National Institute for Space Research
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Classificação baseada em regras da cobertura da terra a partir de imagens multiespectrais de alta resolução espacial
No full textClassification based on pixel become inadequate to explore the variability in high spatial resolution image, being replaced by object oriented approaches. A crucial issue in this process is the creation of objects that represent the cover types of interest. The objects are created through a multiresolution segmentation which defines a hierarchical structure with different levels of spatial resolution, while maintaining relations between objects and sub-objects. This hierarchy is the foundation for the semantic network and the classification is based on fuzzy rules by using descriptors such as: color, shape, texture and relations between objects and sub-objects. Thereby, he objective of this paper is to describe the process of elaboration of a land cover map by means of multiresolution segmentation technique and image classification of high spatial resolution images, based on fuzzy rules. The test area selected was surrounding the Porto Colombia reservoir, on the border of states of São Paulo and Minas Gerais. Firstly, it was necessary to define the land cover classes and generatesv the appropriated objects by a segmentation algorithm from NDVI image, and QuickBird multispectral bands. For the definition of the attributes and their rules of relevance, were selected representative samples for each class, which are used for its characterization. Finally, the classification process was achieved using the descriptors to create the fuzzy sets and the membership functions. The methodological adopted was adequate to map land cover classes.Pages: 1487-149
O uso de imagens de satélite no ensino de geografia
No full textNowadays, we can observe more and more the use of remote sensing products has become a trivial something in our lives. This situation can be clearly observed, for the amount of news newspaper, television news, internet, and a lot of means of communication to inform the population about changes that happens in geographic space. In this context, the images obtained by satellites, become in important cartographic documents to study de changes of (in) Earth surface and, Geography been worried with this phenomena, must use it in school environment. In this context, this project have as aim showing the cartographic games possibilities as a didactic resource in classroom, outstanding the satellite images application in Geography teaching. Thereby; a) elaboration of cartographic games to elementary school students, in order to work the interpretation and perception of geographic phenomena by satellite images, b) test the games inside classroom, observing students interests before the applied content by teacher and, c) enable the cartographic games utilization to work the remote sensing in a funny and educative way, will be the major challenges.Pages: 2665-267
Uso de dados COSMO-SkyMed para o estudo das variações na área das zonas superficiais da península Potter (Antártica Marítima) nos verões austrais 2011 e 2012
No full textWe classified superficial zones on the Potter peninsula (King George Island, South Shetlands archipelago, Maritime Antarctica) in COSMO-SkyMed images, in order to study the spatiotemporal variations of these zones in austral summers of 2011 and 2012. Six superficial zones were recognized in the study area (7.13 km²): Bare Ice Radar Zone (BIRZ), Wet Snow Radar Zone (WSRZ), high-humidity areas, snow-covered areas, permanent lakes and seasonal lakes. We classified these superficial zones in 1m spatial resolution images, supported by fieldwork data collected in February 2012 and mean monthly surface air temperature data from 1986 to 2012. The snow and ice covered areas, located in Polar Club glacier (northern and eastern tip of Potter peninsula), had the highest rate of spatial variation over the analyzed period. The WSRZ and snow-covered areas reduced between February 2011 and February 2012 (5.927 km² and 0.237 km², respectively) and, on the other hand, the BIRZ area increased (5.767 km²) in the same period. The most significant variations occurred in snow-covered areas, whereas the WSRZ reducing was accompanied by BIRZ area increasing in the Polar Club glacier. The high dynamic of superficial zones were not correlated to temperature variations, since there werent any anomalous mean monthly surface air temperature data during the analyzed period.Pages: 8629-863
Morfometria e uso e ocupação da bacia hidrográfica do Carão, Estado do Ceará, Brasil
