Effects of Vegetation, Sediment Supply and Sea Level Rise on the Morphodynamic Evolution of Tidal Channels

Sgarabotto, Alessandro; D’Alpaos, Andrea; Lanzoni, Stefano

doi:10.1029/2020wr028577

Cited by 14 publications

(9 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, the Venice channels investigated here are definitely narrower than synthetic channels recently reproduced in Sgarabotto et al. (2021), where mean channel width reaches 20 m in a basin 100 times larger than that here considered. In the case of WI, simulated channels are generally wider and have a smaller spacing as compared to channels observed in the field.…”

Section: Model Testingcontrasting

confidence: 51%

“…In our simulations, we do not account for the effects of fluvial water discharge. The corresponding sediment input would increase sediment availability, thus favoring vertical accretion and horizontal progradation of salt marshes and, hence, their resilience to sea‐level rise (Alizad et al., 2018; D'Alpaos et al., 2011; Sgarabotto et al., 2021). In addition, the present model investigates channel and salt‐marsh initiation under constant rates of RSLR.…”

Section: Model Testingmentioning

confidence: 99%

“…Only a few studies simulate the intertwined eco‐morphodynamic evolution of salt marshes and tidal channels cutting through them (Belliard et al., 2015; D'Alpaos et al., 2007; Mariotti, 2018; Sgarabotto et al., 2021; Temmerman et al., 2007), accounting for the mutual interactions among these morphological units. These interactions are strongly influenced by the different flow resistance and erosion/deposition rates which characterize various morphological units composing an intertidal system.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Intertwined Eco‐Morphodynamic Evolution of Salt Marshes and Emerging Tidal Channel Networks

Geng

D’Alpaos

Sgarabotto

et al. 2021

Water Resources Research

Self Cite

View full text Add to dashboard Cite

Tidal flats and salt marshes connect the land and the ocean by mediating the exchange of water, sediments, and nutrients within coastal landscapes (FitzGerald & Hughes, 2019;Mitsch & Gosselink, 2000;Zedler & Kercher, 2005). Salt marshes are typically covered by halophytic vegetation. They occupy elevations higher than mean sea level (MSL) and are periodically inundated by the tide (Allen, 2000;Friedrichs & Perry, 2001). Conversely, tidal flats lie below mean sea level and hence, are intermittently exposed during low tides (Zhou et al., 2016). They do not host halophytic vegetation, but can be covered by microbial biofilms or colonized by sea grasses, which contribute to stabilize the sediment bed (Chen et al., 2017;Yallop et al., 1994).Depending on the rate of relative sea level rise (RSLR) and sediment availability, tidal flats can evolve into salt marshes and vice versa (Fagherazzi et al., 2006;Marani et al., 2007;Zhou et al., 2016). As the elevation of the intertidal platform increases within the tidal frame, flow conditions become suitable for the settlement of vegetation seeds. The bare surface of tidal flats is thus progressively encroached by vegetation patches, and eventually a salt marsh forms, as a result of the interaction of physical and biological processes (Bouma et al., 2014;Hu et al., 2015). On the contrary, a salt marsh can experience a transition into a tidal

show abstract

Section: Model Testingcontrasting

confidence: 51%

Section: Model Testingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Intertwined Eco‐Morphodynamic Evolution of Salt Marshes and Emerging Tidal Channel Networks

Geng

D’Alpaos

Sgarabotto

et al. 2021

Water Resources Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…Halophytic vegetation has a stabilizing effect on channel banks (Y. Chen et al., 2019). This effect, coupled with the competing feedbacks produced by vegetation encroachment on salt marsh surfaces (Sgarabotto et al., 2021), leads to small width‐to‐depth ratios. Moreover, the lateral migration rate can be reduced by several orders of magnitude as compared to unvegetated mudflats (Finotello et al., 2018; Gabet, 1998).…”

