<p dir="ltr">The escalating threat of flooding due to climate change, urbanization, and population growth calls for accurate flood estimation, especially as annual flood losses are projected to reach up to $52 billion by 2050. However, factors like changing precipitation patterns, watershed changes, and model uncertainties complicate future flood estimation. Rising global temperatures not only intensify extreme storms but also alter their spatial and temporal characteristics, yet these changes remain poorly understood across different climate regions, hindering effective hydrological response planning. This study investigates how climate change affects storm spatio-temporal patterns and probable maximum precipitation (PMP) estimates, pinpointing regions most vulnerable to these shifts. The specific three objectives of this study are 1) to understand how the spatial extent of short duration precipitation extreme changes across the globe particularly in response to climate variables like temperature 2) to understand and quantify the changes in combined spatio-temporal characteristics of extreme storms in response to rising temperatures; and 3) to evaluate changes in probable maximum precipitation (PMP) estimates in response to climate change, specifically identifying critical infrastructure—such as dams and nuclear facilities—that may be at increased risk.</p><p dir="ltr">In the first objective, a novel grid-based metric called the Spatial Homogeneity (SH) metric is developed to assess the changes in spatial extent of extreme storms of different intensity and across different regions. The study finds that rising temperature results in smaller size extreme storms in the tropics, but larger size storms in the arid regions. It is also found that more intense precipitation events have a smaller spatial extent. Furthermore, larger spatial extent storms were found to be associated with higher total precipitable water, while overall cold vs warm year or overall year around wetness vs dryness of a region had limited impact on the spatial extent of these extreme storms. The results of this study imply that rising temperatures will result in spatially smaller and more intense extreme precipitation storms in the tropics.</p><p dir="ltr">Adding a temporal dimension to the Spatial Homogeneity metric, the second objective introduces the Spatio-Temporal Homogeneity (STH) metric to analyze global patterns in the combined spatio-temporal characteristics of short-duration extreme storms. Findings reveal that extreme storms contract in both space and time in the tropics, while expanding in temperate zones as temperatures rise. Additionally, storms in the tropics and southern temperate regions exhibit increased front-loading, whereas northern temperate storms become slightly more rear-loaded. Short-duration (6–12 hours) storms show heightened sensitivity to temperature increases, underscoring the need for region-specific flood management and adaptation strategies.</p><p dir="ltr">Finally, the third objective assesses how climate change impacts global PMP estimates, focusing on changes in precipitation efficiency and maximum precipitable water<i> </i>𝑃𝑊_𝑚𝑎𝑥. While precipitation efficiency remains relatively unchanged, 𝑃𝑊_𝑚𝑎𝑥 has increased up to 40% in certain regions since the 1960s, establishing a conservative baseline for PMP rises. Future climate projections highlight that PMP estimates are expected to continue increasing even further. Furthermore, longer-duration PMPs show the most significant increases, stressing the need to reassess safety standards for large dams in high-risk areas. The study identifies the regions most at risk and highlights the necessity for updated PMP standards and targeted infrastructure adaptation in vulnerable regions.</p><p dir="ltr">This dissertation advances our understanding of how climate change is reshaping extreme precipitation characteristics, particularly from a hydrologic flood-generation perspective. By providing refined, climate-adjusted representations of future precipitation patterns, it marks a step toward improved accuracy in future flood and hydrologic response estimation. These insights lay a foundation for more informed flood risk assessments and support the development of targeted, resilient water management strategies essential for adapting to a changing climate.</p>

В диссертации рассматривается маркетинговая коммуникация, возникающая между поставщиком туристического продукта и его потребителем, а также особенности организуемого компанией Acerola travel коммуникационного процесса, проявленные в текстах, созданных для реализации туристического продукта и задач, направленных на цедевого потребителя услуг компании. В работе изучаются особенности коммуникационных инструментов, используемых компанией Actrola travel для продвижения своих туристических услуг в интернет-пространстве. / The dissertation examines the marketing communication that arises between the supplier of a tourist product and its consumer, as well as the features of the communication process organized by Acerola travel, manifested in texts created for the implementation of a tourist product and tasks aimed at the primary consumer of the company's services. The paper examines the features of the communication tools used by Actrola travel to promote its travel services in the Internet.