National Institute for Space Research
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Comparação de estimativas de albedo obtidas com imagens de distintas resoluções espaciais na região amazônica
No full textRemote sensing allows generating information input required for climate simulation and weather forecasting models. ASTER and MODIS sensors, on board of the Terra platform have characteristics that make them promising tools for studies on this topic. The aim of this study was to estimate the albedo using high (ASTER) and moderate (MODIS) spatial resolution sensors in an area located in the south-western part of the Brazilian Amazon and compare the estimates obtained by both sensors. MODIS and ASTER data acquired by the Terra satellite on 01/08/2003 were used and albedo was calculated based on the study of Liang (2001). The spatial pattern of the estimate obtained from MODIS data was similar to that using ASTER. However, the smaller pixel area of ASTER sensor allowed a better sense of nuances. The mean values of albedo obtained by both sensors were similar in the three selected test areas (primary rainforest, secondary vegetation and pasture) with deviations ranging between 0.8 and 3.4%. The moderate resolution of MODIS data can cause errors in the estimation of surface biophysical parameters because a pixel can contain several types of land use and land cover. Nonetheless the spatial overview that can be obtained combined with high temporal resolution evidence the potential of this sensor for Earth system modeling studies in the Amazon region.Pages: 1275-128
Uso de dados MODIS LST no cálculo de evapotranspiração no estado do Espírito Santo, Brasil
No full textThe Areas Susceptible to Desertification in Brazil include the areas of Semiarid Climate and Dry Sub-humid Climate, as well as the surrounding areas, located in the Nordeste e Sudoeste do Brasil (the Northeast and Southeast Zones), occupying approximately 1,340 km² in all, and directly affecting 30 million people. Of this total area, 180,000 km², are already found to be in an advanced or very advanced process of desertification. The United Nations definition of aridity is based on methodology developed by Thornthwaite (1941) and adjusted by Penman (1953), in which the aridity index (AI) is the ratio between precipitation and evapotranspiration. The objective of this work was to analyze the correlation of monthly surface temperature data, obtained through use of the Moderate Resolution Imaging Spectrometer (MODIS), (MOD11), with the ambient air temperature, measured at seven meteorological stations in the state of Espirito Santo, averaged over monthly periods, aiming to realize an adjustment of the MODIS land surface temperature (LST) data to mathematical models enabling the estimation of air temperature over wide areas, in that way permitting the calculation of evapotranspiration and the aridity index for such areas.Pages: 6480-648
Modelagem do desmatamento em 30 municípios da região sudeste do Pará
No full textA big problem that threat the Brazilian Amazon is deforestation, cause besides the loss of biodiversity the balance of the planets climate is significantly threatened. The Brazilian government has achieved in recent years actions to combat illegal deforestation in the Amazon, thereat was a fall in annual deforestation rates in the region. However it is necessary to continue monitoring in this area to preserve all the natural wealth of this region. With the help of a statistical technique it is possible to predict a future scenario and have a vision of how deforestation in the Amazon will behave. Using Geographically Weighted Regression this work makes an estimate of deforestation in 30 municipalities of southeastern Pará with three variables: Forest Area, Deforested Area and Source of Forest Fire, and each municipality has its individualized estimate. This technique can be considered good for estimating deforestation in some municipalities and not so good in others. But as the external actions of the Brazilian government and other civil society actions had influence on the decline in deforestation in recent years has to be considered in the analysis of this question. Its a great future challenge try to include these external actions in mathematical model that will estimate deforestation, therewith we will have more accurate estimates about deforestation.Pages: 6775-678
Planejamento da recomposição florestal pela análise multicriterial na sub-bacia do córrego do descalvado visando a conservação de recursos hídricos
