Storm surge

Potential impacts of 0.5 and 1.0 m of relative sea level rise (RSLR) on hurricane surge and waves in southeast Louisiana are investigated using the numerical storm surge model ADCIRC and the nearshore spectral wave model STWAVE. The models were applied for six hypothetic hurricanes that produce approximately 100 yr water levels in southeastern Louisiana. In areas of maximum surge, the impact of RSLR on surge was generally linear (equal to the RSLR). In wetland or wetland-fronted areas of moderate peak surges (2-3 m), the surge levels were increased by as much as 1-3 m (in addition to the RSLR). The surge increase is as much as double and triple the RSLR over broad areas and as much as five times the RSLR in isolated areas. Waves increase significantly in shallow areas due to the combined increases in water depth due to RSLR and surge increases. Maximum increases in wave height for the modeled storms were 1-1.5 m. Surge propagation over broad, shallow, wetland areas is highly sensitive to RSLR. Wave heights also generally increased for all RSLR cases. These increases were significant (0.5-1.5 m for 1 m RSLR), but less dramatic than the surge increases.

Geoscience Australia, in an open collaboration with the Mathematical Sciences Institute, The Australian National University, is developing a software ap- plication, ANUGA, to model the hydrodynamics of floods, storm surges and tsunamis. The free source software implements a finite volume central- upwind Godunov method to solve the non-linear depth-averagedshallowwater waveequations. Inlight of the renewed interest in tsunami forecasting and mitigation,

The scientific literature has documented the growing risks of flooding posed for Asia’s coastal cities by the combination of climate change, as reflected in sea level rise and intensified storms and storm surges, and ongoing urban growth in low-lying coastal zones. These issues were already elaborated in the 2007 IPCC (IPCC, 2007) reports but recent studies indicate that climate change, sea level rise and the sinking of the deltas on which most Asian mega urban regions have arisen, are all occurring at much faster rates than earlier projected and therefore pose even greater risks than previously indicated. Global warming appears to be accelerating and may increase to 4° C or more by the end of this century, twice the earlier IPCC projections. The sea level is now expected to rise by one meter or more by 2100; two or three times the earlier projections. The recent typhoons and rains striking Southeast Asia have been the most intense in decades as would be expected as a result of glob...

The mesoscale (time) control of annual storm-surge activity on quasi-annual saltmarsh (tidal marsh) deposition is studied from two estuarine saltmarshes on the high-energy NW coast of Ireland. Both saltmarshes exhibit a cliffed edge where maximum sedimentary variation is expressed in the form of lamination. Sections were logged and characterised by lithofacies based on grain-size determinations. Sections dated using Cs and

This paper reviews research that has taken place on physical oceanography and sedimentology on New Zealand's estuaries and the inner shelf since c. 1967. It includes estuarine sedimentation, tidal inlets, beach morphodynamics, nearshore and inner shelf sedimentation, tides and coastal currents, numerical modelling, short-period waves, tsunamis, and storm surges. An extensive reference list covering both published and unpublished material is included. Formal teaching and research programmes dealing with coastal landforms and the processes that shape them were only introduced to New Zealand M91078

Although international protection has been granted since 1935, southern right whales have only recently shown signs of recovery, possibly due to anthropogenic factors. Off Brazil, illegal hunting of right whales occurred until 1973. This paper reports on surveys conducted along the southern Brazilian coast and the information recovered on right whale strandings for this area from 1977-1995. In the first 10 years of this period only four cases were registered. However, in contrast, 20 cases were counted during the last nine years. These results are discussed in relation to marine traffic and the fisheries in the area that produce risks of collision and entanglement. Further, the possibility of storm surges being a preponderant factor in the mortalities in this area is presented. These yearly rates are compared with neighbouring areas that are also inhabited by the right whales. Both possibilities fit the hypothesis that the right whales using the Brazilian coast for breeding may finally be showing signs of recovery.

