Energy related geo-systems involve a wide range of engineering solutions from energy piles to energy geo-storage facilities and waste repositories (CO₂, nuclear). The analysis and design of these systems require proper understanding of geo-materials, their properties and their response to extreme temperature and high stress excitations, the implications of mixed-fluid conditions when contrasting fluid viscosities and densities are involved, the effect of static and cyclic coupled hydro-thermo-chemo-mechanical excitations, and rate effects on the response of long design-life facilities. This study places emphasis on thermal geo-systems and associated physical properties. Uncemented soils and rocks are considered. The research approach involves data compilation, experimental studies and analytical methods. Emphasis is also placed to engineer geomaterials in order to attain enhanced performance in energy geo-systems. The thermal conductivity and stiffness of most geomaterials decrease as temperature increases but increase with effective stress. This macroscale response is intimately related to contact-scale conduction and deformation processes at interparticle contacts. Pore-filling liquids play a critical role in heat conduction as liquids provide efficient conduction paths that can diminish the effects of thermal contact resistance. Conversely, grains and fluids can be selected to attain very low thermal conductivity in order to create mechanically sound thermal barriers. In the case of rock masses, heat (and gas) recovery can be enhanced by injecting fluids at high pressure to cause hydraulic fractures. Scaled experiments reveal the physical meaning of hydraulic fractures in pre-structured rocks (e.g., shale) and highlight the extensive self-propped dilational distortion the medium experiences. This result explains the higher production rate from shale gas and fractured geothermal reservoirs that is observed in the field, contrary to theoretical predictions.

Aeolian dune fields form some of the most striking patterns on Earth and Mars. These patterns reflect the internal dune dynamics of self-organization within boundary conditions, which are the unique set of environmental variables within which each dune field evolves. Dune-field pattern self-organization occurs because of interactions between the dunes themselves and the rich diversity of dune-field patterns arises because boundary conditions alter the type and frequency of dune interactions. These hypotheses are explored in three parts. First, source-area geometry and areal limits are two newly recognized boundary conditions. Measurements of crest length and spacing from satellite images of dune patterns with point and line source-area geometries show an increase in crest length and spacing over distance, whereas crest length and spacing in plane-sourced patterns emerge equally across the dune field. The areal limit boundary condition is the size and shape of the dune field itself. Empirical measurements from ten dune fields ranging over four orders of magnitude in area show that spacing increases and defect density decreases as the area of the dune field increases. A simple analytical model indicates that dune fields that are five times longer in the dune migration direction can achieve the greatest spacing for a given area. Second, time-series aerial photographs and airborne LiDAR show that fully developed, crescentic aeolian dunes at White Sands, New Mexico, interact and the dune pattern organizes in systematically similar ways as wind ripples and subaqueous dunes and ripples. Interaction type, classified as constructive, regenerative or neutral in terms of pattern development, changes spatially with the pattern because of the imposition of the line-source area and sediment availability boundary conditions. Upwind dominance by constructive interactions at the field line-source yields to neutral and regenerative interactions in the sediment availability-limited field center. Third, the dune-field pattern in the Olympia Undae Dune Field on Mars is comprised of two generations of dunes. This scenario of pattern reformation with a new wind regime shows that the emergence of the younger pattern is controlled by the boundary condition of the antecedent dune topography imposed upon the interaction between the younger and older patterns. / text

Made available in DSpace on 2016-04-28T18:23:03Z (GMT). No. of bitstreams: 1 Ricardo Mendes Montefusco.pdf: 922623 bytes, checksum: eb75a078704b5c7022ba022b461ec35b (MD5) Previous issue date: 2015-03-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose of this master thesis is the examination of social criticism in the novel Captains of the Sands by Jorge Amado. Captains of the Sands is a realist narrative that deals with the adventures of a group of street children who survives by committing crimes in the streets of Salvador. Since they live in an old warehouse, the boys of the band, led by Pedro Bala, are known by the nickname "captains of the sands". Jorge Amado is known as an advocate for the causes of the poor, excluded by society. This work is a lyrical testimony and romance of protest, bringing social and psychological elements that reflect the entire socio-political instability of the 30s. When creating his stories, the author, a political activist, defends the ideological principles of the left, and, in a way, the narrator works as the author's delegate. Despite all the violence and the rogue behavior of the minors, a close reading reveals that the source of these problems is the neglect of the state itself, the repressive and violent police, and the reformatory, a true hell of torture and misery. Thus, the reactions of these adolescents