The last two decades have seen several large-scale epidemics of international impact, including human, animal and plant epidemics. Policy makers face health challenges that require epidemic predictions based on limited information. There is therefore a pressing need to construct models that allow us to frame all available information to predict an emerging outbreak and to control it in a timely manner. The aim of this thesis is to develop an early-warning modelling approach that can predict emerging disease outbreaks. Based on Bayesian techniques ideally suited to combine information from different sources into a single modelling and estimation framework, I developed a suite of approaches to epidemiological data that can deal with data from different sources and of varying quality. The SEIR model, particle filter algorithm and a number of influenza-related datasets were utilised to examine various models and methodologies to predict influenza outbreaks. The data included a combination of consultations and diagnosed influenza-like illness (ILI) cases for five influenza seasons. I showed that for the pandemic season, different proxies lead to similar behaviour of the effective reproduction number. For influenza datasets, there exists a strong relationship between consultations and diagnosed datasets, especially when considering time-dependent models. Individual parameters for different influenza seasons provided similar values, thereby offering an opportunity to utilise such information in future outbreaks. Moreover, my findings showed that when the temperature drops below 14°C, this triggers the first substantial rise in the number of ILI cases, highlighting that temperature data is an important signal to trigger the start of the influenza epidemic. Further probing was carried out among Maltese citizens and estimates on the under-reporting rate of the seasonal influenza were established. Based on these findings, a new epidemiological model and framework were developed, providing accurate real-time forecasts with a clear early warning signal to the influenza outbreak. This research utilised a combination of novel data sources to predict influenza outbreaks. Such information is beneficial for health authorities to plan health strategies and control epidemics.

Les éboulements rocheux de volume intermédiaire (103-105 m3) posent un problème sérieux dans les régions montagneuses en raison de leur fréquence d'occurrence relativement élevée et de leur fort pouvoir destructeur. En conséquence, il est difficile de mener des travaux de protection pour réduire l'aléa, ce qui souligne le besoin de techniques de suivi et d'alerte précoce avant la rupture. Après l'éboulement, peu d'informations quantitatives sont disponibles sur la phase de propagation en raison de la soudaineté du phénomène et de sa localisation dans des pentes raides et difficiles d'accès. Dans ce travail de thèse, une approche expérimentale est proposée pour extraire des informations à partir d'enregistrements de signaux sismiques durant les phases pré- et post-rupture d'éboulements.La première partie de ce travail vise à tester la pertinence des vibrations ambiantes pour le suivi temporel de la réponse dynamique de compartiments rocheux lors de la phase pré-rupture. Cette technique (couramment employée en génie civil pour le suivi de l'intégrité des structures) permet d'extraire les fréquences de résonance d'une structure, dont la décroissance peut traduire l'endommagement. Une étude antérieure menée sur une colonne calcaire instable a montré une décroissance d'environ 30% de la fréquence fondamentale de résonance (f1) environ deux semaines avant la rupture, interprétée comme une diminution de la rigidité du contact avec le massif stable adjacent. / Mid-size rockfalls (103-105 m3) represent a substantial hazard in mountainous areas, because of relative high rate of occurrence and destructive power. Consequently, few protection means can be applied, emphasizing the need for monitoring techniques and early warning prior to the collapse. After the rupture, quantitative information on the rockfall propagation phase is scarce, owing to their suddenness and location in steep and rugged slopes. In this thesis work, an experimental approach is proposed to derive valuable information from seismic records during rockfall pre-rupture and post-rupture phases. The first part of this work aims at testing the applicability of the ambient vibration technique to monitor unstable rock compartments dynamic response in the pre-rupture phase. This technique (commonly employed in civil engineering for structural health monitoring) reveals the resonant frequencies of a structure, a decrease in frequency revealing potential damage. A previous case study of an unstable limestone compartment brought to light a #30% decrease in fundamental resonant frequency (f1) two weeks before the collapse. Following this innovative work, we selected and instrumented four prone-to-fall medium-size rock compartments located in the Occidental Alps, showing various geological contexts (limestones, argillite and shale-sandstone series), deformation patterns and failure mechnisms. Ambient vibrations recorded on-site revealed caracteristic seismic noise features. Spectral peaks