scholarly journals INVESTIGATION OF WAVE INDUCED STORM SURGE WITHIN A LARGE COASTAL EMBAYMENT - MORETON BAY (AUSTRALIA)

2011 ◽  
Vol 1 (32) ◽  
pp. 22 ◽  
Author(s):  
Philip Treloar ◽  
David Taylor ◽  
Paul Prenzler
Keyword(s):  
Water Level ◽  
Tropical Cyclones ◽  
Storm Surge ◽  
Wave Model ◽  
Water Levels ◽  
Residual Water ◽  
Storm Tide ◽  
Moreton Bay ◽  
Coastal Embayment ◽  
Set Up

Moreton Bay is a large coastal embayment on the south-east Queensland coast which is surrounded by the urbanised areas of greater Brisbane on its western and southern shorelines. It is protected from the open coast by a number of islands, including South Stradbroke, North Stradbroke and Moreton Islands. Tropical cyclones occasionally track far enough south to cause significant damage to south-east Queensland due to flooding, winds, waves and elevated ocean water levels. Distant tropical cyclones which may be several hundred kilometres north of Moreton Bay have been known to cause storm surge, high waves and erosion inside Moreton Bay. These events generally do not generate gale force winds within Moreton Bay, but can generate large ocean swell waves. It has been identified that the wave conditions generated from distant cyclones can cause a variation in water levels inside Moreton Bay. A detailed study was undertaken to investigate the regional wave set-up process which affects Moreton Bay. The simulation of the residual water levels within Moreton Bay using a coupled hydrodynamic and wave model system developed for this study is considerably more accurate than applying a hydrodynamic model alone and explains water level anomalies that have a tidal frequency. The paper discusses the physical process of regional wave set-up inside a large embayment, analysis of observed residual water level and also the modelling study undertaken to quantify the influence of waves on storm tide levels inside Moreton Bay. The storm tide hazard study for the Moreton Bay Councils included the effects of regional wave set-up in the specification of design water levels.

Uncertainty in coastal flooding: modelling and visualisation

2020 ◽  
Author(s):  
John Maskell
Keyword(s):  
Water Level ◽  
Storm Surge ◽  
Return Period ◽  
Flood Risk ◽  
High Water ◽  
Coastal Flooding ◽  
Water Levels ◽  
Tidal Range ◽  
The Uk ◽  
Flood Maps

<p>Two case studies are considered in the UK, where uncertainty and drivers of coastal flood risk are explored through modelling and visualisations. Visualising the impact of uncertainty is a useful way of explaining the potential range of predicted or simulated flood risk to both expert and non-expert stakeholders.</p><p>Significant flooding occurred in December 2013 and January 2017 at Hornsea on the UK East Coast, where storm surge levels and waves overtopped the town’s coastal defences. Uncertainty in the potential coastal flooding is visualised at Hornsea due to the range of uncertainty in the 100-year return period water level and in the calculated overtopping due to 3 m waves at the defences. The range of uncertainty in the simulated flooding is visualised through flood maps, where various combinations of the uncertainties decrease or increase the simulated inundated area by 58% and 82% respectively.</p><p>Located at the mouth of the Mersey Estuary and facing the Irish Sea, New Brighton is affected by a large tidal range with potential storm surge and large waves. Uncertainty in the coastal flooding at the 100-year return period due to the combination of water levels and waves is explored through Monte-Carlo analysis and hydrodynamic modelling. Visualisation through flood maps shows that the inundation extent at New Brighton varies significantly for combined wave and surge events with a joint probability of 100 years, where the total flooded area ranges from 0 m<sup>2</sup> to 10,300 m<sup>2</sup>. Waves are an important flood mechanism at New Brighton but are dependent on high water levels to impact the coastal defences and reduce the effective freeboard. The combination of waves and high-water levels at this return level not only determine the magnitude of the flood extent but also the spatial characteristics of the risk, whereby flooding of residential properties is dominated by overflow from high water levels, and commercial and leisure properties are affected by large waves that occur when the water level is relatively high at the defences.</p>

scholarly journals MODELING SURGE-DEPENDENT VEGETATION EFFECTS ON HURRICANE-GENERATED WAVES

