Cities and coastal erosion: what resilience in West Africa?
The 7,000 km long West African coastline shared by Senegal, Togo, Nigeria and other countries is increasingly threatened by coastal erosion. Benin, for example, loses an average of four meters of shoreline per year along 65% of its coastline. What are the characteristics of this phenomenon and what are the main resilience measures at both national and sub-regional levels? Find out in this article, part of our special feature on seas and oceans.
Nearly 3.5 billion people live within 150 kilometers of the shore, which means that 60% of the world's population lives in the great coastal zone. And yet, no continent today escapes coastal erosion. The impact varies from country to country, but the causes are generally the same: the effects of climate change (flooding and tsunamis), increasing urbanization and the resulting human activity. Environmentalists often call into question certain human activities that accentuate coastal erosion, notably through the weakening of dune belts.
These include the marketing of sea sand by coastal communities, the construction of dams, port developments and underwater oil drilling. In West Africa, where the coast is home to nearly a third of the sub-region's population and generates up to 56% of its gross domestic product(GDP), coastal zone degradation costs Benin, Côte d'Ivoire, Senegal and Togo a total of $3.8 billion a year. According to the World Bank, this is equivalent to 5.3% of their GDP.
In the Senegalese commune of Bargny, this erosion is most often seen in the devastation of beaches, mangroves and agricultural areas that are essential to the livelihoods of communities living by the sea. A similar scenario in Nigeria. In this West African country, where demographic growth (currently 219 million inhabitants, set to rise to 211 million by 2021) is no longer slowing down, several Nigerianrians have over the years settled in coastal cities, including the economic capital Lagos, Port-Harcourt and Ayetoro (Ogun State). The latter, as recently as June 2024, was the target of a spectacular rise in water levels that destroyed everything, starting with fishermen's stores and other facilities.
The "WACA, ResIP West Africa Coastal Area", the major sub-regional response
Beyond the economic consequences, coastal erosion has already killed nearly 13,000 people in West Africa, according to the World Bank. Such a situation cannot continue. The time has come to find solutions. On a sub-regional scale, resilience means pooling the efforts and strategies of six countries. Through the West African Coastal Area Resilience Investment Project (WACA-ResIP), Benin, Côte d'Ivoire, Mauritania, São Tomé Principe, Sénégal and Togo have been pooling their efforts and strategies for dune fixation, construction of protective structures and dikes, restoration of wetlands, mangroves, lagoons and drainage systems since 2018.
At a total cost of 47.3 million euros (31 billion CFA francs), the initiative is co-financed by the Global Environment Facility (GEF) and the World Bank Group via the International Development Association (IDA). The first benefits are expected on the Beninese coast, where the IDA has granted 36 million dollars for the installation of rigid hydraulic structures along the coast.installation of rigid hydraulic structures at the ocean's edge or on a river bank to slow down water currents and limit sediment movements. The other part of the funds from this development partner will finance the "sand recharging of 6.4 millionm3 in thearrondissement d'Agoué and the construction of cycle paths and parking lots" in the coastal areas of Agoué and Hillacondji.
Benin also plans to plant palm trees along its coastline.
But the WACA alone doesn't seem to be enough for the Beninese government, which has been experimenting with other solutions since 2021, including the planting of 500,000 coconut palms and other types of palm on its coastal strip. These plants are produced locally by the Institut national des recherches agricoles du Bénin (Inrab) and should have a dual long-term impact: combating coastal erosion while developing tourism, according to the Beninese Ministry for the Environment and Sustainable Development.
Trees, particularly palms, play an important role in stabilizing wetland ecosystems and the biodiversity of the coastal strip. "Like mangroves, coastal trees provide valuable shelter for fragile ecosystems thanks to their deep roots, and also help stabilize the soil. Trees also form natural barriers that slow wind speeds. By reducing this wind force, the green giants (trees, editor's note) minimize the impact of storms on the coast and mitigate erosion", says the New Caledonian platform Neocean.
Socio-economic reconstruction of coastal communities: the Togolese example
In Togo, whose coastline is 50 km long, the authorities have a very clear roadmap, steered by the High Council for the Sea, which places particular emphasis on the socio-economic reconstruction of victims of coastal erosion. It is within this framework that the project Renforcement de la résilience au changement climatique des communautés côtières du Togo (R4C-Togo) (Strengthening the resilience of Togo's coastal communities to climate change) was launched, benefiting 70 women's cooperatives that depend on marine resources. It is financed to the tune of 8.9 million dollars (over 4.4 billion CFA francs) by the Food and Agriculture Organization of the United Nations (FAO).
Between securing the water supply, collecting fuel for cooking and heating many homes, the stakes are high in the Plateaux reIn 2022, the overflowing waters of the Mono River (on the border with Benin, editor's note) untied the Ila and Anyékpada bridges. Ultimately, the project will boost food security for 99,500 Togolese thanks to innovative technologies and solutions developed by 2,100 local entrepreneurs. However, in view of rising sea levels, coupled with unpredictable flooding, will all these institutional efforts really be able to halt coastal erosion and its many consequences in West Africa?
Source: www.afrik21.africa/
