970 resultados para Daedalus Thematic Mapper


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Em Santa Bárbara D'Oeste,SP, foram realizados dois mapeamentos do uso da terra em área de 14.625 ha. No primeiro utilizou-se fotografias aéreas verticais pancromáticas (data de 25/6/78), na escala 1:35.000, e no segundo utilizou-se imagens orbitais do satélite LANDSAT-5 com sensor Thematic Mapper (data de 12/8/91), escala 1: 100.000, nas bandas 3, 4 e 5 e composição colorida 3/4/5. Para auxiliar a confecção desses mapas, obteve-se chaves de interpretação, tanto para as aerofotos como para as imagens orbitais. As fotografias aéreas proporcionaram um maior nível de detalhamento na identificação do uso da terra. A banda 3 e a composição colorida 3/4/5 foram as mais eficientes entre as imagens orbitais. Entre 1978 e 1991, a área de ocorrência de cana-de-açúcar permaneceu a mesma, as áreas de mata e pastagem diminuíram, enquanto que as áreas de reflorestamento e urbana aumentaram. Essa região teve sua capacidade de uso enquadrada, na maior parte, na classe IV: terras mais apropriadas para pastagens ou plantas perenes como a cana-de-açúcar, devendo-se aplicar técnicas intensivas de conservação, e com aptidão baseada em práticas agrícolas que refletem um alto nível tecnológico.

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Foram estudados, com o auxílio de fotografias aéreas, aspectos qualitativos e quantitativos do relevo e da rede de drenagem de solos de uma área de Santa Bárbara D'Oeste, SP. Esta região compreende 14.625 ha, onde foram selecionadas bacias hidrográficas de 3ª ordem de ramificação e amostras circulares de 5km². As unidades de mapeamento simples ou associações de solos são: Latossolo Vermelho Escuro, Podzólico, Litossolo + Podzólico, Terra Roxa Estruturada + Latossolo Roxo distrófico. Após a caracterização das feições fisiográficas, da área de ocorrência desses solos, foram realizados dois mapas morfopedológicos. No primeiro utilizou-se fotografias aéreas verticais pancromáticas na escala 1: 35.000 (data de 25/6/78) e no segundo imagens orbitais do sensor Thematic Mapper do LANDSAT-5, nas bandas 3, 4 e 5 e composição colorida 3/4/5 na escala 1: 100.000 (data de 12/9/91). As análises qualitativas e quantitativas do relevo (índice de declividade média) e rede de drenagem (densidade de drenagem, freqüência de rios, razão de textura) mostraram-se eficientes na diferenciação das unidades de solo estudadas, tanto em bacias hidrográficas como em amostras circulares. A utilização de fotografias aéreas, permitiu maior riqueza de detalhes na precisão dos limites das unidades de mapeamento e no maior número de unidades de mapeamento discriminadas em relação as imagens orbitais. A composição colorida 3/4/5 permitiu diferenciar os Latossolos argilosos dos Latossolos de textura média, assim como o Latossolo Húmico.

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The purpose of this work was to study fragmentation of forest formations (mesophytic forest, riparian woodland and savannah vegetation (cerrado)) in a 15,774-ha study area located in the Municipal District of Botucatu in Southeastern Brazil (São Paulo State). A land use and land cover map was made from a color composition of a Landsat-5 thematic mapper (TM) image. The edge effect caused by habitat fragmentation was assessed by overlaying, on a geographic information system (GIS), the land use and land cover data with the spectral ratio. The degree of habitat fragmentation was analyzed by deriving: 1. mean patch area and perimeter; 2. patch number and density; 3. perimeter-area ratio, fractal dimension (D), and shape diversity index (SI); and 4. distance between patches and dispersion index (R). In addition, the following relationships were modeled: 1. distribution of natural vegetation patch sizes; 2. perimeter-area relationship and the number and area of natural vegetation patches; 3. edge effect caused by habitat fragmentation, the values of R indicated that savannah patches (R = 0.86) were aggregated while patches of natural vegetation as a whole (R = 1.02) were randomly dispersed in the landscape. There was a high frequency of small patches in the landscape whereas large patches were rare. In the perimeter-area relationship, there was no sign of scale distinction in the patch shapes, In the patch number-landscape area relationship, D, though apparently scale-dependent, tends to be constant as area increases. This phenomenon was correlated with the tendency to reach a constant density as the working scale was increased, on the edge effect analysis, the edge-center distance was properly estimated by a model in which the edge-center distance was considered a function of the to;al patch area and the SI. (C) 1997 Elsevier B.V. B.V.

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Informatics evolution presently offers the possibility of new technique and methodology development for studies in all human knowledge areas. In addition, the present personal computer capacity of handling a large volume of data makes the creation and application of new analysis tools easy. This paper aimed the application of a fuzzy partition matrix to analyze data obtained from the Landsat 5 TMN sensor, in order to elaborate the supervised classification of land use in Arroio das Pombas microbasin in Botucatu, SP, Brazil. It was possible that one single training area present input in more than one covering class due to weight attribution at the signature creation moment. A change in the classification result was also observed when compared to maximum likelihood classification, mainly when related to bigger uniformity and better class edges classification.

