Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-10-05T12:04:14Z No. of bitstreams: 1 gabrieldemendoncadomingues.pdf: 5641783 bytes, checksum: 0251a358b2d999eec22740e1f0b874f7 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-10-05T13:56:35Z (GMT) No. of bitstreams: 1 gabrieldemendoncadomingues.pdf: 5641783 bytes, checksum: 0251a358b2d999eec22740e1f0b874f7 (MD5) / Made available in DSpace on 2016-10-05T13:56:35Z (GMT). No. of bitstreams: 1 gabrieldemendoncadomingues.pdf: 5641783 bytes, checksum: 0251a358b2d999eec22740e1f0b874f7 (MD5) Previous issue date: 2010-04-16 / O crescimento acelerado dos grandes centros urbanos, associado ao crescimento do movimento ambientalista nas últimas décadas, vem impulsionando a migração de um número cada vez maior de pessoas de origem urbana a espaços rurais de significativo valor natural e paisagístico. Questionando a qualidade de vida e o modelo desenfreado de consumo dos recursos naturais observado nos grandes centros urbanos, eles buscam reinventar a sua relação com a natureza e disseminar idéias ambientalistas que tenham em vista uma nova maneira de o ser humano pensar a sua relação com a natureza. Entretanto observa-se que as propostas ambientalistas, apresentadas sob a perspectiva dos moradores de origem urbana ou de atores externos à localidade, chocam-se, muitas vezes, com a visão de mundo, os hábitos tradicionais e os valores culturais, próprios dos moradores de origem rural, gerando desconfiança e resistência às propostas ambientalistas trazidas pelos forasteiros. Evidencia-se assim, os conflitos e as contradições originadas dessa busca da sociedade urbana pelo “reencontro com a natureza”. A pesquisa foi realizada no município de Teresópolis-RJ, junto às comunidades de Canoas, Prata dos Aredes e Varginha, situadas no entorno do Parque Estadual dos Três Picos, maior unidade de conservação administrada pelo Instituto Estadual do Ambiente – Inea. A pesquisa teve como objetivo analisar, sob a perspectiva dos diferentes atores locais, a complexidade sociocultural que se forma na localidade a partir da chegada dos moradores de origem urbana, confrontando as diferentes visões de mundo e explicitando os desafios colocados ao trabalho de educação ambiental na localidade. Nesse contexto, o estudo das interações entre as pessoas de origem rural e urbana deixa clara a importância do trabalho de educação ambiental na promoção do diálogo entre os diversos atores locais, visando à superação dos conflitos e à implantação de um modelo de desenvolvimento local que, de fato, se contraponha ao insustentável modelo urbano-industrial. Esse tipo de trabalho torna-se também fundamental para a realização plena dos objetivos propostos com a criação do PETP, uma vez que cria as condições necessárias para a implantação da sua Zona de Amortecimento. Para a realização da pesquisa, foi adotada uma abordagem qualitativa e utilizados métodos da observação participante, entrevistas não estruturadas e semi-estruturadas, buscando assinalar a influência da maneira de pensar o espaço rural - e as suas relações com o urbano - na qualidade da relação sociedade/natureza. / The fast expansion of urban centers associated with the environmetal movement enlargement has generated a growing flow of migration from urban to rural areas, where significant natural landscapes are found. Dissatisfied with the conditions of life and with the model of uncontrolled consumption of natural resources observed in the big urban centers, they try to reinvent their relationship with nature and disseminate the environmental concepts, aiming at a new way of thinking the human relationship with nature. However, we observe that the environmental proposals presented under the perspective of the outsiders has been clashing itself with the world views, traditional habits and cultural values of the rural people, generating mistrust and showing up the conflicts and contradictions of this urban people’s attempt to meet their “lost relationship with nature”. This work was made in Teresópolis, Rio de Janeiro State, in the communities of Canoas, Prata dos Aredes and Varginha, on the nearside of the Parque Estadual dos Três Picos - PETP (Three Peaks State Park). The research’s objective was to analyse, by the perspective of the different local players, the sociocultural complexity formed with the arrival of urban people at the local, confronting the different world views and setting out the challenges of a work with environmental education on these communities. At that context, the study of interactions between rural and urban people emphasizes the importance of the environmental education to improve the dialogue between the different local actors, aiming at to overcome the conflicts and to implement a model of local development actually different from the urban-industrial model. In the same way, this model becomes fundamental for the complete realization of PETP’s goals, creating the conditions to consolidate its buffering zone. A qualitative perspective was adopted in this research. Participant observation, non structured and semi-structured interviews were the tools used in order to understand the relationship between nature and society, the way of thinking rural space is conceived and its interaction with the urban side.