are nothing more than a vehicle of harsh revenge against the violence they have suffered. The novel analysis is based on theoretical and methodological proposals of Critical Linguistics ― which gives ideological significance to any aspect of linguistic structure ― and of the Systemic Functional Grammar, whose approach to language as a construer of three distinct functions or metafunctions ― namely, Ideational (subject), Interpersonal (interactivity) and textual (internal organization and communicative nature of a text), allows the relationship between lexicogrammatical choices made in the microstructure of the text, with the macrostructure of ideology and power relations. The research should answer the following questions: (a) What choices in the Transitivity System contribute to enable the social criticism in Captains of the Sands? (b) What choices in the Appraisal framework perform this function? / The purpose of this master thesis is the examination of social criticism in the novel Captains of the Sands by Jorge Amado. Captains of the Sands is a realist narrative that deals with the adventures of a group of street children who survives by committing crimes in the streets of Salvador. Since they live in an old warehouse, the boys of the band, led by Pedro Bala, are known by the nickname "captains of the sands". Jorge Amado is known as an advocate for the causes of the poor, excluded by society. This work is a lyrical testimony and romance of protest, bringing social and psychological elements that reflect the entire socio-political instability of the 30s. When creating his stories, the author, a political activist, defends the ideological principles of the left, and, in a way, the narrator works as the author's delegate. Despite all the violence and the rogue behavior of the minors, a close reading reveals that the source of these problems is the neglect of the state itself, the repressive and violent police, and the reformatory, a true hell of torture and misery. Thus, the reactions of these adolescents are nothing more than a vehicle of harsh revenge against the violence they have suffered. The novel analysis is based on theoretical and methodological proposals of Critical Linguistics ― which gives ideological significance to any aspect of linguistic structure ― and of the Systemic Functional Grammar, whose approach to language as a construer of three distinct functions or metafunctions ― namely, Ideational (subject), Interpersonal (interactivity) and textual (internal organization and communicative nature of a text), allows the relationship between lexicogrammatical choices made in the microstructure of the text, with the macrostructure of ideology and power relations. The research should answer the following questions: (a) What choices in the Transitivity System contribute to enable the social criticism in Captains of the Sands? (b) What choices in the Appraisal framework perform this function?

Les gisements de type roll-front du Kazakhstan représentent près de 13% des réserves mondiales en uranium en 2015. Les minéraux argileux, présents à chaque étape du cycle minier, ont récemment suscité l’intérêt des exploitants. L’étude de la distribution et des proportions de ces minéraux dans les sédiments à l’échelle d’un gisement permettraient d’améliorer à la fois l’exploration, l’exploitation et la réhabilitation de ce type de gisement.Différentes méthodes ont été développées pour identifier et quantifier les minéraux d’intérêt à partir de la spectrométrie infrarouge (IR), une technique instrumentale rapide, adaptée à une utilisation sur le terrain. Ces méthodes ont été calibrées à l’aide d’une large base de données de spectres IR et la préparation de sables artificiels.Il est possible d’obtenir, à partir d’une seule mesure spectrale, la teneur en argiles des sables et particulièrement celle en smectite afin d’identifier les zones les plus riches et adapter l’extraction de l’uranium. L’ensemble de ces méthodes permettent de réaliser des cartographies de la répartition des minéraux argileux à l’échelle du gisement pour comprendre sa géométrie et sa mise en place.La migration des corps minéralisés à l’échelle régionale a été mise en évidence par spectrométrie de résonance paramagnétique, avec l’étude des défauts structuraux engendrés par la proximité des minéraux argileux avec les minéraux uranifères. / Uranium roll-front type sandstone-hosted deposits from Kazakhstan account for about 13% of the worldwide uranium reserve in 2015. Clay minerals occur at every step of the mining cycle and recently begun to be considered by mining companies.The proportions and distribution of these clay minerals in the sediments at the roll-front deposit scale could improve the exploration, exploitation and rehabilitation of such uranium deposits.Several methods were developed to identify and quantify minerals using a portable near-infrared spectrometer, a convenient and fast analytical tool for use in the field. These methods were calibrated with the help of a wide spectral database and the conception of artificial sands.The clay mineral content, and more importantly, the smectite content can be obtained from a single spectral measurement. It enables the detection of smectite-rich areas to optimise the uranium extraction process where they occur. Combination of the methods provide a mapping tool for clay minerals at the ore deposit scale, yielding information about its actual geometry and formation.Uranium ore bodies migration was observed at the ore deposit scale with the use of the electron paramagnetic resonance spectroscopy. Crystalline radiation induced defects in clay minerals that were in close contact with uranium showed records of the past migration.

