191 |
Contraintes et potentialités naturelles de quelques sites portuaires antiques de Méditerranée et de mer Noire (Fréjus, Ampurias, Kition, Istanbul, Orgamé) / Natural Constraints and potentials of some ancient harbours in the Mediterranean and Black Sea (Frejus, Ampurias, Kition, Istanbul, Orgame)Bony, Guénaëlle 04 July 2013 (has links)
Il y a 7000 ans BP, la stabilisation du niveau marin a entraîné la formation de deltas. Ces zones deltaïques abritent des milieux aux degrés de protection différents favorables à une activité maritime. Cependant, ces espaces sont soumis à des contraintes naturelles : à l'échelle de la longue durée, l'alluvionnement des deltas entraîne la mobilité des littoraux et le colmatage des milieux portuaires ; à l'échelle de l'événement, les tempêtes, les tsunamis et la mobilité crustale entraînent la destruction, la submersion ou le soulèvement des zones portuaires. Ce travail porte sur l'étude des contraintes et des potentialités environnementales de cinq ports antiques répartis dans le monde Méditerranéen en marge de deltas. L'objectif est d'estimer le poids de ces contraintes sur les sociétés via une approche statistique. Pour quatre des sites d'études, l'alluvionnement est le forçage majeur. A Kition et Orgame, l'impact de l'alluvionnement est indirect. La fermeture des baies marines par l'édification de cordons littoraux crée des environnements lagunaires propices à l'installation de zones portuaires. En revanche, Fréjus et Ampurias sont soumis à un alluvionnement direct qui a rapidement colmaté les bassins. A partir de l'époque romaine et avec l'invention de la pouzzolane, des zones portuaires sont installées en milieu littoral ouvert, comme à Istanbul. Dans un contexte tectoniquement actif, les tsunamis constituent la contrainte majeure opérant sur le port byzantin de Théodose à Istanbul. Un dépôt grossier et chaotique, contenant du matériel marin et archéologique remanié, compose une partie de la séquence stratigraphique de colmatage du bassin et témoigne de ce forçage. / The stabilization of sea level at 7000 years ago led to the formation of deltaic areas. These areas constituted sheltered environments particularly conducive to maritime activity. However, these areas were also subject to natural constraints for human occupation: at long timescales, high sediment supply to deltaic areas led to significative coastal changes and the infilling of harbour areas; at shorter timescales, high-energy events and crustal mobility led to the destruction, submersion and/or uplift of harbour areas. This work focuses on the study of environmental constraints and potentialities governing five ancient harbours, located on deltaic margins in the Mediterranean. The study aims to semi-qualitatively measure of the weight of these constraints on harbour cities, using statistical approach. High sediment supply is the major natural forcing. At Orgame and Kition, the closure of marine bays by coastal barriers led to the formation of lagoon environments conducive to the installation of harbour areas. Frejus and Ampurias were subject to direct siltation which quickly infilled the harbour basin. The invention of the pozzolan in Roman times means that harbours could be constructed in coastal areas open to the sea and away from river mouths, such as Istanbul harbour. In a tectonically active context, tsunamis are the major constraint acting in the Byzantine harbour of Theodosius in Istanbul. There, the stratigraphic sequence contains a coarse and chaotic deposit composed of reworked marine and archaeological material which demonstrates the societal impacts of such a natural and destructive forcing agent.