Le stockage géologique du carbone est l’une des techniques les plus prometteuses pour réduire le taux de CO₂ dans l’atmosphère. La séquestration géologique possède la capacité et la longévité potentielles pour diminuer les émissions de CO₂ vers l’atmosphère. Dans le cadre d’injections à l’échelle industrielle, les réservoirs carbonatés peuvent faire partie des sites aptes à stocker du CO₂. Toutefois, ces injections à grandes profondeurs sont sujettes à des risques de fuites du piège géologique lui-même ou des infrastructures liés à l’exploitation du site de stockage. Ainsi, il existe principalement deux types de fuite : brutale et diffuse. Dans les deux cas, elles sont susceptibles d’entrainer des risques pour l’environnement et de mettre en danger les populations. Il est ainsi nécessaire de développer des outils capables de prévenir une fuite de CO₂ quel que soit son type. Par ailleurs, il est particulièrement indispensable de comprendre les mécanismes de transport réactif qui rentrent en jeu lors de l’arrivée de cette fuite en contexte de proche surface (zone vadose) et ainsi d’essayer d’étudier comment cette fuite peut s’amortir. Ces travaux de thèse traitent donc de la caractérisation, de la quantification et de la modélisation des processus de transferts et des interactions CO₂-H₂O-CaCO₃ dans la zone vadose en contexte de fuite à partir d’un puits de forage. Cette problématique a été d’abord abordée par une approche expérimentale sur un site pilote à Saint-Emilion. Puis, les interactions CO₂-H₂O-CaCO₃ ont été étudiées au travers d’une approche expérimentale à l’échelle de la carotte en laboratoire. L’approche expérimentale a conduit à la réalisation de deux fuites dans la zone vadose du site pilote : une fuite diffuse et une fuite ultra diffuse. Elles furent réalisées dans la continuité des expériences qui avaient déjà eu lieu auparavant. Une comparaison de l’ensemble des fuites a montré la nécessité d’utiliser des gaz nobles comme précurseurs de l’arrivée en surface du CO₂. Selon le type de fuite, l’hélium peut servir de précurseur temporel du CO₂, tandis que le krypton prévient de l’étendue du panache de gaz durant la fuite. Plus la pression d’injection du CO₂ est importante et plus le gaz migre par advection. Par ailleurs, une pression d’injection importante favorise l’existence de passage préférentiel dans la zone vadose. L’utilisation d’isotopes tels que ceux de l’hélium et du carbone permet de mettre en évidence la présence locale de phases aqueuses dans le massif et de déterminer l’origine biologique ou anthropique du CO₂. Les expériences à l’échelle de la carotte permettent d’estimer le pouvoir tampon des calcaires oligocènes en fonction du faciès de la roche. La perméabilité et la porosité de celle-ci conditionnent la dissolution des calcaires. De même, la réactivité des carbonates en contexte de fuite dépend du pH de la phase aqueuse, du débit qui traverse le réseau poreux, de la saturation en eau et des caractéristiques pétro-physiques des carbonates. / Carbon storage is one of the most encouraging methods to decrease CO₂ concentration into the atmosphere. Carbon storage provides the longevity and the capacity needed to decrease CO₂ emissions toward the atmosphere. When dealing with storage on an industrial scale, carbonated reservoirs can be among the most suitable storage sites. However, these high depth injections are subject to leakage risks from the geologic trap itself or from the framework created by the establishment of the site. Two main types of leakage exist: brutal and diffusive leakage. In both cases, they are likely to endanger the environment and the population. Therefore, it is essential to develop tools that are able to anticipate any types of CO₂ leakage. Furthermore, it is also necessary to understand the reactive transport mechanism that take place when the leakage arrives in the shallow subsurface (vadose zone)and to see how the leakage can be buffered. This work deals with the characterization, the quantification and the modelling of transfer processes and CO₂-H₂O-CaCO₃ interactions into the vadose zone in a context of a leakage from a drilling well. This issue was first dealt through field experiment on the site of Saint Emilion. Then, the CO₂-H₂O-CaCO₃ interactions were studied through an experimental approach in laboratory. Two leakage experiments were performed on the site: a diffusive leakage and an ultra-diffusive leakage. They were performed as a sequel of former experiments carried on the pilot site. A comparison of all the leakage experiments revealed the necessity to use noble gases as precursor of the CO₂ arrival at the surface. Depending of the type of the leakage, helium can be a temporal precursor while krypton can anticipate the spread of the CO₂ gas plume. The higher the injection pressure, the more the gas migrates through advective flux. Moreover, a high injection pressure favors the existence of preferential paths in the vadose zone. The use of helium and carbon isotopes makes it possible to reveal the presence of a local aqueous phase within the porous media and to identify the origin of CO₂. The core scale experiments lead to the estimation of the buffering power of Oligocene limestone according to the rock facies. The permeability and the porosity influence the dissolution of the limestone. The reactivity of carbonates during a leakage depends on the pH of the aqueous phase, the flow rate that goes through the porous media, the water saturation and petrophysical characteristics of the carbonates.