The 400-km long coast of the Bight of Benin, formed by sand barriers and lagoons, is bordered to the east by the Niger River Delta and to the west by the Volta River Delta and is characterized by several coastal infrastructures, of which the most important are the deep water harbors of Lomé, Cotonou, and Lagos. In this study, an enhanced version of the CASCADE coastal evolution model was implemented in order to reproduce the evolution of the coast over the period 2000-2015, considering the presence of coastal infrastructure, inlets, and the reduced sediment influx from rivers. The model results showed simulated coastal response around the main coastal infrastructure in agreement with observed data. In addition, the validated model was used to estimate the amount of sediment needed to control erosion through beach nourishment downstream of the harbors. The impact of reducing sediment input on coastal evolution was investigated through model parameterization of the influx at the boundary. Overall, the model may be a useful tool for improving regional coastal policies in the Bight of Benin.

由沙障和泻湖构成的 400 公里长的贝宁湾海岸与尼日尔河三角洲接壤，西与沃尔特河三角洲接壤，具有多个沿海基础设施，其中最重要的是洛美、科托努和拉各斯的深水港。在这项研究中，考虑到沿海基础设施、入口和河流沉积物流入量减少，实施了 CASCADE 海岸演化模型的增强版本，以重现 2000 年至 2015 年期间海岸的演化。模型结果显示主要沿海基础设施周围的模拟沿海响应与观测数据一致。此外，经验证的模型用于估计通过港口下游的海滩营养来控制侵蚀所需的沉积物量。通过边界流入的模型参数化研究了减少沉积物输入对沿海演化的影响。总体而言，该模型可能是改进贝宁湾区域沿海政策的有用工具。