A hurricane is a combination of sustained winds, low atmospheric pressures and precipitation. Over the past decades, Louisiana has experienced several devastating hurricanes. The east bank of the City of New Orleans is bounded by Lake Pontchartrain to the North and the Mississippi River to the South. Lake Pontchartrain is a brackish system connected to the Gulf of Mexico through Lake Borgne to the East. As a Hurricane enters the Estuary from the Gulf of Mexico, it imposes a sustained surge of a few meters which may lead to flooding in areas which are not protected by levees. These flood water may be saline. Saltwater flooding is an environmental issue in flooded marshlands since saltwater can be fatal to some plants. The response of salinity and storm surge to hurricane duration which represents the forward speed of the storm is numerically modeled.

Som en del av Elsäkerhetsverkets klimatanpassningsarbete undersöktes i detta examensarbete vilken kunskap som finns kring personsäkerhet vid översvämning av lågspänningsanläggningar, samt huruvida vanligt förekommande elapparater och elcentraler läcker ut ström när de nedsänks i vatten. Informationsinhämtning skedde genom sökning i artikeldatabaser. Sökningarna resulterade främst i artiklar om person-säkerhet i andra typer av vattenmiljöer med elanläggningar, i huvudsak båt- och hamnmiljöer. Mätningar på ett urval av eluttag, kopplingsdosor och elcentraler nedsänkta i vatten respresenativt för dagvatten visade att samtliga läckte ut ström till en jordelektrod på 1,2 m avstånd, förutom en elcentral av metall med jordat hölje och stängd dörr. De flesta läckströmmar var större än gränsvärden för farlig strömstyrka. Säkringar på 16 A och 25 A löste ut först vid vattenkonduktivitet representativt för havsvatten. Vid mätningarna uppmättes farliga potentialer i vattnet kring apparaterna och centralerna. Simuleringar med dataprogram visade att det elektriska fältets utbredning kunde påverkas stort av den specifika geometrin i rummet, med främmande ledande delar och olika konduktivitet i väggar och golv. Det bekräftar att strömfördelning och det elektriska fältets utbredning i reella översvämningsmiljöer  är svårförutsägbart. / As a part of the work by the Swedish Electrical Safety Authority to adapt rules and regulations to future climate changes, this thesis investigate the present knowledge about personal safety during flooding of low voltage distribution systems and private electrical utilities. It also investigate if common electrical equipment and distribution boxes leak current when immersed in water. Information seeking was done by searches in article databases. The search results mainly concerned personal safety in other types of  environments with water and electric facilities, mostly boats and marinas. Measurements on a selection of electric equipment and distrbution boxes immersed in water, representative of surface water, showed that all but one produced leak current in the water to a ground electrode at a distance of 1,2 m. Only a metal distribution box with grounded casing and closed door did not produce leak current in the water. Most of the leak currents exceeded limits for dangerous current levels. Dangerous potenatials where recorded in the water surrounding the equipment. Simulations with computer programs showed that the distribution of the electrical field could be greatly affected by the particular environment, consisting of different metal structures common in buildings and different conductivity in walls and floor. It confirms that current split and distribution of electric fields i real flooded environments are hard to predict.

