903 resultados para Land cover classification


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This Minor Field Study was carried out during November and December in 2011 in the Mount Elgon District in Western Kenya. The objective was to examine nine small-scale farming household´s land use and socioeconomic situation when they have joined a non-governmental organization (NGO) project, which specifically targets small-scale farming households to improve land use system and socioeconomic situation by the extension of soil and water conservation measures. The survey has worked along three integral examinations methods which are mapping and processing data using GIS, semi structured interviews and literature studies.   This study has adopted a theoretical approach referred to as political ecology, in which landesque capital is a central concept. The result shows that all farmers, except one, have issues with land degradation. However, the extent of the problem and also implemented sustainable soil and water conservation measures were diverse among the farmers. The main causes of this can both be linked to how the farmers themselves utilized their farmland and how impacts from the climate change have modified the terms of the farmers working conditions. These factors have consequently resulted in impacts on the informants’ socioeconomic conditions. Furthermore it was also registered that social and economic elements, in some cases, were the causes of how the farmers manage their farmland. The farmer who had no significant problem with soil erosion had invested in trees and opportunities to irrigate the farmland. In addition, it was also recorded that certain farmers had invested in particular soil and water conservation measures without any significant result. This was probably due to the time span these land measures cover before they start to generate revenue.  The outcome of this study has traced how global, national and local elements exist in a context when it comes to the conditions of the farmers´ land use and their socioeconomic situation. The farmers atMt.Elgon are thereby a component of a wider context when they are both contributory to their socioeconomic situation, mainly due to their land management, and also exposed to core-periphery relationships on which the farmers themselves have no influence.

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As técnicas de sensoriarnento remoto e geoprocessamento são fundamentais para processamento e integração de dados de mapeamento geológico/geotécnico, principalmente estudos de gerenciamento e planejamento. A área estudada compreende o município de Três Cachoeiras. Litoral Norte do Rio Grande do Sul o qual inclui-se na "Reserva da Biosfera da Mata Atlântica". O município tem st: deparado com problemas de localização de sitios adequados à disposição final dos resíduos sólidos. bem como o assentamento de loteamentos residenciais e industriais, localização de jazidas de extração de material para construção, fontes de abastecimento de água e necessidade de criação de áreas de preservação ambiental. O objetivo deste trabalho foi produzir mapeamentos da área em questão, através da pesquisa geológico-geotécnica desenvolvida com emprego de imagens de satélite e fotografias aéreas, em que as informações foram cruzadas no SIG. Baseado nisto, investigaram-se os aspectos acima mencionados. a partir de uma contribuição geológico/geotécnica ao município, incluindo-se levantamento de campo, fotointerpretação, processamento e classificação de imagens do município de Três Cachoeiras, sendo os dados integrados num sistema de geoprocessamento. Utilizando-se cartas planialtimétricas, fotografias aéreas e imagem de satélite LANDSAT TM5. foram criados planos de informação como o limite da área estudada, a estrutura viária municipal, a delimitação de reservas ecológicas baseadas na legislação ambiental vigente e, por meio do modelo numérico do terreno, a carta de declividade. A fotointerpretação gerou planos de rede de drenagem, litológica. morfoestruturas e formações superficiais. Os dados de campo. sobrepostos às litológicas obtidas por fotointerpretação, produziram a carta litológica. No tratamento das imagem, foram gerados produtos com contraste, operações entre bandas, filtragens e análise de componentes principais, os quais contribuíram parira classificação da imagem e resultando nos planos de rochas/solos e cobertura/uso do solo (carta de uso atual do solo). O cruzamento destas informações permitiu a obtenção da carta de formações superficiais, lidrogeológica que, juntamente com as cartas litológica, declividades e uso atual do solo distribuíram os atributos do meio físico em planos elaborados por novos cruzamentos, que satisfazem o objetivo do estudo, sendo estes planos o produto final, ou seja, cartas de recomendação: a extração de materiais para construção civil; a implantação de obras de infraestrutura; a disposição de resíduos sólidos e loteamentos; geotécnica à agricultura; à implantação de áreas destinadas à preservação ambienta1 e recuperação.

