926 resultados para Bacias hidrográficas - solos - erosão


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A realização deste estudo propiciou analisar a aplicação dos instrumentos previstos na legislação brasileira levantada para a gestão dos recursos hídricos, por meio dos Comitês de Bacias Hidrográficas e municípios. Foram eleitos a cidade de Araraquara e o Comitê de Bacia Hidrográfica Tietê-Jacaré, como forma de apurar a aplicação dos instrumentos de gestão existentes nas Políticas Federal e Estadual Paulista de Recursos Hídricos, consubstanciadas nas leis 9.433/97 e 7.663/91, respectivamente. Tal escolha se deu uma vez que o referido município encontra-se, aparentemente, organizado dentro dos ditames existentes no ordenamento ambiental legal brasileiro e faz parte da competência territorial daquele comitê. Constatou-se que o CBH-TJ não realiza suas atividades de forma adequada, pois, além de estar estruturado em desacordo com os ditames na lei federal de recursos hídricos, ainda carece de recursos financeiros, técnicos e de tomada de decisão (por ainda não possuir o Plano de Bacia e Agência de Água). O Poder Executivo do Município de Araraquara, mesmo tendo uma situação ambiental relativamente controlada, não utiliza o comitê da forma preconizada nas políticas de recursos hídricos, pois sua participação nele é pouco efetiva, o que acaba influenciando negativamente seu modo de gestão administrativa municipal, tornando-o apenas local, em alguns aspectos, deixando em segundo plano o restante da bacia hidrográfica.

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As teorias sobre o funcionamento dos sistemas lóticos evoluíram nos últimos anos, os condicionantes geológicos/geomorfológicos como também as regiões de transição têm recebido importância crescente. As regiões de transição merecem destaque uma vez que os sistemas lóticos estabelecem interações de fluxo com os ambientes vizinhos (atmosféricos, terrestres e subterrâneos) e a troca de materiais estabelecida entre esses sistemas é importante para a definição de suas características. As bacias hidrográficas dos ribeirões do Moquém e Água Clara, estudadas no presente trabalho, apresentam: proximidade geográfica além de semelhanças morfológicas e climáticas, porém diferem quanto aos aspectos geológicos e geomorfológicos. A partir desses aspectos, a presente pesquisa investigou as flutuações sazonais nas relações físicas, química e hidrológicas entre águas superficiais e subterrâneas (adjacências do canal), na região do baixo curso dos ribeirões já citados. Foram escolhidos dois trechos em cada ribeirão para a realização de: (1) inventário hidrológico mensal, a partir de medidas de velocidade de escoamento, vazão e do nível de água em poços instalados na região marginal dos rios nos trechos de estudo; (2) caracterização física e química de testemunhos da região marginal dos rios, onde foram utilizadas amostras obtidas durante a perfuração dos poços; (3) amostragens das águas superficiais subterrâneas no mesmo período do inventário para a determinação das características físicas e químicas das mesmas. Os resultados destacaram os seguintes itens. O fluxo de base garantiu vazões regulares e elevadas ao ribeirão Água Clara, ao mesmo tempo que as vazões foram quase insignificantes no ribeirão do Moquém, fato esse que apresenta importância ecológica. A química das águas dos ribeirões estudados é distinta, possivelmente, como resposta às características naturais das bacias. Nos dois trechos de estudo, as águas superficiais e subterrâneas apresentaram diferenças físicas e químicas, o que pode indicar que as trocas entre o canal do rio e suas adjacências são pequenas e/ou lentas. Com base nas observações desta pesquisa, recomenda-se que as características quantitativas e qualitativas, distintas, entre as águas dos ribeirões do Moquém e Água Clara devem ser avaliadas durante a tomada de decisões em processos de gestão de recursos hídricos.