Water resources for outdoor areas, such as lawns and landscapes, continues to become limited in many urban areas, especially in times of acute drought stress. Lawn species selection and cultural practices, such as mowing height, can strongly influence overall seasonal water needs. While previous research has reported various lawn species water use rates and differences in the ability of some cultivars to maintain green coverage during acute drought stress, little is known regarding the irrigation requirements of cool-season lawn species when using a deficit irrigation strategy based on a green coverage target threshold (e.g. 60-80% green) approach. Two greenhouse studies were conducted to screen various candidate species and seed mixtures in a sandy media. The highest water use and worst appearance/green coverage was associated with an inexpensive commercial lawn mixture; and the lowest water use and best appearance was generally associated with improved Kentucky bluegrass (<i>Poa pratensis</i> L.: KBG) cultivars. Field studies were conducted to quantify the irrigation requirements of drought susceptible (DS) and improved, drought tolerant (DT) KBG and tall fescue [<i>Schedonorus arundinaceus</i> (Schreb.): TF] cultivars, blends and mixtures at two mowing heights (5.1 or 8.9 cm). Results from a 74-day field study using a deficit irrigation replacement approach with a 70% green coverage threshold (GCT₇₀) irrigation trigger, demonstrated water savings of approximately 73 to 78% when using a DT TF (60.3 mm) as compared to 100% evapotranspiration (ET­_o) replacement (223.4 mm) and a conventional lawn irrigation approach (268.5 mm), respectively. The time to reach the GCT₇₀ generally ranked: TF=TF:KBG mixture>KBG and ranged from 18.0 days for DS ‘Right’ KBG and 52.5 days for DT ‘RainDance’ TF. Among TF and KBG cultivars using the GCT­₇₀irrigation approach, DT TF required 35 to 68% less supplemental irrigation compared to DT and DS KBG cultivars (92.1 vs. 187.3 mm), respectively. Within KBG cultivars, the DT ‘Desert Moon’ required one-half the irrigation of DS Right (92.1 vs. 187.3 mm), while there were no differences among TF cultivars for irrigation needs. Mowing height did not affect KBG irrigation needs, but TF at 5.1 cm showed increased visual quality and green coverage, and significantly reduced irrigation requirements. Field research also compared species mixtures and blends using DS and DT KBG and TF to determine the amount of a DT species/cultivar that would enhance drought performance with ratios ranging from 25-100% DT as well as 90:10 TF:KBG mixtures. The quantity of a DT KBG in a blend, and DT TF in a TF:KBG mixture reduced irrigation needs, whereas the drought rating of the KBG cultivar in a TF:KBG mixture had no significant effect. In summary, these studies continue to demonstrate that significant supplemental lawn irrigation savings can be achieved by the selection of superior DT species and cultivars combined with a deficit irrigation replacement approach compared to other cool-season species and conventional irrigation practices.

Cette thèse sur travaux vise à rassembler et unifier les travaux réalisés sur le sujet des évènements météo-océaniques extrêmes depuis 2009, dans le cadre de mon travail à SOGREAH, devenu depuis ARTELIA. À mesure que progressaient ces travaux, un thème central a progressivement apparu : la notion d'évènement, tel qu'une tempête. Ce concept fournit un cadre robuste et pertinent, en particulier dans le cas des extrêmes multivariés (par exemple, la probabilité d'occurrence conjointe des vagues et des niveaux marins), ainsi qu'une meilleure compréhension de la notion de période de retour, très utilisée dans le domaine de l'ingénierie.Les principaux résultats des travaux réalisés au cours de la décennie écoulée sont les suivants :- mise à jour de la méthodologie de détermination des houles ou vents extrêmes :- développement et justification d'un cadre en deux étapes pour la modélisation sup-seuil des extrêmes univariés (méthode du renouvellement), introduisant la notion d'évènement et la séparation des seuils physique et statistique,- proposition d'outils pratiques pour le choix du seuil statistique,- introduction de la méthode du bootstrap paramétrique pour le calcul des intervalles de confiance,- identification d'un comportement problématique de l'Estimateur du Maximum de Vraisemblance et proposition d'une solution : utilisation de distributions à trois paramètres avec l'estimateur des L-moments,- application du cadre POT (Peaks-Over-Threshold) à la Méthode des Probabilités Jointes (JPM) pour la détermination des niveaux marins extrêmes :- distinction entre les valeurs séquentielles et les pics des évènements à l'aide d'indices extrémaux pour les surcotes et les niveaux marins,- construction d'un modèle mixte pour la distribution des surcotes,- raffinements pour le traitement de la dépendance marée-surcote,- application du cadre POT-JPM pour l'analyse conjointe des hauteurs de vagues et des niveaux marins :- proposition d'une procédure alternative d'échantillonnage,- analyse séparée de la marée et de la surcote dans le but de modéliser la dépendance entre la hauteur de vagues et la surcote ; avec incorporation dans la distribution conjointe de la hauteur de vagues et du niveau marin à l'aide d'une opération de convolution 2D1D,- utilisation de copules des valeurs extrêmes,- présentation améliorée du chi-plot,- introduction d'une nouvelle classification pour les analyses multivariées :- Type A : un phénomène unique décrit par différentes grandeurs physiques qui ne sont pas du même type,- Type B : un phénomène fait de différentes composantes, décrits par des grandeurs physiques du même type d'un composant à l'autre,- Type C : plusieurs phénomènes décrits par des grandeurs physiques qui ne sont pas du même type,- interprétation de la signification des évènements multivariés :- lien avec l'échantillonnage,- lien avec les différentes définitions de la période de retour,- dans le cas bivarié : transformation d'une distribution conjointe de variables descriptives de l'évènement vers la distribution des couples de variables séquentielles,- génération de graphes de srotie alternatifs tels que les contours d'iso-densité pour les couples de variables séquentielles,- un package R dédié, artextreme, pour l'implémentation des méthodes ci-dessus / This PhD on published works aims at unifying the works carried out on the topic of extreme metocean events since 2009, while working for SOGREAH then ARTELIA.As these works went along, a leading theme progressively appeared: the notion of event, such as a storm. This concept provides a sound and relevant framework in particular in the case of multivariate extremes (such as joint probabilities of waves and sea levels), as well as a better understanding of the notion of return period, much used for design in the field of engineering.The main results of the works carried out in the last decade are as follows:- updating of the methodology for determining extreme wave heights or wind speeds:- development and justification of a two-step framework for extreme univariate over-threshold modelling introducing the concept of event and the separation of the physical and statistical thresholds,- proposal of practical tools for choosing the statistical threshold,- introduction of the parametric bootstrap approach for computing confidence intervals,- identification of a problematic issue in the behaviour of the Maximum Likelihood Estimator and proposal of a solution: use of 3-parameter distributions along with the L-moments estimator,- application of the POT framework to the Joint Probability Method for determining extreme sea levels:- distinction between sequential values and event peaks through extremal indexes for surge and sea level,- construction of a mixture model for the surge distribution,- refinements for handling tide-surge dependence,- application of the POT-JPM framework for the joint analysis of wave height and sea level:- proposal of an alternative sampling procedure,- separate analysis of tide and surge in order to model the dependence between wave height and surge to be incorporated in the joint distribution of wave height and sea level thanks to a 2D1D convolution operation,- use of extreme-value copulas,- improved presentation of the chi-plot,- introduction of a new classification for multivariate analyses:- Type A: a single phenomenon described by different physical quantities that are not of the same kind,- Type B: a phenomenon made of different components, described by physical quantities of the same kind between one component and another,- Type C: several phenomena described by physical quantities that are not of the same kind,- interpretation of the meaning of multivariate events:- link with the sampling procedure,- link with the different definitions of the return period,- in the bivariate case: transformation of the joint distribution of event-describing variables into the joint distribution of sequential pairs,- generation of alternative output plots such as contours of density for sequential pairs;- a dedicated R package, artextreme, for implementing the methodologies presented above

