EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Use of turbidity measurements to monitor suspended sediment loads on the Congo River

Catherine Mushi1,5, Preksedis Marko Ndomba1, Jeffrey Neal2, Jules Beya3,6, and Mark Trigg4
Catherine Mushi et al.
  • 1University of Dar es Salaam, College of Engineering and Technology, Department of Water Resources Engineering, Dar es Salaam, Tanzania
  • 2School of Geographical Sciences, University of Bristol, Bristol, UK
  • 3Department of Natural Resources Engineering, University of Kinshasa, Kinshasa, DRC
  • 4School of Civil Engineering, University of Leeds, Leeds, UK
  • 5Department of Civil Engineering, Ardhi University, Dar es Salaam, Tanzania
  • 6Centre de Recherche en Ressources en Eau du Bassin du Congo (CRREBaC), Kinshasa, DRC

Recent mapping of sediment sources and erosion processes in the Congo basin show that sediment loads may be higher than previously estimated. Stark temporal changes in water turbidity in some of the tributaries observed by satellite images over the past 25 years indicate a need for closer monitoring of sediment load transported in the River. Turbidity sensors present an attractive option for sediment monitoring due to their ability to provide automated continuous time series data for estimation of suspended sediment concentration and suspended sediment fluxes in rivers; an attribute that is particularly important for remote rivers like the Congo. Continuous in-situ turbidity measurements were made using an OBS-501 turbidity sensor at the Kutu Moke monitoring site on the Kasai River, a major tributary of the Congo River between July 2018 and August 2019. The sensor infers turbidity by detecting the intensity of light scattered from suspended particles in water. We explore a field calibration of turbidity measurements with over 120 simultaneous suspended sediment concentration (SSC) measurements for the same period. Sediment loads estimated using high frequency turbidity data measurements (hourly) are then compared to loads estimated using classical sediment rating curves to establish if the turbidity provides a better representation of the suspended sediment load.

How to cite: Mushi, C., Ndomba, P. M., Neal, J., Beya, J., and Trigg, M.: Use of turbidity measurements to monitor suspended sediment loads on the Congo River, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-518,, 2019