Marshes and Mangroves as Nature-Based Coastal Storm Buffers

Annual Review of Marine Science, Journal Year: 2022, Volume and Issue: 15(1), P. 95 - 118

Published: July 18, 2022

Tidal marshes and mangroves are increasingly valued for nature-based mitigation of coastal storm impacts, such as flooding shoreline erosion hazards, which growing due to global change. As this review highlights, however, hazard by tidal wetlands is limited certain conditions, not all hazards equally reduced. effective in attenuating short-period storm-induced waves, but long-period surges, elevate sea levels up several meters more than a day, attenuated less effectively, or some cases at all, depending on wetland properties, larger-scale landscape geometry. Wetlands often limit erosion, damage vegetation (especially mangrove trees) can be substantial, recovery may take years. Longer-term persistence compromised when combined with other stressors, climate change human disturbances. Due these uncertainties, defense projects need adopt adaptive management strategies.

Language: Английский

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Nature-Based Engineering: A Review on Reducing Coastal Flood Risk With Mangroves

Frontiers in Marine Science, Journal Year: 2021, Volume and Issue: 8

Published: July 8, 2021

Integration of mangroves in projects to reduce coastal flood risk is increasingly being recognised as a sustainable and cost-effective alternative. In addition the construction conventional hard protection infrastructure, not only contribute attenuating events ( functionality ), they also recover in, adapt to, changing climate persistence ). The implementation reduction, however, remains complex. This because innate depend on range environmental conditions. Importantly, may collapse when impacts or climatic changes exceed key system thresholds, bringing uncertainty into situation where failure could endanger lives livelihoods. uncertainties mangrove can be dealt with by (1) improving insights how ecological physical processes affect across scales, (2) advancing tools accurately assess predict persistence, (3) adopting an adaptive management approach combined appropriate engineering interventions enhance persistence. Here, we review existing evidence, monitoring techniques modelling approaches from viewpoint Inspired guidelines for Nature-based Solutions (NbS) risk, provide operationalization this new approach. addition, identify further research efforts are required practical application management. Key aspects variability their recovery mechanisms, which greatly site- storm-specific. We propose five characteristic damage regimes that result increasing reductions well post-storm periods. Further quantification these thresholds successful integration Ultimately, challenge development strategies optimise long-term resilience. Such should informed continued assessments, based supported through well-established guidelines.

Language: Английский

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Salt marshes create more extensive channel networks than mangroves

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: April 19, 2022

Coastal wetlands fulfil important functions for biodiversity conservation and coastal protection, which are inextricably linked to typical morphological features like tidal channels. Channel network configurations in turn shaped by bio-geomorphological feedbacks between vegetation, hydrodynamics sediment transport. This study investigates the impact of two starkly different recruitment strategies mangroves (fast/homogenous) salt marshes (slow/patchy) on channel properties. We first compare networks found around world then demonstrate how observed patterns can be explained vegetation establishment using controlled experimental conditions. find that dissected more extensive have shorter over-marsh flow paths than mangrove systems, while their branching remain similar. finding is supported our laboratory experiments, reveal hamper or facilitate development, respectively. Insights crucial understand wetland resilience with rising sea-levels especially under climate-driven ecotone shifts.

Language: Английский

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Impact of mangrove on tidal propagation in a tropical coastal lagoon

Environmental Earth Sciences, Journal Year: 2024, Volume and Issue: 83(2)

Published: Jan. 1, 2024

Language: Английский

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Hydrodynamics of Meander Bends in Intertidal Mudflats: A Field Study From the Macrotidal Yangkou Coast, China

Water Resources Research, Journal Year: 2022, Volume and Issue: 58(12)

Published: Nov. 21, 2022

Abstract Meandering channels are ubiquitous features in intertidal mudflats and play a key role the eco‐morphosedimentary evolution of such landscapes. However, hydrodynamics morphodynamic these poorly known, direct flow measurements virtually nonexistent to date. Here, we present new hydroacoustic data collected synchronously at different sites along mudflat meander located macrotidal Yangkou tidal flat (Jiangsu, China) over an 8‐day period. The studied bend exhibits overall dominance flood flows, with velocity surges about 0.8 m/s occurring immediately below bankfull stage during both ebb tides. Unlike salt‐marsh channels, velocities attain nearly constant, sustained values as long flows remain confined within channel reduce significantly overbank stages. In contrast, curvature‐induced cross‐sectional more pronounced Thus, phase lag exists between streamwise cross‐stream maxima, which limits transfer secondary likely hinders formation helical entire length. Our results support earlier suggestions that morphodynamics meanders does not strongly depend on is most driven by high sustains seepage late‐ebb stages, well other tidally‐mediated processes waves intense rainfall events. By unraveling complex structures intertwined processes, our provide first step toward better understanding meanders, relevant implications for their planform characteristics dynamic evolution.