Este projeto de mestrado apresenta uma caracterização das chuvas estimadas pelo radar meteorológico Doppler de dupla polarização banda S (SPOL) do Departamento de Águas e Energia Elétrica (DAEE) e Fundação Centro Tecnológico de Hidráulica (FCTH) durante eventos com ou sem alagamento para cada bairro da cidade de São Paulo durante o ano de 2015. A caracterização foi determinada a partir da função densidade de probabilidade (PDF) da chuva acumulada e da taxa de precipitação, duração da chuva e fração da área de cada bairro onde ocorreu a chuva. Na média, os eventos de alagamento estavam associados com um volume de chuva maior que 30mm e taxa precipitação máxima maior que 30mm/h. Com relação à duração não foi possível encontrar um padrão médio, pois a chuva teve duração mínima de 20 minutos e máxima de 23 horas. Por outro lado, eventos de alagamento tinham alcançado mais de 27% da área do bairro com taxa de precipitação maior que 30 mm/h e 50 mm/h. Destaca-se ao longo desta análise que os bairros localizados próximos aos rios Tietê e Pinheiros e a região central da cidade de São Paulo apresentaram maior probabilidade de ocorrência de alagamento com volumes de chuva mais baixos do que a média de 30 mm por dia e também registraram maior recorrência de pontos alagados. Por último foi desenvolvido um método de regressão logística binária para calcular a probabilidade de ocorrência de alagamentos nos diversos bairros da cidade São Paulo. Este modelo utiliza como parâmetros de entrada a duração da chuva, a taxa de precipitação máxima e a chuva acumulada nas últimas 24 horas. O modelo apresentou uma probabilidade de detecção (POD) média de 1% e uma taxa de falso alarme média (FAR) de 0,6 para os eventos de alagamento, já para eventos sem alagamento o POD médio foi de 96% e a FAR foi de 2,5%. Portanto o modelo consegue prever os casos sem alagamento. / This dissertation project presents a characterization of the rainfall estimated from a dual-polarization S-band Doppler meteorological radar (SPOL) of the Department of Water and Electric Energy (DAEE) and Foundation Technological Center of Hydraulics (FCTH) during with or without flooding events for each neighborhood of the city of São Paulo over the year 2015. The characterization was determined by the probability density function (PDF) of the accumulated rainfall and the precipitation rate, rainfall duration and rainfall-area fraction in the neighborhoods. In average, flood events were associated with a rainfall volume greater than 30mm and a maximum rainfall rate greater than 30mm/h. Regarding the duration, it was not possible to find an average pattern, because the rain had a minimum duration of 20 minutes and a maximum of 23 hours. On the other hand, flood events had reached more than 27% of the neighborhood\'s area with a precipitation rate greater than 30 mm/h and 50 mm/h. It is highlighted throughout this analysis that the neighborhoods located near the Tietê and Pinheiros rivers and central region of the city of São Paulo presented a higher probability of flood occurrence with rainfall volumes lower than the average of 30 mm per day and also recorded higher recurrence of flooded spots. Finally, a binary logistic regression method was developed to estimate the probability of occurrence of flooding in the various neighborhoods of the city of São Paulo. This model uses as input parameters rainfall duration, maximum rainfall rate and accumulated rainfall in the last 24 hours. The model presented a mean probability of detection (POD) of 1% and a mean false alarm rate (FAR) of 0,6 for flood events. On the other hand, for events without occurrence of flood a mean POD was 96% and FAR 2,5. Therefore, the model can predict the events without flooding.

