Storm Surges

Traditionally, hydraulics and geotechnics are considered as separate disciplines that have not much in common. We think this is a mistake: there are many overlap areas where the two can strengthen each other. Flood risk management is one example, bank/dune erosion is another, local scour near structures a third. In all these cases, geotechnical failure mechanisms are just as important as hydrodynamic and sediment transport processes. I.

The low-lying coastal Sundarban is one of the prominent landfall area of tropical cyclones in this region, causing signifcant
environmental and socio-economic disruptions. Spatial cyclone vulnerability assessment is essential to identify its impact
on people and fragile ecosystems. This study applied a GIS-based Analytic Hierarchy Process (AHP) to assess the spatial
distribution of tropical cyclones in the Indian Sundarban. In the process of this cyclone vulnerability mapping, altogether
fourteen spatial components were considered, fve each from the physical and social vulnerability and four from the mitigation capacity. Based on each individual factor's proportionate contribution to the cyclone vulnerability, fve-point risk
classes’ frameworks were created. The study identifed a combined physical and social vulnerability map showing most of
the coastal community development (CD) blocks like Sagar, Namkhana, Patharpratima, Basanti, Gosaba, and Hingalganj are
highly vulnerable to tropical cyclones. Interestingly, while the earlier vulnerability map is being integrated with mitigation
capacity, the result is showing that Sagar, Namkhana, Patharpratima, and Basanti have fallen under a low vulnerable zone.
This is due to the presence of adequate mitigation capacity and infrastructural facilities in those CD blocks. On the other
hand, due to the lack of cyclone shelters and health centers, weak communication facilities, and inadequate infrastructure in
the development blocks like Kultali, a large part of Gosaba, Jaynagar I, Jaynagar II, Canning I, Canning II, and small parts
of Patharpratima and Hingalganj have fallen under very high to high vulnerable zones. The fndings can be applied towards
an efcient need assessment tool for the policymakers, to identify where and what kinds of mitigation measures are required.

Recent advances in processing multibeam sonar data brought about by the Combined Uncertainty and Bathymetric Estimator (CUBE) have demonstrated the value of identifying and tracking survey uncertainties. Most of these uncertainties were outlined in Hare, Godin, and Mayer uncertainty model developed in 1995 [2]. That report identified the uncertainties in the various electronic systems used to acquire the bathymetric data. However, one of the largest contributors to the overall error budge t in a near coastal hydrographic survey is that contributed by water level uncertainty. As the ocean mapping industry pushes for ever finer spatial details in its data, the traditional method of discrete tide zoning [3] must be abandoned for a more robust method that can match the requirements of the data. The method currently under investigation by the National Oceanic and Atmospheric Administration is the Tidal Constituent And Residual Interpolation (TCARI) method . TCARI has the ability to interpolate the water level at a vessel's position for any location and instance in time. It can also produce a gridded water level surface of the entire survey area. While the potential of this method is encouraging, a rigorous investigation of the uncertainties associated with it has yet to be completed. This research seeks to close that gap by examining the uncertainties in this method, using both observed water level information from around the country as well as data acquired during the original 1995 NOS Kinematic GPS experiment in Galveston Bay, Texas .

1 Новосибирский государственный университет 2 Институт автоматики и электрометрии СО РАН 3 Институт вычислительной математики и математической геофизики СО РАН mmlavr@nsu.ru В работе рассматриваются вопросы применения современных компьютерных архитектур для ускорения обработки данных в применении к такой проблеме, как защита прибрежных территорий от разрушительных волн-наводнений цунами. Актуальность темы обусловлена произошедшими в по-следние пятнадцать лет глобальными катастрофами, связанными с подводными землетрясениями и последовавшими за ними волнами цунами. Обсуждаются способы получения данных о волне цунами и способах быстрого компьютерного моделирования с целью оценить основные параметры волны на побережье. В случае сейсмических событий на Японском жёлобе волна цунами достигает ближайшей точки побережья примерно через 20 минут. Следовательно, система предупреждения о цунами должна получить данные, обработать их и выдать прогноз об опасности цунами за меньшее время. Приво-дят...

Storms over the North Sea can cause storm surges in the the German Bight that reach into the Ems, Jade-Weser and Elbe estuaries. The effect in each estuary can vary due to the different hydrographical structure, bathymetry, location in the the German Bight, exposure to wind direction and fresh-water discharge. A coupled meteorological and hydrodynamical numerical model was used to investigate the relative importance of these effects. With this model the impact of variations in wind speed and direction, in topography, or in fresh-water discharge can be investigated separately or in combination for historical or artificial storm surges. A better insight into the storm surge 'sensitivity' of the individual estuaries is obtained.

