Rangiroa field - may 2025
Objectives :
The mission conducted in Rangiroa in May 2025 with the scientific team of LIENSs aimed to collect data to assess the atoll’s vulnerability to climate risks. The main objectives were to collect data on the potential loss of habitable land and settlements, food security, freshwater supply, and economic activities, to develop a probabilistic model to assess the overall risk to habitability of Rangiroa.
Bursting of a defence structure under the effect of heavy swells.
Embankments created to tackle coastal erosion. The lagoon coast of Avatoru island.
Methodology :
To achieve these objectives, various methods were used: field observations allowed us to identify sensitive areas, such as erosion zones, low-lying areas, exposed buildings, or sand extraction sites. In parallel, 50 questionnaires were conducted with the residents to gather information on their level of concern about climate risks, as well as their food and water consumption practices. Finally, interviews with institutional stakeholders in Rangiroa and Papeete provided information on current climate risks, planned adaptation strategies, and development and conservation priorities.
Preliminary results :
Preliminary results show significant concern about climate risks. In particular, habitable land and freshwater are perceived by residents as vital pillars to be protected as a priority. Economic activities and settlements appear as secondary concerns, although they are not neglected. Cross-analysis of data from questionnaires and institutional interviews will help identify gaps between residents’ concerns and adaptation priorities.
Field observations and all collected data have been incorporated into the probability model (Bayesian network) currently under development. This model aims to provide a combined assessment of the risks to habitable land and settlements, food security, economic activities, and pressures on freshwater supply.
Probabilistic model developed to assess the overall risk to Rangiroa’s habitability.