were observed and attributed to resonant frequencies of the rock compartments, the fundamental resonant frequency (f1) showing clear polarization parallel to the line of maximum slope gradient, and perpendicular to the main bounding fracture observed at most of the sites. Similar findings were made for an unstable rock compartment located in a volcanic caldera, characterized by rapid morphological changes and intense rockfall activity. The dynamic response of the rear fracture network was explored, showing that spectral content of seismic noise is controlled by the caldera structure in the 0.5-5 Hz range. The direction of vibration is polarized perpendicularly to the fractures, while vibration amplitudes are linked to compartment uncoupling from the rock massif. In this case, the physical origin of seismic noise amplification may be due to complex 2D or 3D resonance effects. For the four alpine sites, the fundamental frequency f1 was monitored over more than one year, showing fluctuations clearly correlated with temperature oscillations. The thermal control over f1 is highly complex, showing both positive and negative correlations, depending on site morphology and destructuration, as well as on the studied oscillations periods (daily or seasonal). No change in fundamental frequency resulting from damage was observed over this time span. One site, characterized by intense rock fracturing and a deep-open rear fracture, showed high f1 sensitivity to temperature changes. Thermo-mechanical numerical simulations revealed that both material contraction-dilation and thermal dependancy of the elastic modulus control f1 fluctuations. In addition, high amplitude seasonal f1 oscillations were explained by ice formation in the rear fracture. A criterion was developped to separate thermal-induced f1 fluctuations from damage effects, under the hypothesis that thermal sensitivity of a rock compartment increases towards failure. The second part of this work relates to the post-rupture phase of rockfalls. The seismic records generated by two mid-size rockfalls {one natural, one provoked{ that occured in the same place were analyzed, showing complex enveloppe and spectrogram features. Both events showed close magnitude, duration and spectral content. The seismic signals of the provoked event were calibrated using video shots, allowing estimation of fallen material velocity during the successive propagation phases.

Les crises monétaires sont les premières crises financières de l'histoire économique. Elles se traduisent par l'élimination ou la substitution des monnaies nationales. L'objectif de cette thèse est de poser les fondements théoriques et empiriques des crises monétaires, mais également de proposer un cadre de prévention de ce type de crise qui sévit en zone euro depuis 2008. Les débats économiques et politiques actuels autour des questions de désintégration monétaire témoignent de la persistance et de l'ampleur de la crise, où la légitimité et la souveraineté de la monnaie unique est menacée à moyen long terme. Les divers plans de sauvetage et les politiques d'austérité dans les pays-membres en difficulté ne sont que les conséquences et les coûts directs d'une telle crise. Ces derniers doivent interpeller les autorités de supervision à une plus grande vigilance, ainsi qu'à une politique de prévention plus avisée. L'objectif de cette thèse est double : dans une première partie, nous analysons le concept, les fondements historiques et théoriques des crises monétaires, puis dressons une typologie de celles-ci. Dans une seconde partie, nous apportons une contribution empirique relative aux déterminants des crises monétaires en zone euro et proposons un outil de prévention des crises monétaires, grâce à la mise en place d'un système d'alerte avancée (Early Warning System), par l'approche économétrique de type logit multinomial. Pour ce faire, la détection et la mesure des mésalignements des taux de change réels à l'intérieur de la zone euro est cruciale, puisqu'il constitue l'indicateur premier des crises monétaires. L'estimation des taux de change d'équilibre permettent ainsi d'apprécier la sur ou sous-évaluation des monnaies, indispensable à la mise en place d'un système d'alerte avancée, à des fins de prévention des crises monétaires. / Monetary crises are the first financial crises in economic history, which result in the elimination or substitution of national currencies. The aim of this thesis is to study the theoretical and empirical foundations of monetary crises. Furthermore, a framework for the prevention of such crises, raging in the Euro zone since 2008, is provided. The current economic and political debates about this issue reflect the persistence and the extent of this crisis, in which the Euro's legitimacy and sovereignty is threatened in the medium term. The various rescue plans and austerity policies in troubled member states are direct consequences and costs of this crisis. Consequently, supervisory authorities need to be more vigilant in strengthening their prevention policy. The purpose of this thesis is twofold: in the first part, we analyze the concept, the historical and theoretical foundations of monetary crises, and then develop a typology of them. In the second part, we provide an empirical contribution on the determinants of monetary crises in the euro area and propose a tool for preventing currency crises by setting up an Early Warning System, through the econometric approach of the multinomial logit model. As the primary indicator of monetary crises, the detection and measurement of real exchange rate misalignments within the euro area is decisive. The equilibrium exchange rates estimation allows the assessment of currency over- or undervaluation, which is essential for the implementation of an early warning system

