Sedimentology and prediction of the sand dynamics of the buyo dam lake using the Hjulström model

The objective of this study aims to characterize the sedimentation and mode of transport of sandy sediments in Lake Buyo. The granulometric, morphoscopic and mineralogical analyzes of the surface sediments from the bottom of the lake collected in March 2021 and the use of the Hjulström model, made it possible to determine the sedimentological characteristics and predict the sedimentary processes in the lake. The sedimentological study makes it possible to identify four lithological facies: sands, muds, gravels and mixed sediments. Sands and gravels are the most abundant, with a predominance of sub-angular forms (75.37%). The sands are mainly very poorly classified and transported by saltation (67%). The mineralogical procession consists of garnet, pyroxene, quartz, muscovite, feldspar, limonite and biotite. During the hydrological seasons, the waters of the lake are very calm in the vicinity of the flood spillway and favor the settling of most of the sandy particles present in the water column. The water intake area is where there is a high chance of remobilization or erosion of sand (coarse to fine).