Storm Surges

During the storms of February/March 1978 and December 1981, data from eight tide gauge stations, on the portuguese coast, (Viana do Castelo, Leixões, Aveiro, Cascais, Lisbóa, Tróia, Sines and Lagos) were analised. During these storms the maximum surge ranged in amplitude from 0.4 to 0.9m and from 0.4 to 1 .2m, respectively. The observed maximum water leveIs ranged from 3.8 to 4.3m for the 1978 storm, and from 3.6 to 4.0m, for the 1981 storm. This leveIs exceed the predicted tidal maxima by between 0.4 and 0.7m. The comparision of surge leveIs with the barometric pressure and the wind speed sugest that the surge leveIs are mostly related with the local metereological conditions.

This chapter presents details on a number storms surge cases: along the Southern Baltic sea coast, the estuary of the Elbe in Germany and the East China Sea coast at Qingdao. These case studies feature storm surge characteristics, specifically, losses of life and property, erosion extent, and relationship to extra-tropical and tropical storm intensity. These cases demonstrate the severity of the issue and the need of precautionary measures, not only for limiting the possible damages, but also for being able to manage for a possible failure of the coastal defense measures.

Assessment of vulnerability to storm surge flood is not only significant for the survival of the exposed communities but also for adaptation. Defining vulnerability as the function of exposure, sensitivity and resilience capacity, we propose a composite vulnerability index (CVI) to assess village-level vulnerability to storm surge flood in the Sundarban Biosphere Reserve (SBR), India. The composite vulnerability index based analysis revealed that of the total villages (1063) located in SBR; nearly half of the villages are highly and very highly vulnerable with least capacity to cope with any kind of extreme event. The villages located in the southern parts and adjacent to coast were found more vulnerable to storm surge while those located at higher elevation in the central part showed low vulnerability. Some villages in northern part of the region were under high and very high vulnerability due to presence of low lying and waterlogged wetlands. The findings of the study may have implications for developing resilience capacity in response to storm surge flooding. Thus, the methodology can help the local policymakers in integrating local multi-hazards knowledge and in making information actionable for mitigation and adaptation of storm surge flood hazard.

Chronological history of cyclones in Bangladesh suggests that storm surges are the dominant reasons for cyclonic destruction. Prediction of storm surge height is a vital issue for Bangladesh whereas the current practices are time consuming. On the other hand, analytical and empirical methods may provide a relatively quick prediction of storm surge height at the coast based on minimal and approximate information, which can be used as the first reasonable approximation. This paper presents an empirical method for estimation of the maximum cyclonic wind speed which can be calculated from simple data readily-available from Bangladesh Meteorological Department in real time. A database is prepared for the major cyclonic events from 1960 to 2007. The maximum wind speed is calculated from the central pressure drop, maximum wind speed in the wall cloud region of the cyclone, and a pre-determined regional constant K. For the coast of Bangladesh, K is calculated to be 26.44 from the observed data for 16 cyclonic events. The maximum wind speeds predicted using this K show good correlation with the observed wind speeds during the major cyclones. The predicted wind speed is then used to predict the storm surge height by using two analytical methods for storm surge height prediction. The predicted storm surge heights are in good agreement with the observed surge heights. This simple and quick yet reasonably accurate method for storm surge prediction in real time will be useful for cyclone preparedness, evacuation and disaster management programs.

Keywords:Storm surge prediction,Cyclone, Wind speed, Pressure fall, Bangladesh coastal zone.

2017, Kolaiti E., Papadopoulos G. A., Morhange C., Vacchi M., Triantafyllou I., Mourtzas N. D., Palaeoenvironmental evolution of the ancient harbor of Lechaion (Corinth Gulf, Greece): Were changes driven by human impacts and gradual coastal processes or catastrophic tsunamis? Marine Geology, 392, pp. 105-121.

