Evolution of vulnerability to marine inundation in Caribbean islands of Saint-Martin and Saint-Barthelemy

The islands of Saint-Martin and Saint-Barthe acute accent lemy in the French West Indies are regularly affected by hurricanes and marine inundations. In this study, we investigated the influence of economic, demographic, and urban planning strategies on the construction of buildings located in areas exposed to coastal flooding, using a quantitative analysis based on satellite images and aerial photos from 1954 to 2017. Our results indicated that the number of buildings in coastal flooding areas is higher in Saint-Martin than in Saint-Barthe acute accent lemy. The number of buildings constructed in marine inundation risk areas have increased during the last decades, owing to the tax reduction policies implemented for investment in French overseas territories that favor the development of new constructions in these islands and promote demographic growth. Inheritance of economic policy during the 1980-2010 period is responsible for the present state of vulnerability to marine inundation. A recent decrease (by 45%) in the constructions per year in the marine inundation risk areas observed in Saint-Martin from 2011 to 2017 could have been influenced by (1) the approval of the Natural Hazards Prevention Plan in 2011 and (2) population stagnation since 2007. Prevention plan was implemented late, after many buildings had already been built in marine inundation areas. The reduced prevention plan efficiency is due to the difficulty to conciliate risk mitigation, economic interests and political agenda.

Automated summary

This study investigates the influence of economic, demographic, and urban planning strategies on the construction of buildings in coastal flooding areas in Saint-Martin and Saint-Barthelemy. Using satellite images and aerial photos from 1954 to 2017, the research finds that the number of buildings in coastal flooding areas is higher in Saint-Martin. The increase in buildings constructed in marine inundation risk areas is attributed to tax reduction policies and demographic growth, while the vulnerability to marine inundation is a result of economic policy during the 1980-2010 period.