The City of Jakarta is considered as one of the most vulnerable cities to climate-related disaster, including flooding, sea-level rise, and storm surge. Various climate risks in Jakarta have been accessed. However, the assessments are limited to the physical aspects of climate-change impacts, whereas risks related to the impacts on socio-economic condition have been neglected. Meanwhile, the climate risks campaign is still limited to the government circle and academics. The current Geographic Information System have spatial data and information on the physical aspects of climate-change related vulnerability, but it has not been integrated with data of the socio-economic vulnerability. The local government has not been fully aware of the implications of climate change, and there is a need to strengthen local government agencies responsible for disaster management in Jakarta.

Using newly digitised sea-level data for the ports of Southampton (1935Southampton ( -2005 and Portsmouth on the south coast of the UK, this study investigates the relationship between the 100 highest sea-level events recorded at the two cities and the incidence of coastal floods in the adjoining Solent region. The main sources of flood data are the daily newspapers The Southern Daily Echo, based in Southampton and The News, based in Portsmouth, supported by a range of local publications and records. The study indicates a strong relationship between the highest measured sea levels and the incidence of coastal floods and highlights the most vulnerable areas to coastal flooding which include parts of Portsmouth, Southampton, Hayling Island, Fareham and Cowes. The most severe flood in the dataset resulted from the storm surge events of 13-17 December 1989 when eight consecutive extreme high waters occurred. The data suggest that while extreme sealevel events are becoming more common, the occurrence of flood events is not increasing. This is attributed to improved flood remediation measures combined with a reduction of storm intensity since the 1980s. However, several recent events of significance were still recorded, particularly 3 November 2005 when Eaststoke on Hayling Island (near Portsmouth) was flooded due to high sea levels combined with energetic swell waves.

The risk that tropical storm occurrence may alter as a result of global warming presents coastal managers, particularly in vulnerable areas, with a serious challenge. Many countries are hard-pressed to protect their coastal resources against present-day hazards, let alone any increased threat in the future. Moreover, the threat posed by climate change is uncertain making the increased costs of protection difficult to justify. Here, we examine one management strategy, based on the rehabilitation of the mangrove ecosystem, which may provide a dual, “winwin” benefit in improving the livelihood of local resource users as well as enhancing sea defences. The strategy, therefore, represents a precautionary approach to climate impact mitigation. This paper quantifies the economic benefits of mangrove rehabilitation undertaken, inter alia, to enhance sea defence systems in three coastal Districts of northern Vietnam. The results of the analysis show that mangrove rehabilitation can be desirable from an economic perspective based solely on the direct use benefits by local communities. Such activities have even higher benefit cost ratios with the inclusion of the indirect benefits resulting from the avoided maintenance cost for the sea dike system which the mangrove stands protect from coastal storm surges.

Bangladesh is li:equently visited by natural disasters such as tropical cyclones, storm surges, floods, droughts, tornadoes, and "norwesters." Of these, tropical cyclones originating in the Bay of Bengal and associated storm surges are the most disastrous. There are various reasons for the disastrous effects of cyclones and storm surges in Bangladesh. Superimposed onthese disastrous effects, climate change and any consequent sea level rise are likely to add fuel to the fire. Arise intemperature is likely to change cyclone activity: cyclone intensity, if not cyclone frequency, may increase. As a result, storm surges may also increase substantially. Sea level rise, an increase in cyclone intensity, and consequent increases in storm surge heights will have disastrous effects on a deltaic country like Bangladesh, which is not much above the mean sea level. This paper examines the climatology of cyclones in the Bay &Bengal for the last 110 years and trends in cyclone frequency and intensity. The phenomenon of storm surges in the Bay of Bengal is examined along with the primary reasons for the severity of storm surges in Bangladesh. The paper discusses both qualitatively and quantitatively the impacts &rises in temperature on tropical cyclone intensity in Bangladesh. With the use of a mathematical model developed for the simulation ofstonn surges along the Bangladesh coast, various scenarios of storm surges are developed. Using lower and upper bounds of sea surface temperature rise of 2 and 4°C and of sea level rise of 0.3 and 1.0 m (according to the Intergovemmental Panel on Climate Change standard), the model simulates the maximum possible surges that are likely to occur under these conditions.

