West Africa's Coastal Areas - France (WACA-F)
Benin, Senegal, Togo – West Africa
Duration : 2017-2021
Project coordinator: Cerema
Classification
Risks
Solutions
Actors
Costs
Summary
In view of investing in the WACA project, the Ministry of Ecological Transition and Solidarity decided on March 20, 2017 to endorse a cooperation project with Senegal, Togo and Benin, called WACA-F which draws on the expertise of four public entities, namely BRGM, Cerema, IGN and Shom. Led by Cerema, the project aims to provide these countries with “historical data” on the coastline. Based on nautical charts, bathymetric surveys and aerial photos, these data are an essential source of information for understanding the evolution of coastal erosion and the shoreline adjustment to climate change. In the long run, the observations will allow Cerema to contribute to implementing early warning systems, feed into coastal development planning and support policies for resilient coastal cities and territories.
Actions
The WACA-F project aims to improve the understanding of coastal flooding, erosion and shoreline retreat. It provides three countries – Senegal, Benin and Togo – with mapping data and historical bathymetric surveys of unique value. This historical data, exclusively available in French archives, was acquired over decades and can date back over a century. Nautical charts, bathymetric surveys and aerial photos collected by Shom and IGN constitute a crucial source of information to understand coastal erosion evolution and the adjustment of the shoreline to climate change.
Cerema synthesizes the data sources and knowledge on coastal retreat available in two to three priority sectors identified by each of the steering committees. This work will allow elaborating a common working framework based on shared data. For instance, a coastal erosion indicator is being tested for Senegal over the period 2000-2018. Eventually, Cerema will contribute to implementing early warning systems, feed into coastal development planning and support policies for resilient coastal cities and territories.
Cerema develops a website with more than 2,000 digital and geo-referenced aerial photographs readily available (here). Moreover, the platform identifies coastal works and developments which are visible on satellite images and likely to impact the coastline.
These data support the scientific community and national authorities in understanding and anticipating coastal dynamics. Drawing on the collected material, Cerema examines sustainable solutions to coastal erosion, including nature-based solutions. In addition, WACA-F assists local authorities and populations in their interpretation, thereby supporting the implementation of the World Bank’s WACA project and programme.
Meanwhile, Cerema is involved in the West African Regional Coastal Observatory (ORLOA) development, i.e. legal and institutional framework, IT platform, monitoring protocols, and is now supporting its technical and legal implementation, along with the development of its national applications. Capacity-building training has already begun for several technical and scientific staff and should continue into 2022:
- on the uses of UAVs (drones) and (D)GPS;
- on approaching coastal resilience;
- on approaching managed realignment, the different strategies and tools available to implement local projects;
- on GIS, mapping, semiology of graphics and databases production/management;
- on wave gauges’ uses, maintenance, exploitation and data processing;
- on renewable energies;
- on sustainable mobility and transport infrastructure;
- on spatial and maritime planning.
Outcomes
By the end of this project, a total of 1,792 aerial photographs from 1954 to 1976 were digitised and geo-referenced, and 243 bathymetric minutes dating back to the beginning of the 19th century were digitally recorded. These figures were used to calculate indicators of coastline evolution and urban development as well as to map coastal management works.
Information and corresponding analyses were effectively produced and delivered to each of the participating countries. The analyses were notably used to support coastal adaptation projects such as the “Soft solutions and coastal risk monitoring in Benin, Togo and Senegal” led by the Centre de Suivi Ecologique (CSE).
Methodology handbooks and training courses are provided to pursue and sustain analyses over time. In this respect, three knowledge-sharing events were held in 2018 in France, Senegal and the Netherlands on coastal risk management, sea level observation, coastal infrastructure mapping using photographic interpretation as well as nature-based solutions.
The complementarity of capacity-building and awareness-raising activities among stakeholders is key.
Partners
- Technical partners: French Ministry of Ecological Transition, Cerema, Shom, IGN, BRGM, in partnership with World Bank, ORLOA and its focal points, Centre de suivi écologique (CSE) local agencies (e.g. ministries of the environment).
- Financial partners: French Ministry of Ecological Transition and national agencie