A B S T R A C T The Corinth Gulf, Central Greece, is one of the most rapidly widening tectonic rifts on Earth, where large earthquakes with magnitudes of up ~7.0 have been documented not only by instrumental records but also assessed from historical reports extending back to the 5th century BCE. Several of these earthquakes were associated with tsunamis, particularly in the western part of the Gulf. Of particular interest is the ancient harbor of Lechaion in the eastern side of Corinth Gulf. We reexamine the hypothesis that Lechaion was hit by high-energy tsunami waves in the 8th–6th century BCE, 1st–2nd century CE, and during the 6th century CE. On the basis of sedimentological, seismotectonic, archaeological and historical data, completed with field observations, we support that there is no evidence for tsunami impact in Lechaion. Local stratigraphy and environmental changes are rather interpreted by human impacts and gradual coastal processes. Such interpretations confirm that the tsunami potential in the east Corinth Gulf is relatively low.

Bangladesh, one of the most disaster-prone country in south Asian region experiences tropical cyclones, storm surges, coastal erosions and floods almost every year. Very recently, tropical cyclone ‚Roanu' has caused extreme devastation across the country. Roanu originating from a low pressure area at south of Sri Lanka, gradually drifted towards north and intensified into a cyclonic storm on 19 May 2016. Although, wind shear and land interaction has weaken severity of the cyclone, it casused severe flooding in Bangladesh and Srilanka. Cyclone Roanu turning very deadly for the city of Chittagong, caused severe wind damages, destroyed coastal embankments and triggered heavy rain landslides. Such damages has become great concern to learn flood inundation patterns for such storm surges when sea level will rise due to global warming. To investigate the changes, a hydro-morphological model, Delft3D has been applied and validated for storm surges in the southern coast of Bangladesh. For storm surge simulation, the tropical cyclone toolbox of Delft Dashboard is used on the platform of Delft3D flow module. Model has been calibrated using tidal gague data from BIWTA and simulated to produce inundation maps for Cyclone Roanu under the persent and future conditions considering different sea level rise scenarios.

As standards of living generally improve across the globe, there is a corresponding change in people’s perception and acceptance of risk. The impact of natural hazards is an emerging threat to industrial facilities, pipelines, offshore platforms and other infrastructure that handles, stores or transports hazardous substances. When accidentally released, hazardous substances can lead to fires, explosions, and toxic or radioactive releases. These so-called Natech accidents are a recurring but often overlooked feature of many natural disasters and have often had significant human, environmental and economic impacts. Industries and authorities must be able to learn from incidents and capture the lessons that are needed to safely conduct business and produce goods for the whole of society.

Among natural events, storms can seriously affect the integrity of an industrial installation and lead to accident scenarios such as fires, explosions and the dispersion of chemicals in the environment. In addition, scientists expect an overall worsening of extreme weather events in this century due to climate change, which will further increase the threat to industrial facilities.

This report analyses past technological accidents with hazardous materials releases and damage to industrial facilities caused by the impact of storms. It discusses the vulnerability of industrial sites including that of the main equipment types present at the facility and analyses how they are damaged.

The first part of the report describes the storm hazard. It discusses storm types and their occurrence, as well as the main effects that cause damage to human settlements and the environment. The report lists strong winds, heavy precipitation, lightning and storm surge as the main effects responsible for damage to industrial installations.

In the second part of the report, we perform an analysis of past storm-triggered Natech events. Using different sources of public information on technological incidents, this study:

1. Analyses incident statistics;

2. Reviews a number of “landmark” accidents;

3. Discusses the lessons learned.

From the analysis of past events, the report concludes that Natech events caused by storms are frequent and that their relative occurrence is increasing compared to the overall occurrence of technological incidents from other causes in the analysed databases. The largest losses were generally triggered by heavy rain and flooding, while the most frequent trigger was lightning. The study also highlighted the role of a loss of power supply in triggering an accident or hampering the mitigation of its consequences.