Current metre deployments, suspended sediment measurements and surface sediment samples were collected from three locations within distributary channels of the tidally dominated Fly River delta in southern Papua New Guinea. Net bedload transport vectors and the occurrence of elongate tidal bars indicate that mutually evasive ebb-and flooddominant transport zones occur in each of the distributary channels. Suspended sediment experiments at two locations show a phase relationship between tidal velocity and sediment concentration such that the net suspended sediment flux is directed seaward. Processes that control the export of fluid muds with concentrations up to 10 g l À1 from the distributary channels across the delta front and onto the pro-delta are assessed in relation to the available data. Peak spring tidal current speeds (measured at 100 cm above the bed) drop off from around 100 cm s À1 within the distributary channels to o50 cm s À1 on the delta front. Gravity-driven, 2-m thick, fluid mud layers generated in the distributary channels are estimated to require at least 35 h to traverse the 20-km-wide, low-gradient (2 Â 10 À3 degrees) delta front. The velocities of such currents are well below those required for autosuspension. A 1-month time series of suspended sediment concentration and current velocity from the delta front indicates that tidal currents alone are unable to cause significant cross-delta mud transport. Wave-induced resuspension together with tides, storm surge and barotropic return-flow may play a role in maintaining the transport of fine sediment across the delta front, but insufficient data are available at present to make any reliable estimates.

Fast-growing, coastal mega cities along China's east coast and the rim of the Cross-Straits region, in particular, are becoming increasingly more vulnerable to potential natural disasters such as earthquakes, tsunamis, typhoons, storm surges and floods. The provinces of Shanghai, Guangdong, Fujian, and Zhejiang, as well as Taiwan, are threatened by common disasters. Advancing Cross- Straits ties in mitigating the impact

A technique to evaluate the risk of storm tides (the combination of a storm surge and tide) under present and enhanced greenhouse conditions has been applied to Cairns on the north-eastern Australian coast. The technique combines a statistical model for cyclone occurrence with a state-ofthe-art storm surge inundation model and involves the random generation of a large number of storm tide simulations. The set of simulations constitutes a synthetic record of extreme sea-level events that can be analysed to produce storm tide return periods. The use of a dynamic storm surge model with overland flooding capability means that the spatial extent of flooding is also implicitly modelled. The technique has the advantage that it can readily be modified to include projected changes to cyclone behaviour due to the enhanced greenhouse effect. Sea-level heights in the current climate for return periods of 50, 100, 500 and 1000 years have been determined to be 2.0 m, 2.3 m, 3.0 m and 3.4 m respectively. In an enhanced greenhouse climate (around 2050), projected increases in cyclone intensity and mean sea-level see these heights increase to 2.4 m, 2.8 m, 3.8 m and 4.2 m respectively. The average area inundated by events with a return period greater than 100 years is found to more than double under enhanced greenhouse conditions.

Hurricane Katrina caused significant damage to the transportation system in the Gulf Coast region. The overall cost to repair or replace the bridges damaged during the hurricane is estimated at over $1 billion. This paper describes the observed damage patterns to bridges, including damage attributed to storm surge, wind, impact from debris, scour, and water inundation, as well as examples of repair measures used to quickly restore functionality to the bridges and transportation system. Using the data from the 44 bridges that were damaged, relationships between storm surge elevation, damage level, and repair costs are developed. The analysis reveals that, in general, regions with higher storm surge had more damage, although there were several instances where this was not the case, primarily due to damage resulting from debris impact. It is also shown that a highly nonlinear relationship exists between the normalized repair cost and the damage state. The paper concludes with a brief discussion on the efficacy of using typical seismic design details for mitigating the effects of hurricane loads, and potential design considerations for bridge structures in vulnerable coastal regions.