Magister Artium - MA / The objective of the study was to find out whether the decentralisation of responsibulities for social economics development facilitated the management of disaster risk during the 2007 floods in Mozambique. the specific aims of the study were to : analyse and discuss national policies for decentralisation and their significance for DRM. Investigate which responsibilities, human and financial resources were available to local governments for the planning, implemantations and monitoring of DRM activities. Identify mechanisms institutions and activities for DRM and find out whether they provided to be effective. Explore how concerned communities participated in DRM activitiesto reduce their vulnerability to disaster risk.

La surveillance d’un glissement de terrain vise à anticiper sa rupture pour réduire le risque d’accident. Elle s'opère généralement en mesurant les déplacements du sol. Ce travail propose une nouvelle technique de mesure de déplacement de glissements, flexible et à bas coût, basée sur l’utilisation d’étiquettes d’identification radiofréquence (RFID). La méthode de localisation d’étiquettes par différence de phase à 866 MHz est explorée en conditions extérieures et sur de longues durées. Cette étude a montré une détérioration de la mesure causée par les variations de température, d’humidité, de neige et de végétation. Après application de corrections, la précision de mesure a été améliorée, passant de ±20 cm à ±1 cm en conditions extérieures courantes. Cette technique fonctionne également en conditions neigeuses et en présence d’herbes hautes, mais avec une incertitude de mesure plus élevée (±8 et 4 cm respectivement). Ces erreurs de mesure sont provoquées par des effets de propagation, d’interférence multitrajets, et de per-turbations à proximité des antennes. Un système de mesure en continu a été déployé sur le glissement de terrain de Pont-Bourquin, en Suisse, pendant cinq mois. Ce dispositif a validé l’efficacité de la technique en conditions réelles. De plus, la mesure résiste bien aux intempéries et le dispositif demande peu de maintenance, en comparaison avec les techniques conven-tionnelles (extensomètre, GPS, station totale).Deux méthodes de mesure complémentaires aux déplacements ont ensuite été étudiées. La méthode de corrélation de vibrations ambiantes est prometteuse, mais n’a pas encore été utilisée en surveillance opérationnelle. Une étude bibliographique souligne plusieurs verrous à lever, tels que la correction des variations saisonnières et journalières, l’augmentation de la résolution temporelle, et le choix des paramètres de traitement adaptés au site surveillé. La méthode qui consiste à inverser une fonction de transfert entre des données de pluie et de déplacements est ensuite étudiée. Une inversion haute résolution de cette fonction est proposée. Elle permet d’identifier des comportements hydrologiques complexes (ex : infiltration à deux vitesses sur le site de Pont-Bourquin) et de mesurer leur évolution. Les avancées de cette thèse vont permettre d’améliorer la surveillance opérationnelle tout en réduisant son coût, répondant aux besoins des collectivités territoriales. / Landslide early-warning systems are based primarily on monitoring the displacement of the landslide. This work develops a new technique for monitoring these displacements, using radio-frequency identification (RFID) passive tags and phase-based location technique. This technique is deployed for the first time outdoors and for several months. Outdoor conditions revealed strong environmental influences due to temperature variations, moisture, snow and vegetation. These can cause a ±20 cm measurement uncertainty over a year, which is too large for landslide monitoring applications. The correction of these effects allows reaching the accuracy of ±1 cm under normal conditions, ±8 cm with snow and ±4 cm with dense high grass. The remaining effects due to snow and grass are explained by the influence of this material on the direct propagation, on the multipath interferences and on the antennas. This measurement system has been deployed on the Pont-Bourquin landslide for five months. The results validate the technique for landslide monitoring applications. The technique also shows the operational benefits of robustness to bad weather, easy maintenance and low-cost material, compared to conventional techniques (extensometer, GPS, total station).This thesis then studies two complementary monitoring methods that had recently been shown to provide precursors to landslide rupture. First, ambient seismic noise interferometry is used to detect a drop of shear-wave velocity prior to a rupture. The seismic method was studied in the literature to identify what must be developed to use this technique in an operational early-warning system. It requires getting rid of daily and seasonal environmental influences, choosing the processing parameters appropriate to the monitored landslide, and improving the temporal resolution below one day while keeping a stable enough signal. The other method consists of inverting an impulse response between rainfall and displacement rate, with a high resolution. It can shed light on complex infiltration processes (e.g. infiltration with two different delays at Pont-Bourquin) and detect their abnormal evolution across time. These developments should improve landslide operational monitoring with a low budget.

