In the history of a reservoir, after the period of primary production, about 30 to 40%, of the original oil in place may be produced using a secondary recovery mechanism. Polymer injection, which is classified as a tertiary method, can be applied to the remaining oil in place. In this thesis, oil/water relative permeabilities, effect of polymer injection on end point relative permeabilities and residual oil saturations in heterogeneous carbonate reservoirs were investigated. Numereous core flood experiments were conducted on different heteroegneous carbonate cores taken from Midyat Formation. Before starting the displacement experiments, porosity, permeability and capillary pressure experiments were performed. The heterogeneity of the cores are depicted from thin sections. Besides the main aim stated above, effect of flow rate and fracture presence on end point relative permeability and on residual oil saturation and were investigated. According to the results of the displacement tests, end point hexane relative permeability increased when polymer solution was used as the displacing phase.Besides, end point hexane relative permeability increased with polymer injection and fracture presence.

No description available.

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

The contribution of this thesis is twofold: 1) the development of a hydrodynamic landscape evolution model for use on high-performance computing systems and 2) assessing the sensitivity of hydrogeomorphic processes to high-resolution rainfall input data and erosional parameterisation using the model. The thesis addresses a limitation in numerical landscape evolution models regarding how spatial variation in rainfall is represented or parameterised within such models. Typically, landscape evolution models forsake a realistic representation of rainfall patterns in favour of a simpler treatment of rainfall as being spatially homogeneous across the model domain. This simplification of rainfall spatial variability is still made despite the fact that many geomorphological processes are sensitive to thresholds of sediment entrainment and transport, driven by the distribution and movement of water within the landscape. The thesis starts by exploring current limitations in rainfall representation in landscape evolution models, and assesses various precipitation data sources that could be potentially used as more realistic rainfall inputs to landscape evolution models. A numerical model of landscape evolution is developed for deployment on high-performance parallel computing systems, based on the established CAESAR-Lisflood model (Coulthard et al., 2013). The new model code is benchmarked, showing performance benefits compared with the original CAESAR-Lisflood model it is based on. The model is applied to assessing the sensitivity of flood-inundation predictions, sediment flux, and erosion distribution within river catchments to spatial variation in rainfall during extreme storm events. Two real storm events that caused localised flash flooding in the UK are used as test cases: the Boscastle storm of 2004 and the North York Moors storm of 2005. Flood extent predictions and river discharges are found to be sensitive to the use of spatially variable input rainfall data, with high-resolution rainfall data leading to larger peak flood discharges. However, the differences are less pronounced in smaller catchments. The role of sediment erosion during large floods is also assessed, but it is found to play a minor role relative to spatially variable rainfall data. In contrast, the geomorphological response of catchments to single storm events is shown to be less sensitive to the spatial heterogeneity of rainfall input and controlled more strongly by the choice of erosional process parameterisation within the model. Nonetheless, spatial variability in rainfall data is shown to increase sediment yields during flash flood simulations.

The thesis comprises two separate journal articles that together form a coherent body of work. In this thesis, the key physical processes responsible for the 23-26 September 2012 UK floods are investigated using a case study approach. The cyclone responsible for the floods developed near the Azores on 20¬-22 September following the interaction between an equatorward-moving potential vorticity (PV) streamer and tropical storm Nadine. Convectively-driven latent heat release associated with the developing cyclone reduced upper-level PV and resulted in the fracture of the PV streamer into a discrete anomaly as the cyclone intensified. In Paper 1, convection-permitting model simulations and diabatic heating rate and PV tendency calculations along trajectories demonstrate that deposition heating strongly reduced upper-level PV in the vicinity of the PV streamer, contributing to its fracture into a discrete anomaly. The cyclone deepened further over the UK on 23-26 September, ahead of a second upper-level PV anomaly. In Paper 2, sensitivity simulations of the storm are presented. PV inversion is used to modify the strength and position of the PV anomaly in the initial conditions and to examine whether the event could have been even more extreme with different upper-level forcing. Results show that quasigeostrophic forcing for ascent ahead of the PV anomaly contributed to the maintenance of the rainfall band over the UK. Counterintuitively however, strengthening the upper-level forcing produced a shallower cyclone with lower rainfall totals. Instead of moving eastward over the UK to interact with the cyclone, the strengthened anomaly rotated cyclonically around a large-scale trough over Iceland, resulting in a fragmented rainfall band. The counterintuitive results suggest that the verifying analysis represents almost the highest-impact scenario possible for this flooding event.