The City of Jakarta is considered as one of the most vulnerable cities to climate-related disaster, including flooding, sea-level rise, and storm surge. Various climate risks in Jakarta have been accessed. However, the assessments are limited to the physical aspects of climate-change impacts, whereas risks related to the impacts on socio-economic condition have been neglected. Meanwhile, the climate risks campaign is still limited to the government circle and academics. The current Geographic Information System have spatial data and information on the physical aspects of climate-change related vulnerability, but it has not been integrated with data of the socio-economic vulnerability. The local government has not been fully aware of the implications of climate change, and there is a need to strengthen local government agencies responsible for disaster management in Jakarta.

This paper reviews historical methods for estimating surge hazards and concludes that the class of solutions produced with Joint Probability Method (JPM) solutions provides a much more stable estimate of hazard levels than alternative methods. We proceed to describe changes in our understanding of the winds in hurricanes approaching a coast and the physics of surge generation that have required recent modifications to procedures utilized in earlier JPM studies. Of critical importance to the accuracy of hazard estimates is the ability to maintain a high level of fidelity in the numerical simulations while allowing for a sufficient number of simulations to populate the joint probability matrices for the surges. To accomplish this, it is important to maximize the information content in the sample storm set to be simulated. This paper introduces the fundamentals of a method based on the functional specification of the surge response for this purpose, along with an example of its application in the New Orleans area. A companion paper in this special issue ) provides details of the portion of this new method related to interpolating/extrapolating along spatial dimensions.

On February 17,1996, at 0559 UT, a major earthquake with moment magnitude (Mw) 7.9 killed 107 people and caused major damage at Biak Island, 30-40 km southwest of the earthquake's epicenter (Figures 1 and 2). A devastating tsunami washed away all of the houses at Korim, a small village located in a narrow bay facing directly towards the incoming wave, and it left behind clear evidence of sand erosion and deposition that indicated how far the tsunami advanced. An unexpectedly large tsunami run-up of 7.7 m was measured at Wardo in western Biak, which faces away from the primary tsunami source. This high run-up may have been caused by a local submarine landslide.

About a quarter of the Netherlands is below mean sea level. Without flood protection structures, about two-third of the country would be flooded during storm surges at sea or high discharges in the rivers. That is why in a country such as the Netherlands, protection against flooding is an important task. This protection is provided by an extensive system of so-called primary flood protection structures. The appropriate Legislation, Safety Standards and the Flood Management System have been developed by the Dutch Government to support her safety policy.

Because of its location close to a region of tropical cyclone formation, the city of Cairns is regularly affected by tropical cyclones. Most cyclones occur in the months January-March, although some have affected Cairns in December and April. There is a strong year-to-year variation in tropical cyclone numbers in the Cairns region, with twice as many impacts occurring during La Niña conditions as during El Niño. Several case studies are presented of cyclone impacts on Cairns. Rapidly developing cyclones are a particularly difficult forecast problem, as they can strike the city with less than 24 hours warning. Serious inundation from storm surge often occurs some time after landfall at Cairns.

In this chapter, we will see the geographic and societal situation of the coast and its management on a sub-regional basis. The subregion introduced first is East Asia, for which we will see China, Korea, Taiwan, and Japan. Coastal zones of East Asia are characterized by diversity of coastal morphology and strong oceanic and climatic activities. They have long suffered

Since the IPCC Third Assessment Report (TAR), our understanding of the implications of climate change for coastal systems and low-lying areas (henceforth referred to as 'coasts') has increased substantially and six important policy-relevant messages have emerged. Coasts are experiencing the adverse consequences of hazards related to climate and sea level (very high confidence). Coasts are highly vulnerable to extreme events, such as storms, which impose substantial costs on coastal societies [6.2.1, 6.2.2, 6.5.2]. Annually, about 120 million people are exposed to tropical cyclone hazards, which killed 250,000 people from 1980 to 2000 [6.5.2]. Through the 20th century, global rise of sea level contributed to increased coastal inundation, erosion and ecosystem losses, but with considerable local and regional variation due to other factors [6.2.5, 6.4.1]. Late 20th century effects of rising temperature include loss of sea ice, thawing of permafrost and associated coastal retreat, and more frequent coral bleaching and mortality [6.2.5]. Coasts will be exposed to increasing risks, including coastal erosion, over coming decades due to climate change and sea-level rise (very high confidence). Anticipated climate-related changes include: an accelerated rise in sea level of up to 0.6 m or more by 2100; a further rise in sea surface temperatures by up to 3°C; an intensification of tropical and extratropical cyclones; larger extreme waves and storm surges; altered precipitation/run-off; and ocean acidification [6.3.2]. These phenomena will vary considerably at regional and local scales, but the impacts are virtually certain to be overwhelmingly negative [6.4, 6.5.3].

