Estudo da bacia hidrográfica de Machico: vulnerabilidade de cheias

Esta dissertação de mestrado intitula-se “Estudo da Bacia Hidrográfica da Ribeira de Machico – Vulnerabilidade de Cheias”. Os objetivos deste estudo são: o estudo da Bacia Hidrográfica de Machico, catorze sub-bacias e secções de desembocadura destes afluentes para o curso de água principal, várias secções ao longo da linha de água principal, analisar se tais secções comportam os caudais de cálculo, elaboração de uma carta de vulnerabilidade e elaboração de uma lista de possíveis obras de intervenção e medidas a implementar. O método utilizado consistiu na identificação dos postos de monitorização de precipitação com efeito na bacia, de seguida aplicaram-se estatisticamente as amostras de precipitações máximas anuais com a duração de 1, 2, 3, 4 e 5 dias consecutivos, para que de seguida se estime a precipitação na bacia hidrográfica com o período de retorno e com a duração de 24h. Após determinação da precipitação para vários períodos de retorno, estimou-se o caudal de ponta de cheia através do método racional. Mediram-se as secções em estudo e determinou-se o caudal pela equação de Manning – Strickler nas mesmas. Após tal procedimento, verificaram-se quais as secções que não comportavam tal caudal e por fim elaboraram-se cartas de vulnerabilidade para vários períodos de retorno, quer para as secções de desembocadura de 14 sub-bacias, assim como, para as secções ao longo da ribeira de Machico. Relativamente aos resultados, foram os esperados, pois existem alguns trechos da ribeira que ainda estão por canalizar, assim como, a existência de passagens pedonais, pontes e passagens hidráulicas, onde há uma diminuição da área de vazão da ribeira de Machico. Assim sendo, tais secções apresentavam uma percentagem de preenchimento através da fórmula criada para o efeito, quociente entre o caudal pelo método racional e o caudal de Manning – Strickler, e multiplicado posteriormente por 100 %. Em termos numéricos é de constatar que para o período de retorno de 100 anos, seis das 18 secções estudadas da ribeira canalizada não comportam tal caudal líquido acabando por transbordar. Assim sendo, tem-se que 12 secções acabam por comportar tal volume de água, no entanto se juntarmos diferentes materiais tais como, solo, material rochoso e outros, essas secções não comportarão tal matéria líquida. Em suma, dever-se-á repensar e realizar obras de intervenção nos trechos onde a ribeira ainda está por canalizar como pontes e passagens pedonais. Dada a existência de um grande desnível na linha de água principal a partir do quarto quilómetro de montante para jusante, terá de haver uma série de intervenções a sul desse desnível de modo a mitigar um possível caudal que poderá advir de acordo com precipitações iguais ou superiores aos do período de retorno estudados. Por fim é importante referir que será de igual forma necessário realizar limpezas periodicamente tanto na ribeira principal como nos afluentes que nesta desaguam.

Caracterização físico-mecânica dos solos da bacia hidrográfica de Santa Luzia no âmbito do projeto "MonitorizaRibeiras" do LREC

O conteúdo da presente dissertação aborda a importância da caracterização dos solos, na medida em que estabilidade dos taludes é um fator que depende fortemente da constituição e do tipo de solo presente nos maciços. A realização deste estudo incide sobre os solos da bacia hidrográfica da ribeira de Santa Luzia. O motivo da escolha da bacia em causa prende-se com o facto de a mesma ser uma das ribeiras que, atualmente se encontra sob observação através do projeto “MonitorizaRibeiras” do LREC. Os ensaios laboratoriais de caracterização físico-mecânica dos solos constituem uma das componentes de maior relevância na engenharia geotécnica. Neste trabalho a caracterização mecânica é feita através de ensaios de corte direto (em caixa de corte), que permitem obter os parâmetros de resistência do solo (ângulo de atrito e coesão). A caraterização física foi efetuada recorrendo a ensaios simples que permitem determinar os índices físicos do solo, mais particularmente: determinação da baridade seca in situ, análises granulométricas, determinação de limites de consistência de Atterberg e do teor em água natural, densidade de partículas sólidas e determinação da quantidade de matéria orgânica. Os parâmetros obtidos permitem depois a realização de uma análise a vários taludes com diferentes inclinações, de modo a verificar que influências tais parâmetros geram na obtenção do Fator de Segurança. Verifica-se que à medida que o teor em água aumenta, essa influência traduz-se na perda de resistência de um solo. Tal análise permitiu determinar quais as zonas da bacia de Santa Luzia que com as características obtidas e nas condições estudadas se encontram em maior perigo de escorregamento. Os sensores de saturação do solo, sendo uma útil ferramenta de monitorização remota foram alvo de pesquisa nesta dissertação. Esta pesquisa foi realizada com propósito de contribuir com informação, que posteriormente auxilie, na implementação destes equipamentos no sistema do projeto “MonitorizaRibeiras”.