Este projeto de mestrado apresenta uma caracterização das chuvas estimadas pelo radar meteorológico Doppler de dupla polarização banda S (SPOL) do Departamento de Águas e Energia Elétrica (DAEE) e Fundação Centro Tecnológico de Hidráulica (FCTH) durante eventos com ou sem alagamento para cada bairro da cidade de São Paulo durante o ano de 2015. A caracterização foi determinada a partir da função densidade de probabilidade (PDF) da chuva acumulada e da taxa de precipitação, duração da chuva e fração da área de cada bairro onde ocorreu a chuva. Na média, os eventos de alagamento estavam associados com um volume de chuva maior que 30mm e taxa precipitação máxima maior que 30mm/h. Com relação à duração não foi possível encontrar um padrão médio, pois a chuva teve duração mínima de 20 minutos e máxima de 23 horas. Por outro lado, eventos de alagamento tinham alcançado mais de 27% da área do bairro com taxa de precipitação maior que 30 mm/h e 50 mm/h. Destaca-se ao longo desta análise que os bairros localizados próximos aos rios Tietê e Pinheiros e a região central da cidade de São Paulo apresentaram maior probabilidade de ocorrência de alagamento com volumes de chuva mais baixos do que a média de 30 mm por dia e também registraram maior recorrência de pontos alagados. Por último foi desenvolvido um método de regressão logística binária para calcular a probabilidade de ocorrência de alagamentos nos diversos bairros da cidade São Paulo. Este modelo utiliza como parâmetros de entrada a duração da chuva, a taxa de precipitação máxima e a chuva acumulada nas últimas 24 horas. O modelo apresentou uma probabilidade de detecção (POD) média de 1% e uma taxa de falso alarme média (FAR) de 0,6 para os eventos de alagamento, já para eventos sem alagamento o POD médio foi de 96% e a FAR foi de 2,5%. Portanto o modelo consegue prever os casos sem alagamento. / This dissertation project presents a characterization of the rainfall estimated from a dual-polarization S-band Doppler meteorological radar (SPOL) of the Department of Water and Electric Energy (DAEE) and Foundation Technological Center of Hydraulics (FCTH) during with or without flooding events for each neighborhood of the city of São Paulo over the year 2015. The characterization was determined by the probability density function (PDF) of the accumulated rainfall and the precipitation rate, rainfall duration and rainfall-area fraction in the neighborhoods. In average, flood events were associated with a rainfall volume greater than 30mm and a maximum rainfall rate greater than 30mm/h. Regarding the duration, it was not possible to find an average pattern, because the rain had a minimum duration of 20 minutes and a maximum of 23 hours. On the other hand, flood events had reached more than 27% of the neighborhood\'s area with a precipitation rate greater than 30 mm/h and 50 mm/h. It is highlighted throughout this analysis that the neighborhoods located near the Tietê and Pinheiros rivers and central region of the city of São Paulo presented a higher probability of flood occurrence with rainfall volumes lower than the average of 30 mm per day and also recorded higher recurrence of flooded spots. Finally, a binary logistic regression method was developed to estimate the probability of occurrence of flooding in the various neighborhoods of the city of São Paulo. This model uses as input parameters rainfall duration, maximum rainfall rate and accumulated rainfall in the last 24 hours. The model presented a mean probability of detection (POD) of 1% and a mean false alarm rate (FAR) of 0,6 for flood events. On the other hand, for events without occurrence of flood a mean POD was 96% and FAR 2,5. Therefore, the model can predict the events without flooding.

Este estudo trata da caracterização hidromorfodinâmica de um setor paulista da planície fluvial meândrica do rio Ribeira de Iguape, abordando-se os três níveis da pesquisa geomorfológica de acordo com a concepção de HART (1986), a saber: (a) o nível descritivo da morfologia; (b) o nível descritivo dos materiais superficiais e solos; e (c) o nível analítico interpretativo dos processos, que, no caso, são hidrodinâmicos. Os resultados possibilitaram compreensão da hidromorfodinâmica das planícies fluviais meândricas em ambientes tropicais úmidos e, principalmente, da planície de inundação, podendo servir de subsídios no planejamento físico territorial regional, tendo em vista a importância da ocupação humana dentro desses setores. / The objective of this research is the hydromorphodynamic characterization of the Paulista River Ribeira de Iguape sector, approaching three levels of the geomorphology research according HART (1986), to know: (a) the morphology descriptive level; (b) the superficial materials and ground descriptive level; and (c) the processes interpretation analytical level, or hydrodynamic processes. With these surveys and systematization was possible the partially understanding humid tropical environments hidromorphodynamics trends and, mainly, of the flooding plain, which can be used in the regional territorial physical planning, in view of the importance of the occupation human being on these sectors.

