Floods and droughts are frequent in Central America and cause large social, economic and environmental impacts. A crucial step in disaster risk reduction is to have a good understanding of the causing mechanisms of extreme events and their spatio-temporal characteristics. For this, a key aspect is access to a dense network of long and good-quality hydro-meteorological data. Unfortunately, such ideal data are sparse or non-existent in Central America. In addition, the existing methods for hydro-climatic studies need to be revised and/or improved to find the most suitable for the region’s climate, geography and hydro-climatic data situation. This work has the ultimate goal to support the reduction of risks associated with hydro-climatic-induced disasters in Central America. This was sought by developing ways to reduce data-related uncertainties and by improving the available methods to study and understand hydro-climatic variability processes. In terms of data-uncertainty reduction, this thesis includes the development of a high resolution air temperature dataset and a methodology to reduce uncertainties in a hydrological model at ungauged basins. The dataset was able to capture the spatial patterns with a detail not available with existing datasets. The methodology significantly reduced uncertainties in an assumed-to-be ungauged catchment. In terms of methodological improvements, this thesis includes an assessment of the most suitable combination of (available) meteorological datasets and drought indices to characterise droughts in Central America. In addition, a methodology was developed to analyse drought propagation in a tropical catchment, in an automated, objective way. Results from the assessment and the drought propagation analysis contributed with improving the understanding of drought patterns and generating processes in the region. Finally, a methodology was proposed for assessing changes in both hydrological extremes in a consistent way. This contrasts with most commonly used frameworks that study each extreme individually. The method provides important characteristics (frequency, duration and magnitude), information that can be useful for decisions within risk reduction and water management. The results presented in this thesis are a contribution, in terms of hydro-climatic data and assessment methods, for supporting risk reduction of disasters related with hydro-climatic extremes in Central America. / Översvämningar och torka inträffar ofta i Mellanamerika och orsakar stora skador på samhälle, ekonomi och miljö. En kritisk del av riskreduceringen är förståelsen av mekanismerna bakom extremhändelserna, och deras rumsliga och tidskarakteristik. En nyckelfaktor är tillgång till långa tidsserier av rumsligt täckande hydrometeorologiska data av bra kvalitet. I Mellanamerika är sådana ideala data tyvärr sällsynta eller saknas helt. Dessutom behöver befintliga metoder för hydro-klimatisk analys revideras och/eller förbättras för att identifiera de mest lämpade metoderna för regionens klimat, geografi och situationen vad gäller hydrologiska och meteorologiska data. Det övergripande syftet med denna avhandling har varit att stödja arbetet med riskreducering i Mellanamerika vid hydrologiska extremhändelser som sätts igång av extrema väderhändelser. För att bidra till detta utvecklades metoder för att minska datarelaterade osäkerheter och för att förbättra tillgängliga metoder för att studera och förstå de processer som ligger bakom variabiliteten i hydrologi och klimat. Dataosäkerheten minskades genom utveckling av ett nytt dataset för lufttemperatur med hög rumslig upplösning och en metodik för att begränsa osäkerheten i modellberäknad vattenföring i ett område där det saknas observationer. Det nya datasetet kunde fånga rumsliga mönster på en detaljnivå som hittills inte varit möjlig. Metodiken möjliggjorde en klar minskning i osäkerheten hos vattenföringen i ett avrinningsområde som behandlades som om det saknade data. Avhandlingen innehåller också en metodik för att fastlägga den mest lämpade kombinationen av tillgängliga klimatdataset och torkindex för att karakterisera torka i Mellanamerika. Därutöver utvecklades en metod för att studera torkans fortplantning i ett tropiskt avrinningsområde på ett objektivt och automatiserat sätt. Slutligen föreslås en metod för att hantera förändringar av både översvämning och torka på ett konsistent sätt  som förenklar användningen av resultaten  för en beslutsfattare. Dessa metoder bedömdes användbara för att förbättra karakteriseringen och förståelsen av extrema hydrologiska händelser i Mellanamerika. Resultaten i denna avhandling ger bidrag till förståelsen av hydrologiska och klimatextremer genom förbättrade data och analysmetoder som i förlängningen kommer att stödja riskreduceringsarbetet i Mellanamerika. / Las sequías e inundaciones son frecuentes en Centroamérica y causan grandes problemas sociales, económicos y ambientales. Un aspecto crucial en la reducción del riesgo consiste en entender los mecanismos que causan dichos eventos, y sus características espacio-temporales. Para lograr esto es necesario tener acceso a una red de datos hidro-meterológicos densa, con series largas, y de