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The aim of the study was to evaluate the production of four tomato cultivars of determinate growth, in the field, with and without ground cover. The cultivars examined were: 'AP-533', 'AP-529', 'Hypeel 5131 and 'PS-41816', which were cultivated with a spacing of 1 m between rows and 0.4 m between plants. The experimental design utilized was that of subdivided parcels, where parcels were provided with and without a ground cover of black polyethylene, and subparcels consisted of the cultivars; eight repetitions were used. The eight central plants in the parcel were evaluated according to the following characteristics: fresh weight of fruit per plant and number of fruit per plant, separated by size. For the classification of fruit, the same plants were divided into classes based on the diameter of the fruit. The diameter size was as follows: class 1, 3 cm; class II, 4 cm; class III, 4.5 cm; and class IV, 5.5 cm. The results showed that there were no significant differences in production among the cultivars studied. Cultivars 'AP-533' and 'Hypeel 513' demonstrated greater production per plant, when ground cover was used, yielding 1474 and 1404 g/plant, respectively. When black polyethylene ground cover was not used, these cultivars produced 1258 and 1271 g of fruit per plant, respectively. The cultivars 'AP-529' and 'PS41818' showed a greater yield of fruit when cultivated without ground cover, with 1548 and 1663 g/plant, respectively. The cultivar 'Hypeel 513' had the highest percentage of fruit with the largest dimensions. An interaction was appeared between 'AP-529' and ground cover, where the production of this cultivar was lower with black polyethylene ground cover compared to bare ground. It is concluded that there are no significant differences in the cultivation of the tomato hybrids 'AP-533', 'Hypeel 513' and 'PS-41816' with and without ground cover, but that the cultivar 'AP-529' should be planted preferentially in soil without black polyethylene cover.

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The intensive use of land alters the distribution of the pore size which imparts consequences on the soil physical quality. The Least Limiting Water Range (LLWR) allows for the visualization of the effects of management systems upon either the improvement or the degradation of the soil physical quality. The objective of this study was to evaluate the physical quality of a Red Latosol (Oxisol) submited to cover crops in the period prior to the maize crop in a no-tillage and conventional tillage system, using porosity, soil bulk density and the LLWR as attributes. The treatments were: conventional tillage (CT) and a no-tillage system with the following cover crops: sunn hemp (Crotalaria juncea L.) (NS), pearl millet (Pennisetum americanum (L.) Leeke) (NP) and lablab (Dolichos lablab L.) (NL). The experimental design was randomized blocks in subdivided plots with six replications, with the plots being constituted by the treatments and the subplots by the layers analyzed. The no-tillage systems showed higher total porosity and soil organic matter at the 0-0.5 m layer for the CT. The CT did not differ from the NL or NS in relation to macroporosity. The NP showed the greater porosity, while CT and NS presented lower soil bulk density. No <= 10 % airing porosity was found for the treatments evaluated, and value for water content where soil aeration is critical (theta(PA)) was found above estimated water content at field capacity (theta(FC)) for all densities. Critical soil bulk density was of 1.36 and 1.43 Mg m(-3) for NP and CT, respectively. The LLWR in the no-tillage systems was limited in the upper part by the theta(FC), and in the bottom part, by the water content from which soil resistance to penetration is limiting (theta(PR)). By means of LLWR it was observed that the soil presented good physical quality.

