Monitoramento hidrossedimentológico na bacia hidrográfica do rio pandeiros

Abstract

The Pandeiros River is of great ecological importance for the northern region of the State of Minas Gerais, which has led to the creation of several Special Protected Areas in its basin. On its course is the Pandeiros Small Hydroelectric Plant, built in 1957 and currently in the process of being decommissioned. One of the stages of the decommissioning process is to carry out the studies necessary to assess the impact of the cessation of the project's operations and to guide the decision-making process. Thus, the main objectives of the studies presented here were to evaluate the influence of the Pandeiros Small Hydroelectric Plant reservoir on sediment transport in the Pandeiros River and to fit models to estimate sedimentometric variables (sediment concentration and suspended solids discharge) using the variables flow and turbidity. The objectives were also to evaluate the composition of the solids transported by the Pandeiros River and to assess the correlation between the variables analyzed. The study used data measured between May 2019 and January 2023. The following variables were analyzed: flow, turbidity, precipitation, total solids (fixed and volatile), and suspended solids (fixed and volatile). The results indicated that under the conditions observed during the study, the reservoir did not affect the concentration and composition of the sediments. In addition, it was found that the solids are mainly composed of inorganic material. Regarding the fitted models, the best results were obtained using the potential model to estimate the suspended solids discharge. To estimate the concentration of suspended solids, the best results were obtained by the potential model using flow as the independent variable and the linear model using turbidity as the independent variable. It was concluded that the reservoir did not significantly affect the sediment concentration and that the sediment curves and the models fitted to estimate the suspended solids concentration can be used to assist in the hydrosedimentological monitoring of the Pandeiros River. This work is part of the subproject "Hydrosedimentological Monitoring in the Pandeiros River Basin", which is part of the research and development project "GT-0611 - Decommissioning of the Pandeiros SHP: an unprecedented experience in South America".