Wave dynamics and flooding on low-lying tropical reef-lined coasts

Many tropical islands and coasts are lined with coral reefs. These reefs are host to valuable ecosystems that support
abundant marine species and provide resources for fisheries and recreation. As a flood defense, reefs protect coastlines
from coastal storm damage and flooding by reducing the majority of incident wave energy. However, during storm and
large swell conditions, coastal wave-driven flooding and overwash still occur due to high water levels, (infra) gravity
waves, and/or low-frequency wave resonance. The wave and flooding effects cause erosion, damage to infrastructure,
agricultural crops, and salinization of precious drinking water supplies. These impacts, which are likely to increase due
to climate change and ongoing development on the islands, may cause many low-lying tropical islands and coastal
areas to become uninhabitable before the end of the century. This paper investigates aspects of wave dynamics for the
case of a small island in the tropical Pacific Ocean, shows projections of flooding under climate change scenarios, and
outlines approaches to generalize the results to other islands, including mitigation options.