Análise da influência do uso e ocupação da terra na concentração de sólidos em suspensão em reservatório hidrelétrico com o uso do sensoriamento remoto

Abstract

The use of remote sensing in reservoir sediment monitoring is important for temporal spac knowledge of sediment deposition in dam structures. In this context, this research was developed in the hydrographic basin that covers the Tucuruí HOU reservoir, in which suspended sediment concentration data from the M1 monitoring station located at 2 km upstream of the dam were acquired, and were integrated into the analyses to understand the relationship between the responses of satellite images and field measurements. Sediment analyses were performed with 14-year time series of MODIS images, composed of 8 days. Surface reflectance estimates were calculated using simplinear regression and coefficient of determination (R2). For the use and occupation of the land of the hydrographic basin, a temporal analysis of Landsat-5, Landsat-8 OLI/TIRS images was performed. Next, the land use and occupation were related to water quality analyses of stations upstream 1 (M1), Amount Repartimento (MR) and Montante Pacurui (MP). The results show that the calibration curve generated the linear regression equation with good fit for MI monitoring station, presenting efficiency in the data estimated by reflectance through this model. The analyses of land use and occupation show that over the years there was a reduction in forest formation and at the same time pasture growth occurred. In relation to water quality, the impacts caused by anthropic actions have negative influences. Thus, it is possible to observe the relevance of the use of remote sensing techniques, geoprocessing and geotechnologies, as instruments that help in the planning of land use and occupation, in the analysis of water quality and management of water resources in reservoir regions, since these technologies enable greater spatial scope of the analyses with lower costs.