Made available in DSpace on 2014-12-17T15:55:03Z (GMT). No. of bitstreams: 1 AnnaJPA_DISSERT.pdf: 4374448 bytes, checksum: 0394dbcd3eebb9c5bf4ba04fccb3a5c2 (MD5) Previous issue date: 2013-03-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / At the semiarid regions of developing countries the rural population has always been vulnerable to the climatic variations e its consequences. The effects of the semiarid climate, together with other biophysics, social and political-economic factors, impair the agricultural production, generating a situation of food insecurity and poverty in the rural areas. With the occurrence of climate change, natural resources of the semiarid regions can became scarcer, what would directly affect the agricultural production and those who depend on it. Therefore, the present study sought to study one of the most susceptible areas to the effects of the semiarid climate and desertification of Rio Grande do Norte, the potiguar s Serido. The study aimed to analyze the socioeconomic and environmental factors that put farmers in a position of vulnerability to the effects of climate; assess their perceptions about climate variations that have already occurred and their knowledge about climate change and global warming, also to identify which adaptation strategies to climate they have adopted at the rural establishment. The survey was conducted in 29 communities of four counties of the potiguar s Serido Caico, Parelhas, Lagoa Nova and Acari. Semi-structured interviews were conducted with local leaders and 241 questionnaires were applied with the family farmers. It was found that in addition to environmental factors such as the scarcity of water resources and climatic conditions, other factors such as the environmental degradation, the small size of the properties, the lack of technical assistance and financial resources and also the low education levels reduce the resilience capacity of family farming to the effects of the Semiarid climate. With the occurrence of climate change, the challenges for family farming at Serido will intensify. If farmers cannot adapt, the impacts may preclude this category of agricultural production causing serious harm to food security and further increasing the vulnerability situation of these populations. Although the farmers perceived changes in climate, the lack resources and information appears as the main reasons preventing the adoption of adaptation strategies. The lack of knowledge about climate change and global warming and the impacts that these phenomena may cause are also limiting factors for adaptation. It is therefore essential to identify the factors that influence the adoption of adaptation strategies, and seek alternatives to living with the semiarid that can strengthen the resilience of family farming and social reproduction that allow agricultural segment, even in a climate change scenario / Nas regi?es semi?ridas dos pa?ses em desenvolvimento as popula??es rurais sempre estiveram vulner?veis ?s varia??es clim?ticas e suas consequ?ncias. Os efeitos do clima Semi?rido, aliados ? outros fatores biof?sicos, sociais, pol?ticos e econ?micos, prejudicam a produ??o agr?cola, gerando uma situa??o de inseguran?a alimentar e pobreza no meio rural. Com o advento das mudan?as clim?ticas, os recursos naturais das regi?es semi?ridas poder?o se tornar ainda mais escassos, o que afetaria diretamente a produ??o agr?cola e os que dela dependem. Nesse contexto, a presente pesquisa buscou estudar uma das ?reas mais suscept?veis aos efeitos do clima semi?rido e da desertifica??o do Rio Grande do Norte, o Serid? potiguar. O estudo teve como objetivo analisar os fatores socioecon?micos e ambientais que colocam os agricultores familiares numa situa??o de vulnerabilidade aos efeitos do clima; avaliar suas percep??es sobre as varia??es clim?ticas j? ocorridas e seus conhecimentos sobre mudan?as clim?ticas e aquecimento global, al?m de verificar quais as estrat?gias de adapta??o ao clima foram realizadas no ?mbito do estabelecimento rural. A pesquisa foi realizada em 29 comunidades de quatro munic?pios do Serid? potiguar Caic?, Parelhas, Lagoa Nova e Acari. Foram realizadas entrevistas semiestruturadas com lideran?as locais e aplicados 241 question?rios com os agricultores familiares. Verificou-se que al?m dos fatores ambientais como a escassez dos recursos h?dricos e as condi??es clim?ticas outros fatores como degrada??o ambiental o tamanho reduzido das propriedades, a falta de assist?ncia t?cnica e de recursos financeiros, al?m do baixo n?vel de escolaridade dos agricultores reduzem a capacidade de resili?ncia da agricultura familiar aos efeitos do clima Semi?rido. Com a ocorr?ncia das mudan?as clim?ticas, os desafios para a agricultura familiar do Serid? potiguar ir?o se intensificar e, caso os agricultores n?o consigam se adaptar, os impactos poder?o impossibilitar a produ??o agr?cola dessa categoria, causando graves preju?zos para a seguran?a alimentar e aumentando ainda mais a situa??o de vulnerabilidade dessas popula??es. Apesar de perceberem as altera??es no clima, a limita??o de recursos financeiros e a falta de informa??es aparecem como principais impedimentos ? ado??o de estrat?gias de adapta??o. A falta de conhecimento sobre as mudan?as clim?ticas, aquecimento global e sobre os impactos que esses fen?menos podem causar tamb?m s?o fatores limitantes ? adapta??o. Torna-se assim, essencial identificar os fatores que influenciam a ado??o de estrat?gias de adapta??o, al?m de buscar alternativas para a conviv?ncia com o semi?rido que possam fortalecer a resili?ncia da agricultura familiar e permitir reprodu??o social desse segmento agr?cola, mesmo num cen?rio de mudan?as clim?ticas

