Intense Storms Increase the Stability of Tidal Bays

Castagno, Katherine A.; Jiménez-Robles, A. M.; Donnelly, Jeffrey P.; Wiberg, Patricia L.; Fenster, Michael S.; Fagherazzi, Sergio

doi:10.1029/2018gl078208

Cited by 51 publications

(44 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our model shows how greater waves cause more erosion; however, this trend is not followed by the 0.7 m wave height, as it mainly causes deposition enriching in the marsh (Figure 7). Treating wave heights equal to 0.7 m as a storm-level [15], our results are in agreement with Castagno et al (2018) [48] who demonstrated, using Delft3D, that extreme events are likely to enrich coastal wetlands with more sediments.…”

Section: Discussionsupporting

confidence: 91%

The Impact of Submerged Breakwaters on Sediment Distribution along Marsh Boundaries

Vona

Gray

Nardin

2020

Water

View full text Add to dashboard Cite

Human encroachment and development on coastlines have led to greater amounts of armoring of shorelines. Breakwaters are a common feature along coastlines, which are used to dampen wave energy and protect shorelines from flash floods or overwash events. Although common, their effects on sediment transport and marsh geomorphology are poorly understood. To address this gap, our study quantifies the effects of breakwaters on sediment transport and marsh evolution under different wave regimes using Delft3D-SWAN, a dynamic geomorphodynamic numerical model. Model configurations used the same numerical domain, but scenarios had different sediments, waves, tides, basin slopes and breakwater distances from the shoreline to explore how waves and tidal currents shape coastal margins. Model results suggested breakwaters were responsible for an average wave damping between 10–50%, proportional to the significant wave height across all modeled scenarios. Shear stress at the beginning of the marsh and the volume of sediment deposited at the end of the simulation (into the marsh behind the breakwater) increased on average between 20–40%, proportional to the slope and distance of the breakwater from the shoreline. Sediment trapping, defined as the ratio between the volume of sediment housed into the salt marsh behind and away from the breakwater, was found to be less than 1 from most model runs. Study results indicated that breakwaters are advantageous for wave breaking to protect shorelines from the wave’s energy, however, they might also be an obstacle for sediment transport, negatively affecting nourishment processes, and, consequently, impeded long-term salt marsh survival. Identifying a balance between waves dampening and shoreline nourishment should be considered in the design and implementation of these structures.

show abstract

Section: Discussionsupporting

confidence: 91%

The Impact of Submerged Breakwaters on Sediment Distribution along Marsh Boundaries

Vona

Gray

Nardin

2020

Water

View full text Add to dashboard Cite

show abstract

“…Despite this hypothesis, high marshes/scrub‐shrubs in both Youngs and Coquille, which experience RSLR rates of 0.3 ± 1.1 and −1.4 ± 0.9 mm yr −1 , respectively, are accreting apparently as a result of high annual average suspended sediment loads relative to estuary area. One possible explanation for continued sediment accumulation under these RSLR conditions, which requires further investigation along the Oregon coast, is that storms and other episodic, high‐water events (e.g., exceptionally high tides) may play an important role in controlling long‐term accretion, as others have observed (e.g., Cahoon, ; Castagno et al, ; Goodbred & Hine, ; Reed, ; Turner et al, ; Tweel & Turner, ) and as some are incorporating into morphodynamic models (Schuerch et al, ). Models of tidal wetland morphodynamics thus require better integration with data collected from field observations and experiments, especially in locations that have high capacity to expand our limits of understanding (Wiberg et al, ), such as those that exhibit relative sea level fall and highly episodic sediment fluxes.…”

Section: Discussionmentioning

confidence: 97%

Controls on Sediment Accretion and Blue Carbon Burial in Tidal Saline Wetlands: Insights From the Oregon Coast, USA