Oil companies in Alberta, Canada, invested $32 billion on new oil sands projects in 2013. Despite the size of this investment, there is a demonstrable deficiency in the uniformity and understanding of environmental legislation requirements that manifest into increased project compliance risks. This descriptive study developed 2 prioritized lists of environmental regulatory compliance risks and mitigation strategies and used multi-criteria decision theory for its theoretical framework. Information from compiled lists of environmental compliance risks and mitigation strategies was used to generate a specialized pairwise survey, which was piloted by 5 subject matter experts (SMEs). The survey was validated by a sample of 16 SMEs, after which the Analytic Hierarchy Process (AHP) was used to rank a total of 33 compliance risks and 12 mitigation strategy criteria. A key finding was that the AHP is a suitable tool for ranking of compliance risks and mitigation strategies. Several working hypotheses were also tested regarding how SMEs prioritized 1 compliance risk or mitigation strategy compared to another. The AHP showed that regulatory compliance, company reputation, environmental compliance, and economics ranked the highest and that a multi criteria mitigation strategy for environmental compliance ranked the highest. The study results will inform Alberta oil sands industry leaders about the ranking and utility of specific compliance risks and mitigations strategies, enabling them to focus on actions that will generate legislative and public trust. Oil sands leaders implementing a risk management program using the risks and mitigation strategies identified in this study will contribute to environmental conservation, economic growth, and positive social change.

No description available.

A multi-integrative approach was used to identify spatial and temporal relationships of natural and anthropogenic environmental variables affecting riverine ecosystem structure and function in the Athabasca Oil Sands Region (AOSR). A series of inter-related field studies were conducted to assess three key components of the freshwater food web (physico-chemical environment, basal productivity, benthic macroinvertebrates) utilizing an a priori environmental disturbance gradient experimental design. The gradient design was formulated to best discriminate the possible effects of natural and anthropogenic environmental variables on two river basins (Steepbank and Ells Rivers) each having different levels of oil sands (OS) land use disturbance. Findings from this study showed that natural variation explained most longitudinal and seasonal responses of physico-chemical environmental variables for both rivers, including possible mechanisms such as physical and chemical effects from the OS geological deposit and inputs from shallow groundwater upwelling. Basal productivity was likely controlled by natural variables within the Steepbank and Ells Rivers, such as potential OS deposit effects, nutrient availability and influences from turbidity and physical factors, with disturbance from OS development either negligible or not detected. Longitudinal and seasonal differences in benthic macroinvertebrate community composition were mostly related to natural variation, including possible mechanisms such as high discharge and sediment slump events on the Steepbank River, and community shifts from elevated metal concentrations from natural sources at upstream sites on the Ells River. This study demonstrated that developing baseline information on watersheds can be essential at discriminating sources of disturbance, with natural variation potentially confounding with anthropogenic factors. This study also highlights the need for further research to obtain an improved understanding of mechanistic pathways to better determine natural and anthropogenic non-point source disturbances and cumulative effects on the structure and function of tributary ecosystems in the AOSR at relevant spatial and temporal scales. / Graduate / 0329 / clsuzann@uvic.ca

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: In a minerals processing environment, stable production processes, cost minimisation and energy efficiency are key to operational excellence, safety and profitability. At an ilmenite smelter, typically found in the heavy minerals industry, it is no different. Management of an ilmenite smelting process is a complex, multi-variable challenge with high costs and safety risks at stake. A by-product of ilmenite smelting is superheated carbon monoxide (CO) gas, or furnace off-gas. This gas is inflammable and extremely poisonous to humans. At the same time the gas is a potential energy source for various on-site heating applications. Re-using furnace off-gas can increase the energy efficiency of the energy intensive smelting process and can save on the cost of procuring other gas for heating purposes. In this research project, the management of CO gas from the Tronox KZN Sands ilmenite smelter in South Africa was studied with the aim of optimising the current utilisation of the gas. In the absence of any buffer capacity in the form of a pressure vessel, the stability