Coastal diagnosis and coastal protection projects in the Comoros

Coastal risk management for a safer future in the Comoros

The project led by Egis followed the passage of Cyclone Kenneth, which impacted the Comoros islands in 2019, with gusts estimated at over 200 km/h and torrential rain falling on the archipelago. The damage caused included, in particular, the damage and destruction of coastal roads and retaining walls, as well as the flooding of houses located in coastal areas.

The Post-Kenneth Recovery and Resilience Project was then implemented in partnership with the World Bank with the aim of reducing the risks caused by these disasters and improving the living conditions of the Comorian population. It was proposed to draw up a coastal risk management action plan, consisting of a framework document for investments to be made over the next ten years on the coasts of the islands of Grande Comore, Mohéli and Anjouan.

National diagnosis for coastal protection

The general diagnosis of coastal erosion and marine submersion has been carried out on the entire coastline of the three Comorian islands. It included the collection of existing data and the acquisition and analysis of additional local data, as well as an inventory of existing protective structures. The classification of the levels of risk of marine submersion and coastal erosion led to the identification of priority action zones.

A detailed diagnosis of the risk of erosion and marine submersion was then carried out for the four sites most at risk. Development scenarios were researched to limit the impact of maritime phenomena on the coastline. A Cost-Benefit Analysis (CBA) and a Multi-Criteria Analysis (MCA) of the development scenarios were carried out with a view to developing a decision-making tool to help choose the most relevant development scenarios. The scientific and technical design and dimensioning elements were finally provided for the selected works.

For long-term management of the risks of submersion and erosion

The general assessment of the functioning of the coastline has enabled the development of a 10-year action plan, and the areas subject to the hazards of erosion and submersion and the most vulnerable areas have been identified. Measures incorporating as many soft, nature-based solutions as possible have been proposed for the long-term management of the hazard of submersion and the hazard of erosion in the coastal areas concerned.

Detailed development studies conducted on four sites and the drafting of terms of reference for the supervision and monitoring of the works have now paved the way for the implementation of the actions identified as priorities.

As part of its remit, Egis used a participatory approach involving stakeholders to find solutions that meet the sustainable objectives defined by our client of reducing the vulnerability of the population.

Coastal diagnosis and coastal protection projects in the Comoros.

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Coastal risk management for a safer future in the Comoros

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National diagnosis for coastal protection

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For long-term management of the risks of submersion and erosion

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