The study presents lessons learned from the forensic analysis of past events and puts forward recommendations for future risk reduction for all storm effects. The most important lesson is that storm predictions based on past events are not sufficient to be well prepared for future events, in particular in the face of climate change.

Climate change is having an undeniable influence on coastal areas. This chapter describes the growing threat of climate change on the Baltic Sea coastline, with an emphasis on field research focused on storm surges and coastal retreat. The main climatic factors driving change in the Baltic Sea coastal zone are wind, waves, storm surges, ice jams and flooding. The cumulative effects of these drivers are also important. For example, a costly coastal protection scheme in one area may result in coastal erosion in another. Natural and man-made coastal features are experiencing unprecedented change; important natural habitats, coastal settlements and local economies are all being affected. The extent of storm surge impacts depends on the exposure of a shoreline to a surge event. The submergent and soft coastal relief of the southern Baltic Sea area is under most threat; the rate of retreat depending on the frequency and strength of the storm surges. The rate of coastal retreat has also increased in recent years due to sea-level rise and loss of beaches. Keywords Coast erosion Á Threats for coast Á Coast type response for climate change

Schon immer siedelten Menschen im natürlichen Gefahrenbereich – an der Nordsee somit auch in den
potentiell überfluteten Gebieten der Seemarschen, die seit dem 12. Jahr hun dert von Deichen geschützt
werden. Trotz eines seitdem immer weiter verbesserten Küstenschutzes sind Risiken entstanden, die sich
auch heute nicht beseitigen lassen. Ohne Küstenschutz wären heute etwa ein Viertel der Landesfläche
Schleswig-Holsteins mit über 250000 Menschen und Sachwerten von etwa 50 Milliarden Euro von Überflutung
bedroht. Als der UN-Klimarat am 2. Februar 2007 in Paris mit der Vorlage des jüngsten Reports des
»Intergovernmental Panel on Climate Change« (IPCC 2007) vor einem Treibhauseffekt warnte, einen
Anstieg des Meeresspiegels prognostizierte und eine Zunahme der Temperaturen bis 2100 um wahrscheinlich
3 °C vorhersagte, reagierten Medien und Politik umgehend. Wird es mehr Stürme und Orkane an der
Nord- und Ostseeküste geben? Historisch-geoarchäologische Untersuchungen zeigen, mit welchen Stra -
tegien Menschen früher auf diese Naturgefahren reagierten (Meier 2007b, 9-17. 79-87). Der folgende
Beitrag thematisiert exemplarisch die historische Entwicklung der schleswig-holsteinischen Nordseeküste
zwischen Steinzeit und Mittelalter.

Storm waves and tsunamis have been responsible for the movement and deposition of boulders located near or at a shore. Nott [1,2] proposed a set of formulas to calculate the minimum incident wave velocities required to dislodge cuboid-shaped boulders. These formulas depend on boulder properties, local terrain, water wave parameters and mechanism of dislodgement. Further, Nott proposed a formula to compute the wave height corresponding to the wave velocity, and including a parameter depending on whether the wave arose from a storm or a tsunami. The dislodgement formulas have been improved and extended (cf. Haslett and Wong [3], Nandasena [4]) and references therein) to include additional boulder configurations. Recently, Nott’s approach to inferring wave height and wave type has been criticised. This work is a preliminary study to link boulder- and wave-parameters to a Froude number which might be useful as an alternative approach to deciding between storm waves and tsunami waves as a cause of boulder displacement.