of the available CO gas is directly dependent on the stability of the furnaces. The CO gas has been identified as a partial replacement for methane gas which is currently purchased for drying and heating of feed material and pre-heating of certain smelter equipment. With no buffer capacity between the furnaces and the gas consuming plants, a dynamic prioritisation approach had to be found if the CO was to replace the methane. The dynamics of this supply-demand problem, which has been termed the “CO gas problem”, needed to be studied. A discrete-event simulation model was developed to match the variable supply of CO gas to the variable demand for gas over time – the demand being a function of the availability of the plants requesting the gas, and the feed rates and types of feed material processed at those plants. The problem was formulated as a multi-objective optimisation problem with the two main, conflicting objectives, identified as: 1) the average production time lost per plant per day due to CO-methane switchovers; and 2) the average monthly saving on methane gas costs due to lower consumption thereof. A metaheuristic, namely multi-objective optimisation using the cross-entropy method, or MOO CEM, was applied as optimisation algorithm to solve the CO gas problem. The performance of the MOO CEM algorithm was compared with that of a recognised benchmark algorithm for multi-objective optimisation, the NSGA II, when both were applied to the CO gas problem. The background of multi-objective optimisation, metaheuristics and the usage of furnace off-gas, particularly CO gas, were investigated in the literature review. The simulation model was then developed and the optimisation algorithm applied. The research aimed to comment on the merit of the MOO CEM algorithm for solving the dynamic, stochastic CO gas problem and on the algorithm’s performance compared to the benchmark algorithm. The results served as a basis for recommendations to Tronox KZN Sands in order to implement a project to optimise usage and management of the CO gas. / AFRIKAANSE OPSOMMING: In mineraalprosessering is stabiele produksieprosesse, kostebeperking en energie-effektiwiteit sleuteldrywers tot bedryfsprestasie, veiligheid en wins. ‘n Ilmenietsmelter, tipies aangetref in swaarmineraleprosessering, is geen uitsondering nie. Die bestuur van ‘n ilmenietsmelter is ‘n komplekse, multi-doelwit uitdaging waar hoë kostes en veiligheidsrisiko’s ter sprake is. ‘n Neweproduk van die ilmenietsmeltproses is superverhitte koolstofmonoksiedgas (CO gas). Hierdie gas is ontvlambaar en uiters giftig vir die mens. Terselfdertyd kan hierdie gas benut word as energiebron vir allerlei verhittingstoepassings. Die herbenutting van CO gas vanaf die smelter kan die energie-effektiwiteit van die energie-intensiewe smeltproses verhoog en kan verder kostes bespaar op die aankoop van ‘n ander gas vir verhittingsdoeleindes. In hierdie navorsingsprojek is die bestuur van die CO gasstroom wat deur die ilmenietsmelter van Tronox KZN Sands in Suid-Afrika geproduseer word, ondersoek met die doel om die huidige benuttingsvlak daarvan te verbeter. Weens die afwesigheid van enige bufferkapasiteit in die vorm van ‘n drukbestande tenk, is die stabiliteit van CO gas beskikbaar vir hergebruik direk afhanklik van die stabiliteit van die twee hoogoonde wat die gas produseer. Die CO gas kan gedeeltelik metaangas, wat tans aangekoop word vir die droog en verhitting van voermateriaal en vir die voorverhitting van sekere smeltertoerusting, vervang. Met geen bufferkapasiteit tussen die hoogoonde en die aanlegte waar die gas verbruik word nie, was die ondersoek van ‘n dinamiese prioritiseringsbenadering nodig om te kon vasstel of die CO die metaangas kon vervang. Die dinamika van hierdie vraag-aanbod probleem, getiteld die “CO gasprobleem”, moes bestudeer word. ‘n Diskrete-element simulasiemodel is ontwikkel as probleemoplossingshulpmiddel om die vraag-aanbodproses te modelleer en die prioritiseringsbenadering te ondersoek. Die doel van die model was om oor tyd die veranderlike hoeveelhede van geproduseerde CO teenoor die veranderlike gasaanvraag te vergelyk. Die vlak van gasaanvraag is afhanklik van die beskikbaarheidsvlak van die aanlegte waar die gas verbruik word, sowel as die voertempo’s en tipes voermateriaal in laasgenoemde aanlegte. Die probleem is geformuleer as ‘n multi-doelwit optimeringsprobleem met twee hoof, teenstrydige doelwitte: 1) die gemiddelde verlies aan produksietyd per aanleg per dag weens oorgeskakelings tussen CO en metaangas; 2) die gemiddelde maandelikse besparing op metaangaskoste weens laer verbruik van dié gas. ‘n Metaheuristiek, genaamd MOO CEM (multi-objective optimisation using the cross-entropy method), is ingespan as optimeringsalgoritme om die CO gasprobleem op te los. Die prestasie van die MOO CEM algoritme is vergelyk met dié van ‘n algemeen aanvaarde riglynalgoritme, die NSGA II, met beide toepas op die CO gasprobleem. The agtergrond van multi-doelwit optimering, metaheuristieke en die benutting van hoogoond af-gas, spesifiek CO gas, is ondersoek in die literatuurstudie. Die simulasiemodel is daarna ontwikkel en die optimeringsalgoritme is toegepas.