|
192 |
Geomorphic evolution and coastal hazards along the Iranian coast of Makran / Évolution géomorphologique et risques côtiers le long des rivages du Makran (Iran)Shah-Hosseini, Majid 21 March 2014 (has links)
Cette thèse a deux objectifs principaux: (i) la reconstruction de l'évolution des plaines côtières autour des baies de Chabahar et de Pozm et (ii) L'évaluation des risques côtiers (tsunamis et tempêtes extrêmes) par l'étude des dépôts de haute énergie. Vastes plaines côtières et paleo-rivages protégées par des terrasses marines soulevées sont présents autour des baies de Chabahar et Pozm. Nous avons mise en évidence des changements du niveau marin relatif le long de quatre profils. L'architecture interne des paleo-rivages a été imagée en utilisant le géoradar (GPR). Des analyses sédimentologiques et stratigraphiques des séquences côtières ont été examinées par carottages et tranchées. Les paleo-rivages sont datées entre 4800 et 270 ans BP à des distances respectives de 5 km et de 670 m du rivage actuel. La position spatiale des paléo-rivages montre une chute du niveau relatif de la mer de 15 m au cours des 4800 derniers années. Nous insistons aussi sur le rôle de contrôle des structures géologiques. Les dépôts d'événements (tsunami et tempêtes) ont été étudiés en contexte de côte meuble par Les sédiments sableux et coquilliers d'origine marine, et sur les côtes rocheuses par les dépôt des blocs déplacés. Nous avons appliqué des modèles hydrologiques pour évaluer et comparer la hauteur des vagues et la distance d'inondation. Nos résultats montrent qu'aucun événement de tempête, connu ou potentiel, n'est capable de transporter les blocs observés. Des vagues de tsunamis de l'ordre de 4 m de hauteur sont suffisantes pour transporter les blocs. La côte de Makran a enregistré des indices de paléo-tsunamis probablement générés par de grands séismes dans la zone de subduction. / In this thesis we have two main goals: (i) to reconstruct the Holocene coastal evolution and relative sea-level changes using strandplains around the Chabahar and Pozm bays; and (ii) to evaluate coastal hazards (tsunami and extreme storms) along the Iranian coast of Makran using high-energy deposits. Since the mid-Holocene, the shoreline rimming the bays of Chabahar and Pozm has prograded ~5 km and formed extensive strandplains. We documented relative sea-level changes along four coast-normal profiles. Internal architecture of strandplain imaged using Ground Penetrating Radar (GPR). The sedimentology and stratigraphy of the coastal sequence were studied by coring and trenching. The highest paleo-coastline is located about 5 km inland and stands approximately 15 m above present sea level. Paleo-shorelines date back between 4800 and 270 years BP at respective distances of 5 km to 670 m from the active shoreline. The spatial position of the palaeo-coastlines demonstrates a fall in local sea level of around 15 m during the last ~4800 years. Event deposits attesting to high-energy waves have been studied in low-lying coast by study of Over-washed sandy and shelly marine sediment and on the rocky shore by study of displaced boulder deposits. We applied hydrologic models to estimate the height and inundation distance of exceptional waves. Our results demonstrate that no known or probable storm is capable of detaching and transporting the boulders. Tsunami waves 4 m in height are enough to transport the boulders. We conclude the Makran coast has archived evidence of palaeo-tsunami events generated in the Makran subduction zone.
|
193 |
Caractérisation des vulnérabilités aux catastrophes " naturelles " : contribution à une évaluation géographique multirisque (mouvements de terrain, séismes, tsunamis, éruptions volcaniques, cyclones)Leone, Frédéric 29 November 2007 (has links) (PDF)
Ce mémoire présente à la fois un état des lieux de la recherche scientifique sur le sujet, en réponse à une certaine demande sociale, une synthèse de notre propre activité, et un positionnement scientifique dans le champ de la géographie des risques. Il est alimenté par des réflexions théoriques et méthodologiques plus ou moins abouties, mais illustrées par des résultats concrets issus de nos recherches. Il laisse le champ à des questionnements scientifiques à portée opérationnelle et à des perspectives de recherche visant à mieux caractériser les systèmes de vulnérabilité aux catastrophes naturelles et faciliter ainsi les modes d'évaluation intégrée et spatialisée des risques naturels. Evaluation intégrée, car la vulnérabilité y est appréhendée selon des approches multi-critères propres à caractériser les multiples facettes et facteurs qui la déterminent. Evaluation spatialisée, car le risque est mis en carte, de différentes façons et à différentes échelles, toujours selon une démarche intégrée où se combinent, critères de vulnérabilité, enjeux et aléas.