No full textDifferent approaches can be employed in determining priority areas for conservation, restoration and sustainable use of natural resources. To represent the spatial distribution of landscape, it is essential the use of GIS, because of its ability to analyze spatial data. Among the various methods for the determination of priority areas, we highlight those that are based on the analysis of multiple criteria. The objectives of this study were: to create a database of sub-basin of Descalvado river, allowing a diagnosis of the area as the occupation of territory and, consequently, the degradation processes that occur in it, and the definition of priority areas for reforestation to promote the conservation of water resources through Multicriteria Evaluation in a GIS, using the method of Ordered Weighted Average. The factors used were the distance of the water sources, distance of the drainage network, distance of erosion, slope and distance of forest fragments, all represented as raster maps, where each value was standardized to a single continuous scale of 256 values. The application of this method was important because was discriminated and systematized the scenarios of priority of forestry recovery. With the use of the GIS maps and of the environmental diagnosis, the making of maps of priority areas was very fast. The method used was important because it allows the decision maker to chose one of the proposed scenarios as the best for the area or follow them like stages, evaluating each one and, if necessary, making adjustments during the process.Pages: 4257-426
Separação espectral de alvos do dossel florestal a partir das bandas de uma câmera portátil com bandas Azul, Verde & IVP
No full textThis study examines the usefulness of a portable camera for monitoring the seasonal leaf phenology of a Central Amazon forest canopy as seen in oblique downward view from a tower. A Canon model SD780i was modified to provide Blue, Green and Near-Infrared bands, but the latter is centered on the red-edge of a typical green leaf spectrum (670-770 nm), not on the plateau of high NIR reflectance. Despite a less-than-ideal spectral position, the nominal NIR band contributed useful information for unambiguous separation of two classes of bare wood from three classes of live green leaves. Dead dry leaves, however, were not completely separated from live leaves, even in three-band space. The NIR band also contributed to the unambiguous separation of recently flushed new green leaves from older leaves. This is useful for detecting seasonal greening up. Spectral separation was examined in two-band scatter plots and by Linear Discriminant Analysis of all band combinations, associated with a leave-one-out jackknife validation.Pages: 3157-316
Análise da distribuição espacial do vetor da dengue na cidade de Santarém (PA) a partir de técnicas de geoprocessamento e sensoriamento remoto
No full textDengue is now one of the most important mosquito-borne diseases transmitted to humans constituting a serious public health problem. This study aimed to analyze the relationship between urban infrastructure and distribution vector Aedes aegypti from Infestation Index Building (IIB) in the city of Santarém-PA, through techniques of remote sensing and GIS. In this study we used entomological data distributed across neighborhoods and image Landsat 5 year of 2010. The classification was performed by using the algorithm Bhattacharya because this algorithm showed better classification results. After processing was generated map of land use in the urban area with 5 classes: Bodies of water, vegetation, urban density high, medium urban density, urban density low and cloud/Bare Soil. It was observed that in the urban area of Santarem spatiality of dengue vector does not have a homogeneous distribution with respect to urban density, presenting IIP above rates of 1%, distributed in 3 classes of densification. Furthermore, the levels of infestation of Aedes aegypti are associated with the lack of urban infrastructure, and key services (water supply and garbage collection), thus favoring the spread of vector from potential breeding. This analysis guided in the use of geotechnology shows great applicability and functionality in epidemiological studies, since it allows to evaluate the relationship between the spatial component (geographic space) and the incidence of diseases such as dengue.Pages: 8561-856
Construção da base Otto-codificada em Minas Gerais: implementação da metodologia desenvolvida por Otto Pfafstetter (1989) para escalas 1:100.000 e 1:50.000