Coastal areas of Bangladesh frequently experience tropical cyclones and associated tidal bore. In order to prevent cyclonic or storm-surge flooding and to increase crop production by preventing intrusion of saline ocean water, many coastal embankment projects were initiated in the 1960s by the Bangladesh government. After construction of these embankments, particularly their reconstruction in 1991 has increased the frequency of flash floods in coastal areas. The objective of this study is to examine to what extent the reconstruction of embankment is responsible for the increased severity of flash flooding at the Chokoria thana of the Cox's Bazar district, Bangladesh. Using hydrological data and perception of the respondents on the increased flooding through the rapid rural appraisal (RRA) method, it was found that severity of the flood increased after the reconstruction of embankments in 1991. Other causes of increased flooding is also explored. #

For more than a century, coastal wetlands have been recognized for their ability to stabilize shorelines and protect coastal communities. However, this paradigm has recently been called into question by small-scale experimental evidence. Here, we conduct a literature review and a small meta-analysis of wave attenuation data, and we find overwhelming evidence in support of established theory. Our review suggests that mangrove and salt marsh vegetation afford context-dependent protection from erosion, storm surge, and potentially small tsunami waves. In biophysical models, field tests, and natural experiments, the presence of wetlands reduces wave heights, property damage, and human deaths. Meta-analysis of wave attenuation by vegetated and unvegetated wetland sites highlights the critical role of vegetation in attenuating waves. Although we find coastal wetland vegetation to be an effective shoreline buffer, wetlands cannot protect shorelines in all locations or scenarios; indeed large-scale regional erosion, river meandering, and large Climatic Change tsunami waves and storm surges can overwhelm the attenuation effect of vegetation. However, due to a nonlinear relationship between wave attenuation and wetland size, even small wetlands afford substantial protection from waves. Combining manmade structures with wetlands in ways that mimic nature is likely to increase coastal protection. Oyster domes, for example, can be used in combination with natural wetlands to protect shorelines and restore critical fishery habitat. Finally, coastal wetland vegetation modifies shorelines in ways (e.g. peat accretion) that increase shoreline integrity over long timescales and thus provides a lasting coastal adaptation measure that can protect shorelines against accelerated sea level rise and more frequent storm inundation. We conclude that the shoreline protection paradigm still stands, but that gaps remain in our knowledge about the mechanistic and contextdependent aspects of shoreline protection.

CITATIONS 10 READS 257 4 authors: Some of the authors of this publication are also working on these related projects: EVEX (EVènements EXtrêmes et érosion du trait de côte : mesures, modélisation numérique et impacts sociétaux / Extreme events and erosion of the shoreline: measurements, numerical modeling and societal impacts) View project Coupled ocean-wave model development in forecast environment (WAVE2NEMO) View project X. Bertin Université de La Rochelle a b s t r a c t

Ocean waves can be destructive as steeper waves due to their high energy eroding the sandy beaches. During storm surge or high tide, the water level rises and if large waves occur, they will break closer to the beach, releasing enormous amount of energy resulting in strong currents. This causes heavy loss of beach material due to large-scale erosion. If these waves are made to break prematurely and away from the beach, they can be attenuated so as to reduce beach erosion. The reef, which is a homogeneous pile of armour units without a core, breaks the steeper ocean waves, dissipates a major portion of their energy and transmits attenuated waves. This paper experimentally investigates the armour stone stability of the submerged reef and the influence of its varying distance from shore and crest width on ocean wave transmission. r

