Project period: 2 29 24-2 28 26PROJECT title: rigorously valuing the coastal hazard risks reduction provided by potential coral reef restoration in the territories of guam, american samoa, and the…

Project period: 2 29 24-2 28 26PROJECT title: rigorously valuing the coastal hazard risks reduction provided by potential coral reef restoration in the territories of guam, american samoa, and the commonwealth of the northern mariana islandsover the twenty-first century, sea level rise (SLR) is projected to at least double the frequency of coastal flooding at most locations around the world potentially affecting millions of people living in low-lying coastal zones, unless effective flood mitigation strategies are taken. Coral reef-lined tropical coasts are among the most vulnerable to climate change and SLR these populations are denser, growing faster, and composed of more people from lower-middle income groups than the global average. However, coral reefs also represent a natural infrastructure that, in the U.S., is valued at more than 18,100 people and 1.8 billion in averted flood damages per year. Because reefs attenuate wave energy and reduce flood impacts, reef restoration is increasingly being considered as a nature-based, hazard mitigation strategy that could help reduce risks and increase the resiliency of tropical coastal communities. However, quantitative assessments of where reef restoration can provide effective risk reduction are currently lacking. Further, the aftermath of hurricanes irma and maria in the caribbean spurred new interest in nature-based coastal protection. However, planning and funding reef restoration for risk reduction requires rigorous assessments of their effectiveness. This project will follow a quantitative risk assessment framework combining local climate hazard information, coastal models and socioeconomic analyses to, first, characterize the effects of reef restoration projects on hydrodynamics and flooding, and second, determine of the socioeconomic impacts and benefits from potential interventions. The project is focused on guam, saipan, tinian, and american samoa. Activities to be performed. The proposed work covers two main research activities: (1)assessing reef restoration projects for risk reduction: modeling of coastal flooding hazard risks and quantification of flood risk reduction, valued in socioeconomic terms, from potential coral reef restoration in guam, saipan, tinian, and american samoa. Activities include coastal climate downscaling to shallow coastal areas modelling reef hydrodynamics flood modeling and calculation of damages and benefits, factoring in socioeconomic vulnerability.(2)identification of project effectiveness for flood protection: development of models to predict the effectiveness of coral reef restoration across a broad range of types of coastal geomorphologies such as sandy shorelines, rocky shorelines, coastal infrastructure, etc., as well as advance the understanding of potential of reef restoration for coastal erosion control. Deliverables and expected outcomes. The expected deliverables include peer-reviewed data and maps outlining the benefits of reef restoration projects in the territories of guam, american samoa, and the commonwealth of the northern mariana islands and improved methods and models to predict coral reef restoration effectiveness in these regions and other coastlines. Other more broader outputs include advancement in the modeling and characterization of nature-based solutions for coastal protection. Intended beneficiaries. The main beneficiaries of the outputs are agencies and stakeholders in the territories of guam, saipan, tinian, and american samoa, where these results can (1) guide hazard risk reduction and adaptation action needed by these territories to apply for US federal hazard mitigation funding and (2) inform effective typologies of reef restoration solutions for coastal protection.