|
194 |
Från naturkatastrofdrabbat kaos till rofylld solpaus : En studie om hur reseföretag marknadsför en krisdrabbad destinationHedberg, Rebecca, Kuus, Erika January 2010 (has links)
<p>Syftet med vår studie är att först ta reda på hur reseföretag har han-terat en katastrofsituation på en destination för att sedan kunna hitta strategier som ter sig lämpliga kring marknadsföringsarbetet för att locka tillbaka resenärer till den drabbade destinationen. Vi har valt att fokusera vår uppsats kring tsunamikatastrofen 2004 och hur olika reseföretag har gått till väga för att vinna tillbaka sina kunders förtroende.</p><p>Vi har i denna uppsats valt att använda oss utav en kvalitativ me-tod med en abduktiv och fenomenologisk ansats då vårt syfte är att undersöka fenomenet tsunamikatastrofen 2004 i Thailand och ta reda på hur reseföretag har hanterat katastrofsituationen. Den abduktiva ansatsen har varit central under arbetets gång då vi har kompletterat teorin allt eftersom empirin vuxit fram. Vår empiri består av fem stycken kvalitativa intervjuer med personer som har stor erfarenhet och kompetens inom det undersökta området.</p><p>Vi har utgått från en modell som förklarar hur återhämtnings-processen för en destination bör gå till och implementerat denna modell på reseföretag. De marknadsföringsfaktorer som vi under uppsatsens gång sett vara extra vitala är relationen med kunder samt relationen med media för att kunna återhämta sig efter en kris. För fullständig slutsatsdiskussion hänvisar vi till kapitel sju.</p> / <p>The aim of this study is primarily to explore how travel companies have managed certain crisis situation on a destination to be able to adopt appropriate strategies to be used when marketing such desti-nation with the purpose to reclaim their customers. We have cho-sen to focus this paper on the tsunami disaster in 2004 and how different travel companies handled that situation when trying to regain their customers confidence.</p><p>We have chosen to use a qualitative method with an abductive and a phenomenological approach as our aim with this study is to investigate the phenomena of the tsunami disaster 2004 in Thail-and and in which way travel companies handled this situation. The abductive approach has been fundamental when working with this paper as it made it possible for us to update the papers theory as the empirics has grown. Our empiric approach includes five qual-itative interviews with people who have a lot of experience compe-tence within the area we chosen to investigate.</p><p>We have built this paper upon a model that explains how the reco-very period at a crisis destination should be handled and used this model on travel agencies. The marketing strategies that we have found fundamental during this period and essential for travel agen-cies to be aware of are those relating to the customers and media in order to recover from a crisis in the best possible way. We would like to refer the reader to chapter seven for our complete version of conclusions.</p>
|
195 |
Management of Relief Supply Chain & Humanitarian Aids Logistics through Supply Chain Resilience Case Study : South West Asia Tsunami (2004)Moeiny, Ehsan, Mokhlesi, Javad January 2013 (has links)
Humanitarian logistics and relief supply chain management is a relatively new area of investigation which is typically associated with unexpected disasters that require immediate actions and responses. It can be defined as “the process of planning, implementing, and controlling the efficient, cost-effective flow and storage of goods and materials, as well as related information, from point of origin to point of consumption for the purpose of meeting the end beneficiary‟s requirements” (Thomas, 2005).In both man-made and natural disaster relief processes, humanitarian logistics and relief supply chain operations have been hampered by a lack of information and coordination between actors. Especially in sudden-onset disasters, humanitarian logistics and relief supply chain teams have to be deployed in situations with destabilized infrastructure and with very limited knowledge about the situation at hand (Beamon 2004, Long and Wood 1995, Tomasini and Van Wassenhove 2004).This lack directly affects effective performance in terms of validity and reliability enhancement in which an adapted resiliency management in relief supply chain strategies could offer a solution to cover the problem.The purpose of study ahead is to underline the beneficial advantages offered by using resiliency methods in humanitarian logistics and relief supply chain operations, and enriching the existing benefits that relief chain management teams through the humanitarian logistics techniques have brought to satisfy the survival needs.In fact, the end result of the research will be in both fields of humanitarian logistics and relief supply chain management, and the use of resiliency theories to overcome on barriers and difficulties during relief and aid operations.