Greenhouse gas (GHG) climate change/global warming is one of the most pressing environmental concerns today. Small Island States, such as Trinidad and Tobago, are highly vulnerable to climate change because of their small size and low elevation, as in the case of this study, which increases their sensitivity to climate change and limits their ability to adapt. In fact, the adaptive capacity of human systems is generally low in Small Island States, and vulnerability generally high. The Petroleum Company of Trinidad and Tobago (PETROTRIN) recently conducted a detailed vulnerability assessment survey and storm surge simulation through modelling for the west coast of Trinidad stretching from Vessigny River in the North to Cap-de-Ville in the South along the Gulf of Paria. This survey was undertaken so as to identify the impacts of climate driven, sea level rises and extreme storm surge events on Petrotrin's and Trinmar's infrastructure and operations. The methodology used to conduct this vulnerability assessment survey involved coupling A-OGCM (Atmosphere-Ocean General Circulation) model simulations of future sea level rises and TAOS (Total Arbiter of Storms) estimates of storm surges to a GIS-based inundation and erosion scheme so as to estimate land loss and infrastructure facilities at risk from inundation and erosion. The results of the study show that field installations in Petrotrin at Guapo, such as access roads, pipelines, storage tanks and even pump jacks and the offshore operations of Trinmar including offshore platforms, jetties and harbours and administrative buildings would be at severe risk of inundation and erosion deriving from sea level rises and storm surge events.

Sedimentological and palaeoecological observations, accompanied by archaeological determinations and absolute dating, have been carried out on a recent beach-barrier system succes sion located 20 km south of Siracusa, south-eastern Ionian coast of Sicily (Italy) . These deposits fi ll the back edge of a ria incised within Miocene limestones and are composed of three main stratal units characterized by distinct sedimentological fe atures. The two lower units, fo rmed by cross bedded sands and laminated days, recorded the development of a small confined beach-barrier depo sitional system, influenced by fr equent high-energy events. The upper unit, represented by chaotic coarser sediments, can be attributed to a destructive marine high-energy event. The physical prop erties of the composing stratal units and the morphological setting of the study area allowed us to reconstruct a suite of storm-and tsunami-related marine depositional processes that might have occurred in recent times along this area of elevated seismicity. In particular, absolute dating and archaeological determinations allow correlating the upper unit to a tsunami wave triggered by the 1693 AD catastrophic earthquake. The same depositional mechanism can also account for some of the coarse levels occurring into the underlying stratal units.

Consideration of climate-related impacts on coasts is important to ensure readiness for disaster response. Local risk of storm surge and strong winds from hurricanes affecting Galveston, Texas, is quantified using a bivariate copula model fit to observed data. The model uses a two-dimensional Archimedean copula. Parametric uncertainty (5th and 95th percentiles) is quantified using a Monte Carlo procedure. The annual probability of a hurricane producing winds of at least 50 ms -1 and a surge of at least 4 m is 1.7 percent with a 95 percent confidence interval of (1.33, 1.78) percent. The methodology can be extended to include inland flooding and can be applied elsewhere with available information.

The accumulation of large boulders related to extreme waves are well documented in different areas of the Mediterranean coasts, such as in Turkey, Algeria, Egypt, Greece (Lesbos and Crete islands), France, Spain, Malta, Italy (Sicily and Apulia regions). These deposits have been associated to storm or tsunami events or both, depending on the local history. If compared to the Mediterranean Sea, the Adriatic Sea is considered a shallow basin, with very low wave energy. In particular the NE Adriatic, where Istria Peninsula (Croatia) is located, geological and geomorphological evidences of extreme wave events have never been described, as well as no tsunamis have been registered. We present the boulder deposits that have been recently found out in southern Istria, at Premantura and Marlera localities and we discuss the mechanisms that could have been responsible of the detachment and movement of these large rocky blocks from the emerged part of the coast and from the sea bottom inland. A multidisciplinary approach was adopted: geological and geomorphological surveyings, UAV and digital photogrammetric analysis, applying of the hydrodynamic equations as well as underwater profiles were carried out between 2012 and 2016. The southern Istrian coasts are composed of Cretaceous bedded limestones, sub-horizontal or gently inclined toward the sea and are exposed to southern winds, Scirocco and Libeccio, with wide fetch. The boulder deposits occur in correspondence of flat promontories or ancient quarry pavements, where the topography, together with the bedding planes and a dense fracture pattern constitute the predisposing factors of the boulder sizing and detachment. Boulder sizes, density, position and elevation have been measured in order to apply the hydrodynamic equations, which provide wave height values that can discriminate a storm from a tsunami origin. Biogenic marine encrustations, sometimes very recent, have been observed on large part of the boulders, attesting the infralittoral and sublittoral zones as source area (joint bounded, submerged scenario). Moreover, some boulders show typical coastal karst features that are very similar to those observed in the coastal area, attesting a subaerial scenario and a consequent detachment, lifting and re-arrangement by waves. The comparison between satellite images from 2008 to 2016, pictures collected from the WEB, pictures collected during the swim survey of the coast during summer 2012 and UAV images taken in December 2016 allowed to observe movements of some boulders and the arrival of a new one. The latter is 2.25 x 1.65 x 0.95 m, with an estimate weight of 7.65 tonnes. Our observations and results, compared with the available wave data, seem to refer to multiple storm events, even very recent.

