Determination of the relationship between turbidity and suspended sediment concentration and elaboration of an evaluation model of sediment transport for the Jundiaí River - PCJ Basin

Abstract

The sediment transport in the waterways is directly related to the silting of rivers and reservoirs and the erosion in the banks and the deposition of sediments on the rivers. These occurrences have caused various environmental and economic damages. For example the decrease in the useful life of the reservoirs and the deterioration of the surfaces of the hydraulic structures as a consequence of the water flow with sediments, making sedimentological studies indispensable. Sediment transport is also directly related to the effects of erosion activities on the river banks and the sedimentation process and, consequently, increased flooding. Thus, in both cases, direct measurements of sediment loading are extremely important and necessary for preliminary studies and also for the correct evaluation of the impact caused by this process. Considering that obtaining hydrosedimentological data is not an easy, and that for the Jundiaí River, object of this study, there is no history of sampling, the use of indirect methods through turbidimeters is a practical and economical alternative to obtain this information. This research project is based on data from water samples collected in the Jundiaí River, PCJ basin, with the use of conventional direct sampling techniques and NTU turbidity data obtained with a turbidimeter, to elaborate a model, based on the selection of theoretical equations in the literature that can represent the phenomenon of sediment transport in the Jundiaí river, in a quantitative approach. Also as a product of this research project is meet a mathematical relationship between turbidity and the concentration of suspended solids, allowing to obtain the concentration of suspended solids from the turbidity of the water and also the determination of the curve of solid flow to the study site. (AU)