Coupling of Sea Level Rise, Tidal Amplification, and Inundation

Abstract With the global sea level rising, it is imperative to quantify how the dynamics of tidal estuaries and embayments will respond to increased depth and newly inundated perimeter regions. With increased depth comes a decrease in frictional effects in the basin interior and altered tidal amplification. Inundation due to higher sea level also causes an increase in planform area, tidal prism, and frictional effects in the newly inundated areas. To investigate the coupling between ocean forcing, tidal dynamics, and inundation, the authors employ a high-resolution hydrodynamic model of San Francisco Bay, California, comprising two basins with distinct tidal characteristics. Multiple shoreline scenarios are simulated, ranging from a leveed scenario, in which tidal flows are limited to present-day shorelines, to a simulation in which all topography is allowed to flood. Simulating increased mean sea level, while preserving original shorelines, produces additional tidal amplification. However, flooding of adjacent low-lying areas introduces frictional, intertidal regions that serve as energy sinks for the incident tidal wave. Net tidal amplification in most areas is predicted to be lower in the sea level rise scenarios. Tidal dynamics show a shift to a more progressive wave, dissipative environment with perimeter sloughs becoming major energy sinks. The standing wave southern reach of the bay couples more strongly back to the central portion of the bay, in contrast to the progressive wave northern reach of the bay. Generation of the M4 overtide is also found to vary between scenarios and is a nonnegligible contributor to net changes in high water elevation.

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IMPACT OF SEA LEVEL RISE ON HYDRODYNAMICS OF ESTUARIES WITH RESTRICTED ENTRANCES

Coastal Engineering Proceedings ◽

10.9753/icce.v36v.management.3 ◽

2020 ◽

pp. 3

Author(s):

Danial Khojasteh ◽

Steve Hottinger ◽

Stefan Felder ◽

Giovanni De Cesare ◽

Valentin Heimhuber ◽

...

Keyword(s):

Sea Level Rise ◽

Case Studies ◽

Sea Level ◽

Potential Solution ◽

Tidal Dynamics ◽

Large Ensemble ◽

Clustering Techniques ◽

Tidal Forcing ◽

Tidal Amplification ◽

Static Models

Worldwide, hundreds of millions of people who live on or near estuarine environments are vulnerable to sea level rise (SLR). Using clustering techniques and moving beyond static models and case studies, this study used a large ensemble of idealised estuary models of varying scale, geometry, level of entrance constriction, and SLR scenarios. It was found that tidal forcing, degree of entrance restriction, and estuarine length can primarily control the tidal dynamics of prismatic estuaries under SLR. Further, restricting an entrance can be presented as a potential solution to offset SLR induced tidal amplification if the associated impacts on entrance stability, navigation, and flooding are considered.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/vOptOAbqN3U

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Adapting to sea level rise: Emerging governance issues in the San Francisco Bay Region

10.31230/osf.io/mjkcu ◽

2018 ◽

Author(s):

Pedro J. Pinto ◽

G. Mathias Kondolf ◽

Pun Lok Raymond Wong

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

San Francisco ◽

Urban Areas ◽

Path Dependence ◽

Large Scale ◽

San Francisco Bay ◽

Metropolitan Region ◽

Environmental Benefit ◽

Formidable Challenge

San Francisco Bay, the largest estuary on the Pacific Coast of North America, is heavily encroached by a metropolitan region with over 7 million inhabitants. Urban development and infrastructure, much of which built over landfill and at the cost of former baylands, were placed at very low elevations. Sea-level rise (SLR) poses a formidable challenge to these highly exposed urban areas and already stressed natural systems. “Green”, or ecosystem-based, adaptation is already on the way around the Bay. Large scale wetland restoration projects have already been concluded, and further action now often requires articulation with the reinforcement of flood defense structures, given the level of urban encroachment. While levee setback, or removal, would provide greater environmental benefit, the need to protect urban areas and infrastructure has led to the trial of ingenious solutions for promoting wetland resilience while upgrading the level of protection granted by levees.We analyzed the Bay’s environmental governance and planning structure, through direct observation, interviews with stakeholders, and study of planning documents and projects. We present two cases where actual implementation of SLR adaptation has led, or may lead to, the need to revise standards & practices or to make uneasy choices between conflicting public interests.Among the region’s stakeholders, there is an increasing awareness of the risks related to SLR, but the institutional arrangements are complex, and communication between the different public agencies/departments is not always as streamlined as it could be. Some agencies and departments need to adapt their procedures in order to remove institutional barriers to adaptation, but path dependence is an obstacle. There is evidence that more frank and regular communication between public actors is needed. It also emphasizes the benefits of a coordination of efforts and strategies, something that was eroded in the transition from government-led policies to a new paradigm of local-based adaptive governance.

