GRB)-Furnas is fundamental for the country as the Grande river supplies a cascade of seven downstream hydropower plants directly installed along its course
The authors of [5] detected relevant climate change impacts caused by a significant reduction in precipitation projected throughout the XXI Century, which was observed in this study

Summary

Introduction

The availability of water resources is determined by the complex interaction of natural and human-driven processes occurring along the critical zone. Changes in climate or human activity can result in contrasting hydrological responses with desired or undesired local to regional impacts. Among these changes, developing countries have been more vulnerable to the negative impacts of actual and projected changes in climate [1,2], including the rapid increase of economic and social inequality and the elevated risk of critical infrastructure failure. In Brazil, hydropower plants are responsible for approximately 70% of the country’s electric energy production, making this source highly susceptible to climate changes. These impacts are more evident in the dry season, reducing the hydroelectricity production in hydropower plants as their reservoirs depend on precipitation in the rainy season for hydrological regulation. Changes in the rainy season pattern can threaten the reservoirs’ operation, thereby jeopardizing the hydropower generation [3,4,5,6]

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