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Este trabalho faz parte do Projeto Grande Minas - União Pelas Águas, que realizou o Zoneamento Ambiental das Sub-Bacias Hidrográficas dos Afluentes Mineiros do Médio Rio Grande. O zoneamento foi concluído em 2013 e produziu importantes informações sobre os meios físico, biótico e socioeconômico dos 22 municípios que compõem a bacia hidrográfica, dentre eles o local de estudo, que é o município de Delfinópolis - MG. Dentre os instrumentos que podem contribuir para o desenvolvimento sustentável, o município pode utilizar, além do zoneamento ambiental, o plano diretor municipal e o plano de manejo do Parque Nacional da Serra da Canastra, uma vez que esta unidade de conservação insere-se no município. Torna-se importante, entretanto, a integração destes três importantes instrumentos de gestão para que o planejamento municipal e as ações de política pública possam ser realizados de forma consistente. Este trabalho vem contribuir na avaliação e integração destas informações (Plano Diretor Municipal, Plano de Manejo, Zoneamento Ambiental) e os resultados deverão contribuir com os administradores públicos na tomada de decisões e na resolução dos problemas enfrentados na região, como exemplo as queimadas, o uso inadequado dos recursos hídricos, as atividades modificadoras do meio físico. A sistemática metodológica adotada envolveu a avaliação de dados existentes e a construção de um banco de dados digital do município; análise dos instrumentos legais de planejamento e gestão municipal e elaboração de produtos cartográficos interpretativos de fácil leitura e entendimento que possam ser utilizados diretamente pelos gestores públicos. A análise e avaliação dos dados existentes permitiu diagnosticar algumas características peculiares ao município, como a sua vocação para o turismo, com mais de 40 atrativos ligados ao ecoturismo; o grande número de minerações de areia e cascalho, grande parte delas não regularizada; e os conflitos locais existentes diante das atividades da economia rural e a necessidade de preservação impostas pela unidade de conservação.

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Andryala (Asteraceae: Cichorieae) is a little-known Mediterranean-Macaronesian genus whose taxonomy is much in need of revision. The aim of the present biosystematic study was to elucidate species relationships within this genus based on morphological and molecular data. In this study several taxa are recognised: 17 species, 14 subspecies, and 3 hybrids. Among these, 5 species are Macaronesian endemics (A. glandulosa, A. sparsiflora, A. crithmifolia Aiton, A. pinnatifida, and A. perezii), 4 species are Northwest African endemics (A. mogadorensis, A. maroccana, A. chevallieri, and A. nigricans) and one species is endemic to Romania (A. laevitomentosa). Historical background regarding taxonomic delimitation in the genus is addressed from Linnaean to present day concepts, as well as the origin of the name Andryala. The origin of Asteraceae and the systematic position of Andryala is shortly summarised. The morphological study was based on a bibliographic review and the revision of 1066 specimens of 13 herbaria as well as additional material collected during fieldwork. The variability of the morphological characters of the genus, including both vegetative taxonomic characters (root, stem, leaf and indumentum characters) and reproductive ones (inflorescence, floret, fruit and pappus characters), is assessed. Numerical analysis of the morphological data was performed using different similarity or dissimilarity measures and coefficients, as well as ordination and clustering methods. Results support the segregation of the recognised taxa and the congruence of the several analyses in the separation of the recognised taxa (using quantitative, binary or multi-state characters). The proposed taxonomy for Andryala includes a new infra-generic classification, new taxa and new combinations and ranks, typifications and diagnostic keys (one for the species and several for subspecies). For each taxon a list of synonyms, typification comments and a detailed description are provided, just as comments on taxonomy and nomenclature, and a brief discussion on karyology. Additionally, information on ecology and conservation status as well as on distribution and a list of studied material are also presented. Phylogenetic analyses based on different nuclear and chloroplast DNA markers, using Bayesian and maximum parsimony methods of inference, were performed. Results support three main lineages: separate ones for the relict species A. agardhii and A. laevitomentosa and a third including the majority of the Andryala species that underwent a relatively rapid and recent speciation. They also suggest a single colonization event of Madeira and the Canary Islands from the Mediterranean region, followed by insular speciation. Biogeography and speciation within the genus are briefly discussed, including a proposal for the centre of origin of the genus and possible dispersal routes.

