Designing Coastal Adaptation Strategies to Tackle Sea Level Rise

Abstract

Faced with sea level rise and the intensification of extreme events, human populations living on the coasts are developing responses to address local situations. A synthesis of the literature on responses to coastal adaptation allows us to highlight different adaptation strategies. Here, we analyze these strategies according to the complexity of their implementation, both institutionally and technically. First, we distinguish two opposing paradigms – fighting against rising sea levels or adapting to new climatic conditions; and second, we observe the level of integrated management of the strategies. This typology allows a distinction between four archetypes with the most commonly associated governance modalities for each. We then underline the need for hybrid approaches and adaptation trajectories over time to take into account local socio-cultural, geographical, and climatic conditions as well as to integrate stakeholders in the design and implementation of responses. We show that dynamic and participatory policies can foster collective learning processes and enable the evolution of social values and behaviors. Finally, adaptation policies rely on knowledge and participatory engagement, multi-scalar governance, policy monitoring, and territorial solidarity. These conditions are especially relevant for densely populated areas that will be confronted with sea level rise, thus for coastal cities in particular.

Coastal Flood Modeling to Explore Adaptive Coastal Management Scenarios and Land-Use Changes Under Sea Level Rise

“…They were able to share their experience and learn about regulations, financial levers, public perception, difficulties and possible solutions, as well as get feedback from other stakeholders who have started a managed retreat or ecosystem-based adaptation to SLR. Through these different actions, the multidisciplinary approach used in the Moëze marsh, and broadly in the Adapto project, removes several barriers identified by authors in terms of habitat restoration and adaptation (Lorie et al, 2020;Bongarts Lebbe et al, 2021;Cortina-Segarra et al, 2021). In our case, we can mention the motivation in decision-makers to incorporate innovation, the integrated land-use planning, and the collaboration between different stakeholders, and different expertise domains as barriers removed.…”

“…At local scales, decision-makers have to deal with the legislation, their knowledge of the field and studies conducted by researchers or design offices in order to adapt or to become more resilient to SLR and extreme events leading to coastal flooding. The options proposed are mainly sea-front dikes (Rosenzweig et al, 2011;Ezer and Atkinson, 2014), or naturebased actions such as dune revegetation or habitat restoration (Fernańdez-Montblanc et al, 2020;Grothues and Able, 2020), and dike retreat (Bongarts Lebbe et al, 2021). In order to help local stakeholders in their strategy to protect human activities and improve the resilience, an adaptive coastal management project named Adapto has been initiated by the Conservatoire du Littoral (coastal conservatory), hereinafter CDL.…”

El Niño controls the evolution of shorelines worldwide

“…Coastal areas host a considerable part of human life and activities, providing tremendous societal, economic and ecological benefits. The health of these ecosystems, however, highly depends on the fragile balance between climate influence and local anthropogenic constraint (Oppenheimer et al, 2019;Bongarts Lebbe et al, 2021). Sea level rise, erosion, coastal flooding, and land use changes have already placed ecosystems and seafront population at greater risk (Vousdoukas et al 2018(Vousdoukas et al , 2020Kirezci et al, 2020, Tebaldi et al, 2021, Tiggeloven et al, 2021, Beck et al 2018 and this is only expected to get worse in the future (Ranasinghe et al, 2021).…”

Emulator For Eroded Beach And Dune Profiles Due To Storms

“…Extreme storm events with high waves and elevated water levels can change beaches on timescales of several hours to days (Cohn et al., 2019; Splinter et al., 2018), typically removing considerable volumes of sand from the subaerial beach and dune face to deeper portions of the offshore profile (Gallagher et al., 1998). Predicting beach response to storm waves on varying time horizons is a primary research need of the nearshore scientific community (Elko et al., 2014), motivated by the recognition that global warming‐induced sea level rise will exacerbate storm impacts and require mitigation strategies to protect communities and infrastructure (Bongarts Lebbe et al., 2021).…”

“…Extreme storm events with high waves and elevated water levels can change beaches on timescales of several hours to days (Cohn et al, 2019;Splinter et al, 2018), typically removing considerable volumes of sand from the subaerial beach and dune face to deeper portions of the offshore profile (Gallagher et al, 1998). Predicting beach response to storm waves on varying time horizons is a primary research need of the nearshore scientific community (Elko et al, 2014), motivated by the recognition that global warming-induced sea level rise will exacerbate storm impacts and require mitigation strategies to protect communities and infrastructure (Bongarts Lebbe et al, 2021).Storm impacts are predicted with models that account for a range of complexities, including qualitative frameworks (Sallenger, 2000), data-driven models (Beuzen, Harley, et al, 2019), and process-based approaches that are either empirical or fully physics-based (Sherwood et al, 2022). Simple approaches may track a particular contour (i.e., shoreline models (Yates et al, 2009)) or changes in a particular feature (i.e., dune crest height or dune toe retreat (Palmsten & Holman, 2012)), while physics-based numerical models such as the eXtreme…”