From risk to resilience: geospatial decision support tool and adaptation strategies for coastal flooding in Rodrigues Island

Rodrigues Island, being a small Island Developing State (SIDS) in the Indian Ocean, is increasingly vulnerable to the impacts of climate change, particularly rising sea levels and recurrent storm surges. The motivation for this study stems from the need to safeguard Rodrigues’ socio-economic activities, which are intricately linked to its geophysical landscape and ecosystem services. This study employs a geospatial-based approach to identify the coastal areas most at risk and to provide a foundation for tailored adaptation strategies. Using predefined scenarios established by the Intergovernmental Panel on Climate Change (IPCC) and storm surge models, the research projects sea-level rise for Rodrigues over the next century. Approximately 1.45 km2 of terrestrial land are exposed to flooding under SSP5-8.5, which represents a loss equivalent to above 1.34% of the island's total land territory imperiled by the encroaching and rising sea levels. This will induce infrastructural damage reaching 23.6%. The results additionally reveal that the low-lying coastal regions at risk are Rivière Cocos, Baie Aux Huitres, Anse Mourouk, Grand Baie, and Port Mathurin. The research also highlights that as these vulnerable areas are progressively inundated, increased human migration may become an unavoidable adaptation strategy for the affected communities. The study emphasizes the importance of innovative and multifaceted solutions, including nature-based strategies such as mangrove reforestation, coral reef restoration, and terrestrial conservation, alongside the establishment of Marine Protected Areas and the implementation of advanced coastal engineering techniques. Additionally, the research advocates for a thorough review and enhancement of the legal framework, with particular focus on relocation strategies. This study contributes to a better understanding of climate change impacts on Rodrigues Island and provides a critical basis for policy development.