This paper presents an assessment of the performance of a shoreline revetment; M. Ali Seawall, placed to protect the land behind against flooding and overtopping at coastal site, within Abu Qir Bay, East of Alexandria along the Nile Delta coast. Coastal zone management of the bay coastline is of utmost significance to the protection of the low agricultural land and the industrial complex located in the rear side of the seawall under the current and progressive effects of climate change. The latest storm in December 2010, which hit the Nile Delta and which was the severest in the last decades showed that generated surges, up to 1.0 m as well as a maximum of 7.5 m wave height in the offshore of Alexandria presented a major natural hazard in coastal zones in terms of wave run up and overtopping. The storm, fortunately, resulted in a partial and modest flooding of the zone behind the seawall particularly in the beach segment, located in the middle of the seawall. This research project aims to the design review of the seawall which was first constructed in 1830 to protect the lowland agricultural area, 2.0 m below mean sea level, and was rehabilitated in 1981 as part of the Master Plan of the Nile Delta Coastal Zone Management. The seawall was further upgraded in 2009; one year before the 2010 storm. The paper will give an overview of the seawall design and its upgrades and the current conducted hydrodynamic analyses to estimate wave height distributions, wave run up and overtopping over the seawall and its beach segment. Use has been made of the in-house modified ImSedTran-2D model as well as universal design standards as EurOtop (2008). Based on the results for worst design scenarios, recommendations are given to increase the height of the seawall cap, to strengthen the beach top and back slope with a facility to drain storm water to increase coastal resilience behind the seawall. Comparison of the predicted overtopping with the observed wave overtopping volumes during the 8hrs-2010 storm, allowed the verification of the used universal design tools. Impact of precise estimate of storm and barometric surge as well as seawall armor roughness and shapes on overtopping rates are highlighted.

As hurricanes continue to threaten coastal communities, accurate storm surge forecasting remains a global priority. Achieving a reliable storm surge prediction necessitates accurate hurricane intensity and wind field information. The wind field must be converted to wind stress, which represents the air-sea momentum flux component required in storm surge and other oceanic models. This conversion requires a multiplicative drag coefficient for the air density and wind speed to represent the air-sea momentum exchange at a given location. Air density is a known parameter and wind speed is a forecasted variable, whereas the drag coefficient is calculated using an empirical correlation. The correlation's accuracy has brewed a controversy of its own for more than half a century. This review paper examines the lineage of drag coefficient correlations and their acceptance among scientists.

On 8th November 2013, Typhoon Haiyan, local name Yolanda, made landfall in the central Philippine islands region. Considered one of the most powerful typhoons ever to make landfall in recorded history, the 600 km diameter Typhoon Haiyan crossed the Philippine archipelago, bringing widespread devastation in its path. Strong winds, heavy rainfall, and storm surges caused extreme loss of lives and widespread damage to property. Storm surges were primarily responsible for the 6300 dead, 1061 missing and 28,689 injured in Haiyan's aftermath. Here, we document the storm surge simulations which were used as basis for the warnings provided to the public 2 days prior to the howler's landfall. We then validate the accounts based on field data and accounts provided in the news. The devastating Haiyan storm surges are one of the biggest in several decades, which exacted a high death toll despite its early prediction. There were many lessons learned from this calamity, and information contained in this work may serve as useful reference to mitigate the heavy impact of future storm surge events in the Philippines and elsewhere.

Storm surge induced by tropical cyclones (TCs) has become a global concern due to its catastrophic and expensive impacts on many coastal and tropical areas. It is also evident that global sea level rise (SLR) is expected to amplify coastal flood risk in the future. The exposure and vulnerability to flooding due to storm surge and SLR are particularly higher in the developing countries with densely populated low-lying coastal areas. Bangladesh is known for being one of the most natural disaster prone countries in the world, where storm surge and coastal flooding have lifethreatening impacts to millions of people living in its coastal region. The country lies within an active delta with hydromorphologically dynamic coastal lands and its livelihood is highly dependent on its natural resources. High subsidence rates, increase in upstream river flows, and human interventions are also exacerbating the existing inundation regimes and drainage situations in the coastal areas of Bangladesh. Finally, an ecosystembased approach has the potential to mitigate the twin threats of SLR and TC in a difficult biophysical and socioeconomic setting like that of coastal areas of Bangladesh.