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This work aims to analyze the land use evolution in the city of Santa Cruz do Rio Pardo - SP through supervised classification of Landsat-5 TM satellite images according to the maximum likelihood (Maxlike), as well as verifying the mapping accuracy through Kappa index, comparing NDVI and SAVI vegetation indexes in different adjustment factors for the canopy substrate and determining the vegetal coverage percentage in all methods used on 2007, May 26 th; 2009, January 7 th and 2009, April 29 th. The Maxlike classification showed several spatial changes in land use over the study period. The most appropriated vegetation indexes were NDVI and SAVI - 0,25 factor, which showed similar values of vegetal coverage percentage, but discrepant from the inferred value for Maxlike classification.

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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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The best irrigation management depends on accurate estimation of reference evapotranspiration (ET0) and then selection of the appropriate crop coefficient for each phenological stage. However, the evaluation of water productivity on a large scale can be done by using actual evapotranspiration (ETa), determined by coupling agrometeorological and remote sensing data. This paper describes methodologies used for estimating ETa for 20 centerpivots using three different approaches: the traditional FAO crop coefficient (K-c) method and two remote sensing algorithms, one called SEBAL and other named TEIXEIRA. The methods were applied to one Landsat 5 Thematic Mapper image acquired in July 2010 over the Northwest portion of the Sao Paulo State, Brazil. The corn, bean and sugar cane crops are grown under center pivot sprinkler irrigation. ET0 was calculated by the Penman-Monteith method with data from one automated weather station close to the study site. The results showed that for the crops at effective full cover, SEBAL and TEIXEIRA's methods agreed well comparing with the traditional method. However, both remote sensing methods overestimated ETa according to the degree of exposed soil, with the TEIXEIRA method presenting closer ETa values with those resulted from the traditional FAO K-c method. This study showed that remote sensing algorithms can be useful tools for monitoring and establishing realistic K-c values to further determine ETa on a large scale. However, several images during the growing seasons must be used to establish the necessary adjustments to the traditional FAO crop coefficient method.

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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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The structure of Brazilian savannah, named locally as “cerrado”, tends to change if the human pressures, such as pasture and intensive fire, are suppressed showing a densification of the physiognomies throughout the time. Vegetation Index acquired from remotely sensed data has been a proper way to study and monitoring large areas, and the Normalized Difference Vegetation Index (NDVI) is one of the most used for this purpose. The aim of this study was to assess the dynamic of structural changes in protected and non-protected areas of cerrado vegetation using NDVI. For this purpose, three cerrado fragments in the state of São Paulo, Brazil, were evaluated for a 26 year time span from 1985 and 2011, being two of them protected against anthropogenic interference. Landsat 5 –Thematic Mapper images were used and processed in ArcGIS. In the protected areas NDVI indicated that the vegetation followed the expected trend of changes for cerrado, with more open physiognomies tending to be denser throughout this period of 26 years, whereas in the non-protected fragment the NDVI evidences human pressure, showing lower phytomass in 2011. NDVI showed to be efficient in detecting and monitoring changes in cerrado vegetation structure, and can be useful to study both, the natural dynamics of cerrado vegetation and the anthropogenic interference in protected areas.

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The objectives of this study were to evaluate land use and occupation of Permanent Preservation Areas (PPA) as well as its use conflicts by TM (Thematic Mapper) image of the 2010 Landsat-5 satellite, according to the Forest Code. For that purpose, Geographic Information Systems in the Ribeirão Paraíso watershed, São Manuel, SP were used. The combination of Remote Sensing and Geographic Information System technologies allowed representation of spatial distribution of the landscape and data integration in the diagnosis of geographic interest. The 2010 mapping showed 12 use categories, and the sugar cane crop had the largest land occupation, 48.25% of the area. The areas of permanent preservation amounted to 925.74 ha, which is an ideal value based on the Brazilian legislation. Mapping of land use conflicts showed intensive anthropic actions going 80.13% forward on PPAs, with only 19.87% remaining forests, which highlights their negative impact and illegal situations in these areas.

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This study aimed to evaluate a period of 38 years, the use and soil occupation of the Paradise River watershed, inserted in the citys of São Manuel and Areiópolis-SP using aerial photographs for the year 1972 and TM image (Thematic Mapper) obtained by the Landsat-5 satellite, in 2010, using geoprocessing techniques. The watershed in question is very important for the city of São Manuel-SP, because its urban area is inserted in its divisors which part of it belongs to the Environmental Protection Area (APA) Perimeter Botucatu-SP, considered a recharge area of the aquifer Guarani. Today, the development of agriculture faces challenges, which is to produce more food without impacting the environment. Allied to this concern, research institutions have sought new technologies that allow the detection and quantification of human actions, enabling interventions in order to minimize possible damage to the environment. Among these technologies can be cited Geographic Information Systems (GIS), which a large volume of data and information stored in a region at different times can be evaluated in the same time, suggesting different approaches to the planning of land use. The results of the mapping of areas of use and soil occupation result nine classes in 1972, and the coffee culture showed the biggest occupation (37.94%) of the total area. The 2010 mapping formulated twelve classes of use, which demonstrated the predominance of sugar cane (37.94%), on the areas occupied by coffee and pasture before. The land use maps of 1972 and 2010 showed results that show intense human activity in the modification of natural landscape.