The expected increase in precipitation and temperature in Scandinavia, and especially short-time heavy precipitation, will increase the frequency of flooding. Urban areas are the most vulnerable, and specifically, the road infrastructure. The accumulation of large volumes of water and sediments on road-stream intersections gets severe consequences for the road drainage structures. The need for a tool to identify characteristics that impacts the occurrence of flooding, and to predict future event is thus essential. This study integrates the spatial and temporal soil moisture properties into the research about flood prediction methods. Soil moisture data is derived from remote sensing techniques, with focus on the soil moisture specific satellites ASCAT and SMOS. Furthermore, several physical catchments descriptors (PCDs) are used to identify catchment characteristics that are prone to flooding and an inventory of current road drainage facilities are conducted. Finally, the index of sediment connectivity (IC) by Cavalli, Trevisani, Comiti, and Marchi (2013) is implemented to assess the flow of water and sediment within the catchment. A case study of two areas in Sweden, Västra Götaland and Värmland, that was affected by severe flooding in August 2014 are included. The results show that the method with using soil moisture satellite data is promising for the inclusion of soil moisture data into estimations of flooding and the index of sediment connectivity. / De förväntade ökningarna i nederbörd och temperatur i Skandinavien, och speciellt extrem korttidsnederbörd, kommer att öka frekvensen av översvämningar. Urbana områden är de mest sårbara, och speciellt väginfrastrukturen. Ackumuleringen av stora volymer av vatten och sediment där väg och vattendrag möts leder till allvarliga konsekvenser för dräneringskonstruktionerna. Behovet av ett verktyg för att identifiera egenskaper som påverkar förekomsten av översvämningar, och för att förutsäga framtida händelser är väsentligt. Studien integrerar markfuktighet både rumsligt och tidsmässigt i forskningen om metoder för översvämningsrisker. Markfuktighetsdata är inkluderat från fjärranalysteknik, med fokus på de specifika satelliterna för markfuktighet, ASCAT och SMOS. Vidare är flertalet faktorer (PCDs) inkluderade för att identifiera egenskaper i avrinningsområden som är benägna till översvämning samt en inventering av nuvarande vägdräneringskonstruktioner. Slutligen är ett index med sediment connectivity (Cavalli et al., 2013) implementerat för att se flödet av vatten och sediment inom avrinningsområdet. En fallstudie med två områden i Sverige, Västra Götaland och Värmland, som drabbades av allvarliga översvämningar i augusti 2014 är inkluderat. Resultaten visar att metoden att använda markfuktighet från satellitdata är lovande för inkludering i uppskattningar av översvämningsrisk och i indexet med sediment connectivity.

This MCs thesis is part of the Grant Agency of Czech Republic GACR P504/11/1151 The role of plants in bilance of greenhouse gases in Carex fens. The results of this project will serve as a basis for another analyses of greenhouse gases in natural wetland biotops. Growth and morphological changes of Carex acuta were monitored in mesocosm experiment durig the growing seson. Carex acuta has already been the subjekt of numerous studies. The aim of this study is to compare the growth rate of plants C. acuta grown under controlled conditions, simulating different regimes of flooding habitat. Number of shoots and maximum plant height were observed during the growing season. Destructive method has been used to fall aboveground and belowground biomass in autumn. Elevated water levels in the middle of the growing season caused a slowdown in growth in height and the creation of new shoots. Reduced water level of the mid-growing season seemed to faster growth of plants in height. Underground biomass significantly negatively affected by increased water level in the middle of the growing season.