buena calidad. Desafortunadamente, este no es el caso en Centroamérica. Además, los métodos para hacer estudios hidro-climáticos requieren ser evaluados y/o mejorados para asegurar su aplicabilidad en la región (su clima, su geografía y los datos disponibles). Este trabajo tiene como meta apoyar la reducción del riesgo de desastres asociados a eventos hidro-meteorológicos extremos en Centroamérica. Esto se consigue a partir de la reducción de incertidumbres asociadas a los datos, y de la mejora de métodos para el estudio de la variabilidad hidro-climática. Para reducir la incertidumbre de los datos, este trabajo incluye el desarrollo de una base de datos de temperatura de alta resolución y el desarrollo de una metodología para reducir las incertidumbres en datos simulados de caudal. Con la nueva base de datos se logra reconocer patrones espaciales a un nivel de detalle no antes captado por otras bases de datos. Por otro lado, la metodología redujo significativamente las incertidumbres de los datos simulados de caudal. En cuanto a métodos, esta tesis incluye una evaluación para encontrar la mejor combinación de índices de sequía y base de datos para la caracterización de sequías en la región. Además, se desarrolló una metodología para analizar la propagación de la sequía en una cuenca tropical, de una manera objetiva y automatizada. Los resultados de estos dos pasos ayudaron a mejorar la comprensión de los patrones y los mecanismos de generación de las sequías. Finalmente, se incluyó un método para evaluar los cambios en los patrones de sequías e inundaciones de una manera consistente, y no de manera individual como usualmente se ha hecho. Así fue posible obtener la frecuencia, duración y magnitud en ambos extremos hidrológicos. Esta información podría constituir una herramienta  útil para el manejo del riesgo y del recurso hídrico.

The Mara River Basin (MRB) is endowed with pristine biodiversity, socio-cultural heritage and natural resources. The purpose of my study is to develop and apply an integrated water resource allocation framework for the MRB based on the hydrological processes, water demand and economic factors. The basin was partitioned into twelve sub-basins and the rainfall runoff processes was modeled using the Soil and Water Assessment Tool (SWAT) after satisfactory Nash-Sutcliff efficiency of 0.68 for calibration and 0.43 for validation at Mara Mines station. The impact and uncertainty of climate change on the hydrology of the MRB was assessed using SWAT and three scenarios of statistically downscaled outputs from twenty Global Circulation Models. Results predicted the wet season getting more wet and the dry season getting drier, with a general increasing trend of annual rainfall through 2050. Three blocks of water demand (environmental, normal and flood) were estimated from consumptive water use by human, wildlife, livestock, tourism, irrigation and industry. Water demand projections suggest human consumption is expected to surpass irrigation as the highest water demand sector by 2030. Monthly volume of water was estimated in three blocks of current minimum reliability, reserve (>95%), normal (80–95%) and flood (40%) for more than 5 months in a year. The assessment of water price and marginal productivity showed that current water use hardly responds to a change in price or productivity of water. Finally, a water allocation model was developed and applied to investigate the optimum monthly allocation among sectors and sub-basins by maximizing the use value and hydrological reliability of water. Model results demonstrated that the status on reserve and normal volumes can be improved to ‘low’ or ‘moderate’ by updating the existing reliability to meet prevailing demand. Flow volumes and rates for four scenarios of reliability were presented. Results showed that the water allocation framework can be used as comprehensive tool in the management of MRB, and possibly be extended similar watersheds.

Magnetický tunelový spoj (MTJ) je spintronická součástka komerčně používaná ve vysoce citlivých čtecích hlavách pevných disků. Počínaje rokem 2007 přispěla k udržení exponenciálního nárůstu hustoty magnetického zápisu. Kromě toho se také stala stavebním kamenem rychlé, odolné, úsporné a nevolatilní magnetické paměti s přímým přístupem (MRAM). Tento nový typ polovodičové paměti, stejně jako je tomu u čtecích hlav disků, využívá tunelové spoje založené na krystalickém oxidu hořečnatém (MgO) spolu s 3d kovovými magnetickými prvky (Fe a Co). Pro zmenšení MTJ a současné udržení dlouhodobé stability paměti proti tepelným fluktuacím je zapotřebí silná magnetická anizotropie ve směru kolmém na rozhraní kov|MgO. V této práci proto nejdříve provedeme analýzu magnetokrystalické anizotropie (MCA) kubického prostorově centrovaného Fe, Co a Ni na MgO pomocí ab initio simulací. Dále bude vyvinut program pro výpočet tvarové anizotropie, která je kromě MCA velmi podstatná, neboť v součtu dávají efektivní anizotropii. Na závěr implementujeme program pro výpočet MCA na základě poruchové teorie druhého řádu. To nám umožní dát pozorované anizotropní vlastnosti do souvislosti přímo s elektronickou strukturou systému (pásovou strukturou a hustotou stavů).

