IMPACTO HIDROLÓGICO GERADO PELA INSTALAÇÃO DE RESERVATÓRIOS HIDRELÉTRICOS NA AMAZÔNIA: CASO DE BALBINA E SAMUEL (BRASIL)

Abstract

The Amazon Basin is a region of great hydroelectric potential and its use has generated many debates and controversies around the magnitude of its impacts. These major developments cause irreversible impacts on the ecosystem, changes in the hydrological cycle, changes in the daily life of communities, the proliferation of some diseases, the mortality of aquatic species, and the transformation of river systems. In this perspective, the study proposes to perform a fluvioclimatic impact diagnosis based on data from fluviometric stations located in the Uatumã and Jamari Basins where the UHEs of Balbina and Samuel are located, based on the hydrological observation in two distinct periods: pre-installation (1977-1987) and post-installation (2000-2010). The methods applied in the analysis were: Data processing; Organization of flow and rainfall data; Geographic Information System (GIS) for image processing and morphometric analysis; and Fluvioclimatic impact analysis. The results show that both the Uatumã Basin and the Jamarí Basin present changes in the fluvial system due to the presence of hydroelectric, population increase and inadequate soil management. However, in the Jamari Basin the impacts are more pronounced mainly due to the use and occupation of the soil stimulated by an integrative policy and economic advance. According to the precipitation data, differences were observed in the values before and after the installation of the hydroelectric plants, with higher values in the period after installation. In relation to the impact processes on the river system, the Jamari Basin is more likely to become a system of semi-arid characteristics, and the Uatumã Basin, although presented moderate conditions even after the creation of the artificial lake, shows a slight tendency to become a system with the same characteristics. This denotes how significantly the basins are significantly impacted and how much their seasonal variability has changed. In the case of Balbina, the impact on the fluvial system is directly related to the hydroelectric presence. In the case of Samuel, the impact on the system is associated with the presence of the hydroelectric and the use of land occupation.