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Stacy L. Hutchinson / Precipitation impacts hydrologic structures, agricultural production, water resources management, and recreational activities, all of which significantly affect a state’s economy. Water control structure design is based on the maximum runoff rate resulting from storms with a specific return period and duration. The Rainfall Frequency Atlas (National Weather Service Technical Paper 40, 1961) (TP-40) provided statistical rainfall analysis as the basis for hydrologic structure design until the information was updated for Kansas in February 2013 (National Oceanic and Atmospheric Administration Atlas 14, volume 8) (Atlas-14). With growing concern about the effects of global climate change and predictions of more precipitation and extreme weather events, it is necessary to explore rainfall distribution patterns using the most current and complete data available. In this work, the changes in rainfall patterns were studied using the daily rainfall data from 23 stations in Kansas and 15 stations from adjacent states with daily rainfall data of 1890 through 2012. Analysis showed an increase in extreme precipitation events in Kansas with increase in magnitude from the northwest to southeast part of the state. A comparison of results of the TP-40 analysis to period 1980–2009, showed that approximately 84% of the state had an increase in short-term rainfall event magnitudes. In addition, trend analyzes on the total annual rainfall indicated a gradual increase at 21 out of 23 stations, including eight statistically significant trends. A change-point analysis detected a significant sudden change at twelve stations as early as 1940 and as recently as 1980. The increasing trend, particularly after the significant change-points, is useful in updating water management plans and can assist with agricultural production decisions such as crop selection and new plant variety development. A comparison between 10-yr, 24-hr storms from TP-40 and Atlas-14 indicated a change of -12% to 5% in Kansas. However, the number of exceedances from the 10-yr, 1-, 2-, 3-, 4-, 7-, and 10-day storms demonstrated a tendency towards more exceedances, particularly in the last five decades. Results of this study are useful for hydrologic structure design and water resources management in order to prevent accepting additional risk of failure because of the current changing climate.

Portfolio Management is the process of allocating an investor's wealth to in­ vestment opportunities over a given planning period. Not only should Portfolio Management be treated within a multi-period framework, but one should also take into consideration the stochastic nature of related parameters. After a short review of key concepts from Finance Theory, e.g. utility function, risk attitude, Value-at-rusk estimation methods, a.nd mean-variance efficiency, this work describes a framework for the formulation of the Portfolio Management problem in a Stochastic Programming setting. Classical solution techniques for the resolution of the resulting Stochastic Programs (e.g. L-shaped Decompo­ sition, Approximation of the probability function) are presented. These are discussed within both the two-stage and the multi-stage case with a special em­ phasis on the former. A description of how Importance Sampling and EVPI are used to improve the efficiency of classical methods is presented. Postoptimality Analysis, a sensitivity analysis method, is also described. / Statistics / M. Sc. (Operations Research)

The aim of this study was to explore temperament, psychopathology and quality of life (QOL) in adolescents born at extremely low birth weight (ELBW), i.e., < 1000g. ELBW adolescents (N = 15) completed the Revised Cheek and Buss Scale and Mini International Neuropsychiatric Interview 5.0.0 (M.I.N.I.), while their legal guardians completed a biographical questionnaire and the Short Form 12 version 2. The median age of the sample was 13 SD = 2.526 years (60% male) and all participants spoke English. ELBW adolescents with social phobia (n = 6) were more shy (p = .041) and had poorer mental health-related QOL (p = .041) than those without such symptoms. The results suggest that ELBW could be a predisposing factor for increased shyness and psychological disorders including social phobia. Planning of interventions for ELBW individuals should therefore include strategies to prevent or mitigate the effects of these factors in adolescence / Psychology / M.A. (Clinical Psychology)

The thesis aims at corporate adaptation to climate change impacts in the logistics and transportation industry, especially for the model region Dresden. The paper employs two analyses. The first part deals with a review of the current literature within the topic. 20 references are identified and analysed with a data extraction form. More general adaptation measures are identified in the current literature which can be implemented in the corporate strategy. Crucial effects on company’s operation and its profit have flooding and sea level rise. In comparison adaptation measures, which are identified within five interviews of transportation providers in the model region Dresden, are of technological nature. The interviewed companies adapted significantly to weather extremes in the past. It is identified that heavy precipitation like rain and snow lead to crucial negative impacts to their operations which cause lost profit and customer dissatisfaction in long periods of time. On the other hand these weather conditions may have positive effects in short periods of time. Region-specific analyses in climate change impacts and the implementation of potential adaptation measures for logistics and transportation companies is still in a stage of infancy. Further research is needed on more region-specific analyses and on logistics companies in the model region Dresden as only five of them analysed in this thesis.