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A newly reconciled data set for identifying sea level rise and variability in Dublin Bay

10.5194/os-2021-92 ◽

2021 ◽

Author(s):

Amin Shoari Nejad ◽

Andrew C. Parnell ◽

Alice Greene ◽

Peter Thorne ◽

Brian P. Kelleher ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Tide Gauge ◽

High Water ◽

Data Set ◽

Quality Checks ◽

Bayesian Linear Regression ◽

The Mean ◽

Water Values ◽

Water Level Measurements

Abstract. We provide an updated sea level dataset for Dublin for the period 1938 to 2016 at yearly resolution. Using a newly collated sea level record for Dublin Port, as well as two nearby tide gauges at Arklow and Howth Harbour, we perform data quality checks and calibration of the Dublin Port record by adjusting the biased high water level measurements that affect the overall calculation of mean sea level (MSL). To correct these MSL values, we use a novel Bayesian linear regression that includes the Mean Low Water values as a predictor in the model. We validate the re-created MSL dataset and show its consistency with other nearby tide gauge datasets. Using our new corrected dataset, we estimate a rate of 1.08 mm/yr sea level rise at Dublin Port between 1953–2016 (95 % CI from 0.62 to 1.55 mm/yr), and a rate of 6.48 mm/yr between 1997–2016 (95 % CI 4.22 to 8.80 mm/yr). Overall sea level rise is in line with expected trends but large multidecadal varaibility has led to higher rates of rise in recent years.

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Changes in Liquefaction Severity in the San Francisco Bay Area with Sea-Level Rise

10.1061/9780784483695.030 ◽

2021 ◽

Author(s):

Alex R. R. Grant ◽

Anne M. Wein ◽

Kevin M. Befus ◽

Juliette Finzi Hart ◽

Mike T. Frame ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

San Francisco ◽

San Francisco Bay ◽

San Francisco Bay Area ◽

Bay Area

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Mudflat Morphodynamics and the Impact of Sea Level Rise in South San Francisco Bay

Estuaries and Coasts ◽

10.1007/s12237-016-0129-6 ◽

2016 ◽

Vol 40 (1) ◽

pp. 37-49 ◽

Cited By ~ 21

Author(s):

Mick van der Wegen ◽

Bruce Jaffe ◽

Amy Foxgrover ◽

Dano Roelvink

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

San Francisco ◽

San Francisco Bay ◽

The Impact

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The impact of sea-level rise on tidal characteristics around Australia

Ocean Science ◽

10.5194/os-15-147-2019 ◽

2019 ◽

Vol 15 (1) ◽

pp. 147-159 ◽

Cited By ~ 4

Author(s):

Alexander Harker ◽

J. A. Mattias Green ◽

Michael Schindelegger ◽

Sophie-Berenice Wilmes

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Open Boundary ◽

Open Boundary Conditions ◽

Tidal Dissipation ◽

North West ◽

The North ◽

Tidal Changes ◽

Tidal Characteristics ◽

The Impact

Abstract. An established tidal model, validated for present-day conditions, is used to investigate the effect of large levels of sea-level rise (SLR) on tidal characteristics around Australasia. SLR is implemented through a uniform depth increase across the model domain, with a comparison between the implementation of coastal defences or allowing low-lying land to flood. The complex spatial response of the semi-diurnal M2 constituent does not appear to be linear with the imposed SLR. The most predominant features of this response are the generation of new amphidromic systems within the Gulf of Carpentaria and large-amplitude changes in the Arafura Sea, to the north of Australia, and within embayments along Australia's north-west coast. Dissipation from M2 notably decreases along north-west Australia but is enhanced around New Zealand and the island chains to the north. The diurnal constituent, K1, is found to decrease in amplitude in the Gulf of Carpentaria when flooding is allowed. Coastal flooding has a profound impact on the response of tidal amplitudes to SLR by creating local regions of increased tidal dissipation and altering the coastal topography. Our results also highlight the necessity for regional models to use correct open boundary conditions reflecting the global tidal changes in response to SLR.

