The Coast2Coast zoominar series started during the May 2020 covid lockdown as a way of facilitating networking and interactions between researchers in a year when conferences and travelling were not going to happen. The Coast2Coast has quickly grown to become a prestigious seminar series with presenters from many parts of the world.
Giovanni Coco (University of Auckland), Kristen Splinter and Mitch Harley (University of New South Wales), Ana Vila-Concejo (University of Sydney), and Ryan Lowe (University of Western Australia) are the hosts of Coast2Coast... at least for now!
Life on the Reef - examining the interactions
this presentation investigates the fascinating interaction between tidal fluctuations and wave characteristics on the lagoon hydrodynamics. The analysis was based on several months of intense hydrodynamic field data collection including bathy-topo surveys, current metering, wave and water level gauging.
BEACH DUNE SUBSURFACE HYDRODYNAMIS AND THE FORMATION OF DUNE SCARPS
We carried out a 1:2.5 scale beach dune erosion experiment to study the subsurface hydrodynamics involved in scarp formation. Measurements of the subsurface hydrodynamics and external forcing of the prototype dune were collected in the NSF NHERI O.H. Hinsdale Wave Research Laboratory Large Wave Flume at Oregon State University.
Global wave climate frameworks for the near and far future
We discuss global wave climate types and how they are driven by the pressure and planetary wind systems. We will analyse the signals of natural variability and global warming on these wave climates over the last 35 years. In addition, we will discuss how these wave climates are interconnected across the oceans. Finally, we will evaluate changes of these wave climates for the next century, under the climate change scenario RCP 8.5.
Controls on the geomorphic response of beach-dune systems to water level rise
This presentation offers a synthesis of the disparate evidence on the importance of the magnitude and duration of water level rise in both lacustrine and marine environments in relation to other long term controls on the coastal response (e.g., wind climatology, vegetation growth, geological context).
Things that make you go “hmmm...” Testing geological concepts using numerical hydrodynamic process models
The purpose of this presentation is to start a discussion regarding two conceptual paradigms prominent in sedimentary geology: 1) that unfilled atoll lagoons represent a transient state, destined to be filled by debris from their annular reef, and 2) that “fair-weather wave base” and “storm wave base” represent consistent, objectively definable datums for facies and stratigraphic interpretation. Simple numerical hydrodynamic simulation models reveal several insights that cast doubt on the plausibility of these paradigms, in stark contrast with their widespread application in stratigraphic interpretations.
The science of returning freshwater to estuaries
In this talk, I will discuss estuarine restoration attempts by returning freshwater inflows, with a focus on the current Aotearoa New Zealand example of Te Awa o Ngātoroirangi (the Maketū Estuary). Here, the major freshwater source (the Kaituna River) has been partially returned to the estuary over the past year, after being diverted out in 1956.
***Please note we were zoombombed so there is an interruption about 12.5 minutes into the video***
Predicting future coastal behaviour: can we do it?
In this talk Dano Roelvink will take you through principles of modelling coastal hydrodynamics and morphology, highlight some new model developments and then will discuss what we can and cannot do when asked to provide predictions of coastal behaviour in 2100.
Wave runup, forecasting, and enhanced observations with a drone-mounted LiDAR.
Extreme runup estimates may be improved, relative to predictions from general empirical formulae with default parameter values, by using historical storm waves and eroded profiles in numerical runup simulations. For use in a local flood warning system, the relationship between incident wave energy spectra E(f) and SWASH-modeled shoreline water levels is approximated with the numerically simple integrated power law approximation (IPA), wherein broad and multi-peaked E(f) are accommodated by characterizing wave forcing with frequency-weighted integrals of E(f). Work to integrate uncertainties and improve and expand the flood warning system is ongoing.
Initiation of Coastal Transgressive Sand Sheets and Dunefields Transgressive aeolian sand sheets and dunefields are coastal aeolian sand deposits formed by the downwind or across- and/or alongshore movement of sand over landward terrain. Transgressive aeolian sand sheets may be flat to undulating with minimal dunes, or slipface-less dunes on the surface, whilst transgressive dunefields are characterised by various types of dunes (e.g. barchans, barchanoid and transverse dunes). This talk will examine and critique the known triggers or initiation mechanisms of transgressive sand sheets and dunefields, and explore very recent evidence of the formation of new ones on the SE South Australian coast.