This thesis focuses on two extreme weather years in 1867-1868 that led to crop failure and subsistence crisis in parts of Sweden. Specifically it focus on Gävleborgs County and one parish, Hanebo Parish, in south west Hälsingland. The study presents contemporary examples from original sources on the national, regional and local level and one secondary source. With a qualitative approach, the study investigates the social impacts of sudden extreme weather and following harvest failure and assess signs of a possible subsistence crisis on regional and local level in the years of 1867-68. The empirics are analyzed trough demographic methodology often used to evaluate ”famine-like” situations, theories on famine and its causes and the three concepts: vulnerability, resilience and exchange entitlement. The result of the study shows a subsistence crisis in Gävleborg county and Hanebo Parish, in the years of 1867-68. These indications included poor harvest, demographic impact on parochial level and visible mitigating strategies for coping with the situation. Social hierarchies which are making impact on attitudes within the contemporary context of crisis are also discovered in the empiric material. The study also shows that state incentives and publically organised incentives can mitigate disaster both over short and long term.

Communication plays a fundamental role in shaping our understanding of complex issues such as climate change. Too often scientists and journalists complain that the public does not fully comprehend climate change as they cannot see it. Adhering to calls for a need to propel away from media representations of climate change to a focus on more case-specific research, this Master Thesis analyses the aspect of visualisation within climate change communication with a focus on a contemporary example, the Extreme Ice Survey (EIS), as a case-specific study. EIS give a visual voice to our planets changing eco-systems, where an emphasis is placed on visually documenting the adverse effects climate change has on the planets glaciers, through conventional photography and time-lapse photography. Adhering to the need for further studies of visual representations towards the environment this thesis deploys an image analysis to investigate how meaning is framed through the EIS’s photographs and time-lapse videos. A collective reading between the photographs and their accompanying written captions highlighted contradictive frames of beauty and uncertainty. Additionally, as climate change is predominately seen as an abstract entity, a metaphor analysis was also applied to open further frames of thought into more comprehensible understandings. Integrating both still images and moving images into the study provided different results. Time-lapse videos were analysed to open up new developments of seeing and to extract potential frames of unfolding narratives, perspective and time.

Increases in temperature, altered precipitation patterns, and the occurrence and severity of extreme climatic events have been important characteristics of the climate change observed to date. This has had many and diverse impacts upon the living world, with one recent observation being a global reduction in the net primary production of all terrestrial vegetation. Increases in temperature and the frequency of extreme events are predicted to continue throughout the 21st century, and can be expected to have far reaching effects on global terrestrial ecosystems. Increases in temperature and drought occurrence could fundamentally impact upon the growth rates, species composition and biogeography of forests in many regions of the world, with many studies indicating that this process is already underway. European beech, Fagus sylvatica, is one of Europe’s most widespread and significant broadleaved tree species, forming an important and frequently dominant component of around 17 million hectares of forest. However, the species is also considered to be drought sensitive. Thus, much research interest has focused on eliciting the details of its physiological response to increased water stress, whilst dendroecological studies have attempted to identify sites and regions where reductions in growth might be found. A significant knowledge gap exists regarding a multi-regional, range-wide view of growth trends, growth variability, climate sensitivity, and drought response for the species. Predicting the potential effects of climate change on competition and species composition in mixed species forests remains an important challenge. In order to address this knowledge gap, a multi-regional tree-ring network was constructed comprising of 46 sites in a latitudinal transect across the species’ Western European range. This consisted of 2719 tree cores taken from 1398 individual trees, which were used to construct tree-ring chronologies for each site in the network. As a first step in a multi-regional assessment for F. sylvatica, a combination of the tree-ring chronologies and environmental data derived from a large scale gridded climate dataset were used in a multivariate analysis. Sites in the latitudinal transect were partitioned into geographically meaningful regions for further analysis. The resulting regions were then studied using climate-growth analysis, pointer year analysis of drought years, analysis of growth trends and growth variability, in order to examine regional variation in the response of the species to climate. Furthermore, a combination of long-term monitoring data from one specific site was combined with tree-ring sampling of multiple cohorts of F. sylvatica and one co-dominant competitor, Quercus petraea, to study the effects of an extreme drought event in 1976 on mortality and subsequent recovery. Key results of the multi-regional analysis are that large scale growth reductions are not evident in even the most southerly and driest portions of the species’ range. Radial growth is increasing, both in the north and in the core of the species’ range, with southern range edge forests maintaining stable growth. However, the variability of growth from year to year is increasing for all regions, indicative of growing stress. Crucially, the southern range edge, which previous studies had identified as an ‘at risk’ region, was shown to be more robust than expected. Climate sensitivity and drought impacts were low for this region. Instead, forests in the core of the species range, both in continental Europe and in the south of the UK, were identified as having the highest climate sensitivity, highest drought impacts, and experiencing periodic reductions in growth as a result. Northern range edge forests showed little sign of being affected by drought, instead having low climate sensitivity and strongly increasing growth trends. Extreme drought was found to affect species differently: the dominant species (F. sylvatica) failed to recover pre-drought levels of growth, whilst a transient effect of competitive release occurred for the co-dominant species (Q. petraea). There was also a long term effect on the relative abundance of the two species within the woodland, due to differences in the levels of drought induced mortality experienced by the species. This shows that in the case of extreme climatic events where thresholds in the ability of species to tolerate water stress are breached, the effects of drought can be rapid and long lasting. Drought impacts can cascade beyond that experienced by the most drought sensitive species, due to changes in competitive interactions between species in mixed species forests. The implications of this work suggest opportunities, risks and strengths for F. sylvatica. In the northern portion of the species’ range, predicted increases in productivity are confirmed by recent growth trends, indicating a good outlook for the species. At the southern range edge, F. sylvatica forests exist either in locations where precipitation is high or locations where local environmental conditions buffer them from an inhospitable regional climate. These factors result in southern range edge forests which are highly resilient to the effects of increasing climate stress. It is instead in the core of the species’ range where the most sensitive forests are found. The effects of extreme drought on a range core forest demonstrated here provide a cautionary note: where drought stress tolerance thresholds are breached, rapid and long lasting effects on growth and mortality can occur, even in regions where drought has not previously been considered to pose a strong risk to the species.

Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Tropical cyclones are synoptic scale rotating storms capable of generating intense wind speeds and rainfall with potentially devastating social and economic consequences. In addition to abnormally high winds and rainfall, the associated storm surge and extreme waves can lead to severe coastal erosion, damage to coastal property and inundation. A good understanding of the risk exposure to these events is therefore of great importance to planners and designers of coastal infrastructure in vulnerable regions. Probabilistic approaches have been routinely adopted for the calculation of extreme tropical cyclone induced wind speeds, with significant developments in these techniques over the last few decades. While the application of these approaches has become widely adopted in regions such as the North Atlantic, North Pacific and South Pacific Oceans, relatively little attention has been paid to the South-West Indian Ocean. This thesis focusses on the quantification of the risk exposure to tropical cyclones over the South-West Indian Ocean, using current state-of-the-art techniques. The primary results of the thesis are extreme wind speed maps at various return periods of interest for engineering design. Best track data for the South-West Indian Ocean, as archived by the Joint Typhoon Warning Centre (JTWC), has been used as the primary dataset forming the basis of this study. These data provide estimates of the location and intensity of historical tropical cyclones at six hourly intervals. Location data are provided as estimates of longitude and latitude of the eye, while intensity data are provided as estimates of the maximum sustained surface (10 m elevation) wind speed and/or minimum central pressure. The modelling of tropical cyclone wind fields has been carried out using both the Holland (1980) and the Willoughby et al. (2006) parametric wind field models. Using the limited information available in the best track data as input to the model, surface wind fields which reasonably resemble those of actual storms have been generated. Both considered parametric wind field models have been shown to yield reasonable wind speeds and directions when compared with measurements. Of the two considered models the Willoughby et al. (2006) model has been shown to provide the best fit to historical wind speed measurements. Extreme value analyses of tropical cyclone induced wind speeds based on historical data alone have been shown to lead to potentially large errors, owing to the small sample size of the historical data. This highlights the need to augment the historical database through a probabilistic approach. Largely following the methods described in Powel et al. (2005) and Emanuel et al. (2006), a synthetic track model for the South-West Indian Ocean has been developed. The objective of the synthetic track model is to simulate thousands of years of tropical cyclone tracks, thereby circumventing errors induced by small sample sizes in the available historical best track data. The synthetic track model developed as part of this study is a Markov chain model, capable of simulating track propagation and intensity evolution along the track, from track genesis through to termination. The model is purely statistical, based on properties derived from the historical best track data. Adjustments have however been made to account for physical limitations such as those imposed by the equator and the maximum potential intensity which an event can attain. The statistical characteristics of synthetic tracks have been shown to agree well with those of the historical population. Applying the Willoughby et al. (2006) wind field model along synthetic tracks has enabled the simulation of 5 000 years of tropical cyclone induced wind speeds at any location of interest in the South-West Indian Ocean. Applying calculations on a 1 degree geographical grid, wind speed maps corresponding to return periods of 50, 100, 200 and 500 years have been generated for the South-West Indian Ocean. Extreme wind speeds along coastal regions provide valuable input for the design of coastal infrastructure in the region. / AFRIKAANSE OPSOMMING: Tropiese siklone is sinoptiese orde roterende storms wat in staat