Co-Developed Assessment of Inundation Risk at Puʻuhonua o Hōnaunau National Historical Park, HI

Puʻuhonua o Hōnaunau National Historical Park is an important archeological and spiritual site in ancient and contemporary Hawaiian culture. Recent anecdotal evidence from park staff describes inundation events on park grounds in areas that have not previously flooded, placing valuable cultural assets at risk. The primary goal of this study is to work with park staff and the surrounding community to understand the impacts of increasing sea level on the park, including wave-induced and high-tide flooding. Thus, community and cross-agency engagement is an essential component of the project, and we detail how this community input is driving scientific inquiry in this case. Preliminary analysis of wave and tide climatology shows that most of the high total water level events occur during the winter months due to swells from the west-northwest direction. An array of pressure sensors was deployed on August 17-18, 2019 and will measure water level at a frequency of 1 Hz continuously through March 2020, capturing this high-risk season. These measurements are used to validate and optimize a wave model that describes the physical processes leading to inundation in the park. Results from the modeling work are jointly analyzed with observations and projections of sea level change to answer questions posed by park staff and the community, which will support effective decision-making and resource management in the park.