Numerical simulations of along-slope, down-slope, and cross-shelf flows on passive margins
The hydrodynamic and sedimentary processes that operate on submerged passive continental margins are often difficult to study due to their remoteness and the sparse data coverage associated with these regions. Numerical simulations provide a powerful experimental framework to investigate such physical processes. This talk will cover “three short stories” of a variety of numerical models used to provide process-based insights into the regional-scale hydrodynamic and sedimentary consequences of margin flows.
Combining a stochastic climate emulator with surrogate models of dynamic coastal simulators to drive coastal hazards impacts research
This talk will primarily focus on an application of efficient hybrid statistical-dynamical framework to probabilistically explore coastal flood impacts along both the oceanside and bayside of San Diego, CA.
Dr Mitch Harley from the Water Research Laboratory at the University of New South Wales in Australia will tell us about CoastSnap App, the new citizen science App to monitor your local beach using your mobile. Make sure you download it and start using it before the zoominar so you can ask Mitch directly all your questions!
Building new land to hold the line on sea-level rise: the interactions between mangroves, bed properties and hydrodynamics
Despite expanding invasively locally, mangroves are declining worldwide, substantially depleting one of the world’s most effective carbon-burial ecosystems. Mangroves spread seaward by establishing seedlings and roots, which alter the hydrodynamics and ultimately change the way in which sediment is deposited and morphology changes. This talk will summarise our recent work on mangroves and their role in building intertidal land.
Wave transformation through reef surf zones
This presentation will summarise recent research designed to elucidate how incident wind-wave energy is transformed across reefs, becomes converted to other energy forms via nonlinear energy transfers, and ultimately is dissipated by a combination of wave breaking and bottom friction. An overview of recent results from field, laboratory and numerical modelling studies will be presented, with a particular focus on the dynamics of the energetic surf zone region where plunging wave breaking occurs.
Multiple intertidal bars on beaches
To date, a detailed understanding of the formation of MITB has remained elusive and their precise definition is still unclear. It has been suggested that MITB features are the result of both swash and surf zone processes acting on the intertidal beach profile. These processes are involved in the formation, the long-term persistence, and behaviour of MITB.
The Search for Australia's Next Top Coastal Flood Zone
In this talk Ben will discuss how his work on defining impact-based thresholds for coastal inundation has progressed research on some of these questions, with a focus on Sydney, New South Wales, including: - How can we define impact-based metrics for coastal flood monitoring? - How frequently does coastal flooding occur around Australia? - How is sea level rise affecting coastal flooding? - When will frequent flooding (e.g. weekly, daily) occur under various sea level rise scenarios?
Mapping the shoreface: geomorphology, sediments, the active zone and system feedback. Which will control future coastal change, and when?
- What do seabed geomorphology and sediment distributions tell us about sediment budgets and shoreline behaviour?
- Identifying the shoreface ‘active zone’ and ‘morphodynamic state’ – response timescales and feedback processes
- Which aspects of the coupled beach-shoreface system will influence future shoreline response to sea-level rise?
Subaerial and subtidal sand exchange at a swell dominated beach on seasonal and interannual scales
Assessment of risk reduction measures to minimise the impacts of storms at sandy shores
Coastal storms often cause damages and losses in occupied areas. This presentation focus on the assessment, trough modelling and field validation, of disaster risk reduction measures at sandy shores. The proposed methodology is adaptable to any coastal region and can be used to test (and improve) management options at a broad number of coastal areas, helping to optimise implementation costs while reducing the risk to the occupation and people.
Simulation of volume change in the backshore at Hasaki, Japan
A one-dimensional model is developed and applied to the Hasaki Coast in Japan to predict changes in backshore volume. The model is calibrated and validated using beach profile data obtained weekly at the Hasaki Coast over a 28-year period from 1987 to 2014. The validation suggests that the model can reasonably reproduce the cumulative volume change, but it underestimates the time-varying fluctuations of the weekly averaged volume change rate.
Can transport from the lower shoreface save beaches from SLR?