O efeito de instalação de estacas cravadas em areia, que promove um aumento da compacidade do solo e de seus parâmetros de resistência e deformabilidade, é analisado nesta dissertação em conjunto com o efeito de grupo. O procedimento estabelecido objetiva quantificar a melhoria após a instalação de um grupo de estacas e foi desenvolvido nesta pesquisa a partir da contribuição de Alves (1998). Para a utilização deste procedimento, foram propostas correlações do módulo de Young do solo em função da resistência à penetração NSPT (ou da resistência à penetração normalizada N60), a partir de um banco de dados obtido da literatura, visando não apenas as aplicações implementadas neste estudo, como também nortear futuras aplicações práticas. Na análise de casos documentados da literatura, foi utilizado o programa Plaxis 3D Foundation. Inicialmente foi procedida a calibração do programa através da reprodução de um caso de instrumentação de um grupo de estacas na argila rija de Londres, muito bem documentado por Cooke et al. (1980). Os resultados das simulações, com parâmetros do solo obtidos da literatura, se ajustaram muito bem aos resultados experimentais, seja nos valores de recalque, seja nos diagramas de transferência de carga. Posteriormente, a melhoria do solo por efeito da instalação foi estimada, através do procedimento estabelecido nesta dissertação, baseado em Alves (1998), a partir das características iniciais do solo antes da instalação de um grupo de estacas em modelo reduzido em solo arenoso. Obtidos os parâmetros melhorados previstos para o solo após a instalação, estes foram aplicados a um grupo de 9 estacas, para diferentes espaçamentos relativos, como dados de entrada no programa Plaxis. A comparação dos resultados experimentais com aqueles simulados numericamente sinaliza para o potencial tanto do programa Plaxis, na reprodução do comportamento do conjunto, como do modelo de Alves (1998), que norteou o procedimento proposto nesta pesquisa. O fator de escala, ressaltado na dissertação, bem como outros aspectos relevantes observados nas análises realizadas, são propostos como temas futuros a serem investigados na continuidade desta linha de pesquisa. / The installation effect of piles driven in sand, which increases soill density, strength and deformability parameters, is analyzed in this research, together with the pile-group effect. The procedure has been established aiming at the soil improvement achieved after installation of the piles. The proposed procedure is based on Alves (1998). In order to apply the procedure, correlations between the soil Young modulus and the NSPT blow count (or the normalized N60) have been established from a database obtained in the literature, aiming not only at the applications implemented in this study but also as a guideline for future practical applications. The program Plaxis 3D Foundation has been used in the analysis of documented cases from the literature, as an initial step to implement the procedure proposed in this thesis. Initially, the program has been calibrated by application to a well-documented piling group in the London stiff clay by Cooke et al. (1980). The results of the numerical simulations with soil parameters obtained from the literature have been very close to the experimental values, not only for the settlements, but also for the load transfer diagrams. The soil improvement due to pile installation has been implemented in this thesis based on Alves (1998). It has been applied to a case of small-scale model piling group in sands, taking into consideration the initial characteristics of the soil before installation and the soil improvement after driving. The updated parameters, together with different pile spacing in the 9-pile group, have been entered as input in the program Plaxis 3D Foundation. The comparison of the experimental results with those numerically simulated shows the potentiality of Plaxis program, due to its ability to properly reproduce the piling group behavior, and also of the model by Alves (1998), which guided the soil improvement procedure proposed in this research. The scale factor, highlighted in the thesis, as well as other relevant factors observed in the analyses, are topics for further investigation in continuity of this research.

