Relationship between turbidity and suspended sediment concentration from a small hydrographic basin in Santa Maria (Rio Grande do Sul, Brazil)

Abstract

ABSTRACTSediment production has been the focus of many studies due to the problems caused by the alterations of the natural environment which are driven by the urbanization process. In Santa Maria, Brazil, urban area expansion and population growth have caused changes in the environment, such as in the structure and natural form of the land, in drainage channels, quality and quantity of water resources, soil sealing and intensive agricultural cultivation. Consequently, studies are necessary to quantify the sediment in rivers for a better understanding and also to develop tools in order to minimize impacts to the environment. This study assesses the relationship between turbidity and suspended sediment concentration (SSC) from a small hydrographic basin located in Santa Maria (Brazil). The methodology was based on monitoring the suspended sediment transport using automated turbidity registrations and suspended sediment samples, which were collected by automatic ISCO sampler. To do so, four field measurements were carried out from 2 September to 6 October 2014. The research has resulted in a good correlation between SSCs and turbidity (T), r = 0.8602, (P < .001), when the SSC data were analysed as a function of T it was observed that follow a model SSC=0.833T1.2266 (P < .001), with a coefficient of determination R2 = 0.740. Therefore, it may be a good alternative to generate continuous records of SSCs in rivers as a tool for water management in a hydrographic basin.