A geração de sedimentos e seus reflexos no assoreamento da PCH Piedade - Monte Alegre de Minas MG

Abstract

The Small Hydro Power has been shown as an alternative on power generation contribution in Brazil. Spite of being a smaller structure in respect to hydroelectric power stations, reservoirs of SHP and its surroundings require some care on the environmental preservation issues. In this sense, the objective of this study was to evaluate the potential generation of sediment in the reservoir contribution area of Piedade SHP by identifying, mapping, ranking and analysis of factors that affect this process; and the collection, measurement and confirmation of its siltation effects in the dam. To achieve the purpose were produced, analyzed and related maps that focused on factors that affect sheet erosion as morphopedology, slope, land use. From these data were pointed out the different classes of susceptibility and the potential sheet erosion. The area morphometry was also analyzed by addressing the drainage density as a factor that determines the transmissibility of the land. Finally the map was organized which identified the areas with greatest potential for generating sediment that may contribute to the silting of the Piedade SHP reservoir. The final map showed a predominance of low potential to siltation, however, the areas that have greater potential to generate sediment are located in areas around the reservoir, which requires care. In line with the preparation of cartographic material were obtained data from the transport and deposition of sediments in the Piedade SHP reservoir during a hydrologic cycle with bathymetric campaigns and sampling suspended and bottom sediment. The data analysis revealed the predominance of sediment discharge mainly in the rainy season, and dissolved solids in the dry season. The sampling of bottom sediments demonstrated changes between textural proportions. The bathymetry showed no significant changes in the bottom relief of the reservoir. Based on these results we tried to help a better use of environmental resources, enabling the increase of the reservoir life.