2012 ◽  
Vol 1 (33) ◽  
pp. 67 ◽  
Author(s):  
Qin Chen ◽  
Haihong Zhao ◽  
Don Liu
Keyword(s):  
Energy Dissipation ◽  
Storm Surge ◽  
Reduction Rate ◽  
Wave Model ◽  
Water Levels ◽  
Marsh Vegetation ◽  
Vegetation Effects ◽  
Vegetation Height ◽  
The Impact ◽  
Surge Height

The study utilizes a coupled wave-surge-vegetation modeling system to quantify the effects of salt marsh vegetation on hurricane-generated waves. The wave model incorporates the energy dissipation model of Chen and Zhao (2012) for random waves over vegetation. The storm surge model incorporates the vegetal drag for both rigid and flexible types of vegetation. The surge and wave models with the vegetation effects are coupled, allowing the spatially and temporally varying vegetation heights, water levels and depth-averaged currents from the storm surge model to be fed into the wave model. Numerical experiments have revealed that vegetation can change the surge height and a storm surge can change the vegetation height. Both control the wave reduction rate in flooded wetlands. The impact of vegetation on hurricane-generated waves consists of indirect and direct effects. The former is caused by the changes in surge height due to vegetation. The latter comes from the direct interaction between vegetation and the oscillatory motion of surface waves. It has been found that flexible marsh vegetation deflects under the hydrodynamic force produced by a hurricane. The deflected height not only reduces the flow resistance in the surge model, but also decreases the energy dissipation caused by vegetation in the wave model. Consequently, neglecting plant flexibility may lead to overestimates of vegetation effects and exaggeration of wetland potential for flood risk reduction.

scholarly journals Wave model verification based on measurements in the Wadden Sea

2016 ◽  
Author(s):  
Cordula Berkenbrink ◽  
Luise Hentze ◽  
Andreas Wurpts
Keyword(s):  
Water Level ◽  
Wadden Sea ◽  
Wave Attenuation ◽  
Calculated Data ◽  
Barrier Islands ◽  
Wave Model ◽  
Water Levels ◽  
Model Verification ◽  
Coastal Protection ◽  
Lower Saxony

Abstract. The design height of coastal protection structures in Lower Saxony / Germany is determined by the design water level and the corresponding wave run up. For the calculation of these parameters several mathematical models are used which need to be verified for the conditions at the East Frisian Wadden Sea area. For this issue a wave measuring programme is operationally run, which includes various measurement locations and devices around the islands Norderney and Juist. The measurements are continuously extended and adapted in order to improve models and measurements. This paper shows a comparison between measured and calculated data for the storm surge of the 10.–11.01.2015 incorporating to new wave and water level gauges operated within COSYNA as well as a second research project dealing with wave attenuation behind barrier islands. Water levels within the investigation area were calculated by hydrodynamic models driven with a wind field originating from weather forecast and compared to water level measurements. The corresponding wave energy field was calculated by means of a third generation wave model and results compared to measurements of several devices located around the barrier Islands. The aim of the study shown here is to give a brief overview of possible error sources for model-data as well as data-data comparisons.

scholarly journals WAVE MODELING WITH SWAN+ADCIRC FOR THE SOUTH CAROLINA COASTAL STORM SURGE STUDY

2012 ◽  
Vol 1 (33) ◽  
pp. 48
Author(s):  
Christopher Bender ◽  
William Miller ◽  
Ashley Naimaster ◽  
Tucker Mahoney
Keyword(s):  
South Carolina ◽  
Water Level ◽  
Storm Surge ◽  
Water Levels ◽  
The South ◽  
Wave Parameters ◽  
Water Level Changes ◽  
Tightly Coupled ◽  
Wave Induced ◽  
Adcirc Model

The South Carolina Surge Study (SCSS) used the tightly coupled SWAN+ADCIRC model to simulate tropical storm surge events. The tightly coupled model allowed calculation of wave-induced water level changes within the storm surge simulations. Inclusion of the wave-induced water level changes represents a more physics-based approach than previous methods that added wave setup after model simulations ended. Development of the SWAN+ADCIRC model included validation of water levels to local tidal forcing and for three historical hurricanes — Hazel (1954), Hugo (1989), and Ophelia (2005). The validation for waves did not include Hurricane Hazel because measured data was unavailable. Additional comparisons with WAM model results provided supplemental support to the SWAN model results. Model output applied in comparisons included contour plots of maximum wave parameters, time series of wave parameters at selected locations, and wave spectra.