Na região da campanha gaúcha, no sudoeste do estado do Rio Grande do Sul, existem áreas que demonstram fragilidade em relação às características litológicas, pedológicas e da cobertura vegetal, principalmente, quando relacionadas às dinâmicas do clima. Os areais da região têm despertado especial atenção nas últimas décadas, devido a questões históricas, socioeconômicas e ambientais. O processo de arenização está relacionado à dinâmica de fenômenos naturais como as precipitações intensas e período de estiagens, estes associadas à dinâmica dos ventos. Contudo, frente aos estudos de simulação climática que projetam os possíveis cenários climáticos futuros, quais seriam as possíveis dinâmicas processuais na região dos areais? O presente trabalho tem por objetivo geral desenvolver um estudo observacional sobre a dinâmica das precipitações para a região no decorrer do século XX, buscando encontrar possíveis evidências de modificação na sua dinâmica em relação ao processo de arenização. O trabalho, também, analisou os dados de precipitação a partir do modelo downscaling Eta/CPTEC 40 km acoplado ao Modelo Climático Global HadCM3 para o cenário SRES A1B. Foram utilizados dados pluviométricos diários dos postos de Alegrete (RS) disponíveis pela Agência Nacional de Águas, os quais foram tratados estatisticamente (preenchimento de falhas, consistência dos dados, análise dos totais anuais, totais trimestrais, totais mensais, dias com chuvas ≥ 1, 10, 20, 30, 50, 80, 100 mm, índice simples de intensidade diária – SDII, número de dias com chuvas ≤ 1 mm, comprimento máximo do período seco – CDD e o comprimento máximo do período seco mensal – CDDmês), em relação a sua dinâmica no decorrer da série (variabilidade, tendências e ocorrência de eventos extremos) através da aplicação do Teste de Mann-Kendall de significância estatística. Após a aplicação deste teste, os resultados demonstraram que a maior parte da série não apresentou tendência significativa à modificação, sendo encontradas variações normais durante o período analisado. Em relação aos fenômenos climáticos de baixa frequência como o El Niño Oscilação Sul (ENOS) e a Oscilação Decadal do Pacífico (ODP), foram verificadas suas correspondências utilizando o Índice de Anomalia de Chuva. Após sua aplicação, os resultados demonstraram que ambos os fenômenos (ENOS e ODP) modulam as precipitações anuais na região. Verificou-se, também, que as mudanças consideradas significativas pelo Teste de Mann-Kendall no século XX, sobretudo quanto à ocorrência de eventos extremos de precipitação, apresentaram forte relação com os processos de arenização associados à dinâmica hídrica. O aumento da frequência desses eventos no decorrer do século XX pode ter contribuído para a intensificação de parte dos processos de arenização na região. Já os resultados da modelagem climática apontaram para um aumento das precipitações nas estações da primavera, verão e outono, com incrementos pluviométricos nos meses de novembro, janeiro e março, que podem vir a influenciar nos processos arenização associados às precipitações torrenciais. / In the southwestern state of Rio Grande do Sul, in the Campos/grassland there are areas showing fragility related to soil, vegetation and climatic characteristics. The sands of the region in recent decades have attracted special attention due to historical issues, socio economic and environmental factors. The process of sandization is related to the dynamics of natural phenomena such as intense rainfall and drought period, which are associated to winds dynamic. However, compared to studies of climate simulation to design the possible future climate scenarios, which would be possible in the area dynamics of sands? The aim of this study is to develop observational analysis on the dynamics of rainfall for the region during the twentieth century, trying to find possible evidence of change in its dynamics in relation to the process of sandization. The study analyzed rainfall data from climate simulation of the precipitation from the downscaling model Eta / CPTEC 40 km coupled to the Global Climate Model output of HadCM3 for the SRES A1B scenario. Daily rainfall data of stations Alegrete (RS) available through the Agência Nacional de Águas were used, which were statistically (gap filling, data consistency, analysis of annual totals, quarterly totals, monthly totals, days with rainfall ≥ 1, 10, 20, 30, 50, 80, 100 mm, simple daily intensity index - SDII, number of days with rains ≤ 1 mm, maximum length of the dry period - CDD and the maximum length of the dry period monthly – CDDmonthly), analyzed in terms of their dynamic throughout the series (variability, trends and extreme events) by applying the Mann-Kendall. The results showed that most of the series showed no significant tendency to changes, with normal variations encountered during the period. The low frequency climatic phenomena such as El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) were evaluated for their correspondences using the rainfall anomaly index (RAI). The results showed that both phenomena (ENSO and PDO) modulate annual rainfall in the region. It is also significant that the changes assessed by the Mann-Kendall in the twentieth century, on the occurrence of extreme precipitation events, showed a great relationship with the processes associated with sandization water dynamics. The increased frequency of these events during the twentieth century may have contributed to the intensification of the processes of sandization in the region. The results of climate modeling indicated increased rainfall in the seasons of spring, summer and fall, with increases rainfall in the months of November, January and March what may influence the sandization processes associated with torrential rainfall.