Introdução. A cidade de São Paulo vem adotando medidas no enfrentamento das inundações, como a implantação dos Reservatórios de Contenção de Cheias \"Piscinões\", que no período de estiagem, após as precipitações, propiciam a formação de criadouros de culicídeos, especialmente nos componentes hidráulicos. Objetivos. Avaliar os aspectos ecológicos da fauna de culicídeos nos Reservatórios de Contenção de Cheias Caguaçu e Inhumas, verificando a diversidade, dominância, similaridade e riqueza de espécies. Correlacionar fatores abióticos com a abundância numérica de mosquitos. Materiais e Métodos: Coletas mensais de culicídeos, no período de março de 2006 a fevereiro de 2007, empregando-se os métodos de conchas e aspirador à bateria. Em laboratório, após o desenvolvimento das larvas, os adultos foram identificados até a categoria de espécie. Resultados. Foram coletados 8.917 espécimes de culicídeos, dos quais 7.750 larvas e pupas e 1.167 adultos. Os espécimes identificados foram distribuídos em 4 gêneros e 13 espécies. Observou-se a dominância de Culex (Culex) quinquefasciatus, que representou 98% dos espécimes coletados no Inhumas e 92% no Caguaçu. A maior freqüência de mosquitos foi registrada no Piscinão Inhumas (6.378 larvas e 930 adultos) e maior riqueza de espécies no Caguaçu (11 espécies). Verificou-se correlação positiva entre a temperatura a e abundância numérica de imaturos nas duas áreas, correlação positiva no Piscinão Caguaçu e correlação negativa no Inhumas entre a precipitação e a abundância numérica de imaturos. As análises estatísticas demonstraram que os fatores abióticos analisados exercem pouca influência na população de adultos. Conclusões. A espécie Culex quinquefasciatus mostrou-se dominante e mais freqüente nos dois ambientes. Medidas de controle da espécie nos piscinções estudados se fazem necessárias tendo em vista seu potencial epidemiológico na transmissão de agentes patogênicos. / Introduction. The City of São Paulo has been adopting highly measures to enable it to face up to the problem of flooding, among them being the construction of Reservoirs for the Containment of Flood Waters, known as \"piscinões\". In the dry season, after the occasional rains, these reservoirs, especially their hydraulic machinery, serve as breeding places for the Culicidae. Objectives. The assessment of the ecological aspects of the Culicidae fauna in the Reservoirs for the Containment of Flood Waters at Caguaçu and Inhumas to establish their diversity, dominance, similarity and species richness and, further, to correlate a-biotic factors with the numerical abundance of the mosquitoes. Materials and Methods: Monthly collections of Culicidae were undertaken during the period from March 2006 to February 2007, using the shell and battery aspirator methods. Results. A total of 8,917 Culicidae specimens were collected, 7,750 of which were larvae and pupae and 1,167 adults. The specimens were identified as belonging to 4 genera and 13 species. Culex quinquefasciatus, accounting for 98% of the specimens collected in the Inhumas Reservoir and 92% of those collected in Caguaçu, was the dominant species. The greatest frequency of mosquitoes was registered in the Inhumas Reservoir (6,378 larvae and 930 adults) and the greatest species richness in the Caguaçu Reservoir (11 species). A positive correlation was found as between the temperature and the numerical abundance of immature forms of the two areas and a positive correlation in Caguaçu and a negative correlation in Inhumas between the rainfall the and numerical abundance of immature forms. The analyses demonstrated that the a-biotic factors analyzed exercised little influence on the adult population. Conclusions. The species Culex quinquefasciatus was the dominant and most frequent species in both environments. Methods for the control of the species in the Reservoirs studied are necessary in view of their epidemiological potential in terms of the transmission of pathogenic agents.