|
196 |
Le risque tsunami en France : contributions méthodologiques pour une évaluation intégrée par scénarios de risque.Sahal, Alexandre 10 December 2011 (has links) (PDF)
Bien souvent segmentées, les approches visant à évaluer le risque tsunami se contentent tantôt d'évaluer l'aléa, tantôt d'estimer les enjeux et leurs vulnérabilités, ce bien souvent de manière disciplinaire. Les différents spécialistes des composantes du risque (géophysiciens, modélisateurs, géographes, économistes, sociologues, etc.) travaillent à des échelles différentes, parlent un langage qui leur est propre. Les opérationnels de la sécurité civile tentent tant bien que mal d'y puiser des solutions de gestion de crise. La démarche proposée dans cette thèse consiste à fédérer l'ensemble de ces composantes pour une évaluation intégrée du risque tsunami. Elle présente des méthodes relatives à l'évaluation : (1) de l'historique de l'aléa et sa modélisation selon différents scénarios probables, (2) des enjeux humains et structurelles suivant les dynamiques spatio-temporelles de la fréquentation humaine des lieux exposés à l'aléa (scénarios d'enjeux), et (3) des capacités de réponse des institutions en charge de la sécurité civile. La confrontation des scénarios d'enjeux et de gestion de crise aux scénarios d'aléas permet une évaluation des dommages potentiels dans des conjonctures spécifiques. La démarche, appliquée à trois sites exposés à forts enjeux, en métropole (Antibes) comme en Outre-mer (La Réunion et Mayotte), apporte ainsi une méthode d'évaluation complète du risque tsunami. Elle fournit aux opérationnels des outils et des solutions de gestion de crise (sélection de zones refuge, modélisation des temps d'évacuation etc.), et des recommandations pour limiter les impacts de futurs événements (préparation et information des populations). Elle fait le lien entre sciences dures, sciences sociales et gestionnaires du risque à travers une approche intégrée et appliquée de l'évaluation du risque.
|
197 |
Analytical Solutions Of Shallow-water Wave EquationsAydin, Baran 01 June 2011 (has links) (PDF)
Analytical solutions for the linear and nonlinear shallow-water wave equations are developed for evolution and runup of tsunamis &ndash / long waves&ndash / over one- and two-dimensional bathymetries. In one-dimensional case, the nonlinear equations are solved for a plane beach using the hodograph transformation with eigenfunction expansion or integral transform methods under different initial conditions, i.e., earthquake-generated waves, wind set-down relaxation, and landslide-generated waves. In two-dimensional case, the linear shallow-water wave equation is solved for a flat ocean bottom for initial waves having finite-crest length. Analytical verification of source focusing is presented. The role of focusing in unexpectedly high tsunami runup observations for the 17 July 1998 Papua New Guinea and 17 July 2006 Java Island, Indonesia tsunamis are investigated. Analytical models developed here can serve as benchmark solutions for numerical studies.
|
198 |
Development Of A Web Gis-based Tsunami Inundation Mapping Service / A Case Study For Marmara Sea RegionAyca, Aykut 01 June 2012 (has links) (PDF)
Tsunamis, as the catastrophic disasters, can cause loss of live and property when they come to the shores. Preparation of emergency plans is essential to reduce the damage. Consequently, any initiative in tsunami modeling and inundation mapping is of vital importance for progressing safety surveillance and maintenance.
In an effort to achieve a thorough analysis of effect of tsunami, it is critical to estimate the geographical extent of possibly affected area and to predict tsunami impacts. The inundation mapping system also must serve to manage the simulation data in a scalable environment to reach end-users in the time of event. For this purpose, in this study, the generation of a Web based Geographic Information System (GIS) to serve inundation maps through web.
The research methodology consists of four main stages: (i) simulating tsunamis based on six different scenarios (ii) processing simulation data through a GIS application / (iii) development of web interfaces and implementation of the developed model for Web-GIS application / (iv) verification of the created model for Marmara Sea Region. The proposed system is expected to be an efficient tool for improving inundation mapping efforts for expected tsunamis in Turkey.
