Variability of the Xingu River's discharge in the Belo Monte HPP region under scenarios of paleoclimatic reconstruction and climate change projections

Abstract

Several dams for hydropower generation in rivers in the eastern Amazon (Tocantins-Araguaia, Xingu and Tapajós rivers) are in the initial stages of operation, construction or planning. However, climate projections point to reduced precipitation in the eastern Amazon in the coming decades, which can be further intensified by accumulated deforestation over the last decades. This scenario calls into question the real cost-benefits of the hydroelectric use of rivers in the Amazon, in view of the serious socio-environmental impacts resulting from its construction and operation. In this context stands the Xingu River, where the Belo Monte Hydroelectric Power Plant (HPP) was built. Preliminary projections obtained by the proponent of this master's project (Camargo, 2016) indicate future flows on average 28% lower than those historically observed in the Xingu River. This preliminary result suggests that the future generation of energy by the Belo Monte Hydroelectric Power Plant is expected to be adversely affected under a scenario of climate change projected for the coming decades.The objective of this project is to evaluate hydropower generation by the Belo Monte HPP under multidecadal climatic variability to the secular of the middle and late Holocene (last 5,000 years) and future scenario of climate change. This will involve precipitation scenarios generated by climate models and Xingu river flow simulations, with special emphasis on extreme events of precipitation variation in the coming decades (up to the year 2100). The influence of abrupt climatic events on the flow of the Xingu River will be considered under different vegetation scenarios of the basin.For the simulation of the Xingu River flow, a numerical hydrological model will be used, which simulates the flow through surface flow calculations derived from the interaction between topography and precipitation. This allows simulating Xingu river flows from past reconstructions and future precipitation projections obtained through climate models, such as those used in the International Panel on Climate Change (IPCC) projections.This project is linked to the FAPESP Global Climate Change Research Program (process 2016 / 02656-1) and is justified by the relevance and urgency of projecting the effect of climate change on the hydric resources of eastern Amazonia. This is fundamental for the discussion of energy policies for the country, with greater energy security, efficiency and sustainability.