The current study area is coastal zone of Cuddalore, Pondicherry and Villupuram districts of the Tamil Nadu along the southeast coast of India. This area is experiencing threat from many disasters such as storm, cyclone, flood, tsunami and erosion. This was one of the worst affected area during 2004 Indian Ocean tsunami and during 2008 Nisha cyclone. The multi-hazard vulnerability maps prepared here are a blended and combined overlay of multiple hazards those affecting the coastal zone. The present study aims to develop a methodology for coastal multi-hazard vulnerability assessment. This study was carried out using parameters probability of maximum storm surge height during the return period (mean recurrence interval), future sea level rise, coastal erosion and high resolution coastal topography with the aid of the Remote Sensing and GIS tools. The assessment results were threatening 3.46 million inhabitants from 129 villages covering a coastal area 360 km 2 under the multi-hazard zone. In general river systems act as the flooding corridors which carrying larger and longer hinterland inundation. Multihazard Vulnerability maps were further reproduced as risk maps with the land use information. These risk caused due to multi-hazards were assessed up to building levels. The decision-making tools presented here can aid as critical information during a disaster for the evacuation process and to evolve a management strategy. These Multi-hazard vulnerability maps can also be used as a tool in planning a new facility and for insurance purpose.

In this study critical thresholds are defined for storm impacts along the Spanish coast of the Gulf of C??diz. The thresholds correspond to the minimum wave and tide conditions necessary to produce significant morphological changes on beaches and dunes and/or ...

An assessment is made of contemporary effective sea-level rise (ESLR) for a sample of 40 deltas distributed worldwide. For any delta, ESLR is a net rate, defined by the combination of eustatic sea-level rise, the natural gross rate of fluvial sediment deposition and subsidence, and accelerated subsidence due to groundwater and hydrocarbon extraction. ESLR is estimated under present conditions using

Geological evidence suggests that during a future eruption, Cumbre Vieja Volcano on the Island of La Palma may experience a catastrophic failure of its west flank, dropping 150 to 500 km 3 of rock into the sea. Using a geologically reasonable estimate of landslide motion, we model tsunami waves produced by such a collapse. Waves generated by the run-out of a 500 km 3 (150 km 3 ) slide block at 100 m/s could transit the entire Atlantic Basin and arrive on the coasts of the Americas with 10-25 m (3-8 m) height.

Large tsunamis strike the British Columbia coast an average of once every several hundred years. Some of the tsunamis, including one from Alaska in 1964, are the result of distant great earthquakes. Most, however, are triggered by earthquakes at the Cascadia subduction zone, which extends along the Paci"c coast from Vancouver Island to northern California. Evidence of these tsunamis has been found in tidal marshes and low-elevation coastal lakes on western Vancouver Island. The tsunamis deposited sheets of sand and gravel now preserved in sequences of peat and mud. These sheets commonly contain marine fossils, and they thin and "ne landward, consistent with deposition by landward surges of water. They occur in low-energy settings where other possible depositional processes, such as stream #ooding and storm surges, can be ruled out. The most recent large tsunami generated by an earthquake at the Cascadia subduction zone has been dated in Washington and Japan to AD 1700. The spatial distribution of the deposits of the 1700 tsunami, together with theoretical numerical modelling, indicate wave run-ups of up to 5 m asl along the outer coast of Vancouver Island and up to 15}20 m asl at the heads of some inlets.

Hurricane Katrina has had a devastating impact on the US Gulf Coast. Forecasts of such events, coupled with timely response, can greatly reduce casualties and save billions of dollars. In our effort, we use sophisticated surface, flow and volume visu- alization techniques show the storm surge and atmospheric simula- tions simulation results superimposed with actual observations, in- cluding satellite cloud

... doi:10.1016/j.geomorph.2006.06.007 | How to Cite or Link Using DOI Copyright © 2006 Elsevier ... luminescence (OSL) to both trace and contribute to the debate on coastal dune initiation. ... the Danish Wadden Sea barriers are likely to have formed mainly through onshore directed ...