Efficient coastal inundation early-warning system for low-lying atolls, dealing with lagoon and ocean side inundation in Tarawa, Kiribati

• DOI: 10.1016/j.wace.2023.100615
• Publication Date: 2023-10-10T09:07:21Z
• Authors: Antonio Espejo; Moritz Wandres; Hervé Damlamian; Anuj Divesh; Judith Giblin; Jerome Aucan; Mauna Eria; Ueneta Toorua
• Keywords: Atoll; Storm Surge; Coastal flood; Wave height; Coastal hazards

Tarawa is a low-lying atoll in the Gilbert Island group, capital of Republic Kiribati and home nearly 70.000 inhabitants. With limited land area, rapid population growth urbanization, strong interannual sea level variability induced by ENSO rise, highly vulnerable to coastal flooding. In this context, Early Warning Systems are proven cost-effective climate adaptation measure strengthen community resilience. virtually enclosed atolls, water experienced at shore compounded tides, anomaly, storm surge contribution waves. While wave setup runup, primary components driving inundation along ocean-facing shorelines, wind pumping through rim contributes more inside lagoons. paper we present an efficient process-based approach forecast flooding events both, ocean lagoon coasts islands. intention being scalable other island countries, system has been designed as lightweight accurate tool, that provides actionable user-friendly predictions 7 days advance. Publicly available global products ingested high-resolution model tailor-made metamodels translate forcings levels shore. absence comprehensive topography dataset, extreme value distributions 27-year hourly were evaluated every 500 m coast define communicate different warnings according recurrence interval forecasted event. The long-term climate, nearshore transformation, produced under work increase Tarawa's risk knowledge support informed investments future development strategies. will significantly enhance services Kiribati, improving baseline data still remains critical need for government communities decision making better cope with increased hazards.