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WITHDRAWN: Sea level rise and estuarine tidal dynamics: A review

Earth-Science Reviews ◽

10.1016/j.earscirev.2020.103166 ◽

2020 ◽

pp. 103166 ◽

Cited By ~ 1

Author(s):

Danial Khojasteh ◽

William Glamore ◽

Valentin Heimhuber ◽

Stefan Felder

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Tidal Dynamics

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The significance of coastal bathymetry representation for modelling the tidal response to mean sea level rise in the German Bight

Ocean Science ◽

10.5194/os-16-31-2020 ◽

2020 ◽

Vol 16 (1) ◽

pp. 31-44 ◽

Cited By ~ 2

Author(s):

Caroline Rasquin ◽

Rita Seiffert ◽

Benno Wachler ◽

Norbert Winkel

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

North Sea ◽

German Bight ◽

Coastal Areas ◽

Tidal Dynamics ◽

Mean Sea Level ◽

The North ◽

The North Sea ◽

The Impact

Abstract. Due to climate change an accelerated mean sea level rise is expected. One key question for the development of adaptation measures is how mean sea level rise affects tidal dynamics in shelf seas such as the North Sea. Owing to its low-lying coastal areas, the German Bight (located in the southeast of the North Sea) will be especially affected. Numerical hydrodynamic models help to understand how mean sea level rise changes tidal dynamics. Models cannot adequately represent all processes in overall detail. One limiting factor is the resolution of the model grid. In this study we investigate which role the representation of the coastal bathymetry plays when analysing the response of tidal dynamics to mean sea level rise. Using a shelf model including the whole North Sea and a high-resolution hydrodynamic model of the German Bight we investigate the changes in M2 amplitude due to a mean sea level rise of 0.8 and 10 m. The shelf model and the German Bight Model react in different ways. In the simulations with a mean sea level rise of 0.8 m the M2 amplitude in the shelf model generally increases in the region of the German Bight. In contrast, the M2 amplitude in the German Bight Model increases only in some coastal areas and decreases in the northern part of the German Bight. In the simulations with a mean sea level rise of 10 m the M2 amplitude increases in both models with largely similar spatial patterns. In two case studies we adjust the German Bight Model in order to more closely resemble the shelf model. We find that a different resolution of the bathymetry results in different energy dissipation changes in response to mean sea level rise. Our results show that the resolution of the bathymetry especially in flat intertidal areas plays a crucial role for modelling the impact of mean sea level rise.

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Transgressivity in Key Functional Traits Rather Than Phenotypic Plasticity Promotes Stress Tolerance in A Hybrid Cordgrass

Plants ◽

10.3390/plants8120594 ◽

2019 ◽

Vol 8 (12) ◽

pp. 594

Author(s):

Blanca Gallego-Tévar ◽

Brenda J. Grewell ◽

Rebecca E. Drenovsky ◽

Jesús M. Castillo

Keyword(s):

Phenotypic Plasticity ◽

Sea Level Rise ◽

Stress Tolerance ◽

Sea Level ◽

San Francisco ◽

Functional Traits ◽

Salt Marshes ◽

Parental Species ◽

Expression Patterns ◽

Phenotypic Expression

Hybridization might promote offspring fitness via a greater tolerance to environmental stressors due to heterosis and higher levels of phenotypic plasticity. Thus, analyzing the phenotypic expression of hybrids provides an opportunity to elucidate further plant responses to environmental stress. In the case of coastal salt marshes, sea level rise subjects hybrids, and their parents, to longer tidal submergence and higher salinity. We analyzed the phenotypic expression patterns in the hybrid Spartina densiflora x foliosa relative to its parental species, native S. foliosa, and invasive S. densiflora, from the San Francisco Estuary when exposed to contrasting salinities and inundations in a mesocosm experiment. 37% of the recorded traits displayed no variability among parents and hybrids, 3% showed an additive inheritance, 37% showed mid-parent heterosis, 18% showed best-parent heterosis, and 5% presented worst-parent heterosis. Transgressivity, rather than phenotypic plasticity, in key functional traits of the hybrid, such as tiller height, conveyed greater stress tolerance to the hybrid when compared to the tolerance of its parents. As parental trait variability increased, phenotypic transgressivity of the hybrid increased and it was more important in response to inundation than salinity. Increases in salinity and inundation associated with sea level rise will amplify the superiority of the hybrid over its parental species. These results provide evidence of transgressive traits as an underlying source of adaptive variation that can facilitate plant invasions. The adaptive evolutionary process of hybridization is thought to support an increased invasiveness of plant species and their rapid evolution.

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