Section: Feedbacks Between Bank Retreat and Morphodynamicsmentioning

confidence: 99%

A Review on Bank Retreat: Mechanisms, Observations, and Modeling

Zhao

Coco

Gong

et al. 2022

Reviews of Geophysics

Self Cite

View full text Add to dashboard Cite

Bank retreat plays a fundamental role in fluvial and estuarine dynamics. It affects the cross‐sectional evolution of channels, provides a source of sediment, and modulates the diversity of habitats. Understanding and predicting the geomorphological response of fluvial/tidal channels to external driving forces underpins the robust management of water courses and the protection of wetlands. Here, we review bank retreat with respect to mechanisms, observations, and modeling, covering both rivers and (previously neglected) tidal channels. Our review encompasses both experimental and in situ observations of failure mechanisms and bank retreat rates, modeling approaches and numerical methods to simulate bank erosion. We identify that external forces, despite their distinct characteristics, may have similar effects on bank stability in both river and tidal channels, leading to the same failure mode. We review existing data and empirical functions for bank retreat rate across a range of spatial and temporal scales, and highlight the necessity to account for both hydraulic and geotechnical controls. Based on time scale considerations, we propose a new hierarchy of modeling styles that accounts for bank retreat, leading to clear recommendations for enhancing existing modeling approaches. Finally, we discuss systematically the feedbacks between bank retreat and morphodynamics, and suggest that to move this agenda forward will require a better understanding of multifactor‐driven bank retreat across a range of temporal scales, with particular attention to the differences (and similarities) between riverine and estuarine environments, and the role of feedbacks exerted by the collapsed bank soil.

show abstract

“…First, fundamental species niches are typically approximated by the realized ones. Therefore, although field studies suggest performances of individual species to increase steadily with elevation in the absence of competition, habitat quality and vegetation performances are typically assumed to peak at an optimum marsh elevation, and to decrease as elevation moves away from such optimum (Morris et al, 2002;Morris, 2006;Morris, 2007;D'Alpaos et al, 2007;Kirwan and Murray, 2007;Kirwan and Guntenspergen, 2010;Fagherazzi et al, 2012;Da Lio et al, 2013;Marani et al, 2013;Kirwan et al, 2016;Geng et al, 2021;Kalra et al, 2021;Sgarabotto et al, 2021). Second, competition in numerical models of marsh vegetation dynamics, with few exceptions (e.g., Marani et al, 2006), does not occur by direct species interaction.…”

Section: Introductionmentioning

confidence: 99%

A Minimalist Model of Salt-Marsh Vegetation Dynamics Driven by Species Competition and Dispersal

et al. 2022

View full text Add to dashboard Cite

We present a new bidimensional, spatially-explicit ecological model describing the dynamics of halophytic vegetation in tidal saline wetlands. Existing vegetation models employ relatively simple deterministic or stochastic mechanisms, and are driven by local environmental conditions. In the proposed model, in contrast, vegetation dynamics depend not only on the marsh local habitat, but also on spatially-explicit mechanisms of dispersal and competition among multiple interacting species. The role of habitat quality, here determined by the local elevation relative to the mean sea level as a proxy for environmental conditions, is mathematically modeled by a logistic function that represents the fundamental (theoretical) niche of each halophytic species. Hence, the model does not artificially impose any constraints to the ability of a species to colonize elevated areas where it is usually not observed: such limitations naturally arise through competition with fitter species across marsh topographic gradients. We qualitatively test our model against field data based on a suitable assemblage of focus species, and perform a sensitivity analysis aimed at determining how dynamic equilibria in vegetation distributions are affected by changes in model input parameters. Results indicate that the model is robust and can predict realistic vegetation distributions and species-richness patterns. More importantly, the model is also able to effectively reproduce the outcomes of classical ecological experiments, wherein a species is transplanted to an area outside its realized niche. A direct comparison shows that previous models not accounting for dispersal and interspecific competitions are unable to reproduce such dynamics. Our model can be easily integrated into virtually any existing morphodynamic model, thereby strengthening our ability to simulate the coupled biotic and abiotic evolution of salt marshes under changing climate forcings.

show abstract

Effects of Vegetation, Sediment Supply and Sea Level Rise on the Morphodynamic Evolution of Tidal Channels

Cited by 14 publications

References 78 publications

Intertwined Eco‐Morphodynamic Evolution of Salt Marshes and Emerging Tidal Channel Networks

Intertwined Eco‐Morphodynamic Evolution of Salt Marshes and Emerging Tidal Channel Networks

A Review on Bank Retreat: Mechanisms, Observations, and Modeling

A Minimalist Model of Salt-Marsh Vegetation Dynamics Driven by Species Competition and Dispersal

Contact Info

Product

Resources

About