Este artigo apresenta resultados de um experimento de campo realizado para avaliar a resposta morfológica de uma praia arenosa durante um evento de ressaca do mar. O estudo foi realizado na Praia do Icaraí, localizada no litoral da Região Metropolitana de Fortaleza, estado do Ceará. O experimento de campo foi baseado no acompanhamento contínuo de cinco seções de controle a partir de informações topográficas e oceanográficas. Foram realizadas 7 campanhas de campo (28/01/14 a 09/02/14). As respostas morfológicas dos trechos observados foram diferentes em termos de erosão e deposição. A seção limitada por dunas antropizadas (S1) apresentou erosão da berma e da praia submersa. Os trechos costeiros limitados por uma estrutura de proteção costeira (S2 a S4) apresentaram recuo da parte superior do perfil. No trecho de dunas frontais (S5), houve uma erosão generalizada da duna e da berma. De forma geral, a Praia do Icaraí é vulnerável a eventos de ressaca do mar. Palavras-Chave: Ressacas do Mar; Erosão Costeira; Balanço Sedimentar. This paper presents results of a field experiment conduced to evaluate the morphological answer to a sandy beach for a storm surge event. The study was realized in Icaraí Beach (Caucaia – CE) located on the coast of the Metropolitan Region of Fortaleza, Ceará state. The field experiment was based on continuous monitoring of five control sessions from topographic and oceanographic information. Was done 7 field campaigns between 01/28/2014 and 09/02/2014. The morphological response of observed excerpts was noticed were different in terms of erosion and deposition. The limited section by anthropic dunes (S1) presented berm and submerged beach erosion. Coastal stretches limited by shell-work of a coastal protection (S2 to S4) presented a decrease of the upper part of the beach profile. On the front stretch of the dune (S5) there was a general erosion of the dune and berm. The results showed this beach is quite vulnerable to storm wave action.

Washover-Prozesse und -Ablagerungen sind weltweit an vielen Küsten verbreitet und gehören zum geomorphologischen Formenschatz vieler Dünen- und Barriereinseln. Auf den Nordseeinseln Sylt und Amrum sind rezente Washover-Areale besonders im Bereich der Inselenden zu finden. Dort sind in Folge winterlicher Sturmfluten Inseldurchbrüche zu befürchten. Durch die Arbeiten sollte nachgewiesen werden, ob und in welchem Maße Washover-Prozesse bereits in der Vergangenheit am Aufbau der Nordseeinseln beteiligt waren und welche Auswirkungen sie auf die Inselgenese hatten. Washover-Prozesse können sowohl erosive als auch akkumulative Prozesse in Gang setzen. Auf der Grundlage bekannter Washover-Areale auf Sylt wurden typische Reflexionsmuster und -geometrien analysiert, die eine Identifizierung von Washover-Sedimenten und -strukturen mittels Georadar erlauben. Durch Bohrungen auf Amrum konnten Washover-Sedimente, die auf Dünendurchbrüche zurückzuführen sind, im sedimentologischen Profil nachgewiesen und mit Sturmfluten korreliert werden. Die Daten zeigen, dass die Georadarmethode bei der Untersuchung von Washover-Ablagerungen im Vergleich zu anderen geomorphologischen Methoden bedeutende Vorteile bietet. Die Ergebnisse lassen sich zudem zur Identifizierung und Abgrenzung historischer Washover-Events im sandigen Sedimentationsraum einer Dünen- und Barriereinsel, die aus dem gleichen geomorphologischen Prozesssystem hervorgehen, anwenden.