Based on hydrological parameters, the Bengal Delta is divided into three (Mukherjee, 1976), viz., (1) the Moribund Delta, where land building practically ceased and drainage channels became functionally inoperative. Example: Murshidabad and Nadia districts; (2) the Mature Delta, where rivers still have well-defined channels and provide some impetus for irrigation and induce drainage disposal under normal conditions. Example: Mostly the northern part of the 24 Pgs. (S), Calcutta, roughly to the north of a line joining Kakdwip with Canning; and (3) the Active Delta, where the dynamic functions of the hydrological system are more manifested. The channels and creeks are wide, deep, and well-defined; the land building is still in its current phase, in which upland flow changes regime with marine incursions. Example: Southern Basanti, Gosaba, and so on. Matla-Bidyadhari Interfluve falls under the mature and active deltaic parts, as this interfluve provides some impetus for irrigation and induces drainage disposal, as well as the dynamic functions of delta building processes in the hydrological systems are manifested here.

Сборник включает доклады, представленные на Всероссийской научной конференции с международным участием «Моделирование коэволюции природы и общества: проблемы и опыт. К 100-летию со дня рождения академика Н.Н. Моисеева». Доклады отражают достижения в области моделирования эколого-экономических систем, управления и оптимизации, механики, теории принятия решений, автоматизации проектирования.

Here, we demonstrate that reductions in the depth of inlets or estuary channels can be used to reduce or prevent coastal flooding. A validated hydrodynamic model of Jamaica Bay, New York City (NYC), is used to test nature-based adaptation measures in ameliorating flooding for NYC's two largest historical coastal flood events. In addition to control runs with modern bathymetry, three altered landscape scenarios are tested: (1) increasing the area of wetlands to their 1879 footprint and bathymetry, but leaving deep shipping channels unaltered; (2) shallowing all areas deeper than 2 m in the bay to be 2 m below Mean Low Water; (3) shallowing only the narrowest part of the inlet to the bay. These three scenarios are deliberately extreme and designed to evaluate the leverage each approach exerts on water levels. They result in peak water level reductions of 0.3%, 15%, and 6.8% for Hurricane Sandy, and 2.4%, 46% and 30% for the Category-3 hurricane of 1821, respectively (bay-wide

In recent years, spline-function methods have been widely used to solve the problem of digital analysis and recovery of signals, and we this article is about building spline models end algorithms for digital processing of geophysical signals. As an example, local spline and natural spline interpolation models were constructed for digital processing of geophysical signals. The use of cubic basis splines in a number of tasks, for example, in digital signal processing with large gradients, resonant peaks, and outliers, gives better accuracy results.

This paper presents recent developments of the CoastFLOOD numerical model for the high-resolution simulation of coastal inundation induced by extreme Sea Level Elevation due to storm surges intensified by astronomical tides and Sea Level Rise. The scope of the study is to evaluate the interannual spatial variability of impacts from coastal inundation due to seawater flooding over characteristic important areas of Miami. The study period refers to the recent 30-year period of 1994 to 2023. We aspire to identify in high detail all the important environmental and socioeconomic implications that are recognized as important factors in the sustainability of coastal environments. The main motivation of the study is to contribute to a better understanding of climatic impacts along the exposed coastal areas, by examining the increasing sea level trends of coastal Total Water Level (TWL). This can be potentially useful to research on the implications to public plot-holdings’ and individual properties’ prices and insurance fees.

In the Casablanca-Mohammedia corridor (Morocco), flooding episodes have happened frequently over the past 20 years, damaging coastal settlements through overtopping and overflowing processes. In this context, a realistic assessment of the flood risk on this coastline is required. For this, the marine water level variations were computed by combining the involved variables (astronomical tide, storm surge, wave run-up, and sea level rise) during energetic events. They were compared with the seafront altitude to delineate the maximum spatial extent of flooded areas for the current and future (2100) time horizons. These variables were obtained through numerical and empirical modeling using topobathymetry, tide gauge, wind, and reanalysis data for wave and atmospheric pressure. Statistical methods were used to determine trends and distributions, including linear regression and the GEV model. Our approach was validated by comparing the estimated results of the total water level with the observations made in situ during previous events. Results show that flooding occurs mainly at high tides. The run-up is the largest contributor to total water level during energetic events (45-60% in structure defense areas against ~ 35% in natural areas). Currently, the floodable area for all of Casablanca-Mohammedia's coastline (109 km 2) is estimated to be ~ 23.5 km 2 , of which ~ 13.9 km 2 is urban. This area would grow by 10.87% and 20.9% by 2100, respectively. The most vulnerable zones are Mohammedia, Ain Sbâa, and Merzeg quarters, as well as Tamaris beaches. The touristic quarters of Ain Diab and the promenades on either side of the Hassan II Mosque are also vulnerable and can be dangerous for pedestrians. This study is crowned by the proposal of numerous necessary protection and adaptation measures, considering the specificities of the sections characterizing this coastline.