Gestão Social em Empreendimentos Econômicos Solidários: uma abordagem no Oeste Potiguar

The central research question was to search for data to ratify the theory and discourse of the so-called practitioners of economic solidarity, by defending the substantive rationality should guide the principles of economic solidary, designing the space economy incidental and not the primacy of relations in determining social as well, reflecting the predominance of dimensions of social management in administrative practices of ESS's. For both analyzed the theoretical dimensions of social management - sociopolitical, economic, organizational and environmental - manifested in organizational practices supportive of economic organization Potiguar West. For the success of the research realized the triangulation involving a combination of quantitative and qualitative methodological approaches. At first the research will use a quantitative approach, from the cluster analysis, to verify the behavior of the sample chosen for this study. In the second stage of the qualitative study was carried out focus group technique (FLICK, 2002) for further analysis of the dimensions of social management on organizational practices supportive of economic organization, related to the principles of Solidary Economy, established in a quantitative approach. In quantitative analysis, the socio-political dimension, it was clear that the more equity instruments of internal and external, from the purposeful living in public spaces, the best monetary results. Another point worth stressing concerns the economic dimension, with the practice reciprocity prevailing in market. Thus, the qualitative approach was possible to understand the processes of exchange of product or service. Rural enterprises surveyed in the allocation of the agro-ecological products have the following scale of priority, sequentially: self-consumption (domestic), market and exchange. The research leads to the fact that training and practices that enhance the socio-political dimension (knowledge, empowerment, sense of belonging) become the guiding principle for the strengthening of the social management in the context of other dimensions, leading to gains sociopolitical, economic, organizational and environmental. Despite the weaknesses found in the organizational dimension and environment, both in a quantitative as in qualitative, we determined that the practices of ESS's Potiguar West incorporate predominantly elements of social management and economic solidarity, with a preponderance of substantive rationality in the primacy of the instrumental. Finally, research has brought information that the participants of the ESS's do not give the money economy primacy in determining social relations, which in turn leads to the confirmation that, in practice the solidarity economy, prevailing the dominance of substantive rationality, as a guide for organizational practices

Da promessa à realidade: a cidade potiguar do século XIX, a partir do olhar da elite

The purpose of this research is to apprehend the perception that the ruling elite, especially the Presidents of the province of Rio Grande do Norte/Brazil, had about the potiguar city, that is, the urban localities existing in the province along the 19th century. By interweaving political, administrative, socioeconomic and spatial aspects, the study of this perception involves two distinct moments, which are also linked: a moment of apprehension of the city, that is, how the elite seizes, describes and criticizes the city; and, a second moment, which occurs simultaneously or after the first moment, of intervention in the city, in which the elite exposes its vision and projects for the city and for the territory. Rather than describing the potiguar city in itself, the research is an attempt to reveal how it was perceived along this process from a particular standpoint or discourse, official and elitist, which did not correspond necessarily or completely to what it was in reality. We tried to understand, always through the lens of the discourse, how the ruling elite perceived the potiguar city based on what their members thought about other urban realities, particularly of the advanced countries; how, within an integrated vision, this city was characterized in political, administrative, socioeconomic and spatial terms and how it consolidated itself along the period established for the research. Qualitative and historical in nature, this study was also methodologically developed based upon bibliographical and documental research. Given the fact that this research works with descriptions, comparisons and interpretations, it was necessary to make use of tools such as the discourse analysis in order to apprehend, as much as possible, what lay behind the words of the elite. The primary sources used were essentially the official documents produced by the Presidents of the province, as well as other documents written by top government officials and other members of the administration staff, all of them composing the so-called ruling elite of Rio Grande do Norte. Secondary sources were books and other publications, theses and dissertations, among others. The research made possible the identification of a certain perception of the potiguar city in the 19th century, which is certainly limited because it is grounded on a specific discourse - that of the political and administrative elite, but which, in spite of such a limitation, is still useful to understand the city and its evolution along the period established, among other noteworthy remarks

Eutrofização e capacidade de carga de fósforo de seis reservatórios a bacia do Rio Seridó, região semi-árida do Estado do RN

