Quality sediments assessment from a Sub-basin of the Low Tietê (SP)

Abstract

Human activities exert such influence on erosive processes that the erosion rate can be 100 times greater than would be considering only geological features. The sediment production reduces soil fertility and productivity, contributes to water bodies siltation and can cause aquatic environment eutrophication due to the nutrients accumulation. The knowledge of transport, deposition and suspended sediment processes is very important for conservation, development and management of water resources. This research project objectives to characterize physical and chemically the sediments of the sub-basin of Ribeirão das Cruzes, a right bank tributary of Três Irmãos Reservoir, in Low Tietê Water Resources Management Unit. The sediment samples will be collected in the riverbed by manual dredging and at different depths by sedimentation traps. These sampling will be conducted in two phases: one during the rainy season and the other in drought. Will be done general physical characterizations of sediments, such as granulometric analysis, density, among other parameters. Furthermore, will be analyzed the cation interchange capacity, the concentration of nitrate, nitrite, total dissolved phosphate, reactive silicates, and organic and inorganic matter. It's expected with this project, develop a nutrients dispersal model in the sub-basin and assess the qualitative and quantitative contribuition of soil use and occupation on sedimentation processes. (AU)