Climate change, a reality, a myth, a conspiracy, remains a point of research and concern, specifically with regards to the impact it has on human health. Reports concerning climate change are accepted by many but are also rejected by prominent figures of society and powerful enterprises flourishing in the race for economic development. Yet all living organisms on Earth are dependent on its natural resources and delicate balance of co-existence. A disruption of ecological balance will bring about changes to biomes and niches. These changes will affect disease patterns and well-being for all. Vulnerable groups will be most affected. If these changes have occurred and continue to occur what provision should be made to reduce population vulnerability? What investment should be made to public healthcare to assist vulnerable population groups and improve adaptability? This study was conducted with the aide of the South African Red Cross Society in three large South African provinces, Limpopo, Mpumalanga and Kwa-Zulu Natal, each known for its rich diverse ecologies and tropical to sub-tropical climates. The study aimed to determine the level of awareness amongst the healthcare workers with emphasis on education. The participants were counsellors working closely with the National Department of Health and local clinics. A total of 101 participants completed a close-ended questionnaire. The results indicated a strong workforce of young people with post-matric qualifications and strong views. Qualitative research was used with descriptive statistics to analyse and describe the data collected. It was, therefore, recommended that investment be made into this growing workforce in healthcare, as well as healthcare as a whole, since climate change, as documented, will threaten food security and water availability, see altered diseases patterns including emerging and re-emergence of infectious diseases and cardiovascular concerns brought on by heat stress. Funding must support education and training to strengthen awareness and preparedness so as to empower this workforce so that they may assist local populations to better adapt to the changes, become more resilient and, thereby, reduce their vulnerability and risk / Health Studies / M.Sc. (Life Sciences)

By means of car2x communication technologies (car2x) driver warnings can be presented to drivers quite early. However, due to their early timing they could be misunderstood by drivers, distract or even disturb them. These problems arise if, at the moment of the warning, the safety–critical situation is not yet perceivable or critical. In order to examine, when drivers want to receive early warnings as a function of the situation criticality, a driving simulator study was conducted using the two early warning stages of a multi stage collision warning system (first stage: informing the driver; second stage: prewarning the driver). The optimum timing to activate these two early warning stages was derived by examining the drivers’ evaluation of these timings concerning their appropriateness and usefulness. As situational variation, drivers traveling at about 100 km/h were confronted with slow moving traffic either driving at 25 km/h or 50 km/h at the end of a rural road. In total, 24 participants were tested in a within-subjects design (12 female, 12 male; M = 26.6 years, SD = 7.2 years). For both stages, drivers preferred an earlier timing when approaching slow moving traffic traveling at 25 km/h (first stage: 447 m, second stage: 249 m ahead of the lead vehicle) compared to 50 km/h (first stage: 338 m, second stage: 186 m ahead of the lead vehicle). The drivers’ usefulness rating also varied with the timing, spanning a range of 8 s for driver-accepted timing variations and showed correspondence to the drivers’ appropriateness ratings. Based on these results and those of a previous study, a timing function for each of the two early warning stages depending on the speed difference between the safety–critical object and the host vehicle is presented. Indirectly, similar adaptations are already implemented in current collision warning systems, which use the time-to-collision to give drivers acute warnings in a later stage, when an immediate reaction of the driver may still prevent a collision. However, this study showed that drivers also favor this kind of adaptation for earlier warning stages (information and prewarning). Thus, adapting the timing according to the drivers’ preferences will contribute to a better acceptance of these collision warning systems.