Made available in DSpace on 2015-03-13T17:08:23Z (GMT). No. of bitstreams: 1 LindaraySC.pdf: 4257838 bytes, checksum: 9412fe333ae2e7c2ddef65c89e08a35e (MD5) Previous issue date: 2009-06-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The study area is located at the eastern-central portion of the Serid? Belt, on the interface between the Serid? Group Metasediments and the crystalline basement rocks of the Caic? Complex (RN). Petrographic and geochemical data allow us to define aspects related to the genesis and evolution of the Serra Verde Pluton magmas, which composes the goal of this dissertation The Serra Verde Pluton is a stock with outcropping area of about 25 km?, which is intrusive into metasedimentary sequence and the basement gneisses. The pluton intrusion is sintectonic to the Brasiliano event, elongated along the NE direction, developing a cornue geometry. The rock is a monzogranite mainly composed by K-feldspar, plagioclase and quartz, which usually compose more than 85% of the modal analisys. The main mafic mineral is the biotite, while amphibole, sphene, epidote, opaque minerals, allanite, zircon and apatite occur as accessory minerals. It features still a latemagmatic paragenesis composed by chlorite, granular epidote, carbonates and muscovite, developed through the percolation of late CO2 and H2O rich fluids. Chemically, the Serra Verde Pluton rocks may be classified as metaluminous, of calc-alkaline affiliation, sometimes showing trondhjem?tic characteristics, with high Na2O (>4,5%), Sr (>400ppm) and Ba (>800ppm) and low K2O (&#8804;3,0%), MgO (<1,0%), TiO2 (<0,5%), Rb (<90ppm), Y (&#8804;16ppm) and Zr (&#8804;13ppm). Micropetrographic evidences (mineral assembly and microtextures) indicate that the magma evolution occurred in moderated to high fO2 conditions, above the FMQ buffer. Thermo-barometric data obtained by minor elements geochemistry and the CIPW data, suggest a final/minimal pressure crystallization for the Serra Verde Pluton samples of about 3 to 5 kbar, liquidus temperature around 800o C, solidus temperature between 680o and 660o C. This data is compatible with those observed by many authors for the Neoproterozoic granites of the Serid? Belt. The group of analyzed data (Petrographic, microtextural and geochemical), suggests that the dominant process of the generation and evolution of the Serra Verde Granite magma was the fractional crystallization, probably from basement quartz-dioritic and tonalitic orthogneisses source / A ?rea estudada situa-se na por??o centro-leste da Faixa Serid?, na interface dos metassedimentos do Grupo Serid? e as rochas do embasamento cristalino do Complexo Caic? (RN). Dados petrogr?ficos e qeoqu?micos permitem definir os aspectos relativos ? g?nese e evolu??o do(s) magma(s) do Pl?ton Serra Verde, que constitui o alvo desta Disserta??o de Mestrado. O Pl?ton Serra Verde constitui um stock com ?rea aflorante de aproximadamente 25 Km2, intrusivo na seq??ncia metassedimentar e nos gnaisses do embasamento. Este pl?ton corresponde a uma intrus?o sintect?nica ao evento brasiliano, alongada na dire??o NE, com geometria en cornue. Trata-se de um monzogranito cuja assembl?ia mineral ominante ? composta por K-feldspato, plagiocl?sio e quartzo, que usualmente somam mais de 85% modal. Tem como m?fico principal a biotita, enquanto que anfib?lio itanita, ep?doto, opacos, allanita, zirc?o e apatita s?o os acess?rios. Apresenta ainda uma parag?nese tardi-magm?tica constiut?da de clorita, ep?doto granular, carbonato e muscovita, desenvolvida a partir da atua??o de flu?dos tardios ricos em CO2 e H2O. Quimicamente, as rochas do Pl?ton Serra Verde podem ser classificadas como metaluminosas, de filia??o c?lcio-alcalina, por vezes com caracter?sticas de associa??es trondhjem?ticas, com altos teores de Na2O (>4,5%), Sr (>400ppm) e Ba (>800ppm), e baixos teores de K2O (&#8804;3,0%), MgO (<1,0%), TiO2 (<0,5%), Rb (<90ppm), Y (&#8804;16ppm) e Zr (&#8804;13ppm). Evid?ncias micropetrogr?ficas (assembl?ias minerais e microtexturais) indicam que a evolu??o do magma ocorreu em condi??es de fO2 moderadas a elevadas, acima do tamp?o FMQ. Dados termobarom?tricos obtidos atrav?s da geoqu?mica de elementos menores, tra?os e dados normativos CIPW sugerem uma press?o final/m?nima de cristaliza??o para as amostras do Pl?ton Serra Verde em torno de 3 a 5 kbar, temperatura do l?quidus em torno de 800?C, e temperatura do solidus em torno 680 a 660?C. Estes dados s?o compat?veis com os observados por diversos autores em granit?ides neoproteroz?icos do Dom?nio Serid?. O conjunto de dados analisados (petrogr?ficos microtexturais e geoqu?micos), sugerem ainda que o processo dominante na gera??o e evolu??o do magma do granito Serra Verde se deu por cristaliza??o fracionada, sendo ortognaisses quartzo dior?ticos a tonal?ticos do complexo do embasamento, prov?veis candidatos para sua fonte