In the Casablanca-Mohammedia corridor (Morocco), flooding episodes have happened frequently over the past 20 years, damaging coastal settlements through overtopping and overflowing processes. In this context, a realistic assessment of the flood risk on this coastline is required. For this, the marine water level variations were computed by combining the involved variables (astronomical tide, storm surge, wave run-up, and sea level rise) during energetic events. They were compared with the seafront altitude to delineate the maximum spatial extent of flooded areas for the current and future (2100) time horizons. These variables were obtained through numerical and empirical modeling using topobathymetry, tide gauge, wind, and reanalysis data for wave and atmospheric pressure. Statistical methods were used to determine trends and distributions, including linear regression and the GEV model. Our approach was validated by comparing the estimated results of the total water level with the observations made in situ during previous events. Results show that flooding occurs mainly at high tides. The run-up is the largest contributor to total water level during energetic events (45-60% in structure defense areas against ~ 35% in natural areas). Currently, the floodable area for all of Casablanca-Mohammedia's coastline (109 km 2) is estimated to be ~ 23.5 km 2 , of which ~ 13.9 km 2 is urban. This area would grow by 10.87% and 20.9% by 2100, respectively. The most vulnerable zones are Mohammedia, Ain Sbâa, and Merzeg quarters, as well as Tamaris beaches. The touristic quarters of Ain Diab and the promenades on either side of the Hassan II Mosque are also vulnerable and can be dangerous for pedestrians. This study is crowned by the proposal of numerous necessary protection and adaptation measures, considering the specificities of the sections characterizing this coastline.

W. F. Baird & Associates Coastal Engineers Ltd. (“Baird”) was retained by the Barbados Coastal Zone Management Unit (“CZMU”) to undertake a shoreline improvement study for a 1.8 km stretch of coastline on the south coast of Barbados. The shoreline improvement study was the second major component of a broader coastal infrastructure improvement initiative to address public waterfront access, shore protection and beach stabilization on the south coast of Barbados, from St. Lawrence Gap to Rockley Beach. A 3D physical model study was used to support the design of a continuous oceanfront promenade and corresponding coastal protection that would (1) provide lateral pedestrian access along a shoreline that had limited or no access, and (2) improve shoreline stability to resist current and future coastal threats. The physical model study provided a unique opportunity to test a variety of coastal improvement techniques that would distinguish this section of shoreline, provide coastal protect...

Major potential marine hazards affecting the coasts of the northern and eastern parts of the Baltic Sea are reviewed. While several classical hazards such as tsunamis are immaterial here, changes in sea level and its variability, wave regime, and wind-induced coastal flooding can significantly impact coastal environments. Recent advances in detecting, analysis, and quantification of the influence of the natural factors and their changes in different Baltic Sea regions are described. Promising technologies for the monitoring of changes in the coasts and ways of mitigation of marine hazards are discussed.

Meteorological tsunamis are frequently observed in different tide stations at the southeastern coast of South America. They are associated with the occurrence of atmospheric gravity waves during the passages of cold fronts over the Buenos Aires Province continental shelf. On the other hand, storm surges are also frequent in the region, and they are associated with strong and persistent southerlies, which are also frequent during cold front passages. The impact of meteorological tsunamis in coastal erosion and in the statistics of storm surge trends is discussed in this paper. For this study, fifteen meteorological tsunamis (with maximum wave heights higher than 0.20 m), seven of them simultaneous to the occurrence of storm surge events (with extreme levels higher than |±0.60 m|), are selected from April 2010 to January 2013. The impact of meteorological tsunamis in the storm erosion potential index (SEPI) is evaluated. Not significant differences are obtained between SEPI calculated with and without filtering the meteorological tsunami signal from

fue una operación de ingeniería marítima e ingeniería social en Montevideo del siglo XX. Para proteger los barrios al sur de la ciudad, muy afectados por un temporal en 1923 que inundó la ciudad y destruyó las construcciones cercanas a la costa, se planeó un muro marítimo en el mar, ganar terrenos, y al mismo tiempo desalojar la segunda sección de la ciudad vieja, una zona roja donde no entraba ni la policía. Funcionó bien, se creó la CFRS, una entidad financiera que con la venta de terrenos en la zona ganada al mar financiaba las extensiones de la rambla. En 1993 una gran tormenta, con recurrencia de 10.000 años, afectó el muro marítimo y la rambla sur. Destruyendo parte de estas estructuras, incluso del relleno detrás del muro. En un convenio de la Facultad de Ingeniería con la Intendencia de Montevideo, el autor diseñó la reconstrucción del muro, incluyendo un deflector de olas y vientos que es el objeto de este trabajo.