ABREU, Nair Júlia Andrade de. Percepção dos riscos de inundações no Bairro Preguiça – Maranguape (CE). 2015. 140 f. Dissertação (Mestrado em geografia)- Universidade Federal do Ceará, Fortaleza-CE, 2015. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-10-14T13:07:26Z No. of bitstreams: 1 2015_dis_njaabreu.pdf: 22293137 bytes, checksum: 9ff2ecabd7e318cec8f174a7d2fe2392 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2016-10-18T18:57:50Z (GMT) No. of bitstreams: 1 2015_dis_njaabreu.pdf: 22293137 bytes, checksum: 9ff2ecabd7e318cec8f174a7d2fe2392 (MD5) / Made available in DSpace on 2016-10-18T18:57:50Z (GMT). No. of bitstreams: 1 2015_dis_njaabreu.pdf: 22293137 bytes, checksum: 9ff2ecabd7e318cec8f174a7d2fe2392 (MD5) Previous issue date: 2015 / This research addresses the risks of flooding in the Preguiça neighborhood, Maranguape / Ceará, covering more specifically the perceptual approach these risks. This approach is of great importance in that it presents data showing how residents perceive and understand the context of risks to which they belong, including information that can be extremely useful to risk management. In addition, aspects related to perception are hardly highlighted in studies of risks. Thus, this study aimed to analyze the perception that of the residents of the Preguiça neighborhood have about the flooding risk in that area, addressing the different aspects that may have influenced the observed perceptions. At the same time, the objective was to verify the measures taken (and to be made) in respect of such risks. The development of this study was performed by means of surveying and mapping and literature review; field observations; making maps; development and implementation of questionnaires; and discussion of the data obtained through the questionnaires and field surveys. The data on the perception of residents and issues relating to it were organized and analyzed on the following variables: experiences and knowledge related to accidents and / or alert conditions; conditions of flooding, causality and responsibility; evaluation and choice; threshold security and lastly, adjustments and other reactions to the risks. The results show that 92% of respondents consider the existence of flood risk in the area, 58% have adopted at least one preventive measure of immediacy and only 22% had changes in the structure of their respective residences. In the end, proposals were presented and discussed measures to be taken in order to reduce the risk of flooding in the area and prevent accidents. / A presente pesquisa aborda os riscos de inundações existentes no bairro Preguiça, Maranguape/Ceará, contemplando mais especificamente a abordagem perceptiva desses riscos. Esse tipo de abordagem reveste-se de grande importância na medida em que apresenta dados que revelam como os moradores locais percebem e compreendem o contexto de riscos no qual estão inseridos, informações que inclusive podem ser extremamente úteis à gestão de riscos. Além disso, aspectos relacionados à percepção dificilmente são destacados nos estudos sobre riscos. Desse modo, objetivou-se analisar a percepção que alguns dos residentes do bairro Preguiça apresentam sobre os riscos de inundações na referida área, abordando os diferentes aspectos que podem ter influenciado nas percepções observadas. Paralelamente, objetivou-se verificar as medidas tomadas (e a serem tomadas) em relação a esses riscos. O desenvolvimento desse estudo deu-se por meio de levantamento e revisão bibliográfica e cartográfica; observações em campo; confecção de mapas; elaboração e aplicação de questionários; bem como discussão dos dados obtidos por meio dos questionários e dos levantamentos de campo. Os dados referentes à percepção dos moradores e aos aspectos relacionados a ela foram organizados e analisados em torno das seguintes variáveis: experiências e conhecimentos relacionados à ocorrência de acidentes e/ou a situações de alerta; condicionantes e deflagradores, causalidade e responsabilidade; avaliação e escolha; limiar de segurança e por último, ajustamentos e outras reações frente aos riscos. Os resultados obtidos mostram que 92% dos pesquisados consideram a existência de riscos de inundações na área, 58% já adotaram pelo menos uma medida preventiva de caráter imediato e apenas 22% deles realizaram modificações na estrutura de suas respectivas residências. Ao final são apresentadas e discutidas propostas de medidas a serem tomadas no intuito de reduzir os riscos de inundações na área e prevenir acidentes.