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The stabilization of energy supply in Brazil has been a challenge for the operation of the National Interconnected System in face of hydrological and climatic variations. Thermoelectric plants have been used as an emergency source for periods of water scarcity. The utilization of fossil fuels, however, has elevated the cost of electricity. On the other hand, offshore wind energy has gained importance in the international context and is competitive enough to become a possibility for future generation in Brazil. In this scenario, the main goal of this thesis was to investigate the magnitude and distribution of offshore wind resources, and also verify the possibilities of complementing hydropower. A data series of precipitation from the Climatic Research Unit (CRU) Blended Sea Winds from the National Climatic Data Center (NCDC/NOAA) were used. According to statistical criteria, three types of complementarity were found in the Brazilian territory: hydro × hydro, wind × wind and hydro × wind. It was noted a significant complementarity between wind and hydro resources (r = -0.65), mainly for the hydrographical basins of the southeast and central regions with Northeastern Brazil winds. To refine the extrapolation of winds over the ocean, a method based on the Monin-Obukhov theory was used to model the stability of the atmospheric boundary layer. Objectively Analyzed Air-Sea Flux (OAFLUX) datasets for heat flux, temperature and humidity, and also sea level pressure data from NCEP/NCAR were used. The ETOPO1 from the National Geophysical Data Center (NGDC/NOAA) provided bathymetric data. It was found that shallow waters, between 0-20 meters, have a resource estimated at 559 GW. The contribution of wind resources to hydroelectric reservoir operation was investigated with a simplified hybrid wind-hydraulic model, and reservoir level, inflow, outflow and turbine production data. It was found that the hybrid system avoids drought periods, continuously saving water from reservoirs through wind production. Therefore, from the results obtained, it is possible to state that the good winds from the Brazilian coast can, besides diversifying the electric matrix, stabilize the hydrological fluctuations avoiding rationing and blackouts, reducing the use of thermal power plants, increasing the production cost and emission of greenhouse gases. Public policies targeted to offshore wind energy will be necessary for its full development.

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The Atlantic Forest in Rio Grande do Norte (RN) is included in Pernambuco biogeographic sub-region and it is composed by Semi-deciduous Forest, deciduous Forest, Mangrove and Restinga. We assessed the conservation status of Atlantic Forest in the RN through remnants mapping using high resolution satellite images and landscape ecology approaches. We evaluated if there is difference between the north and south coastal regions considering their natural a historical land use differences. We also assessed the influence of the small remnants on landscape cover and configuration. The proportion of the original biome area with remnants larger than 3 hectares is 15.60% for the official governmental limit and is 16.60% for the alternative limit (SNE, 2002). This remnants proportion varies between 0.56 and 46.52% in the hydrographic basins. 89.70% of the remnants are smaller than 50 hectares. Only 6.00% of the remnants are greater than 100 hectares, and these remnants are responsible by 65% of remaining area. The patches with smaller area influence all calculated metrics. The south coastal hydrographic basins have higher percentage of coverage of remnants, larger patch densities and fragments with larger areas than north coastal hydrographic basins. The diffuse drainage basins of the southern coastal have the highest percentage of coverage with remnants. 18.28% and 10% of the biome area are protected by reserves, according to the official governmental and alternative limits respectively. The reserves are mainly of sustainable use (IUCN V-VI). Therefore, the Atlantic Forest in Rio Grande do Norte is in critical situation, with low proportion of remaining area and high fragmentation level. It’s indispensable to biome conservation keep all the remaining area, especially the large remnants, and restore areas to increase remnants proportion and to increase landscape connectivity

