Taxa de assoreamento no reservatório da Usina Hidrelétrica do Funil - MG

Abstract

Soil degradation by water erosion is a problem, not only for the loss of soil and water which is as a support for productive activities, but also for negative consequences related to silting and contamination of streams, lakes and reservoirs. Therefore, this study aimed to develop an evaluation of sedimentation in Funil reservoir based on Digital Elevation Model generated from bathymetric surveys conducted in 2014, determining the current capacity storage of the reservoir and development a diagnosis of the situation 12 years after the hydroelectric power plant operation. It can be concluded that the annual reduction in capacity storage reservoir presented for the last two operating years which was about 2.8 million cubic meters per year or 1.05%, quite above the expected value during the project designed, and reference values from the order of 0.5% for Brazilian reservoirs found in the literature, compromising significantly the useful life operation if this situation continues. The main points of siltation are at the delta of Rio das Mortes and Rio Capivari due to channel narrowing with sediments concentrated slightly upstream of the delta. Siltation is accelerating in recent years and consequently the bottom of the reservoir relevation increases the risk of interference and floods in anthropic areas that grows around the reservoir.