Modeling the hydrodynamic functioning of the mouth of the Bandama River, Grand-Lahou, Côte d'Ivoire

Abstract

Coastal erosion is a real threat on the Ivorian coast and particularly at the mouth of the Bandama River. Hydrosedimentary dynamics led to the relocation of the city of Grand-Lahou to the northern part of this region in the 1970s. Erosion not only modifies the coastline but also causes migration from the mouth of the Bandama River, destroying homes and plantations. This study, based on a 2D hydrodynamic model, using Mike 21 HD software, reconstructed the flow in the Grand-Lahou estuary. The strongest currents are located at the mouth and particularly in the pass. During low water periods, flow currents reach 1.4 m/s in the channel, while during high water periods, high flows tend to block flow currents and intensify ebb currents. Current velocities reach 1.8 m/s in the pass during ebb and are reduced to 0.35 m/s in the flow.