L’objectif de cette thèse est la mise en place d’un Système d’Alerte Précoce comme instrument de prévision de la survenance des crises bancaires et des crises de la dette souveraine dans 48 pays de 1977 à 2010. Il s’agit à la fois d’identifier les facteurs capables de prédire ces événements et ceux annonçant leurs interactions éventuelles. La présente étude propose une approche à la fois originale et robuste qui tient compte de l’incertitude des modèles et des paramètres par la méthode de combinaison bayésienne des modèles de régression ou Bayesian Model Averaging (BMA). Nos résultats montrent que les avoirs étrangers nets en pourcentage du total des actifs, la dette à court terme en pourcentage des réserves totales et enfin la dette publique en pourcentage du PIB ont un pouvoir prédictif élevé pour expliquer les crises de la dette souveraine pour plusieurs pays. De plus, la croissance de l’activité et du crédit bancaire, le degré de libéralisation financière et le poids de la dette extérieure sont des signaux décisifs des crises bancaires. Notre approche offre le meilleur compromis entre les épisodes manqués et les fausses alertes. Enfin, nous étudions le lien entre les crises bancaires et les crises de la dette souveraine pour 62 pays de 1970 à 2011, en développant une approche basée sur un modèle Vecteur Auto-Régressif (VAR). Nos estimations montrent une relation significative et bidirectionnelle entre les deux types d’évènements. / The main purpose of this thesis is the development of an Early Warning System to predict banking and sovereign debt crises in 48 countries from 1977 to 2010. We are interested in identifying both factors that predict these events and those announcing their possible interactions. In particular, our empirical works provide an original and robust approach accounting for model and parameter uncertainty by means of the Bayesian Model Averaging method. Our results show that: Net foreign assets to total assets, short term debt to total reserves, and public debt to GDP have a high predictive power to signal sovereign debt crises in many countries. Furthermore, the growth rates of economic activity and credit, financial liberalization, and the external indebtedness are decisive signals of banking crises. Our approach offers the best compromise between missed episodes and false alarms. Finally, we study the link between banking and sovereign debt crises for 62 countries from 1970 to 2011 by developing an approach based on a Vector Autoregressive model (VAR). Our estimates show a significant two-way relationship between the two types of events.