Las surgencias costeras en la costa de Chile central son causadas por la interacción entre el patrón de vientos dominante y la topografía local. En consecuencia, para interpretar los procesos oceanográficos costeros es sumamente útil contar con una buena medida o ...

Accurate representation of wind forcing and mean sea level pressure is important for modeling waves and surges. This is especially important for complex coastal zone areas. The Weather Research and Forecasting (WRF) model has been run at 12-, 4-, and 1.33-km resolution for a storm event over the Irish Sea. The outputs were used to force the coupled hydrodynamic and the Proudman Oceanographic Laboratory Coastal Ocean Modeling System (POLCOMS)–Wave Model (WAM) and the effect on storm surge and waves has been assessed. An improvement was observed in the WRF model pressure and wind speed when moving from 12- to 4-km resolution with errors in wind speed decreasing more than 10% on average. When moving from 4 to 1.33 km no further significant improvement was observed. The atmospheric model results at 12 and 4 km were then applied to the ocean model. Wave direction was seen to improve with increased ocean model resolution, and higher-resolution forcing was found to generally increase the w...

A model for breach erosion in dikes is outlined. The model is based on the five-stage breach erosion process as described in [1] and [2]. For the final two stages three breach types are distinguished in the model, depending on the erodibility of the base of the dike, the presence (or absence) of a solid toe protection on the outer slope and the presence and erodibility of a high foreland. The model version for sand-dikes has been calibrated with the data of a field experiment and tested to the data of a 3D laboratory experiment, yielding good agreement. The confrontation of the model with the data of the failure of a prototype dike in the Netherlands yields results more or less in agreement with an eye-witness report. The model version for clay-dikes has been calibrated and tested with the data of a 2D laboratory experiment, the data of the laboratory experiment of the EC IMPACT Project and the data of a prototype dike-burst in China. The agreements between model predictions and the data are fairly good.

Storm tides represent a major threat to the lowlying German North Sea coast. Knowledge of extremes is essential for the design of reliable and robust coastal defences. A storm tide that occurred on 12-13 March 1906 along the German Bight coastline still represents one of the strongest events on record. For this event, detailed knowledge of atmospheric and hydrodynamic conditions is still lacking. To assess the potential impact of such an event on today's coastline, century-long atmospheric reanalysis data together with a manual synoptic reconstruction based on archived weather data were used to drive a tide-surge model and to simulate water levels during the event. Sensitivity experiments were performed to estimate potential amplification of water levels that could have been caused by different time lags between the storm and the astronomical tide. Comparison between the model results and the limited available observational data indicated that the water levels could be reasonably reconstructed using wind fields from the manual synoptic approach and some of the reanalysis ensemble members. The amplification potential was found to be low because the storm occurred during spring tide and shifts in the phase of the astronomic tide yielded only small changes in total water levels. To summarise, if pressure data are available at relevant locations, historical storm surges can be simulated with reanalysis products and also with a manual synoptic reconstruction.

The expected climate change and the associated possible increase of the frequency and magnitude of extreme storm surges may lead to larger storm surge hazards than have been observed in the past. Therefore, the German XtremRisK project aims to improve the understanding of the impact of extreme storm surges under current and future climate conditions by conducting an integrated flood risk analysis for two selected pilot sites in Germany which may be representative for an open coast (Sylt Island) and a megacity in an estuarine area (Hamburg). The research has also been focused on developing and improving the knowledge, methods and models for the assessment of intangible losses (social and environmental), their spatial modelling as well as their integration with direct and indirect economic losses. After a brief introduction into the integrated flood risk analysis being implemented, the paper describes the methodologies and discusses the results with a focus on the modelling of tangible and intangible losses in the pilot site Hamburg-Wilhelmsburg.

The accumulation of large boulders related to waves generated either by tsunamis or extreme storm events has been observed in different areas of the Mediterranean Sea. Along the NE and E low-lying rocky coasts of Malta tens of large boulder deposits have been surveyed, measured and mapped. These boulders have been detached NHESSD 3, 5977-6019, 2015 Boulder accumulations related to extreme wave events on the coast of Malta S. Biolchi et al.