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Este trabalho teve o objetivo de avaliar a evolução do uso da terra no município de Botucatu - SP, no período de três anos, considerando-se seis tipos de cobertura vegetal (cana-de-açúcar, reflorestamento, floresta nativa, pastagem, cítrus e outros), tendo como base as imagens de satélite Landsat 5, bandas 3; 4 e 5, órbita 220, ponto 76, quadrante A, passagem de 8 de junho de 1999. O Sistema de Informações Geográficas - IDRISI for Windows 3.2, foi utilizado para as análises. Os resultados mostraram que esse programa foi eficiente para auxiliar na identificação e mapeamento das áreas com uso da terra, facilitando o processamento dos dados. As imagens de satélite TM/LANDSAT 5 forneceram um excelente banco de dados para a classificação supervisionada. O município não vem sendo preservado ambientalmente, pois apresenta-se coberto com menos de 20% de florestas nativas, mínimo exigido por lei. As áreas de pastagem, principal componente da paisagem do município, confirmam a vocação da região para a pecuária.

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This study explores, in 3 steps, how the 3 main library classification systems, the Library of Congress Classification, the Dewey Decimal Classification, and the Universal Decimal Classification, cover human knowledge. First, we mapped the knowledge covered by the 3 systems. We used the 10 Pillars of Knowledge: Map of Human Knowledge, which comprises 10 pillars, as an evaluative model. We mapped all the subject-based classes and subclasses that are part of the first 2 levels of the 3 hierarchical structures. Then, we zoomed into each of the 10 pillars and analyzed how the three systems cover the 10 knowledge domains. Finally, we focused on the 3 library systems. Based on the way each one of them covers the 10 knowledge domains, it is evident that they failed to adequately and systematically present contemporary human knowledge. They are unsystematic and biased, and, at the top 2 levels of the hierarchical structures, they are incomplete.

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Several studies suggest that, on a large scale, relief conditions influence the Atlantic Forest cover. The aim of this work was to explore these relationships on a local scale, in Caucaia do Alto, on the Ibiúna Plateau. Within an area of about 78 km2, the distribution of forest cover, divided into two successional stages, was associated with relief attribute data (slope, slope orientation and altitude). The mapping of the vegetation was based on the interpretation of stereoscopic pairs of aerial photographs, from April 2000, on a scale of 1:10,000, while the relief attributes were obtained by geoprocessing from digitalized topographic maps on a scale of 1:10,000. Statistical analyses, based on qui-square tests, revealed that there was a more extensive forest cover, irrespective of the successional stage, in steeper areas (>10 degrees) located at higher altitudes (>923 m), but no influence of the slope orientation. There was no sign of direct influence of relief on the forest cover through environmental gradients that might have contributed to the forest regeneration. Likewise, there was no evidence that these results could have been influenced by the distance from roads or urban areas or with respect to permanent preservation areas. Relief seems to influence the forest cover indirectly, since agricultural land use is preferably made in flatter and lower areas. These results suggest a general distribution pattern of the forest remnants, independent of the scale of study, on which relief indirectly has a strong influence, since it determines human occupation.

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Taking benefit of the new Galileo ranging signals, the ENCORE (Enhanced Code Galileo Receiver) project aims to develop a low-cost Land Management Application to cover needs of the Brazilian market in terms of geo-referencing and rural/urban cadastre, using a low-cost Enhanced Galileo Code Receiver as baseline. Land management applications require precision and accuracy levels from a few to several decimetres that are under-met with current pseudorange-based receiver and over-met with phase observations. This situation leads either to a waste of resources, or to lack of accuracy. In this project, it is proposed to fill this gap using the new possibilities of the Galileo ranging signals, in particular E5 AltBOC and E1 CBOC. This approach reduces the cost of the end-user solution, helping the rapid penetration of Galileo technology outside Europe. ©2010 IEEE.