The Practical Predictability of Storm Tide from Tropical Cyclones in the Gulf of Mexico

2017 ◽  
Vol 145 (12) ◽  
pp. 5103-5121 ◽  
Author(s):  
Kathryn R. Fossell ◽  
David Ahijevych ◽  
Rebecca E. Morss ◽  
Chris Snyder ◽  
Chris Davis
Keyword(s):  
Gulf Of Mexico ◽  
Tropical Cyclones ◽  
Storm Surge ◽  
Lead Times ◽  
Translation Speed ◽  
Storm Tide ◽  
Coastal Inundation ◽  
Observational Uncertainty ◽  
Extensive Property ◽  
Landfalling Tropical Cyclones

The potential for storm surge to cause extensive property damage and loss of life has increased urgency to more accurately predict coastal flooding associated with landfalling tropical cyclones. This work investigates the sensitivity of coastal inundation from storm tide (surge + tide) to four hurricane parameters—track, intensity, size, and translation speed—and the sensitivity of inundation forecasts to errors in forecasts of those parameters. An ensemble of storm tide simulations is generated for three storms in the Gulf of Mexico, by driving a storm surge model with best track data and systematically generated perturbations of storm parameters from the best track. The spread of the storm perturbations is compared to average errors in recent operational hurricane forecasts, allowing sensitivity results to be interpreted in terms of practical predictability of coastal inundation at different lead times. Two types of inundation metrics are evaluated: point-based statistics and spatially integrated volumes. The practical predictability of surge inundation is found to be limited foremost by current errors in hurricane track forecasts, followed by intensity errors, then speed errors. Errors in storm size can also play an important role in limiting surge predictability at short lead times, due to observational uncertainty. Results show that given current mean errors in hurricane forecasts, location-specific surge inundation is predictable for as little as 12–24 h prior to landfall, less for small-sized storms. The results also indicate potential for increased surge predictability beyond 24 h for large storms by considering a storm-following, volume-integrated metric of inundation.

scholarly journals STORM SURGE FORECASTING METHODS IN ENCLOSED SEAS

1978 ◽  
Vol 1 (16) ◽  
pp. 58
Author(s):  
P.F. Hamblin
Keyword(s):  
Water Level ◽  
Storm Surge ◽  
Storm Surges ◽  
High Water ◽  
Computational Effort ◽  
Water Levels ◽  
Large Lakes ◽  
Forecasting Methods ◽  
The Stability ◽  
Storm Surge Forecasting

Storm surges in enclosed seas although generally not as large in amplitude as their oceanic counterparts are nonetheless of considerable importance when low lying shoreline profiles, shallow water depth, and favourable geographical orientation to storm winds occur together. High water may result in shoreline innundation and in enhanced shoreline erosion. Conversely low water levels are hazardous to navigation. The purpose of this paper is to discuss the problem of storm surge forecasting in enclosed basins with emphasis on automated operational procedures. In general, operational forecasting methods must be based on standard forecast parameters, require a minimum of computational effort in the preparation of the forecast, must be applicable to lakes of different geometry and to any point on the shore, and to be able to resolve water level changes on an hourly basis to 10 cm in the case of high water level excursions associated with large lakes and less than that for smaller lakes. Particular physical effects arising in lakes which make these constraints difficult to fulfill are the reflections of resurgences of water levels arising from lateral boundaries, the stability of the atmospheric boundary layer and the presence of such subsynoptic disturbances as squall lines and travelling pressure jumps.

scholarly journals Storm Surge Causes and Different Variations

2017 ◽  
pp. 1-10
Author(s):  
Park Mao
Keyword(s):  
Tropical Cyclones ◽  
Storm Surge ◽  
Water Body ◽  
Meteorological Factors ◽  
Storm Surges ◽  
Low Pressure ◽  
Storm Tide ◽  
Normal Movement ◽  
Coastal Flood

