Sea Grant programs across the United States and its territories are working with coastal communities to enhance their resilience to hazards and weather extremes exacerbated by climate change. Drawing on the expertise of the authors, many of whom have multiple years or decades of experience in the Sea Grant network, the article identifies five key strategies that Sea Grant programs employ to support the process of coastal hazards and extreme weather adaptation and resilience-building. The application of these strategies, most of which have their roots in the historical legacy of extension, are then illustrated through summaries of current Sea Grant activities and projects, showcasing how they have been applied in real-world situations. These strategies allow Sea Grant programs to fill a unique and valuable niche in national efforts to enhance coastal resilience. The article concludes with a discussion of emerging challenges and recommendations for strengthening Sea Grant’s capacity to support adaptation in coastal communities into the future.
Sandy barrier systems are highly dynamic, with the most significant natural morphological changes to these systems occurring during high-energy storm conditions. These systems provide a range of economic and ecosystem benefits and protect inland areas from flooding and storm impacts, but the persistence of many coastal barriers is threatened by storms and sea-level rise (SLR). This study employed observations and modeling to examine recent and potential future influences of storms on a sandy coastal barrier system in Nauset Beach, MA. Drone-derived imagery and digital elevation models (DEMs) of the study area collected throughout the 2023–2024 winter revealed significant alongshore variability in the geomorphic response to storms. Severe, highly localized erosion (i.e., an erosional “hotspot”) occurred immediately south of the Nauset Bay spit as the result of a group of storms in December and January. Modeling results demonstrated that the location of the hotspot was largely controlled by the location of a break in a nearshore sandbar system, which induced larger waves and stronger currents that affected the foreshore, backshore and dune. Additionally, model simulations of the December and January storms assuming 0.3 m (1 ft) of SLR showed the system to be relatively resistant to major geomorphic changes in response to an isolated storm event, but more susceptible to significant overwash and breaching in response to consecutive storms. This research suggests that both very strong isolated storm events and sequential moderate storms pose an enhanced risk of major overwash, breaching, and possibly inlet formation today and into the future, raising concern for adjacent communities and resource managers.
Coastal communities are unquestionably threatened by sea level rise and storm intensification. Their vulnerability is primarily function of their exposure, increasing in time, resulting into cascading effects affecting the spatial and temporal risk variability along shorelines. Many coastal communities, fearing for their future, are considering interventions aimed at improving their resilience, in particular, Natural and Nature-Based Features (NNBF) to respect the functionality of the local ecosystem and minimize negative feedback effects, that are often induced by interventions. While such features are appealing, their long-term efficiency in a changing environment is not always anticipated, and sometimes misunderstood or overestimated. In the present study, which is sponsored by the United States (US) NOAA’s “Effects of Sea-Level Rise (SLR) 2021, Coastal Resilience” Program, building on over a decade of hazard and risk assessment studies along the US New England shoreline (e.g., Grilli et al., 2017, 2020; Schuh et al., 2023), we assess the efficiency of selected NNBF in changing climate conditions, while integrating local concerns, observed trends, and supporting local ecosystem and people’s way of life.
1 September 2023 in Coastal Engineering Proceedings
Beach barrier systems (BBS) act as “ecosystem engi-neers” (EE), protecting the mainland and back bays from direct wave impact and reducing storm surge and flow passing through their inlets. BBS naturally adapt to slowly evolving wave climates by regressing or transgressing. However, observations show that BBS have been destabilized during past periods of fast changes in sea level or wave climate, potentially leading to drowning of the barrier. In this respect, current predictions of large changes in future Sea Level Rise (SLR) and wave climate, combined with anthropogenic effects, are concerning as these could challenge the natural adaptability of BBS. This raises the following questions: (1) can the future protective ability of local EE be predicted? (2) can the added benefits of implementing selected Nature Based Solutions (NbS) to enhance this natural protective ability be quantified, as well as their potentially negative feedback effects? In this study, these questions are considered for the south shore of Rhode Island (RI) through numerical modeling, in part based on earlier regional storm hazard assessment (Grilli et al., 2020). Specifically, here, as part of a NOAA project (“Effects of Sea-Level Rise 2021, Coastal Resilience” program), we assess the efficiency of NbS in changing climate conditions, while integrating local concerns, observed trends, and supporting local ecosystem and people’s way of life.