The eutrofization is a natural process of accumulation of nutrients in aquatic´s body that it has been accelerated for the human´s actives, mainly the related with the activities of camp, industrial and the inadequate disposition of the domestic sewage. The enrichment of the aquatic´s body with nutrients, mainly the nitrogen and the phosphorus, and the consequent proliferation of algae and Cyanobacteria can commit the quality of the water for the public provisioning, for the fish farming and for other ends. The problem becomes more critical when there is a shortage of water naturally as in the semi-arid area of the Brazilian northeast. Before that problem this work had as objective evaluates the trophic state of six reservoirs of the basin of River Seridó of Rio Grande of Norte and also estimate the capacity of load of match of the reservoir and risk probabilities based on the established limits by the resolution Conama 357/05. The results demonstrate that the six reservoirs are eutrofization, with concentration of total phosphorus and cloro a in the water upster to 50 e 12 μg l-1. The results show that space homogeneity exists in the state trophic of the reservoirs, but a significant variation interanual in function of the increase of the concentrations of nutrients and decrease of the transparency of the water with the reduction of the body of water accumulated in the reservoirs.The results of the simulation risk estocastic show that the reservoirs could receive annually from 72 to 216 Kg of P, assuming a risk of 10% of increasing in more than 30 μg l-1 the annual medium concentrations of total match in the water of these reservoirs. This load could be high in until 360 kg of P a year in case the managers assume a risk of 10% of increasing in more than 50 μg l-1 the annual medium concentrations of total phosphorus in the waters of these reservoirs

Diversidade Ictiofaunística e Ecologia reprodutiva de uma espécie nativa de peixe da Bacia Piranhas-Assu, RN

The Caatinga biome is rich in endemic fish species fauna. The present study the results of fish faunal surveys conducted in the hydrographic basin of Piranhas-Assu of the Brazilian Caatinga biome. The fish samples collected were distributed in four orders (Characiformes, Perciformes, Siluriformes and Synbranchiformes), 11 families (Characidae, Curimatidae, Auchenipteridae, Anostomidae, Prochilodontidae, Erythrinidae, Cichlidae, Sciaenidae, Heptapteridae, Loricariidae, Synbranchidae) and 22 species, of which 17 are endemic and five have been introduced from other basins. The order Characiformes was the most representative in number of species (46,35% ) followed by Perciformes (35,38%), Siluriformes (17,44%) and Synbranchiformes (0,5%). The Nile tilapia, Oreochomis niloticus, the only exotic species, was most expressive in number of individuals (24.92%) followed by the native species piau preto, Leporinus piau (18,77 %). Considering the relative frequency of occurrence of the 22 species, 13 were constant, five were accessory and four were occasional. This study investigated the reproductive ecology of an endemic fish black piau, Leporinus piau from the Marechal Dutra reservoir, Acari, Rio Grande do Norte. Samplings were done on a monthly basis from January to December 2009, and a total of 211 specimens were captured. The environmental parameters such as rainfall, temperature, pH, electrical conductivity and dissolved oxygen of water were recorded. The sampled population showed a slight predominance of males (55%), however females were larger and heavier. Both sexes of L. piau showed positive allometric growth, indicating a higher increase of weight than length. The first sexual maturation of males occurred at smaller size, with 16.5 cm in total length than females (20.5 cm). During the reproductive period, the condition factor and gonadosomatic index (GSI) of L. piau were negatively correlated. This species has large oocytes with a high mean fecundity of 54.966 with synchronous oocyte development and total spawning

Desenvolvimento de formulações para produção de grés porcelanato a partir de matérias-primas da região da bacia do Parnaíba

Brazil is a great ceramic raw materials productor because of the its big number of clay deposits, in various areas of the ceramic industry. Although, the majority of the natural reservations are unknown or not studied yet, so there is no scientific technical dates that can guide their usage and industrial application, as well as the racional and optimazed way of usage by the industrial sector. The state of Maranhão has a gigant mineral wealth as esmectite, bentonite, kaolin, clays, feldspates, marine salt, iron and others, but produce only products with small agregated value compared to the porcelanato, one of the most expensives ceramic cover tiles, the reason for that is the low water absorption (lower than 0,5%), beside present amazing tecnicals features, like mechanical resistence. The main objective of the work is to do the characterization of four clays, with the finallity of find an application by the results and develop formulations to produce porcelanato using these raw materials from Timon-MA. For this were made the raw materials characterization using X ray fluorecence; X ray diffraction; Differencial thermal analysis; Dilatometric analysis and Tecnological properties, planing three formulations that were sinterized at six different temperatures: 1150, 1170, 1190, 1210, 1230 and 1250ºC for 7 minutes. After the sinteratization, the samples were submitted to tension resistance analysis. Were attained two formulations with the requested properties to produce porcelanato

Adição do resíduo de biomassa da cana-de-açúcar em pastas para cimentação de poços petrolíferos produtores de óleos pesados