is om aansienlike windspoed en reënval, tot gevolg te hê met potensiële vernietigende sosiale en ekonomiese gevolge. Benewens die abnormale sterk winde en hoë reënval kan die verwante stormdeinings en vloedgolwe lei tot ernstige kus-erosie, skade aan kusfront-eiendom en oorstromings. ‘n Goeie begrip van die risiko-blootstelling aan hierdie gebeurtenisse is daarom van groot belang vir die beplanners en ontwerpers van kus-infrastruktuur in kwesbare gebiede. As gevolg van die beduidende ontwikkeling van probabilistiese benadering tot die berekening van windspoed wat veroorsaak word deur ekstreme tropiese siklone, word hierdie tegnieke huidiglike op ‘n roetine basis aangewend. Terwyl die toepassing van hierdie benaderings wyd aanvaar word in gebiede soos die Noord-Atlantiese, Noordelike- en Suidelike Stille Oseaan, word relatief min aandag gegee aan die Suid-Westelike Indiese Oseaan. Hierdie tesis fokus op die kwantifisering van die risiko-blootstelling aan tropiese siklone in die Suid-Westelike Indiese Oseaan met die gebruik van die huidige gevorderdste tegnieke. Die primêre resultaat van die tesis is uiterste wind spoed kaarte vir ‘n verskeindenheid herhaal periodes wat van belang in vir engenieursontwerp. Beste roete-ata vir die Suid-Westelike Indiese Oseaan, soos voorsien deur die Gesametlike Tifoon Waarskuwing Sentrum (JTWC), is gebruik as die primêre data stel wat die basis vorm van hierdie studie. Hierdie data gee die beste skattings van die ligging (lengte- en breedtegraad), en intensiteit (maksimum volgehoue oppervlak (10m hoogte) wind spoed en/of sentrale druk tekort) van historiese tropiese siklone teen ses-uurlikse intervalle. Die modelering van tropiese sikloon windvelde was uitgevoer met die gebruik van die Holland (1980) en die Willoughby et al. (2006) parametriese windveldmodelle. Met die gebruik van beperkte inligting wat beskikbaar is in die beste roete data as invoer vir die model, was oppervlak wind velde gegenereer wat ‘n billike ooreenstemming het met die van werklike storms. Beide tegnieke se parametriese windveldmodelle is al bewys om redelike akkurate windspoed en windrigtings te lewer in vergelyking met waargenome waardes. Van die twee modelle het die Willoughby et al. (2006) model se resultate die beste ooreenstemming gewys met historiese wind spoed metings. Dit is al uitgewys dat uiterste waarde-analises van tropiese sikloon veroorsaakte windspoed moontlik kan lei tot groot foute in die resultate as gevolg van die klein monster-grootte van die historiese data. Dit beklemtoon die noodsaaklikheid om die historiese databasis aan te vul met behulp van probabilistiese metodes. Die metodes soos beskryf deur Powel et al. (2005) en Emanuel et al. (2006) is hoofsaaklik gebruik om ‘n sintetiese roete-model vir die Suid-Westelike Oseaan te ontwikkel. Die doelwit van die sintetiese roete model is om duisende jare se tropiese sikloonroetes te produseer, en in effek foute te vermy as gevolg van die gebruik van klein monster groottes van die beskikbare historiese beste roete data. Die sintetiese roete model wat tydens hierdie studie ontwikkel is, is ‘n Markov kettingmodel wat in staat is om die roete verspreiding asook die evolusie van intensiteit saam die roete te simuleer vanaf die onstaan tot die beëindiging van die sikloon se roete. Die model is suiwer statisties en is gebasseer op die eienskappe soos afgelei vanaf die historiese beste roete data. Aanpassings is gemaak om rekening te hou van die fisiese beperkings soos die wat opgelê word deur die ewenaar en die maksimum potensiële intensiteit wat ‘n sikloon kan bereik. Dit is voorgelê dat die statistiese einskappe van die sintetiese roetes goed saamstem met die van die historiese populasie. Die toepassing van die Willoughby et al. (2006) wind veld model langs die sintetiese roetes het dit moontlik gemaak om 5000 jaar se windspoed, wat veroorsaak is deur tropiese siklone, te genereer by enige ligging wat van belang is in die Suid-Westelike Indiese Oseaan. Met berekeninge wat op ‘n 1 grade geografiese ruitnet gedoen is, is windspoedkaarte vir herhaal periodes van 50, 100, 200 en 500 jaar opgestel vir die Suid-Westelike Indiese Oseaan. Die uiterste wind spoed in kusgebiede gee waardevolle invoer vir die ontwerp van kus-infrastruktuur in die omgewing.