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Resource management policies are frequently designed and planned to target specific needs of particular sectors, without taking into account the interests of other sectors who share the same resources. In a climate of resource depletion, population growth, increase in energy demand and climate change awareness, it is of great importance to promote the assessment of intersectoral linkages and, by doing so, understand their effects and implications. This need is further augmented when common use of resources might not be solely relevant at national level, but also when the distribution of resources ranges over different nations. This dissertation focuses on the study of the energy systems of five south eastern European countries, which share the Sava River Basin, using a water-food(agriculture)-energy nexus approach. In the case of the electricity generation sector, the use of water is essential for the integrity of the energy systems, as the electricity production in the riparian countries relies on two major technologies dependent on water resources: hydro and thermal power plants. For example, in 2012, an average of 37% of the electricity production in the SRB countries was generated by hydropower and 61% in thermal power plants. Focusing on the SRB, in terms of existing installed capacities, the basin accommodates close to a tenth of all hydropower capacity while providing water for cooling to 42% of the net capacity of thermal power currently in operation in the basin. This energy-oriented nexus study explores the dependency on the basin’s water resources of the energy systems in the region for the period between 2015 and 2030. To do so, a multi-country electricity model was developed to provide a quantification ground to the analysis, using the open-source software modelling tool OSeMOSYS. Three main areas are subject to analysis: first, the impact of energy efficiency and renewable energy strategies in the electricity generation mix; secondly, the potential impacts of climate change under a moderate climate change projection scenario; and finally, deriving from the latter point, the cumulative impact of an increase in water demand in the agriculture sector, for irrigation. Additionally, electricity trade dynamics are compared across the different scenarios under scrutiny, as an effort to investigate the implications of the aforementioned factors in the electricity markets in the region.

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This study was developed in objecting to investigate the use and occupation of land in 1999, 2005, 2011 e 2015 and estimate soil degradation by laminar erosion and the relation with water quality in 2015 in the catchment basin of the Barro Preto river, Coronel Vivida – PR. For multitemporal analysis of use and occupation of land in the basin used in the Landsat 5, 7 and 8 images and Geographic Information System. The laminar erosion was estimated by the Universal Soil Loss Equation through the systematization of calculations of the factors that compose the equation in SPRING/INPE. The water quality of the studied river section was evaluated according to the Water Quality Idex and the Resolution CONAMA n. 357/2005. The multitemporal analysis of the use and occupation of land has demonstrated that basin is predominantly agricultural in all years studied, as well as the permanent preservation area presents it not regularized during the period in accordance with the Brazilian Forest Code in force. In relation the quantification of laminar soil erosion in the study period, the rainfall and runoff factor was estimated considering the rainfall data from 1986 to 2014 and resulted in a value of 11.573,47 MJ/ha.mm/a. The Dystrophic Red Latosol, Dystrophic Red Nitisol, Fluvisol and Leptosol soil erodibility factor were 0,0138, 0,0137, 0,0207, 0,0196 t.ha.h/ha.MJ.mm/a, respectively. The topographical factor has demonstrated that the catchment basin has the rough terrain because the moderate and moderate strong classes are dominant in the study area. The cover and management and support practice factors were estimated according to the multitemporal analysis of the use and occupation of land in the basin and the values ranged from 0,0006 to 0,0688. The soil losses by laminar erosion were simulated with agriculture areas with corn and soybeans in no-till. The soil losses with maize crop in no-till in 1999, 2005, 2011 and 2015 were 9.782,75, 10.592,71, 9.636,61 e 11.058,26 t/year, respectively, and soybeans crops in no-till were 15.140,01, 16.645,20, 14.662,14 e 17.049,85 t/year, respectively. In relation with water quality of the section studied river, the average of Water Quality Index during the season were 55,47, 53,09 and 49,72, for the first, second and third sample point, respectively. Indication a decrease in water quality since the source to the last sample point. It is concluded that the use and occupation of land in the catchment basin interferes in the water quality, as well as in soil degradation.

