ADVANCED SHORELINE-CHANGE MODELING OF HAWAIIAN BEACHES

As the climate changes, we are experiencing rising sea levels that lead to erosion and inundation in coastal communities. Coastal erosion is mainly driven by wave action, sea levels, geology, and beach shape. The state of Hawaii is known for its sandy beaches, as well as for its diverse geologic coastlines and powerful wave climate. Hawaii will experience rising sea levels, but of the state’s more than 900 miles (1440 km) of unique coastline, only select areas have been well-studied with it in mind. There is a need for a comprehensive coastline-change study as a part of the state’s climate mitigation plans. Here we present a process-driven model that can project shoreline change on nearly all of Hawaii’s beaches. The model will be informed by historical imagery via automated high-resolution satellite shoreline detection, as well as extensive wave hindcasting and forecasting. When completed, our model will show how Hawaii's coasts will grow or diminish with different future sea level rise projections, wave behavior, and climate mitigation scenarios. We anticipate that this model will be the starting point for advanced shoreline modeling in Hawaii and a crucial step towards developing policies that benefit the state’s future.