USE OF PROXIMAL SENSORS IN THE EVALUATION OF A RESERVOIR SEDIMENTS IN VIÇOSA-MG

Abstract

The municipality of Viçosa has experienced problems of water scarcity. In order to evaluate the thickness of the deposition layer at one of the municipal reservoirs, a ground penetrating radar (GPR) was used. Sediment samples were analyzed using X-Ray fluorescence spectrometry (XRF) to determine the chemical composition of the sediments. GPR analysis showed that the reservoir has a sediment layer with three meters of average depth, which corresponds to a significant loss of its initial water storage capacity. Heavy metals such as Mn, Pb, Cr, Cu and Zn were present at potentially toxic levels. These values were mainly attributed to fertilizers, correctives and pesticides contamination. P contents, on the other hand, were related to sewage effluents discharge into the drainage system. Therefore, measures involving the recovery of degraded pastures, soil conservation practices, rational use of fertilizers and infrastructure investment in sewage are recommended to improve quantity and quality of water supplied to population. De-silting is also seen as an efficient short-term measure to increase the water reservoir’ storage capacity.