<p>Stochastic information, to be understood as &quot;information gained by the application of stochastic methods&quot;, is proposed as a tool in the assessment of changes in climate.</p> <p>This thesis aims at demonstrating that stochastic information can improve the consideration and reduction of uncertainty in the assessment of changes in climate. The thesis consists of three parts. In part one, an indicator is developed that allows the determination of the proximity to a critical threshold. In part two, the tolerable windows approach (TWA) is extended to a probabilistic TWA. In part three, an integrated assessment of changes in flooding probability due to climate change is conducted within the TWA.</p> <p>The thermohaline circulation (THC) is a circulation system in the North Atlantic, where the circulation may break down in a saddle-node bifurcation under the influence of climate change. Due to uncertainty in ocean models, it is currently very difficult to determine the distance of the THC to the bifurcation point. We propose a new indicator to determine the system's proximity to the bifurcation point by considering the THC as a stochastic system and using the information contained in the fluctuations of the circulation around the mean state. As the system is moved closer to the bifurcation point, the power spectrum of the overturning becomes &quot;redder&quot;, i.e. more energy is contained in the low frequencies. Since the spectral changes are a generic property of the saddle-node bifurcation, the method is not limited to the THC, but it could also be applicable to other systems, e.g. transitions in ecosystems. </p> <p>In part two, a probabilistic extension to the tolerable windows approach (TWA) is developed. In the TWA, the aim is to determine the complete set of emission strategies that are compatible with so-called guardrails. Guardrails are limits to impacts of climate change or to climate change itself. Therefore, the TWA determines the &quot;maneuvering space&quot; humanity has, if certain impacts of climate change are to be avoided. Due to uncertainty it is not possible to definitely exclude the impacts of climate change considered, but there will always be a certain probability of violating a guardrail. Therefore the TWA is extended to a probabilistic TWA that is able to consider &quot;probabilistic uncertainty&quot;, i.e. uncertainty that can be expressed as a probability distribution or uncertainty that arises through natural variability.</p> <p>As a first application, temperature guardrails are imposed, and the dependence of emission reduction strategies on probability distributions for climate sensitivities is investigated. The analysis suggests that it will be difficult to observe a temperature guardrail of 2&deg;C with high probabilities of actually meeting the target.</p> <p>In part three, an integrated assessment of changes in flooding probability due to climate change is conducted. A simple hydrological model is presented, as well as a downscaling scheme that allows the reconstruction of the spatio-temporal natural variability of temperature and precipitation. These are used to determine a probabilistic climate impact response function (CIRF), a function that allows the assessment of changes in probability of certain flood events under conditions of a changed climate. </p> <p>The assessment of changes in flooding probability is conducted in 83 major river basins. Not all floods can be considered: Events that either happen very fast, or affect only a very small area can not be considered, but large-scale flooding due to strong longer-lasting precipitation events can be considered. Finally, the probabilistic CIRFs obtained are used to determine emission corridors, where the guardrail is a limit to the fraction of world population that is affected by a predefined shift in probability of the 50-year flood event. This latter analysis has two main results. The uncertainty about regional changes in climate is still very high, and even small amounts of further climate change may lead to large changes in flooding probability in some river systems.</p> / <p>Stochastische Information, zu verstehen als &quot;Information, die durch die Anwendung stochastischer Methoden gewonnen wird&quot;, wird als Hilfsmittel in der Bewertung von Klima&auml;nderungen vorgeschlagen.</p> <p>Das Ziel dieser Doktorarbeit ist es, zu zeigen, dass stochastische Information die Ber&uuml;cksichtigung und Reduktion von Unsicherheit in der Bewertung des Klimawandels verbessern kann. Die Arbeit besteht aus drei Teilen. Im ersten Teil wird ein Indikator entwickelt, der die Bestimmung des Abstandes zu einem kritischen Grenzwert ermöglicht. Im zweiten Teil wird der &quot;tolerable windows approach&quot; (TWA) zu einem probabilistischen TWA erweitert. Im dritten Teil wird eine integrierte Absch&auml;tzung der Ver&auml;nderung von &Uuml;berflutungswahrscheinlichkeiten im Rahmen des TWA durchgeführt.