Language: Английский

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Hydrodynamics of Meander Chute Cutoffs in Microtidal Mudflats

Water Resources Research, Journal Year: 2024, Volume and Issue: 60(6)

Published: June 1, 2024

Abstract River cutoffs and oxbow lakes represent ubiquitous features in alluvial plains, shaped by unidirectional meandering flow. Extensive studies have been conducted on these as their presence immediately decreases meander sinuosity plays a significant role the long‐term eco‐morphodynamic sedimentary evolution of landscapes they carved in. In contrast, limited attention has given to formed tidal environments bidirectional currents, corresponding hydrodynamical processes within are poorly understood. Here, we present new, first‐handed hydroacoustic data collected through series fixed‐point cross‐sectional flow measurements along chute cutoff located microtidal Diaokou Mudflat, Yellow Delta, China. The investigated bend displays higher hydrologically active than newly‐formed channel at low tide, whereas gradually become main conduit for propagation with water stage increasing. Specifically, poorly‐developed separation zones compensated widespread secondary circulation cells that more pronounced under influence turbulences complex bedforms rather curvatures. Unlike fluvial cutoffs, which tend be disconnected parent channels coarse‐grained bed sediment plugging near entrances, our study case is characterized absence plug bars bank slumps instead. Consequently, results support earlier suggestions seldom disconnect from due frequent overbank events confluences, can keep flushing away fine‐grained, cohesive sediments, especially mudflat systems.

Language: Английский

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Actionable Science for Small Island Communities: Wind Velocity and Sea‐Level Rise Enhance Tidal Flooding on Little Cumberland Island, Georgia

Community Science, Journal Year: 2025, Volume and Issue: 4(2)

Published: April 3, 2025

Abstract Small island communities are among the first and hardest impacted by sea‐level rise, though climate initiatives often focus on more heavily populated economically productive coastal cities. Furthermore, most climate‐impact studies regional scales that may be less applicable to small islands with locally unique morphodynamics. Little Cumberland Island, Georgia, located in southeastern USA, is one example of an often‐overlooked community. The minimally developed; a single dock dirt roads connect ∼40 homes. Residents report tidal flooding low‐elevation has increased frequency magnitude over remembered history primary concern for longevity infrastructure. However, without site‐specific predictions, they unsure how or when develop roads. Through community science, this study (a) quantified impact wind velocity flooding, (b) predicted future due (c) provided actionable results advice residents. Superimposing rise onto observed elevations suggests high‐tide flood events which inundate at least 15 cm nearly double 2030 triple 2040. We advise residents flood‐resilient elevated within next decade. This community‐driven project involved local knowledge, collective action, social learning external internal expertise, communal agreement governance resilient development would benefit from alignment conservation values extended period time.

Language: Английский

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Quantifying Mangrove Forest Attributes Using Terrestrial Laser Scanning

Estuaries and Coasts, Journal Year: 2025, Volume and Issue: 48(4)

Published: April 30, 2025

Abstract Mangroves are increasingly recognised for their ecosystem services, including capacity to store carbon and adapt climate pressures by stabilising shorelines acting as storm barriers. To quantify these relevant parameters such mangrove biomass drag coefficients have been calculated using allometric equations fitted field measurements of physical attributes. However, previous research attributes has involved time-consuming hand long processing times associated with terrestrial laser scanning (TLS). more efficiently capture process attributes, the density, diameter, height, projected area stems roots, a novel method collecting data TLS was developed. Recorded were compared conducted in 12 Avicennia marina forests across 10 estuaries 4 unique estuary typologies. The results demonstrated reliable estimation revealed link between estuarine geomorphology. Mangrove accurately identified all typologies, attribute estimations accurate Drowned River Valleys (DRVs). A sensitivity analysis that 10–20 trees DRVs 35–45 barrier require point cloud characterise forest 400–1300 m 2 achieve convergent stem diameter tree height results. presented herein offers an efficient way aboveground root surface trees. This can be used worldwide provide fundamental quantifying services.

Language: Английский

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Depositional control on composition, texture and diagenesis of modern carbonate sediments: A comparative study of tidal channels and marshes, Abu Dhabi, United Arab Emirates

Sedimentary Geology, Journal Year: 2024, Volume and Issue: 472, P. 106744 - 106744

Published: Aug. 31, 2024

Language: Английский

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Mangrove ecosystem properties regulate high water levels in a river delta

Published: May 22, 2023

Abstract. Intertidal wetlands, such as mangroves in the tropics, are increasingly recognized for their role nature-based mitigation of coastal flood risks. Yet it is still poorly understood how effective they attenuating propagation extreme sea levels through large (order 100 km2) estuarine or deltaic systems, with complex geometry formed by networks branching channels intertwined mangrove and intertidal flat areas. Here, we present a delta-scale hydrodynamic modelling study, aiming to explicitly account these landforms, case Guayas delta (Ecuador), largest system at Pacific coast Latin America. Despite coping data scarcity, our model accurately reproduces observed high water during spring tide. Further, based on sensitivity analysis, show that most sensitive platform elevation degree channelization, but much lesser extent vegetation-induced friction. Mangroves lower surface elevation, vegetation density higher channelization all favour more efficient flooding therefore effectively attenuate channels. Our findings indicate vast areas channelized forests, rather than densely vegetated risk river delta.

Language: Английский

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