2020

View full text Add to dashboard Cite

Oregon estuaries provide important opportunities to assess controls on tidal saline wetland carbon burial and sediment accretion as both rates of relative sea level rise (RSLR; −1.4 ± 0.9 to 2.8 ± 0.8 mm yr−1) and fluvial suspended sediment load relative to estuary area (0.23 to 17 × 103 t km−2 yr−1) vary along the coast. We hypothesized that vertical accretion, measured using excess 210Pb in least‐disturbed wetlands within seven Oregon estuaries, would vary with either RSLR or sediment load relative to estuary area, and carbon burial would correlate strongly to sediment accretion. Mean rates of high marsh accretion (0.8 ± 0.2 to 4.1 ± 0.2 mm yr−1) indicate that Oregon tidal wetlands have mainly kept pace with twentieth‐century RSLR with the exception that the accretionary balance in the central coast is negative, suggesting drowning. Experiencing the fastest rates of RSLR, central‐coast estuaries may foreshadow the fates of other Oregon estuaries under future accelerated sea level rise. Comparison of mass accumulation rates with sediment loads, however, indicates low trapping efficiency and therefore no fluvial sediment limitation. Thus, nonlinear feedback between RSLR and sediment accretion may enhance wetland resistance to drowning. Among wetlands keeping pace with or exceeding RSLR, sediment accretion displays no significant relationship with elevation but rather appears controlled by both the rate of RSLR and relative sediment load, highlighting the importance of incorporating both factors into future studies of tidal saline wetlands. Carbon burial rates, controlled by sediment accretion, will likely increase with future accelerated sea level rise.

show abstract

“…Several studies have already demonstrated the ability of these natural solutions to efficiently attenuate storm surge, wave energy, and current velocities (Costanza et al, 2008;Garzon et al, 2019;Glass et al, 2017;Maza et al, 2015;Mendez & Losada, 2004;Möller et al, 2014;Möller & Spencer, 2002;Nepf, 2004;Resio & Westerink, 2008). Furthermore, these ecosystems continuously provide (not only during storm events) many cobenefits in addition to wave protection services, including water quality improvements, sediment budget, carbon sequestration and storage, fishery habitat, and opportunities for tourism, recreation, education, and research (Barbier et al, 2011;Castagno et al, 2018;Donatelli et al, 2018;Sutton-Grier et al, 2015). Another highly important coastal protection service of these ecosystems is the capacity of accreting vertically and maintaining shallow water depths under certain sea level rise rates (D'Alpaos et al, 2011;Kirwan et al, 2010;Temmerman et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Wave Attenuation by Spartina Saltmarshes in the Chesapeake Bay Under Storm Surge Conditions

et al. 2019

View full text Add to dashboard Cite

This study investigates the capacity of a Spartina alterniflora meadow to attenuate waves during storm events based on field observations in the Chesapeake Bay. These observations reveal that environmental conditions including the ratio between water depth and plant height (hr), the ratio between wave height (HS) and water depth, and current directions impact the wave height decay. Further, we present empirical representations of the bulk drag coefficient (Cd) as a function of the Keulegan‐Carpenter (KC) and Reynolds (Re) numbers, and the hr ratio. When applying the distinction between current directions, this representation exhibits better agreement when using the Re (ρ2 = 54%) and hr (ρ2 = 77%) than with the KC (ρ2 = 39%). Furthermore, we show that the representation of Cd can be improved by using a hr‐based modified Re and KC formulation, yielding correlations of 76% (modified Re) and 78% (modified KC). The proposed expressions are validated during another storm and predicted HS computed within the marsh results in a root‐mean‐square error of 0.014 m, overestimating the largest HS (0.22 m) by 18%. Finally, these expressions are applied to several hypothetical sea conditions. Under similar vegetation characteristics, HS of 1.55 and 0.8 m (close to a 10,000‐ and 100‐year recurrence interval storm) are attenuated by 50% and 70%, respectively, at 250 m from the marsh edge. This study provides evidence that validates the saltmarsh wave attenuation capacity during storms, quantifies this attenuation, and supports the transferability of the existing formulas in the literature across similar coastal marshes.

show abstract

Intense Storms Increase the Stability of Tidal Bays

Cited by 51 publications

References 50 publications

The Impact of Submerged Breakwaters on Sediment Distribution along Marsh Boundaries

The Impact of Submerged Breakwaters on Sediment Distribution along Marsh Boundaries

Controls on Sediment Accretion and Blue Carbon Burial in Tidal Saline Wetlands: Insights From the Oregon Coast, USA

Wave Attenuation by Spartina Saltmarshes in the Chesapeake Bay Under Storm Surge Conditions

Contact Info

Product

Resources

About