Estimating Fluvial Sediments Loads Using Surrogate Techniques in A Data-Poor Catchment -The Case of The White Volta Basin

Abstract

In the economically-important but data-poor trans-boundary White Volta Basin shared between Ghana and Burkina Faso, information on the amount and timing of sediment loads is very limited. Monitoring of sediments is almost always ignored when designing Water Resources Information Systems (WRIS) in the Volta Basin, resulting in lost opportunities to expand our understanding of the hydrological processes (including sediment transport processes, erosion and sedimentation) at the river-basin scale. This paper presents the results of a study using surrogate techniques for estimating long-term sediment loads as a function of turbidity and stream flow data at Nawuni in the White Volta Basin. A comparison is made between the suspended sediment concentration (SSC) derived from a simple linear regression model and multiple linear regression model. The simple-linear regression model relating turbidity to SSC was found to be the most reliable method of estimating the SSC at Nawuni in the White Volta Basin. Due to the cost associated with collecting SSC and inadequate funding by the two riparian countries, this method presents a more reliable and accurate means of estimating long-term suspended sediment concentrations and loads than the traditional sediment rating curve relating SSC to streamflow in the White Volta Basin.