</p> <p>Die thermohaline Zirkulation (THC) ist ein Zirkulationssystem im Nordatlantik, in dem die Zirkulation unter Einfluss des Klimawandels in einer Sattel-Knoten Bifurkation abreißen kann. Durch Unsicherheit in Ozeanmodellen ist es gegenw&auml;rtig kaum m&ouml;glich, den Abstand des Systems zum Bifurkationspunkt zu bestimmen. Wir schlagen einen neuen Indikator vor, der es erm&ouml;glicht, die N&auml;he des Systems zum Bifurkationspunkt zu bestimmen. Dabei wird die THC als stochastisches System angenommen, und die Informationen, die in den Fluktuationen der Zirkulation um den mittleren Zustand enthalten sind, ausgenutzt. Wenn das System auf den Bifurkationspunkt zubewegt wird, wird das Leistungsspektrum &quot;roter&quot;, d.h. die tiefen Frequenzen enthalten mehr Energie. Da diese spektralen Ver&auml;nderungen eine allgemeine Eigenschaft der Sattel-Knoten Bifurkation sind, ist die Methode nicht auf die THC beschränkt, sondern weitere Anwendungen k&ouml;nnten m&ouml;glich sein, beispielsweise zur Erkennung von &Uuml;berg&auml;ngen in &Ouml;kosystemen.</p> <p>Im zweiten Teil wird eine probabilistische Erweiterung des &quot;tolerable windows approach&quot; (TWA) entwickelt. Das Ziel des TWA ist die Bestimmung der Menge der Emissionsreduktionsstrategien, die mit sogenannten Leitplanken kompatibel sind. Diese Leitplanken sind Begrenzungen der Auswirkungen des Klimawandels, oder des Klimawandels selber. Der TWA bestimmt daher den Spielraum, den die Menschheit hat, wenn bestimmte Auswirkungen des Klimawandels vermieden werden sollen. Durch den Einfluss von Unsicherheit ist es aber nicht m&ouml;glich, die betrachteten Auswirkungen des Klimawandels mit Sicherheit auszuschlie&szlig;en, sondern es existiert eine gewisse Wahrscheinlichkeit, dass die Leitplanke verletzt wird. Der TWA wird daher zu einem probabilistischen TWA weiterentwickelt, der es erm&ouml;glicht, &quot;probabilistische Unsicherheit&quot;, also Unsicherheit, die durch eine Wahrscheinlichkeitsverteilung ausgedr&uuml;ckt werden kann, oder die durch den Einfluß von nat&uuml;rlicher Variabilit&auml;t entsteht, zu ber&uuml;cksichtigen.</p> <p>Als erste Anwendung werden Temperaturleitplanken betrachtet, und die Abh&auml;ngigkeit der Emissionsreduktionsstrategien von Wahrscheinlichkeitsverteilungen über die Klimasensitivit&auml;t wird bestimmt. Die Analyse ergibt, dass die Einhaltung einer Temperaturleitplanke von 2&deg;C sehr schwierig wird, wenn man hohe Wahrscheinlichkeiten des Einhaltens der Leitplanke fordert.</p> <p>Im dritten Teil wird eine integrierte Absch&auml;tzung der &Auml;nderungen von &Uuml;berflutungswahrscheinlichkeiten unter Einfluss des Klimawandels durchgef&uuml;hrt. Ein einfaches hydrologisches Modell wird vorgestellt, sowie ein Skalierungsansatz, der es erm&ouml;glicht, die raum-zeitliche nat&uuml;rliche Variabilit&auml;t von Temperatur und Niederschlag zu rekonstruieren. Diese werden zur Bestimmung einer probabilistischen Klimawirkungsfunktion genutzt, einer Funktion, die es erlaubt, die Ver&auml;nderungen der Wahrscheinlichkeit bestimmter &Uuml;berflutungsereignisse unter Einfluss von Klima&auml;nderungen abzusch&auml;tzen.</p> <p>Diese Untersuchung der Ver&auml;nderung von &Uuml;berflutungswahrscheinlichkeiten wird in 83 großen Flusseinzugsgebieten durchgef&uuml;hrt. Nicht alle Klassen von &Uuml;berflutungen k&ouml;nnen dabei ber&uuml;cksichtigt werden: Ereignisse, die entweder sehr schnell vonstatten gehen, oder die nur ein kleines Gebiet betreffen, k&ouml;nnen nicht ber&uuml;cksichtigt werden, aber großfl&auml;chige &Uuml;berflutungen, die durch starke, langanhaltende Regenf&auml;lle hervorgerufen werden, k&ouml;nnen ber&uuml;cksichtigt werden. Zuguterletzt werden die bestimmten Klimawirkungsfunktion dazu genutzt, Emissionskorridore zu bestimmen, bei denen die Leitplanken Begrenzungen des Bev&ouml;lkerungsanteils, der von einer bestimmten Ver&auml;nderung der Wahrscheinlichkeit eines 50-Jahres-Flutereignisses betroffen ist, sind. Letztere Untersuchung hat zwei Hauptergebnisse. Die Unsicherheit von regionalen Klima&auml;nderungen ist immer noch sehr hoch, und au&szlig;erdem k&ouml;nnen in einigen Flusssystemen schon kleine Klima&auml;nderungen zu gro&szlig;en &Auml;nderungen der &Uuml;berflutungswahrscheinlichkeit f&uuml;hren.</p>

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