The Potiguar basin has large fields of viscous oil where the used method for recovering is based on vapor injection; this operation is carried out by injecting vapor in the oilwell directly, without the protection of a revetment through thermal insulation, what causes its dilation and, consequently, cracks in the cement placed on the annular, and lost of hydraulic insulation; this crack is occasioned by the phenomenon of retrogression of the compressive resistance due to the conversion of the hydrated calcium silicate in phases calcium-rich, caused by the high temperatures in the wells, subjected to thermal recuperation. This work has evaluated the application of composite pastes with addition of residue of biomass of ground sugar-cane bagasse as anti-retrogression mineral admixture for cementation of oil-wells subjected to thermal recuperation. The addition of the mineral residue was carried out considering a relative amount of 10, 20, 30, 40 and 59% in relation to cement mass, trying to improve the microstructure of the paste, still being developed a reference paste only with cement and a paste with addition of 40% of silica flour - renowned material in the oil industry as anti-retrogression additive. Pozzolanic activity of the ash was evaluated through XRD, TG/DTG, as the resistance to compression, and it was also determined the physical and mechanical behavior of the pastes when submitted to cure at low temperatures (22 and 38º C); besides it was evaluated the behavior of the pastes when submitted to two cycles of cure at high temperature (280ºC) and pressure (7 MPa). It was verified that the ash of the sugar-cane biomass presents pozzolanic reaction and has great efficiency in decrease the permeability of the paste by filler effect, as well as that addition of ash in a relative amount of 10, 20 e 30% increases cured compressive resistance at low temperatures. It was also showed that the ash in a relative amount of 40% and 59% has very significant efficiency as anti-retrogression additive, since it prevents the decrease of compressive resistance and forms hydrated calcium silicate type xenotlita and tobermorita which have more resistance and stability in high temperatures

Avaliação da incorporação combinada dos resíduos de cascalho de perfuração de poço de petróleo e de polimento do porcelanato em cerâmica vermelha

Among the industries, those that produce ceramic porcelain for use in construction industry and oil, during the exploration and production period, play an important role in the production of waste. Much research has been carried out both by academia and the productive sector, sometimes reintroducing them in the same production line that generated them, sometimes in areas unrelated to their generation, as in the production of concrete and mortar for the construction, for example, but each one in an isolated way. In this research, the aim is to study the combined incorporation of the waste drill cuttings of oil well and the residue of the polishing of porcelain, generated in the final stage of finishing of this product in a clay matrix, for the production of red pottery, specifically bricks, ceramic blocks and tiles. The clay comes from the municipality of São Gonçalo, RN, the drilling waste is from the Natal basin, in Rio Grande do Norte, and the residue of the polishing proceeds from a ceramic porcelain of the State of Paraíba. For this purpose, we used a mixture of a plastic clay with a non-plastic, in a ratio of 50% each, settling formulations with the addition of these two residues in this clay matrix. In the formulations, both residues were incorporated with a minimum percentage of 2.5% and maximum of 12.5%, varying from 2.5% each, in each formulation, which the sum of the waste be no more than 15%. It should be noted that the residue of the polishing of ceramic porcelain is a IIa class (not inert). The materials were characterized by XRF, XRD, TG, DTA, laser granulometry and the plasticity index. The technological properties of water absorption, apparent porosity, linear shrinkage of burning, flexural tensile strength and bulk density were evaluated after the sintering of the pieces to 850 °C, 950 °C and 1050 °C, with a burning time of 3 hr, 3 hr and 30 minutes, and 3 hr and 50 minutes, respectively, with a heating rate of 10 °C/minute, for all formulations and landing of 30 minutes. To better understand the influence of each residue and temperature on the evaluated properties, we used the factorial planning and its surfaces of response for the interpretation of the results. It was found that the temperature has no statistical significance at a 95% of reliability level in flexural tensile strength and that it decreases the water absorption and the porosity, but increases the shrinkage and the bulk density. The results showed the feasibility of the desired incorporation, but adjusting the temperature to each product and formulation, and that the temperatures of 850 °C and 950 °C were the one that responded to the largest number of formulations

Injeção de vapor e solvente como um método de recuperação avançada em reservatório avançada em reservatórios de óleo pesado

Currently a resource more and more used by the petroleum industry to increase the efficiency of steam flood mechanism is the addition of solvents. The process can be understood as a combination of a thermal method (steam injection) with a miscible method (solvent injection), promoting, thus, the reduction of interfacial tensions and oil viscosity. The use of solvent alone tends to be limited because of its high cost. When co-injected with steam, the vaporized solvent condenses in the cooler regions of the reservoir and mixes with the oil, creating a zone of low viscosity between the steam and the heavy oil. The mobility of the displaced fluid is then improved, resulting in an increase of oil recovery. To better understand this improved oil recovery method, a numerical study of the process was done contemplating the effects of some operational parameters (distance between wells, injection steam rate, kind of solvent and injected solvent volume)on the accumulated production of oil, recovery factor and oil-steam rate. Semisynthetic models were used in this study but reservoir data can be extrapolated for practical applications situations on Potiguar Basin. Simulations were performed in STARS (CMG, 2007.11). It was found that injected solvent volumes increased oil recovery and oil rates. Further the majority of the injected solvent was produced and can be recycled