Climate Science and Policy

As rising sea levels are anticipated to threaten coastal communities around the world within the next century, many low-lying coastlines are already experiencing threats of coastal flooding. The scientific research community is contributing to our understanding of these hazards by collecting data on historically significant flood events, developing short-term flood forecasting models, and projecting future coastal flood risks and vulnerabilities that combine with rising sea levels. For coastal leaders, hazard managers, planners, and residents, effective communication of this data is important to how well it is applied to local impacts, policies, and adaptive measures. A number of U.S. government agencies (e.g., NOAA, NASA) have developed educational guidelines and data mapping tools to enhance understanding of science and coastal flood risks. However, these resources often require a general understanding of flood science, coastal oceanography, or climatic influences. Accessible online communication tools can provide a public benefit by increasing community risk perception and engagement, but these resources should understand their specific audience needs to ensure that relevant language, data, and local priorities are incorporated. In Imperial Beach, California, the low-lying coastal city currently experiences occasional coastal flooding during periods of high tides concurrent with winter storms or large wave events. To better prepare and mitigate the impacts of these events, the City of Imperial Beach has become a longstanding collaborator with the Scripps Institution of Oceanography. This partnership has led to increased technical guidance and support, as well as an abundance of Imperial Beach coastal flood data. Utilizing the flood risk science available in Imperial Beach, this research project sought to work with city staff to identify opportunities and limitations of communicating flood risk in Imperial Beach. The research design included four components. First, a review of flood risk literature and three types of flood risk communication available for Imperial Beach: historical flooding, short-term flood forecasting, and projections of future flood frequency. An ArcGIS storymap was then developed compiling and demonstrating potential methods for communicating Imperial Beach flood risk data in a centralized and publicly accessible format. The storymap was used to facilitate an informal interview and survey with Imperial Beach staff to obtain input on the utility and effectiveness of flood risk communication formats. Finally, an analysis of limitations and opportunities was conducted based on climate risk communication literature and input received from Imperial Beach government staff. This assessment found that communicating historical flood data that could be validated using in-situ observations such as images, videos, or other media was effective for communicating past events. However, historical flood risk communication could be improved if it better described what the different coastal flood drivers were. The short-term flood forecasting system was found to be useful in increasing collaboration between researchers and city officials, as well as increasing hazard response capabilities. However, future workshops between specialists and the public could increase public understanding and engagement, while offering feedback and validation of forecasting models and warning systems. Future projections of sea level rise and coastal flooding communication often relies too much on projections of worst-case scenarios in the long term (100+ years into the future). Additionally, flood frequency projection tools were useful for establishing a future timeline of increasing flood events, but inconsistent vocabulary defining flood days and events may complicate communication. Future coastal flood research projects could significantly benefit from increased stakeholder engagement, and relying on a bottom-up approach to communication and educational resource development.