The use of nature-based solutions (NBSs) in coastal management strategies is gaining popularity, with broad consensus on the critical role of public engagement in assessing the benefits of sustainable practices. However, the number of existing studies that tackle public knowledge and perception of NBSs in coastal management is still low and most studies only target specific communities. As a result, it is challenging to determine whether these findings reflect general trends or are influenced by unique circumstances in the studied communities. To clarify this, it is essential to assess the broader public perspective on the use of NBSs in coastal management. Here we assess the results of a pilot study conducted across Europe to evaluate technical experts’ and community members’ knowledge and perception on the use of NBSs for coastal protection. The evaluation was conducted by collecting responses provided to a survey distributed via social media. The study focuses on three countries: United Kingdom, Netherlands and Italy. The survey revealed common trends across the three countries. There is general support for the application of these solutions in coastal management amongst both groups, which correlates positively with concern for flooding and erosion. While technical experts have a solid understanding of the topic, which corresponds to a considerable degree of awareness and a higher level of consciousness regarding NBSs implementation, the community members’ support is accompanied by an overall more limited knowledge of what NBSs entail (higher amongst residents of coastal areas) but also a considerable desire for more sustainable and eco-friendly management practices. While offering an initial insight into public perceptions of NBSs for coastal planners, these results can also guide larger-scale perception studies, provide a framework for interpreting community-scale research, and highlight opportunities to improve knowledge exchange between technical experts and community members.

Employing Lagrangian particle tracking models for the study of coastal sediment transport dynamics is highly beneficial as they record the complete history of sediment transport pathways. Correctly simulating bed-particle interactions and its stochastic nature in Lagrangian models is essential to accurately estimate the direction and timescale of sediment transport. In this study we compare and assess the performance of two stochastic approaches for simulating particle erosion and deposition in Lagrangian sediment tracking models: 1) formulations proposed by Soulsby et al. (2011) that calculate probability of particles erosion and deposition from empirically-derived parameters and 2) newly-developed formulations that calculate probability of particles erosion and deposition from physical parameters. The two approaches are evaluated in the Lagrangian sediment tracking model SedTRAILS using a simulation of the dispersal of a pilot ebb-tidal delta nourishment in Ameland Inlet (Wadden Sea, Netherlands) as a case study. Our results show that the new physics-based approach represents the diffusive behavior of the nourished sediment better than the empirical approach. However, the new approach could not be fully validated yet, and the implementation of a slope term for bedload transport in the SedTRAILS transport formulations is necessary to further evaluate the new physics-based approach.

Identifying sedimentary signatures of tsunamis within long-term records (hundreds to thousands of years) is time and labour intensive using existing techniques. The lack of rapid identification restricts our ability to reconstruct past (palaeo-) tsunamis on the large spatial and temporal scales necessary for accurate hazard and risk assessment needed by vulnerable, low-lying populations. Here we pioneer the use of portable optically stimulated luminescence (POSL) in rapidly assessing in the field the occurrence and imprint of palaeotsunamis in sedimentary records. Pescadero Marsh (California) has a 2000-year sedimentary record of high-energy events constrained by a robust chronology derived from multiple techniques (luminescence dating, pollution markers). Tsunamis on the Californian coast rework nearshore sediments that have well reset luminescence signals. In slowly-accreting settings with well reset baseline signals, it is difficult to identify tsunamis remobilising locally-derived, well-reset sediments. However, tsunami signatures are readily detectable under rapidly-accreting, back-barrier saltmarsh conditions where they contrast the intercalating, poorly-reset luminescence signals of the marsh sediments deposited under tidal and fluvial conditions. Thus, POSL can allow for rapid, in-the-field assessment of tsunami deposits because their luminescence properties differ from the baseline sedimentary signal. POSL also documents changes in environmental conditions arising from a tsunami event, such as marsh recovery after an erosional and/or co-seismic subsidence event. Where there is a contrast in properties of the tsunami signatures and the baseline sediments, the rapid POSL assessment will allow for landscape-wide datasets to be obtained that can fully capture tsunami signatures globally as the minerals used for measurements are almost ubiquitous on Earth.