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Uppsatsens syfte är att analysera hur nedskalning av en global vision till en lokal kontext tar sig uttryck i Oslo kommuns klimatstrategi. Valet av Oslo kommuns klimatstrategi som studieobjekt baserades på Oslos samarbete med UN-Habitat samt utnämnandet av Oslo till Europas miljöhuvudstad 2019 och Norges petroleumverksamhet. Dokumentet Klimastrategi mot Oslo 2030 (2020) har analyserats utifrån begreppen Urbanitet och Hållbar övergång samt innebörden med nedskalning av klimatpolitiken och tre förmedlingsmetoder. Uppsatsen förankras i den tidigare forskningen som behandlar Köpenhamn och Stockholm. För att besvara frågeställningarna; vilka åtgärder presenteras som viktigast för att bli en nollutsläppsstad 2030? Hur beskrivs kopplingarna mellan den lokala klimatstrategin och den globala måluppfyllelsen? Vad finns det för kritiska punkter med strategins åtgärder och lösningar? används en kvalitativ analysmetod där empirin och den vetenskapliga förankringen får lika mycket utrymme. Utifrån den avslutande diskussionen framkommer det i slutsatserna att den största åtgärden i klimatstrategin är CCS-anläggningen på Klemetsrud. Även en fossilfri omställning av transportsektorn samt en minskad energianvändning är av vikt för att Oslo ska lyckas bli en nollutsläppsstad till 2030. Det belyses att den lokala utsläppsredovisningen påverkar den globala måluppfyllelsen. De kritiska punkterna i klimatstrategin som identifierats är; oklarhet gällande biobränslets framtida roll, den diffusa målformuleringen i Indirekta utsläpp samt problematiken med att ta efter åtgärder och lösningar från strategin för andra internationella städer. / The purpose of the thesis is to analyze how downscaling of a global climate vision to a local context is expressed in Oslo Muncipality’s climate strategy. The choice of Oslo municipality's climate strategy as a study object was based on Oslo's collaboration with UN-Habitat, the nomination of Oslo as Europe's environmental capital in 2019 and Norway's petroleum operations. The document Klimastrategi mot Oslo 2030 (2020) has been analyzed on the basis of the concepts of Urbanity and Sustainable Transition, as well as the meaning of downsizing climate policy and three communication methods. The thesis is anchored in the previous research that treats Copenhagen and Stockholm. To answer the questions; which measures are presented as most important to become a zero-emission city in 2030? How are the links between the local climate strategy and global goal fulfillment described? What are the critical points of the strategy's measures and solutions? a qualitative analysis method is used where the empirical data and the scientific foundation are given equal space. Based on the concluding discussion, it appears from the conclusions that the largest measure in the climate strategy is the CCS facility at Klemetsrud. A fossil-free restructuring of the transport sector and a reduction in energy use are also important for Oslo to succeed in becoming a zero-emission city by 2030. It is highlighted that local emission accounting affects global target fulfillment. The critical points in the climate strategy that have been identified are; uncertainty regarding the future role of biofuels, the diffuse goal formulation in Indirect Emissions and the problem of following measures and solutions from the strategy for other international cities.

<p>  </p> <p>The management of water resources in East Africa is inherently challenged by rainfall variability and the uneven spatial distribution of freshwater resources. In addition to these issues, meteorological and water data collection has been inconsistent over the past decades, and unclearly defined purposes or end goals for collected data have left many datasets ineffectively curated. In light of the data intensiveness of current modelling and planning methods, data scarcity and inaccessibility have become substantial impediments to informed decision-making. Among the outputs of this research are 1) a revised technique for evaluating bias correction performance on reanalysis data for use in regions where precipitation data is temporally discontinuous which can potentially be applied to other types of climate data as well, 2) a new methodology for quantifying qualitative information contained in legislation and official documents and websites for the assessment of relationships between documented meteorological and water data policies and resulting outcomes in terms of data availability and accessibility, and 3) a fresh look at data needs and the value data holds with respect to water resources decision-making and management in the region.</p>

Wind power presently plays a minor role in Western Canada as compared to hydroelectric power in British Columbia and coal and natural gas thermal power generation in Alberta. However, ongoing reductions in the cost of wind power generation facilities and the increasing costs of conventional power generation, particularly if the cost to the environment is included, suggest that assessment of the present and future wind field in Western Canada is of some importance. To assess present wind power, raw hourly wind speeds and homogenized monthly mean wind speeds from 30 stations in Western Canada were analyzed over the period 1971-2000 (past). The hourly data were adjusted using the homogenized monthly means to attempt to compensate for differences in anemometer height from the standard height of 10m and changes in observing equipment at stations. A regional reanalysis product, the North American Regional Reanalysis (NARR), and