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

ABSTRACT

Sediment 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=0.833T^1.2266 (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.

KEYWORDS:

• Sediment production
• suspended sediment
• turbidity
• ISCO sampler

Acknowledgements

We would like to thank Alcides Sartori for managing the field data collection.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by CT-Hidro - Setorial fund for research in Water Resources of the Brasilian Ministry of Science and Technology, thru CNPq - Federal agency for research funding and FINEP - a Brasilian developing bank for studies and projects and by FAPERGS: Foundation of supporting to scientific research of the State of Rio Grande do Sul.