Devido às facilidades que a proximidade de leitos de rios oferece à população, muitas cidades concentram-se em torno de encostas. Por vezes, essa ocupação ocorre de forma irresponsável, alterando a cobertura original do solo, se estabelecendo em áreas cada vez mais próximas de margens de rios e sem realizar os devidos estudos sobre possíveis mudanças no volume da bacia hidrográfica devido ao aumento da precipitação média. Como conseqüência, ocasionalmente a profundidade da água supera as margens e atinge áreas ocupadas pelas construções e vias de acesso, causando prejuízos financeiros e riscos para o bem-estar da população. Para mitigar os danos, criando soluções imediatas, como a evacuação das áreas de risco, ou em longo prazo, como a reestruturação do sistema de drenagem de águas pluviais da cidade, é essencial uma análise das áreas suscetíveis a inundações. Este estudo tem como objetivo demonstrar o comportamento deste tipo de evento na cidade de Lages, Santa Catarina. Para tal, é utilizado um modelo digital de elevação, imagens obtidas a partir de um levantamento aerofotogramétrico, dados coletados no limite das linhas de ocorrências de cheias anteriores no seu volume máximo, usando tecnologia GNSS e utilizando softwares de Sistemas de Informação Geográfica Sistemas (SIG). Isto permite determinar quais são as áreas de risco de inundação na cidade, com base em informações coletadas no local e conhecimento em SIG. / Due the facilities that the proximity to riverbeds offers, many cities settle around those slopes. Sometimes it is done irresponsibly, changing the natural soil, occupying areas increasingly close to the banks and without conduct studies about possible changes that may happen on the basin's volume due increase of the average rainfall. The consequence of this is that sometimes water depth goes beyond the margins and reaches areas occupied by building and access roads, causing financial losses and risks to the welfare of the population. To be able to collect damages, whether creating immediate solutions, as evacuating the risk areas, or in long term, as city's rainwater drainage system being restructured, is essential an analysis study of areas susceptible to flooding. This study aims to demonstrate the behavior of this type of event in the city of Lages, Santa Catarina. For this, is used a digital elevation model, images captured by an aerophotogrammetric survey, collecting points on the limit of the previous occurrences flood lines at its maximum volume using GPS technology, and using software’s of Geographic Information Systems Studies (GIS). This is was possible to determine which are the flooding risk areas in the city, based on information collected on the local and knowledge in GIS.

Made available in DSpace on 2014-06-11T19:31:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-26Bitstream added on 2014-06-13T20:07:56Z : No. of bitstreams: 1 andriucci_lr_dr_prud.pdf: 2790189 bytes, checksum: af00e84dbb28e78b5759978c359627d1 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A presente pesquisa tem como objetivo propor uma metodologia que permita analisar e discutir a relação existente entre o clima urbano e a economia. A área escolhida para esse estudo foi à cidade de São Paulo, mas, destacando a ocupação da marginal do rio Tietê. Para tanto, analisou-se os seguintes temas: economia ambiental; histórico de ocupação e desenvolvimento da área urbana tanto da cidade de São Paulo, como do rio Tietê; e o clima urbano, que foi divido em três etapas: caracterização geral do clima da cidade de São Paulo; caracterização dos totais pluviométricos da cidade de São Paulo; e levantamento do comportamento das chuvas excepcionais na marginal do rio Tietê. Com essa investigação foi possível isolar elementos identificados como externalidades ambientais. O resultado da pesquisa mostrou que: a Valoração Climática é a relação estabelecida entre a Economia Ambiental e a Climatologia Geográfica; a metodologia utilizada alcançou o objetivo de mostrar que a apropriação indevida do meio pelo homem gera externalidades negativas, ou seja, promovem perdas também econômicas; e a compreensão de que o elemento Clima, faz parte de nosso contexto econômico-social, e que a sua interação com a sociedade geram prejuízos significativos para a economia, como os observado em cada análise específica das externalidades negativas (alagamentos, trânsito urbano, e notadamente por meio de um estudo de caso, o mercado imobiliário) / This research aims to propose a methodology for analyzing and discussing the relationship between the urban environment and economy. The area chosen for this study was the city of São Paulo, but, highlighting the ocupation of marginal Tietê river; that’s why, it was examined the following topics: environmental economics; history of occupation and development the urban area the city of São Paulo as the Tietê river; and the urban climate, it was divided into three stages: general characterization of the climate the city of São Paulo; the total rainfall characterization the city of São Paulo; and a behavior the exceptional rainfall in marginal Tietê river. With this research it was possible to isolate elements identified as environmental externalities. The result of the investigation showed that: the valuation climate is the valuation between the environmental economics and the geographical climatology; the methodology used it reached the order to show that misappropriation of the environment by man generates negative externalities, in other words, promote economic losings too; and understanding that the climate factor, makes part of our economic-social context, and that interaction with the society generally significant damage for the economy as noted in each specific analysis of negative externalities (flooding, urban traffic, and especially through a case study, the housing market)