simulations conducted with the Canadian Regional Climate Model (CRCM) driven with global reanalysis boundary forcing, were compared to the adjusted station wind-speed time-series and probability distributions. The NARR had a better temporal correlation with the observations, than the CRCM. We posit this is due to the NARR assimilating regional observations, whereas the CRCM did not. The NARR was generally worse than the CRCM in reproducing the observed speed distribution, possibly due to the crude representation of the regional topography in NARR. While the CRCM was run at both standard (45 km) and fine (15 km) resolution, the fine grid spacing does not always provide better results: the character of the surrounding topography appears to be an important factor for determining the level of agreement. Multiple simulations of the CRCM at the 45 km resolution were also driven by two global climate models (GCMs) over the periods 1971-2000 (using only historic emissions) and 2031-2060 (using the A2 emissions scenario). In light of the CRCM biases relative to the observations, these simulations were calibrated using quantile-quantile matching to the adjusted station observations to obtain ensembles of 9 and 25 projected wind speed distributions for the 2031-2060 period (future) at the station locations. Both bias correction and change factor techniques were used for calibration. At most station locations modest increases in mean wind speed were found for most of the projected distributions, but with a large variance. Estimates of wind power density for the projected speed distributions were made using a relationship between wind speed and power from a CRCM simulation for both time periods using the 15km grid. As would be expected from the wind speed results and the proportionality of wind power to the cube of wind speed, wind power at the station locations is more likely than not to increase in the 2031-2060 period from the 1971-2000 period. Relative changes in mean wind speeds at station locations were found to be insensitive to the station observations and choice of calibration technique, suggesting that we estimate relative change at all 45km grid points using all pairs of past/future mean wind speeds from the CRCM simulations. Overall, our results suggest that wind energy resources in Western Canada are reasonably likely to increase at least modestly in the future. / Graduate / 0725 / 0608 / jtdaines@uvic.ca

Le changement climatique dû à l'augmentation des émissions de gaz à effet de serre est considéré comme l'un des principaux défis pour les êtres humains dans 21ème siècle. Il conduira à des changements dans les précipitations, l'humidité atmosphérique, augmentation de l'évaporation et probablement augmenter la fréquence des événements extrêmes. Les conséquences de ces phénomènes auront une influence sur de nombreux aspects de la société humaine. Donc, il y a une nécessité d'avoir une estimation robuste et précise de la variation des facteurs naturels dus au changement climatique, au moins dans les événements de cycle et d'inondation hydrologiques pour fournir une base solide pour atténuer les impacts du changement climatique et s'adapter à ces défis. Le but de cette étude est de présenter une méthodologie pour évaluer les impacts de différents scénarios de changement climatique sur une zone inondable du bassin de la rivière côtière dans la région centrale du Viet Nam - bassin versant de Vu Gia Thu Bon. Les simulations hydrologiques sont basées sur un modèle hydrologique déterministe validé qui intègre la géologie, les sols, la topographie, les systèmes fluviaux et les variables climatiques. Le climat de la journée présente, sur la période de 1991-2010 a été raisonnablement simulée par le modèle hydrologique. Climat futur (2091-2100) information a été obtenue à partir d'une réduction d'échelle dynamique des modèles climatiques mondiaux. L'étude analyse également les changements dans la dynamique des inondations de la région de l'étude, le changement hydrologique et les incertitudes du changement climatique simulation. / Climate change due to the increase of greenhouse gas emissions is considered to be one of the major challenges to mankind in the 21st century. It will lead to changes in precipitation, atmospheric moisture, increase in evaporation and probably a higher frequency of extreme events. The consequences of these phenomena will have an influence on many aspects of human society. Particularly at river deltas, coastal regions and developing countries, the impacts of climate change to socio-economic development become more serious. So there is a need for a robust and accurate estimation of the variation of natural factors due to climate change, at least in the hydrological cycle and flooding events to provide a strong basis for mitigating the impacts of climate change and to adapt to these challenges. The aim of this study is to present a methodology to assess the impacts of different climate change scenarios on a flood prone area of a coastal river basin in the central region of Viet Nam – Vu Gia Thu Bon catchment. The hydrological simulations are based on a validated deterministic hydrological model which integrates geology, soil, topography, river systems and climate variables. The present day climate, over the period of 1991-2010 was reasonably simulated by the hydrological model. Future climate (2091-2100) information was obtained from a dynamical downscaling of the global climate models. The study also analyzes the changes in the flood dynamics of the study region, the hydrological shift and the uncertainties of climate change simulation.