Estimativa da concentração de sedimento em suspensão no canal São Gonçalo a partir de equipamentos acústicos

Abstract

Quantifying the discharge of suspended solids is very important for different areas, such as hydro-energy, environmental quality, hydraulic structures, and navigation. However, using traditional methods of sampling suspended sediments, as well as, EWI (Equal-Width-Increment), and EDI (Equal Discharge Increment), the determination of Suspended Solids Concentration (SSC) can be a time-costly process, financial and human resources consumption. As a result, alternative methods for estimating SSC have been applied, such as the use of ADCP’s (Acoustic Doppler Current Profiler) types of equipment. Although the São Gonçalo Channel has great social and economic importance for the region which it is part of, being the main fluvial link between Brazil and Uruguay, as well as, responsible for the total flow that comes from Mirim Lagoon towards Patos Lagoon, there is no continuous monitoring of SSC. Thus, this work aims to estimate the SSC at the São Gonçalo Channel considering the relation between the backscatter. Thus, this work aims to estimate the SSC at the São Gonçalo Channel considering the relation with the backscatter. For this, 21 suspend sediment surveys were conducted in the channel, using traditional sampling methods, besides the backscatter correction was made from a static type ADCP equipment. The methodology used was applied at two distinct sections in the channel being 70km apart from each other. By the applied strategy, is a strong correlation between corrected backscatter data and observed SSC. From the equation made here, it was possible to build a historical series of data for both locations, as well as, to start continuous monitoring of SSC in the channel. Certainly, a larger dataset of SSC samples can expand or obtain a higher degree of certainty about the estimated variable (SSC), considering a longer period of analysis, where seasonal fluctuations and flow in the opposite direction would be quite expressive and able to predict extreme events.