Energy systems can be vulnerable to climate change. This paper summarizes the contribution of their authors to a few strategic studies, research workshops, development forum and international conferences related to Climate and Energy. It presents a review of the impacts that climate change may have throughout the energy chain and identifies current knowledge gaps and areas for future research development. One of the greatest challenges is how to assess impacts which may occur as a consequence of the projected increase in the intensity of extreme weather events: the majority of current methodologies rely on past experience but this may not be a sufficiently good guide for planning and operational activities in the coming decades. Also, climate impact assessments on energy planning and operation need to take into account a greater number of scenarios, as well as investigate impacts on particular energy segments. Therefore, we identify energy segments for which little climate impact research has been conducted. Finally, because climate impact assessment for energy systems is a relatively new research field, it is expected that methodological developments will increase in the near future with a consequent broadening of the knowledge base on the subject.

Two distinct microtidal estuarine systems were assessed to advance the understanding of the coastal dynamics of sea level rise in salt marshes. A coupled hydrodynamic-marsh model (Hydro-MEM) was applied to both a marine-dominated (Grand Bay, Mississippi) and a mixed fluvial/marine (Weeks Bay, Alabama) system to compute marsh productivity, marsh migration, and potential tidal inundation from the year 2000 to 2100 under four sea level rise scenarios. Characteristics of the estuaries such as geometry, sediment availability, and topography, were compared to understand their role in the dynamic response to sea level rise. The results show that the low sea level rise scenario (20 cm) approximately doubled high-productivity marsh coverage in the marine-dominated estuary by the year 2100 due to an equilibrium between the rates of sea level rise and marsh platform accretion. Under intermediate-low sea level rise (50 cm), high-productivity marsh coverage in the year 2100 increased (doubled in the marine-dominated estuary and a seven-fold increase in the mixed estuary) by expanding into higher lands followed by the creation of interior ponds. The results also indicate that marine-dominated estuaries are vulnerable to collapse as a result of low, relatively uniform topography and lack of sediment sources, whereas mixed estuaries are able to expand due to higher elevations and sediment inputs. The results from the higher sea level rise scenarios (the intermediate-high (120 cm) and high (200 cm)) showed expansion of the bays along with marsh migration to higher land, producing a five-fold increase in wetland coverage for the mixed estuary and virtually no net change for the marine-dominated estuary. Additionally, hurricane storm surge simulations showed that under higher sea level rise scenarios, the marine-dominated estuary demonstrated weaker peak stage attenuation indicating that the PLOS ONE | https://doi.

In present day Polish coastal dunes' development, heavy storms and human activity play a significant role. Natural or almost natural dune processes and accumulation of the coast is observed only in a few places, such as the S ´ wina Gate Sandbar (also called barrier). As far as the spit number and morphology of the youngest ridges is concerned, they are different in the western, the middle and the eastern part. In the western part, ridges are smaller and closer to each other, thus depressions between them are narrower. Moreover, beach is widely covered by small hillocks. In the middle part, ridges are higher but narrower. Likewise, depressions between them are wider. The beach is wide and covered by large numbers of plants and dune hillocks. In the eastern part, dunes are also high but tend to be narrow, with steep seaside slope having the most frequent occurrence. Depressions and beach are narrow. The number of plants is not considerable compared with other parts. Since 1997 an increase of the new dune ridge on the still developing beach has been observed. Each year the beach is becoming wider and covered by larger number of plants. Plants lead to the development of new dunes and increase of the sandbar. The new foredune ridge consists of several hillocks joined into irregular ridge. This new first ridge is also shaped by storm waves but still becomes a real ridge. This development may be caused by continuous sand supply and by very strong north and west winds. A lot of different dune psammophyties on the beach are in favour of sand fixing on the increasing beach far from the first ridge. Only on part of spit with a tendency to erosion, accumulation of the dunes is not to be observed. Additionally, human activity stops aeolian accumulation and plant growth on the beach.

