Human Interventions and Climate Change on the West African Coastal Sand River: A Preliminary Quantitative Assessment

The West African coastal barrier is maintained by a strong wave-driven longshore transport of sand which can be compared to a "sand river". This sand originates from rivers and from large coastal sand deposits. Today, however, much of the fluvial sand is retained behind river dams and/or interrupted at several locations by harbour jetties. For these reasons the sandy coastal barrier is eroding almost everywhere.

The aim of this study is to derive a large-scale sediment budget analysis for the following countries: Ivory Coast, Ghana, Togo and Benin. This estimation is carried out using a consistent approach based on numerical modelling. In particular, the model chain is based on: Delft3D-WAVE models (one regional model + 15 nested models) and one UNIBEST-CL+ sediment transport and shoreline evolution model, covering the entire study area. Modelling results are validated by means of shoreline changes derived from historical satellite images and literature value.

Scenario runs are carried out aiming at:

  • Assessing the effects of the major anthropogenic interventions on the sediment budget and shoreline changes (i.e. harbour jetties and river dams) and with focus on possible trans-boundary implications between different countries
  • Assessing the possible effect of climate change
  • Creating awareness on the interdependency of any action taken along the coast and major rivers on the sediment budget and shoreline changes.

For information about the project please contact:

Alessio Giardino
Reinier Schrijvershof
Miquel Antonio Toquica Onzaga