Dinâmica espacial e temporal da qualidade da água no lago de Balbina, Presidente Figueiredo – AM

Abstract

The Uatumã River is a notable tributary situated on the left bank of the Amazon River. It is distinguished by its extensive biological and ecosystem diversity. The region is notable for its rich fauna and flora, which includes numerous endemic and endangered species. The formation of Balbina Lake was the result of the construction of the Balbina Hydroelectric Plant (UHE Balbina), which was completed in 1987. The construction of this dam significantly altered the physical and chemical properties of the water. This study sought to examine the spatial and temporal dynamics of water quality in Balbina Lake, situated in Presidente Figueiredo, Amazonas State, Brazil. The specific objectives were as follows: i) To analyze the spatial and temporal variation of water quality parameters in the area influenced by Balbina Lake; ii) To estimate the concentration of suspended sediments using MODIS sensor imagery; iii) To investigate the relationship between spatial transformations and water quality in Balbina Lake. To analyze the physicochemical parameters of the water in Balbina Lake from 2020 to 2021, limnological reports from the IPAAM were utilized in conjunction with MODIS sensor reflectance data (2003-2017) to estimate suspended sediment concentration (SSC). The results indicated the following annual average values for physicochemical parameters in Balbina Lake: (a) electrical conductivity of 9.3 µS/cm; (b) pH of 6.4; (c) dissolved oxygen of 7.1 mg/L. d) Turbidity of 1.6 NTU; e) Total dissolved solids of 5.9 mg/L; f) Total suspended solids of 3.3 mg/L; g) Total solids of 6.2 mg/L. The estimated SSC using MODIS imagery indicated an annual average of 2.19 mg/L in the Balbina UHE, 3.49 mg/L in the Uatumã River upstream of the UHE, and 6.33 mg/L in the Pitinga River. The observed concentrations of suspended particulate matter suggest that during the dry season, there is greater retention of suspended sediments upstream of the UHE.