An historical analysis of the occurrence of storms and their damage intensity is presented. The work analysed historical large-scale events from The Middle Ages to the 1960s at case study sites along the coasts of North Norfolk (UK); Charente-Maritime and Vend ee (France); Cinque Terre-Liguria coast (Italy); Emilia-Romagna coast (Italy) and Ria Formosa (Portugal). The work presented here used a database of events built by the RISC-KIT project, including the characteristics of the storms as well as recorded human impacts. Historical records can provide an important test bed to complement the statistical analysis of the return period of events based on measurements and provide important indicators of past events and their impact that are no longer within the historical memories of resident populations and coastal managers.

Extreme wave analysis is essential for the design and deployment of marine structures. Since extremes in natural phenomena tend to occur in clusters, it is necessary to de-cluster them in order to form a dataset of independent samples. There are several algorithms used to identify independent storms (clusters of significant wave height extremes), most of which have the disadvantage of relying on an arbitrarily selected de-clustering parameter. In this paper, an existing statistical method for systematic cluster size inferencing is used with runs de-clustering, and applied for the first time to extreme wave analysis. The Generalised Pareto Distribution (GPD) is fitted to an extreme wave dataset, and the return periods of significant wave height extremes are calculated using the resulting model function. The methodology proposed in this paper is illustrated using hindcast data for the winter months of two locations: one that is exposed to the long Atlantic swell off the west coast of France, and another in the North Sea that is characterised by short fetch. This work demonstrates how extremal index estimation may be used in conjunction with the well-known runs de-clustering algorithm to predict the return periods of significant wave height extremes.

The aim of this book series is to disseminate information to the coastal research community. The Series covers all aspects of coastal research including but not limited to relevant aspects of geological sciences, biology (incl. ecology and coastal marine ecosystems), geomorphology (physical geography), climate, littoral oceanography, coastal hydraulics, environmental (resource) management, engineering, and remote sensing. Policy, coastal law, and relevant issues such as conflict resolution and risk management would also be covered by the Series. The scope of the Series is broad and with a unique cross-disciplinary nature. The Series would tend to focus on topics that are of current interest and which carry some import as opposed to traditional titles that are esoteric and non-controversial. Monographs as well as contributed volumes are welcomed.

Although this thesis might only have my name under its title, it is the result of four years of intense cooperation with many people. Because expressing gratitude is something I do too little, I would like to take this chance for doing it properly. First of all, I want to thank the Research Fund Flanders (FWO), who supported the research project "Medieval Bruges and its outer ports. A landscape-archaeological contribution to the Zwin-debate", which created the framework of this dissertation, and in which I had the pleasure to cooperate. Hence, my first words of thank go to my promotor Prof. dr. Wim De Clercq, who first triggered my interest for medieval archaeology through his passionate teachings, then guided me through my master dissertation, and finally steered this project in the right direction. Although probably half of our discussions centred around cycling and politics, the other half was still more than a PhD-candidate could wish for, and enough to leave a fundamental imprint on the content of this thesis. Also the copromotors of this project: Prof. dr. Jan Dumolyn, Prof. dr. Erik Thoen, Prof. dr. Marc Van Meirvenne and dr. Geert Verhoeven are thanked for their guidance and feedback during the past four years. I am particularly grateful to my project-colleagues Samuël Delefortrie, Ward Leloup and Kristof Dombrecht, who helped taking the interdisciplinarity intentions of this project into successful practice. Samuël, I would not only like to thank you for the many hours and hectares you have been surveying in this project, you also have my gratitude for your thoughts and processing skills regarding the fieldwalking data, and for your pertinent and useful comments in proofreading papers. Ward & Kristof, many thanks for the translation and interpretation of the-for me-illegible archival sources. With great joy I look back to the afternoons in which the three of us spatially deciphered medieval texts and reconstructed them into GIS-shapefiles. Many colleagues from our department contributed to this thesis, yet some deserve a special word of thank. First and foremost, I am in great debt to Jeroen De Reu, my academic godfather who mentored me throughout every single step of this PhD. Thanks for the unlimited amount of answers and for initiating me into the art of writing papers. A second colleague I want to thank is the ever-smiling Maxime Poulain, my accomplice in the attempt to make sense out of a molehill-dotted field, and a stalwart helping hand in picking up and determining thousands of ceramics. Special thanks goes out to Sadi viii Maréchal, a friend who became an all-round-employable colleague, who fieldwalked all three sites, and who proofread parts of this thesis. Also Jeroen Verhegge deserves a personal word of gratitude for helping me with the coring survey.