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Aquatic ecosystems are final collectors of all kinds of pollution as an outcome of anthropogenic inputs, such us untreated industrial and municipal sewage and agricultural pollutants. There are several aquatic ecosystems that are threatened by mineral and organic pollution. In Northeastern Portugal, near Bragança, different watercourses are suffering negative impacts of human activities. It has been developed several studies in the monitoring of environmental impacts in these river basins, namely in Rio Fervença, affected by organic pollution, and in Portelo stream, affected, since 2009, by the collapse and continuous input of mining deposits. In this sense, the present study aimed to continue the monitoring study of ecological status of freshwater ecosystems of Northeastern Portugal, namely the following objectives: a) mineral pollution effects of mining deposits sudden incorporated into Portelo stream; b) organic pollution due to domestic and industrial inputs in River Fervença. Also, since fish are useful experimental models to evaluate toxicological mechanisms of contaminants, c) acute toxicity tests with Cu were conducted in laboratory conditions. During 2015/2016, it was made abiotic and biotic characterization of 16 sampling sites distributed by both Portelo and Fervença rivers, tributaries of main River Sabor (Douro Basin). Several physicochemical parameters were determined and Riparian Quality (QBR Index) and Channel Quality (GQC) Indexes were determined for habitat evaluation. Fish and invertebrate communities were sampled, according to protocols of Water Framework Directive (WFD). Several metrics were determined, with particular emphasis on the Biotic Index IBMWP and the Northern Portuguese Invertebrate Index (IPtIN). Acute toxicity tests were conducted with an Iberian fish species, common barbel (Luciobarbus bocagei) and some plasmatic electrolytes levels were evaluated, to assess their contribution to mitigate osmoregulatory adverse effects of Cu. Also, same electrolytes were measured after changing to clean water, in attempt to assess fish capacity to reverse this situation. Results obtained for both rivers showed a significant level of disturbance that affected decisively water, habitat and biological quality of aquatic ecosystems. Mineral and Organic Pollution in River Sabor (NE Portugal): Ecotoxicological Effects on Freshwater Fauna Due to this change of environmental conditions in Portelo stream (extreme pH values, high conductivity and presence of heavy metals), several biological metrics (e.g. taxonomic richness, abundance, diversity, evenness) confirmed, comparatively with reference sites, a substantial decrease on ecological integrity status. The same pattern was found for Fervença River; however other water parameters, namely the content of most limiting nutrients (e.g. N and P) seemed to have more influence in the composition and structure of macroinvertebrate and fish communities. In fact, despite the operation of the Sewage Treatment Plant of Bragança, Fervença River presented significant levels of disturbance that affected decisively the quality and ecological integrity of the aquatic ecosystem. The synergic effect of domestic and industrial pollution, intensive agriculture, regulation and degradation of aquatic and riparian habitats contributed to the decrease of ecological condition, namely in the downstream zones (after Bragança). The results for acute toxicity, showed that fish can change Na+ and K+ levels face to Cu exposition and, depending of Cu concentration tested, can also return to normal levels, providing some insights to that are believed to occurred in fish population, near the Portelo mines. The low ecological integrity status detected in the lotic ecosystems in NE Portugal as a result of mineral and organic pollution deserves the development of several measures for rehabilitation and improving of water quality. On the other hand, environmental education actions are needed to contribute to improvement of ecological integrity of the river and its conservation.

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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Humanas, Departamento de Geografia, 2015.

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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Humanas, Departamento de Geografia, 2016.

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Dissertação de Mestrado, Ecohidrologia - Erasmus Mundus, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2014

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Doutoramento em Restauro e Gestão Fluviais - Instituto Superior de Agronomia / Faculdade de Arquitetura / Instituto Superior Técnico - UL

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Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, 2015.

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Dissertação de Mestrado, Economia do Turismo e Desenvolvimento Regional, Faculdade de Economia, Universidade do Algarve, 2016