As a result of the United Nations’ International Decade for Natural Disaster Reduction (1990-2000), and recent high profile disasters, disaster risk reduction has climbed high on the international political agenda. There has been a paradigm shift from reacting to disasters towards preparing for and mitigating effects of disasters. Among the measures that have been highlighted on the disaster risk reduction agenda are early warning systems. In a Swedish context, there are needs for early warnings for various flood risk types. Municipalities carry big responsibilities for managing flood risks, and early warnings have a potential to facilitate decision-making and ultimately reduce flood losses. The aim of this thesis is to describe how a variety of flood warning signals are used in the risk management process of Swedish municipalities, how they can contribute to the flood risk reducing process, and which factors influence the success of this. The thesis is based on two papers. Paper I is based on interviews with three respondents from Swedish municipalities that have invested in and established local early warning systems. The paper shows that the possible effects from a local early warning system are not only reduced flood losses but also potential spinoff, the occurrence of which is dependent on the well-being of the organisation and its risk management processes. Paper II is based on interviews with 23 respondents at 18 Swedish municipalities, who have responsibilities related to flood risk management, and one respondent who works at SMHI with hydrological warning. The paper shows that municipalities can use a variety of complementary flood warning signals to facilitate decision-making for a proactive flood response. This is however not systematically the case, and is dependent on available resources. The theoretical contribution of this thesis is a development of existing conceptual models of early warning systems with respect to risk management and system contexts, and the use of complementary warning signals. / Following the United Nations’ International Decade for Natural Disaster Reduction (1990-2000), and recent high profile disasters, disaster risk reduction has climbed high on the international political agenda. Among the measures that have been highlighted are early warning systems – for Swedish municipalities who are responsible for managing flood risks, early warnings have a potential to facilitate decision-making and ultimately reduce flood losses. This licentiate thesis, based on two articles, aims to describe how a variety of flood warning signals are used in the risk management process of Swedish municipalities, how they can contribute to the flood risk reducing process, and which factors influence the success of this. The articles show that the possible effects from a local early warning system are not only reduced flood losses but also potential spin-off benefits, the occurrence of which is dependent on factors such as organisational culture and the functioning of the wider risk management system, and that municipalities can use a variety of complementary flood warning signals to facilitate decision-making for a proactive flood response which, however, is not systematically the case as benefits are dependent on available resources.

[pt] A seca é um dos desastres naturais mais críticos que tem efeitos devastadores sobre habitats naturais, ecossistemas e muitos setores econômicos e sociais. Devido a esses graves impactos dos eventos de seca, muitos estudos estão focados no monitoramento, previsão e análise de risco de secas para auxiliar os planos de preparação e medidas de mitigação. Esta tese propõe um sistema de monitoramento e alerta de secas na região do semiárido do Brasil, chamado Drought Risk Assessment Interface (DRAI), que se baseia em um índice composto de risco de seca. O índice de risco possui duas componentes: ameaça e vulnerabilidade. A ameaça considera indicadores meteorológicos, enquanto a vulnerabilidade considera variáveis sociais. Com base na opinião de especialistas de vários países do mundo, com mais de 10 anos de experiência na área, foi definido o peso de cada um desses indicadores usando o processo de hierarquia analítica (AHP - Analytical Hierarchy Process). Os resultados foram comparados com outros índices de seca com o intuito de validar o índice proposto. Em seguida, foram levantados os principais sistemas de monitoramento e alertas em nível nacional e internacional e, então, foi proposto um padrão para geração de alertas no DRAI. Os alertas foram associados à sete medidas de mitigação de risco de seca validadas por técnicos locais. O DRAI tem como usuário final, além de outros pesquisadores, as Defesas Civis que poderão atuar diretamente nas ações de mitigação dos riscos. Como pesquisas futuras, sugere-se a automatização da coleta dos dados que compõem o índice de ameaça bem como a aplicação do estudo para todo o território brasileiro. / [en] Drought is one of the most critical natural disasters that have devastating effects on natural habitats, ecosystems and many economic and social sectors. Due to these severe impacts of drought events, many studies are focused on monitoring, forecasting and analyzing drought risk, to help with drought preparedness plans and mitigation measures. This study presents a drought early warning system in the semiarid region of Brazil, called the Drought Risk Assessment Interface (DRAI), which is based on a composite index of meteorological drought risk. The risk index has two components: hazard and vulnerability. The hazard considers meteorological indicators while the vulnerability considers social variables. Based on the opinion of experts from several countries in the world, with more than ten years of experience in the field, we define the weight of each of these indicators using the analytical hierarchy process (AHP). Then, the main early warning systems at national and international level were raised and then, a standard for generating warnings in the DRAI was proposed. The warnings were associated with seven drought risk mitigation measures validated by local technicians. DRAI has as its end user, in addition to other researchers, Civil Defenses that can act directly in risk mitigation actions. Finally, the system and its main features are presented. As future research, we suggest automating the collection of data that make up the hazard index as well as applying the study to the entire Brazilian territory.