Meteorological tsunamis are frequently observed in different tide stations at the southeastern coast of South America. They are associated with the occurrence of atmospheric gravity waves during the passages of cold fronts over the Buenos Aires Province continental shelf. On the other hand, storm surges are also frequent in the region, and they are associated with strong and persistent southerlies, which are also frequent during cold front passages. The impact of meteorological tsunamis in coastal erosion and in the statistics of storm surge trends is discussed in this paper. For this study, fifteen meteorological tsunamis (with maximum wave heights higher than 0.20 m), seven of them simultaneous to the occurrence of storm surge events (with extreme levels higher than |±0.60 m|), are selected from April 2010 to January 2013. The impact of meteorological tsunamis in the storm erosion potential index (SEPI) is evaluated. Not significant differences are obtained between SEPI calculated with and without filtering the meteorological tsunami signal from

Recently, the coastal zone in Vietnam has experienced more intensive sea attacks due to severe typhoons, climate change, and humsection an activities. Sea level rise has been recorded all along the coast. Moreover, sand exploitation and engineering measures have significantly changed local reliefs and led to apparent sea water level change on the coast of Nam Dinh province. Coastal erosion and sea dike failures have become a serious problem in the region. The site investigation of nearshore topography shows the recent changes to the coast. Hydrodynamic models show that changes of relief and increased wave attacks on dikes. The main reason for sea dike instability is soil erosion due to wave topping; meanwhile, the dikes are stable in terms of sliding. The coast should be reinforced with properly constructed revetments, wave topping preventive measures, and nearshore sand exploitation should be halted.

Non-stationary time series modelling is applied to long tidal records from Esbjerg, Denmark, and coupled to climate change projections for sea-level and storminess, to produce projections of likely future sea-level maxima. The model has several components: nonstationary models for mean sea-level, tides and extremes of residuals of sea level above tide level. The extreme value model (at least on an annual scale) has location-parameter dependent on mean sea level. Using the methodology of Bolin et al. (2015) and Guttorp et al. (2014) we calculate, using CMIP5 climate models, projections for mean sea level with attendant uncertainty. We simulate annual maxima in two ways-one method uses the empirically fitted nonstationary generalized extreme-value-distribution (GEV) of 20th century annual maxima projected forward based on msl-projections, and the other has a stationary approach to extremes. We then consider return levels and the increase in these from AD 2000 to AD 2100. We find that the median of annual maxima with return period 100 years, taking into account all the nonstationarities, in year 2100 is 6.5 m above current mean sea level (start of 21 st C) levels.

Over the centuries, the depths of the most severe storm surges that have  ooded Venice have been measured using different reference frames, i.e., related to the algae belt (CM), mean sea level (MSL), local land (ZMPS), large-scale leveling (IGM), and satellite altimetry (SA). Some reference frames, i.e., IGM and SA, are absolute, while the others are relative and represent two different physical points of view, i.e., CM and MSL refer to the sea that is rising and ZMPS refers to the land that is subsiding. The perceptions derived from the different systems are contradictory. This paper discusses and compares surges from 1821 to 2021 measured with these frames, also including the commemorative plaques that report the  ood depths on walls in Venice. The paper explains the consequences of a change in frame and zero reference, and it transforms the  ooding depths from the original systems to make them homogeneous. The severity of  flooding changes in terms of rating with the choice of frame. In the 19th century,  ve storm surges exceeded the famous level of 1966 and, if they were to recur today or in the future, the sea level rise and the local land subsidence that have occurred in the meantime would greatly exacerbate the situation.

Storms over the North Sea can cause storm surges in the the German Bight that reach into the Ems, Jade-Weser and Elbe estuaries. The effect in each estuary can vary due to the different hydrographical structure, bathymetry, location in the the German Bight, exposure to wind direction
and fresh-water discharge. A coupled meteorological and hydrodynamical numerical model was used to investigate the relative importance of these effects. With this model the impact of variations in wind speed and direction, in topography, or in fresh-water discharge can be investigated separately or in combination for historical or artificial storm surges. A better insight into the storm surge ‘sensitivity’ of the individual estuaries is obtained.

Storm related sea level variations 1958-2002 along the North Sea coast from a high-resolution numerical hindcast are investigated and compared to the results of earlier studies. Considerable variations were found from year to year and over the entire period. The large scale pattern of these variations is consistent with that derived from previous studies while the magnitudes of the long-term trends differ. The latter is attributed to different analysis periods and improvements in the atmospheric forcing and the enhanced spatial resolution of the numerical simulation. It is shown that in particular the different analysis periods represent an issue as the increase in storm related sea levels was found to be weaker over the last few years that have not been included in earlier studies. These changes are consistent with observed changes of the storm climate over the North Sea. In addition it is shown, that observed and hindcast trends may differ significantly. While the latter are in agreement with observed changes in the storm climate it may be concluded that observed sea level changes along the North Sea coast comprise a considerable fraction that can not be attributed to changes in the large scale atmospheric circulation.