|
199 |
Från naturkatastrofdrabbat kaos till rofylld solpaus : En studie om hur reseföretag marknadsför en krisdrabbad destinationHedberg, Rebecca, Kuus, Erika January 2010 (has links)
Syftet med vår studie är att först ta reda på hur reseföretag har han-terat en katastrofsituation på en destination för att sedan kunna hitta strategier som ter sig lämpliga kring marknadsföringsarbetet för att locka tillbaka resenärer till den drabbade destinationen. Vi har valt att fokusera vår uppsats kring tsunamikatastrofen 2004 och hur olika reseföretag har gått till väga för att vinna tillbaka sina kunders förtroende. Vi har i denna uppsats valt att använda oss utav en kvalitativ me-tod med en abduktiv och fenomenologisk ansats då vårt syfte är att undersöka fenomenet tsunamikatastrofen 2004 i Thailand och ta reda på hur reseföretag har hanterat katastrofsituationen. Den abduktiva ansatsen har varit central under arbetets gång då vi har kompletterat teorin allt eftersom empirin vuxit fram. Vår empiri består av fem stycken kvalitativa intervjuer med personer som har stor erfarenhet och kompetens inom det undersökta området. Vi har utgått från en modell som förklarar hur återhämtnings-processen för en destination bör gå till och implementerat denna modell på reseföretag. De marknadsföringsfaktorer som vi under uppsatsens gång sett vara extra vitala är relationen med kunder samt relationen med media för att kunna återhämta sig efter en kris. För fullständig slutsatsdiskussion hänvisar vi till kapitel sju. / The aim of this study is primarily to explore how travel companies have managed certain crisis situation on a destination to be able to adopt appropriate strategies to be used when marketing such desti-nation with the purpose to reclaim their customers. We have cho-sen to focus this paper on the tsunami disaster in 2004 and how different travel companies handled that situation when trying to regain their customers confidence. We have chosen to use a qualitative method with an abductive and a phenomenological approach as our aim with this study is to investigate the phenomena of the tsunami disaster 2004 in Thail-and and in which way travel companies handled this situation. The abductive approach has been fundamental when working with this paper as it made it possible for us to update the papers theory as the empirics has grown. Our empiric approach includes five qual-itative interviews with people who have a lot of experience compe-tence within the area we chosen to investigate. We have built this paper upon a model that explains how the reco-very period at a crisis destination should be handled and used this model on travel agencies. The marketing strategies that we have found fundamental during this period and essential for travel agen-cies to be aware of are those relating to the customers and media in order to recover from a crisis in the best possible way. We would like to refer the reader to chapter seven for our complete version of conclusions.
|
200 |
Tsunami amplification phenomenaStefanakis, Themistoklis 30 September 2013 (has links) (PDF)
This thesis is divided in four parts. In the first one I will present our work on long wave run-up and some resonant amplification phenomena. With the use of numerical simulations for the nonlinear shallow water equations, we show that in the case of monochromatic waves normally incident on a plane beach, resonant run-up amplification occurs when the incoming wavelength is 5.2 times larger the beach length. We also show that this resonant run-up amplification can be observed for several wave profiles such as bichromatic, polychromatic and cnoidal. However, resonant run-up amplification is not restricted to infinitely sloping beaches. We varied the bathymetric profile, and we saw that resonance is present in the case of piecewise linear and real bathymetries. In the second part I will present a new analytical solution to study the propagation of tsunamis from a finite strip source over constant depth using linear shallow-water wave theory. The solution, which is based on separation of variables and a double Fourier transform in space, is exact, easy to implement and allows the study of realistic waveforms such as N-waves. In the third part I will explore the effect of localized bathymetric features on long wave generation. Even when the final displacement is known from seismic analysis, the deforming seafloor includes relief features such as mounts and trenches. We investigate analytically the effect of bathymetry on the surface wave generation, by solving the forced linear shallow water equation. Our model for bathymetry consists of a cylindrical sill on a flat bottom, to help understand the effect of seamounts on tsunami generation. We derive the same solution by applying both the Laplace and the Fourier transforms in time. We find that as the sill height increases, partial wave trapping reduces the wave height in the far field, while amplifying it above the sill. Finally, in the last part I will try to explore whether small islands can protect nearby coasts from tsunamis as it is widely believed by local communities. Recent findings for the 2010 Mentawai Islands tsunami show amplified run-up on coastal areas behind small islands, compared with the run-up on adjacent locations, not influenced by the presence of the islands. We will investigate the conditions for this run-up amplification by numerically solving the nonlinear shallow water equations. Our bathymetric setup consists of a conical island sitting on a flat bed in front of a plane beach and we send normally incident single waves. The experimental setup is governed by five physical parameters. The objective is twofold: Find the maximum run-up amplification with the least number of simulations. Given that our input space is five-dimensional and a normal grid approach would be prohibitively computationally expensive, we present a recently developed active experimental design strategy, based on Gaussian Processes, which significantly reduces the computational cost. After running two hundred simulations, we find that in none of the cases considered the island did offer protection to the coastal area behind it. On the contrary, we have measured run-up amplification on the beach behind it compared to a lateral location on the beach, not directly affected by the presence of the island, which reached a maximum factor of 1.7. Thus, small islands in the vicinity of the mainland will act as amplifiers of long wave severity at the region directly behind them and not as natural barriers as it was commonly believed so far.
|
Page generated in 0.0215 seconds