A storm surge, storm flood or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low pressure weather systems (such as tropical cyclones and strong extra-tropical cyclones), the severity of which is affected by the shallowness and orientation of the water body relative to storm path, as well as the timing of tides. Most casualties during tropical cyclones occur as the result of storm surges. It is a measure of the rise of water beyond what would be expected by the normal movement related to tides. The two main meteorological factors contributing to a storm surge are a long fetch of winds spiraling inward toward the storm, and a low-pressure-induced dome of water drawn up under and trailing the storm's center.

scholarly journals Storm-Surge Induced Water Level Changes in the Odra River Mouth Area (Southern Baltic Coast)

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1559
Author(s):  
Halina Kowalewska-Kalkowska
Keyword(s):  
Water Level ◽  
Storm Surge ◽  
River Mouth ◽  
Storm Surges ◽  
Mouth Area ◽  
Water Levels ◽  
Szczecin Lagoon ◽  
Sea Levels ◽  
River Mouth Area ◽  
Odra River

The Odra River mouth area is a region of the Southern Baltic coastal zone especially prone to the influence of storm surges. In the present study, the height and extent of the Baltic storm surges, and temporal offsets of the respective maximum water level occurrences in the Odra River mouth area were explored using cross-correlation, cluster analysis and principal component analysis. The analyses were based on hourly water level readings retrieved from water gauging stations located along the lower Odra reaches and at the coasts of the Szczecin Lagoon and the Pomeranian Bay during storm surge years 2008/2009–2019/2020. The analysis of mutual relationships between water levels during storm surges indicated that the extent of marine influence on the lower Odra River and within the Szczecin Lagoon was variable during the studied surge events, and dependent on meteorological conditions (the strongest during the sustained occurrence of wind blowing from the northern sector), discharge from the Odra River catchment (the strongest at low discharge), ice conditions on the lower Odra (suppressing the storm surge propagation upstream), and general sea level in the Pomeranian Bay (stronger at high sea levels). The strongest correlation between sea levels at Świnoujście and water levels in the Szczecin Lagoon and the lower Odra was found at a 6–7 h offset. The extent of storm surges usually reached 100 km up the lower Odra channels, less frequently reaching 130 km away from the sea.

Monitoring zero water level in a drought-affected headwater stream network

2021 ◽  
Author(s):  
Amelie Herzog ◽  
Kerstin Stahl ◽  
Markus Weiler ◽  
Veit Blauhut
Keyword(s):  
Water Level ◽  
Monitoring Network ◽  
Water Levels ◽  
Added Value ◽  
Low Flow ◽  
Main Stream ◽  
Stream Network ◽  
Drying Up ◽  
Set Up ◽  
Level Monitoring

<p>Even largely perennial rivers can fall dry during drought events. A resulting partial or full drying-up of streambeds is difficult to monitor with conventional gauging stations, but important as it heavily impacts water availability, quality and aquatic ecosystems. With a predicted tendency towards more extreme droughts, event-based intermittency is likely to increase requiring a better longitudinal quantification of water level and streamflow conditions. The Dreisam River in the south-west of Germany is a stream with a highly dynamic hydrology. In the recent extreme drought years of 2015, 2018 and 2019 the main stream and tributaries partly fell dry; whereas the main gauging station still recorded flow. Furthermore, several tributaries fell dry in 2016, 2017 and 2019.To improve the understanding of the interaction between streamflow, groundwater and water usages in low flow and zero-flow situations, a flexible longitudinal water quality and quantity monitoring network was developed. Different techniques such as QR-code-reading camera systems and ultrasound devices to log water levels as well as water temperature and electrical conductivity sensors were used. The set-up was additionally equipped with conventional capacitive water level loggers. Here, we present a comparison of the different water level monitoring techniques in order to a) evaluate the advantages and limits of the novel techniques and b) investigate any added value of longitudinal, catchment wide zero level monitoring. The results show that the choice of the measurement sites' environment, including shading of QR-codes, light reflections of the water surface and streambed topography, is crucial for a successful application of the used techniques. The distributed gauges reveal a highly variable longitudinal drying pattern within the river network that appears to be event-specific and may not be explained without consideration of all natural and altered system fluxes.</p>

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