It was the objective of this study to characterize erosional and depositional sedimentary features caused by overwash events at barrier islands. Investigations took place at the East Frisian Island of Norderney as well as at the North Frisian Island of Amrum, which both are part of a barrier system that belongs to an island chain lining the Southern North Sea. Coring data of Northern Amrum show a washover-sequence caused by several storm surge induced overwash flooding of the last century. Today, overwash processes are prevented by coastal protection arrangements that preserve the entire sedimentary sequence. The eastern part of Norderney is currently affected by storm surge events and represents a vivid example for studying today’s overwash dynamics of a young barrier island. A variety of different erosional and depositional sedimentary features like washover channel and washover fans can be recognised straight next to each other.

Сахалинская область – единственная область в Российской Федерации, которая расположена на многочисленных островах в Японском, Охотском морях и в Тихом океане. Область является уникальным для России морским регионом, географическое положение которого обязывает активно развивать системы мониторинга и контроля морских акваторий, поддерживать эффективность функционирования морских служб и действенность систем предупреждения об опасных морских, метеорологических и сейсмических явлениях.

Развитие систем контроля и наблюдения за обстановкой на море знаменуется активной интеграцией идей и методов исследования Мирового океана, быстрым внедрением новых технических средств и телеметрических систем оперативного обнаружения потенциально опасной динамики взаимодействия атмосферы и океана, катастрофических процессов геофизического или техногенного характера.

Современные технические средства контроля состояния моря развиваются на фоне возрастающих возможностей вычислительной техники. Это открывает перспективы активного использования прямого численного моделирования гидродинамических процессов в открытом океане и вблизи защищаемых участков морского побережья. В режиме автоматического построения вычислительных экспериментов, с опорой на использование телеметрических систем оперативного контроля динамики моря и атмосферы, новые методы численного моделирования способны дать заблаговременный прогноз развития опасной ситуации на море и позволят предварительно изучить гидродинамические условия при обустройстве морской инфраструктуры и проектировании морских стационарных и плавучих инженерных сооружений.

При оперативном анализе информации о состоянии моря, непрерывно поступающей по телеметрическим каналам связи, могут, также, использоваться данные от других систем наблюдения, к примеру, материалы дистанционного зондирования Земли из космоса, но все эти разрозненные во времени и пространстве данные могут быть увязаны с помощью единой модели состояния моря и атмосферы, построенной на основе непрерывного численного моделирования гидрофизических процессов в морских акваториях.

В настоящем исследовании созданы теоретические основы, разработаны новые математические модели и технические средства измерений, реализовано программное обеспечение ЭВМ и методы комплексного изучения длинноволнового режима в открытом море, в мелководной шельфовой зоне и на акваториях закрытых бухт и гаваней портов, необходимых для гидротехнических изысканий и контроля потенциально опасных морских явлений, а также для принятия эффективных решений по защите прибрежной инфраструктуры и минимизации ущерба от геофизических катастроф на море.

The flood of 1607 was the worst natural disaster ever recorded in the British Isles. The flood affected most of the South Wales coast from Carmarthenshire in the west to Monmouthshire in the east. On the other side of the Bristol Channel and Severn Estuary, parts of Southwest England were also severely affected stretching from North Devon, through to Somerset and Gloucestershire, which together with South Wales amounts to 570 km of coastline. The coastal population was devastated with at least 2000 fatalities according to one of the contemporary sources. In some parts of the coast the population never recovered from the social and economic disaster. But what caused the flood? This seminar looks at historical documentary and geographical fieldwork evidence collected by Professor Simon Haslett and co-workers in proposing that the 1607 flood may have been due to a tsunami.

Storm surges are behind the geophysical risk of short term and abrupt inundating low‐lying coastal regions known along most coasts of the world. They are related to meteorological phenomena, mostly wind storms. Storm surges represent a challenge for science and risk management with respect to short term forecasts of specific events but also with long‐term changes of the statistics of storm surges due to anthropogenic global climate change, sinking coasts and estuarine water works. Storm surges are expected to become more severe in the coming decades and centuries because of ongoing and expected accelerated mean sea level, and much less so because of more energetic wind storms.