No full textThis paper has like aim to present the application of Otto-codification in Minas Gerais. The methodology is based on the hierarchization of watersheds according to its area of unique contribution and was developed by Pfafstetter (1989). The Agência Nacional de Águas ANA, generates the otto-codification base to Brazil in millionth scale. However, this scale of analysis does not adequately represent local information, compatible with the 1:50.000 and 1:100.000 base. Thus, the Instituto de Gestão das Águas de Minas Gerais - IGAM through partnership with UFMG adapted the otto-codification methodology to be compatibility with more detail. To generate the Otto-codification base is necessary some pre-processing steps such as: hydrographic network topologic correction, SRTM image processing, review and adaptation of Pfafstetter methodology. With the otto-codification is possible to extract lots of information about the basin, such as: contribution area of each basin, upstream area contribution, length of watercourse, stretch immediately upstream and downstream of the confluence and others informations.The first hydrographic otto-codification base version encoded by ANA was created on 07/12/2006, has reached 178.561 pieces and up to order 12 from Brazil. The base produced by IGAM has 974.494 for the State of Minas Gerais, and can reach the order 14. This difference of numbers and scale was the great challenge beaten in IGAM Project. The success of result of otto-codification base construction is an important step to improve water resources management in Brazil.Pages: 2455-246
Emprego de imagens do sensor Operational Linescan System para estimar a ação depredatória do Bioma Cerrado
No full textThe Brazilian Cerrado is experiencing an accelerated process of degradation due to the intense process of converting this anthropic environment. Among other factors the growth of cities located on it are significant measurable impacts. This work consists of a brief analysis of the expansion of light pollution within the limits of the Cerrado biome limit through image data obtained by Meteorological Satellite Program Defense satellites (or DMSP - Defense Meteorological Satellite Program) from the Department of Defense American and administered by the Center for Space and Missile Systems of the United States Air Force. The DMSP has an OLS sensor (Operational Linescan System), which can detect low levels of radiation in the near infrared (VNIR) overnight that the premise of this study are (lights) indicative of urban settlement. Through data collection / satellite pictures of the year 1992 to 2009, cut for the limits of Cerrado, vectorization and analysis of vector data in SIG environment each year, we could see an increased incidence of light in some areas of Cerrado, these areas are indicated in other studies (mapping PROBIO) as areas of greater conversion of the Cerrado and the resulting urban sprawl, which validates the results.Pages: 7484-749
Aplicação de Geotecnologias para a elaboração do Plano Ambiental de Conservação e Uso do Entorno do Reservatório Artificial (PACUERA) da UHE Salto do Rio Verdinho/Goiás
No full textThis article aims to present the stages of preparation of update PACUERA (Environmental Plan of Conservation and Surrounding Artificial Reservoir) Hydroeletric Plant Salto do Rio Verdinho, Goiás, Brazil, and demonstrate the contribution to the development of the geotechonologys to elaboration diagnosis and environmental zonings that are required to direct the action set. The PACUERA presents the set of normative actions that supported the environmental regulations are essential to ensure the environmental sustainability of hydroelectric plant reservoirs and actions indicative of character they have alternatives on the multiple use of the reservoir and its surroundings. The mapping of land cover and use the buffer of 1000 meters, fundamental step for this type of analysis, will subsidize the zoning ordinance and the activities to be developed, which will follow the restrictions set by the physical and biotic environmental.Pages: 6548-655
Modelos Digitais de Elevação no mapeamento de suscetibilidade de inundação no município de Pedro Osório/RS
No full textSpatial information of risk on floods areas in Brazil, which includes inundation maps and estimations of flood damage are essential tools for the creation of effective plans for both flood protection and mitigation. In flood modelling, the accuracy of the model geometry used has a remarkable impact upon flood mapping. Therefore, in this study, flood hazard mapping was undertaken with two existing DTM (Digital Terrain Model) products. Their characteristics were evaluated with respect to flood hazard mapping. An accuracy assessment of these digital terrain models and their applicability for one-dimensional flood inundation mapping clearly showed a little difference. The assessment of the potential use of MDEs products ASTER GDEM and TOPODATA for characterization of flood areas, found for the city (which has a total area of around 600 km2), the larger the dimension of flooding to calculate the greater the floodplain difference between the DTM used, getting ASTER GDEM always with the largest area.Pages: 6417-642