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Physical fractions (free light fraction, intra-aggregate light fraction and heavy fraction) of soil organic matter (SOM) are good indicators of soil quality for sustainable land use. The objective of this study was to evaluate the effect of cover crops on total organic carbon (TOC) and physical fractions of soil organic matter in soil under a no-tillage system (NTS) and a conventional tillage system (CTS, one plowing and two disking). A three-year field experiment was carried out as a cover crop-rice (Oryza sativa)-cover crop-rice rotation. Treatments included cover crops (Panicum maximum, Brachiaria ruziziensis, Brachiaria brizantha, and pearl millet (Pennisetum glaucum), fallow, till or no till. The SOM was physically fractionated in free light fraction (FLF), intra-aggregates light fraction (IALF) and heavy fraction (HF). The levels of C in whole soil were also evaluated, as well as C in the light fractions (FLF+IALF) and in the HF. Results indicated that concentrations of C in the FLF and IALF in surface soils (0-0.05m) were much higher (10.8 and 1.95gkg-1, respectively) than that in the 0.05-0.1m soil depth (7.68 and 1.54gkg-1, respectively) and in the 0.1-0.2m soil depth (4.98 and 1.24gkg-1, respectively). The NTS resulted in higher levels of FLF (12.2gkg-1) and IALF (2.19gkg-1) than with CTS (1.37-7.30gkg-1). Millet had the highest C (19.5gkg-1) and N (1.1gkg-1) concentrations in soil. There was an accumulation of TOC and total N in the surface soil with cover crops, and concentrations of TOC were higher in the HF (79.0%) than in the light fractions (21.0%). Although SOM changed little during the two years of this experiment, the various C fractions were significantly affected by the tillage treatments. We conclude that SOM physical fractionation allowed seeing significant differences caused by the soil management in the organic matter dynamics in a short period of time. © 2013 Elsevier B.V.

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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The main objective of this study was to perform a temporal analysis of land use and cover of Itirapina – São Paulo estate, Brazil, for 1962, 2000 and 2008 scenarios, indicating the rate of change in native vegetation and contextualizing its modifications. Based on photointerpretation performed by supervised classification using the method of Bhattacharya, the thematic classes were mapped and characterized in an area equivalent to 56400 hectares. Using remote sensing technologies and geographic information systems, was structured and implemented a georeferenced and relational database, allowing the analysis of the size of the area occupied. The results showed that the expansion of cultivation of cane sugar and reforestation in the past 45 years has been conditioned the fragmentation of natural vegetation cover in the city, which fell by 34793 ha (61,7%) in 1962 to 9765,2 ha (17,3%) in 2008, with the loss of 25027,8 hectares.

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The aim of this note is to describe preliminary results on assessment of land use by cattle, obtained in a pilot study using Geographic Information System (GIS). The research was carried out on a semi-natural pasture in Sweden, where the geographic positions of one cow were recorded during 25 consecutive days during summer. The cow, wearing a GPS collar, was integrated in a herd of 53 Hereford cattle. Each location point registered for the animal was considered as a sampling unit (N=3,097). The spatial distribution of ground declivity, water sources, cattle tracks, and classes of woody vegetation cover (forest, grassland with trees and open grassland) were recorded. The storage, processing and data analysis were carried out using the Idrisi and GS+ softwares. Three occupation zones were identified in function of the variation in the space used by the animal, which were occupied in a cyclical pattern; with the animal moving from one zone to another in cycles of five days. It was also clear that the cattle distribution in the area was neither random nor uniform, and it was affected by environmental characteristics that act as conditioners on its distribution. These preliminary results suggest that definition of zones of occupation and the environmental conditioners are promising tools to understand the land use by cattle

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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This book offers the texts of twenty-four presentations given in a series of mini symposia organized to commemorate the centennial of Texas A&M's Department of Entomology. Although not stated explicitly by the editors, the central theme for these symposia seems to be the contributions of the discipline of entomology to modern society. The presentations cover a wide range of topics dealing with the importance of insects in both natural ecosystems and agricultural systems; insects as models for scientific research; challenges associated with effective management of those species that are pests in systems designed for food and fiber production; and the role of entomology departments within academic institutions, particularly land-grant universities. The list of contributors to these symposia is impressive, as are the universities and other institutions they represent across the United States as well as in Europe and Africa.