A related article is von Storch, H. and K. Woth, 2008: Storm surges, perspectives and options. Sustainability Science 3, 33-44; DOI 10.1007/s11625-008-0044-2

A state-of-the-art forecasting system (WaveForUs: Wave climate and coastal circulation Forecasts for public Use) is implemented, delivering 3-day forecasts of spectral wave characteristics, hydrodynamic circulation and storm surges for the Thermaikos Gulf (North Aegean Sea). The forecasts are disseminated to the public via television broadcasts and internet applications. The WaveForUs platform is fully functional and aspires to provide users with an invaluable tool for their sea-based activities in Greece. The simulations are based on a storm surge hydrodynamic model, a circulation ocean model and a wave model, while necessary atmospheric input data are provided by a well-validated atmospheric model. The main characteristics of the WaveForUs system and the sea-state models that comprise the core of the modelling system are presented and discussed, while results from calibration/validation tests support the accuracy of the forecasts.

Several impacts of high-energy marine events – tsunamis and storms – which have occurred along the Mediterranean coasts, have determined boulder displacements in different ways, spanning from sliding and overturning to saltation. The dynamics of these transport modes to the incipient motion of boulders, strictly connected to the pre-setting scenarios, has been extensively studied considering the boulder size and the hydrodynamic parameters of high-energy marine events, such as the wave flow velocity. Notwithstanding this, known hydrodynamic relationships provide some unrealistic flow values concerning the real wave flow velocity registered along the Mediterranean coasts. In this work, a new deterministic and theoretical approach has been developed to assess the minimum flow velocities required to move coastal boulders. The proposed approach is based on the introduction of modified parameters, which consider the real dimensional features of the boulders
assessed by means of modern geophysical survey techniques, into the incipient motion formulas. To accurately define these parameters, we created a database composed of boulders located along the coasts of Apulia and Sicily (Italy) that were surveyed in previous studies through photogrammetric and Terrestrial Laser Scanner techniques. Results highlighted that the incipient motion formulas, revised with the new proposed parameters, provided minimum flow velocity values for boulder transport initiation, which were significantly lower compared to those calculated using the previous approach. Thus, the proposed modifications are a step forward towards defining the dynamics of boulder displacement.

Characterization of scour due to free fall of water during storm surge is important for transportation related structures. The roads and streets behind levees are the most typical structures, which are vulnerable to storm surge. A sustained storm surge overtopping a floodwall or weir can cause scour of landside embankment soils, which can compromise embankment stability. Presence of wave action also contributes to scour progression and loss of lateral support. As lateral support is reduced, the overloaded retaining structure can start tilting and exacerbating the instability. Scour depth and stresses due to vertical flow are dependent on shear stresses induced by the plunging water or vertical jet, height of the wall, storm surge and wave heights, depth of the plunge pool on the landside of the retaining structure or a floodwall, and erosion rate of the levee soils. This paper focuses on estimating scour depth and hydraulic stresses imposed by overtopping due to a sustained storm surge. The analysis results are compared to observed scour depths on the landside of floodwalls after Hurricane Katrina along the Inner Harbor Navigation Channel (IHNC). The findings show that for transportation structures which are prone to water free fall during storms, it is important to consider impinging effect of water on soil supporting transportation structures.

After a hurricane strikes areas where tourists are located will have issues that will need to be addressed if tourism is to remain sustainable. The various factors are reviewed here, with specific reference to hurricane Dorian which struck the islands of Abaco and Grand Bahamas in early September 2019. Physical damage, especially to infrastructure, is examined. In the early stages after Dorian communications were a problem, followed by fresh water supplies and the electrical power. Flooding from a significant storm surge affected the towns of Marsh Harbour on Abaco and Freeport on Grand Bahama. The international airports in both these settlements were severely affected. Evacuation of tourists and the suitable location of tourist properties before and after a hurricane is discussed. Security issues and media perception in the aftermath are examined.