Skillful and reliable predictions of week-to-week rainfall variations in South America, two to three weeks ahead, are essential to protect lives, livelihoods, and ecosystems. We evaluate forecast performance for weekly rainfall in extended austral summer (November-March) in four contemporary subseasonal systems, including a new Brazilian model, at 1-5-week leads for 1999-2010. We measure performance by the correlation coefficient (in time) between predicted and observed rainfall; we measure skill by the Brier skill score for rainfall terciles against a climatological reference forecast. We assess unconditional performance (i.e., regardless of initial condition) and conditional performance based on the initial phase of the Madden-Julian oscillation (MJO) and El Niño-Southern Oscillation (ENSO). All models display substantial mean rainfall biases, including dry biases in Amazonia and wet biases near the Andes, which are established by week 1 and vary little thereafter. Unconditional performance extends to week 2 in all regions except for Amazonia and the Andes, but to week 3 only over northern, northeastern, and southeastern South America. Skill for upper-and lower-tercile rainfall extends only to week 1. Conditional performance is not systematically or significantly higher than unconditional performance; ENSO and MJO events provide limited ''windows of opportunity'' for improved S2S predictions that are region and model dependent. Conditional performance may be degraded by errors in predicted ENSO and MJO teleconnections to regional rainfall, even at short lead times.

La reproduction des champs de vent cycloniques est une étape cruciale pour l'étude des impacts des cyclones en termes de submersion marine, de transport sédimentaire, ou encore d'états de mer. Qu'il s'agisse de prévision ou de caractérisation de l'aléa, cette phase repose à ce jour encore très largement sur des modèles paramétriques dont la validité n'est établie qu'à l'aide d'un nombre limité d'observations. Par ailleurs, le choix d'un modèle plutôt qu'un autre relève bien souvent de l'arbitraire plutôt que de considérations scientifiques objectives. Ce travail a pour principal objectif de montrer que la télédétection spatiale permet aujourd'hui de mieux représenter la structure des champs de vent cycloniques, et donc de choisir le modèle qui se rapproche le plus de la réalité en fonction du cas d'étude. Les résultats obtenus suggèrent par ailleurs que la plupart des modèles paramétriques utilisés à ce jour présentent des biais systématiques. Le travail initié dans cet article devrait permettre à la communauté scientifique d'améliorer la représentation des champs de vent cycloniques et de mieux évaluer les impacts de ces événements extrêmes.

We consider the Norwegian Meteorological Institute’s system regarding the daily forecasts of water level, and warnings of possible dangerous water level events along the Norwegian coast. The system consists of three parts, the production of water level forecasts, a decision support system, and a system for dissemination of warnings to key users and the general public. Included is a brief description of the forecasting model and the parallel ensemble prediction system, and an assessment of the forecasts produced by them. Based on the assessment of the production models for a three year period we find that they provide sufficiently trustworthy forecasts of water levels for the purpose at hand. Also included is a description of the web based decision support system for issuing warnings. The decision support system was for instance used during the extreme weather event “Elsa” in February 2020, and was found to be an efficient tool both to monitor the event in its early stages and to exp...

Part I of this two-part paper provides an overview of the HAZUS-MH Flood Model and a discussion of its capabilities for characterizing riverine and coastal flooding hazard. Included is a discussion of the Flood Information Tool, which permits rapid analysis of a wide variety of stream discharge data and topographic mapping to determine flood-frequencies over entire floodplains. Part II reports on the damage and loss estimation capability of the Flood Model, which includes a library of more than 900 damage curves for use in estimating damage to various types of buildings and infrastructure. Based on estimated property damage, the model estimates shelter needs and direct and indirect economic losses arising from floods. Analyses for the benefits of flood warning, levees, structural elevation, and flood mapping restudies are examples of analyses that can be performed with the Flood Model.

Based on a database of sea state parameters in the Adriatic Sea, wave statistics has been developed at three different geographic locations along the busy Adriatic shipping route. The underlying database consists of a systematic numerical hindcast calibrated by 24-year satellite measurements and represents the most comprehensive data source of wave parameters available for the region. Joint probability distributions of significant wave heights and peak spectral periods are derived, thus enabling extreme sea states to be determined. Furthermore, waves have been evaluated with respect to the well-known dominant wind patterns in the Adriatic and compared to the Tabain's spectrum, a single parametric spectral description developed for local conditions and widely used in engineering practice. Statistics for three geographical locations are compared with one another as well as with data from other available references. These long-term statistics and regression equations developed can be used not only for fatigue and extreme wave loads of ships, offshore installations and renewable energy devices intended for the Adriatic Sea, but also for planning and carrying out various marine operations in that specific environment. At the end of the study, some consideration is given to the effects of climate changes on the variability of sea states in the Adriatic.