No full textThe aim of this work was to analyze the morphometry and the type of use and occupancy of the basin Carão reservoir, located in the municipality of Tamboril - Ceará, seeking to understand the natural and anthropogenic processes acting in this enviroment, favoring thus the development of conservation plans and natural resources management. The reliefs morphometric characteristics and the basins ways to use and occupation were obtained by the software ArcGIS 9.3\uae, from techniques of remote sensing and GIS. The basin is considered small, with estimated area of 309.55 km2 and 103.16 km perimeter. Among other things, an elongated and narrow shape was verified, with low drainage density and flat terrain and slightly wavy, whose slopes are presented below 20%, configuring thus so little disposition to flooding in the basin. It was observed a relationship of use and occupation targeted by the lower slope of the terrain and hydrographic presence,determining a bigger pressure by humam activities in these areas, representing a potential modifier of the water quality of the reservoir Carão. Relationship was observed for use and occupation targeted by the lower slope of the terrain and the presence basin, causing increased pressure in these areas by human activities, representing a potential modifier of the water quality of the Carão reservoir.Pages: 8138-814
Refinamento das Unidades Geomorfológicas do Estado do Espírito Santo com Emprego de Novas Tecnologias
No full textThis paper is part of a larger project aimed at providing a refinement of geomorphological mapping carried out by the Project Radambrasil 1:250,000 for the State of Espírito Santo, using current technology advances and data and GIS techniques integrated with Remote Sensing. The procedure of delimitation/subdivision of geomorphological units occurred with use of the technique of vector editing screen across the data and information. The validation of the map was performed with random points record with GPS Photo showing extremely satisfactory results. Among the products generated was the classification of Structures, Regions and Units in Shapefile format containing tabular information of types of modeled area, percentage of occupancy in the state of Espírito Santo.Pages: 1982-198
Avaliação de Áreas de Preservação Permanente (APP's) na microbacia do Córrego Santa Barbara / ES, através do uso de Modelos Digitais de Elevação
No full textThis study was automatically delimit the Permanent Preservation Areas (PPAs) of nascent, slopes, streams, and hilltops, through the use of Geographic Information System (GIS), comparing the method of Digital Models elevation (DEM) generated from contour lines with vertical contour interval of 20 m, contained in the IBGE topographic maps in the scale of 1:50000, with the method of remote sensing images of the Shuttle Radar Topography Mission (STRM) developed by Embrapa monitoring by Satellites, available for free in electronic address http://www.relevobr.cnpm.embrapa.br. in the sub-basin's stream Santa Barbara, located in the municipality of Ibitirama - ES. For delimitation of APP `s (of water courses, nascent, slopes and hilltops), we used the Brazilian environmental legislation and Resolution CONAMA No. 303/2002 which establishes parameters, definitions and boundaries of these areas. For the generation of analysis tools were used in computer application ArcGIS\uae 10, and the data obtained individually in the mapping of each class of APP were grouped without overlapping on a single map, generating two maps of APP's, one using the MDE from the contour and using the SRTM. For classes of APP `s nascent and slopes, we can conclude that the results presented by the models used were similar. In general, the two models used show similarities in the results for delimitation of areas of APP `s and can be applied to delimit them.Pages: 282-28
Mapeamento multitemporal da cobertura da terra do município de Imbituba (SC) utilizando imagens do sensor Landsat 5 TM
No full textThe objective of this work was the multitemporal land cover mapping of the Imbituba (SC) municipality through a supervised image classification of Landsat satellite TM 5. It was selected the images of the study area, and then, it was obtained samples of land cover classes (open natural areas, urbanized areas, water bodies, forest, pasture and rice) and performed a supervised classification using the maximum likelihood method. They were produced thematic maps of land cover the years 1990 and 2010 individually, that showed excellent values for validation using Kappa index. It was also noted a gradual decrease in the original areas of Atlantic Forest, resulting in the increase of the areas of grazing and cultivation of eucalyptus.Pages: 7602-760
DINAMICA EGO e Land Change Modeler para simulação de desmatamento na Amazonia brasileira: análise comparativa
No full textEnvironmental modeling is an important tool that allows making hypotheses, diagnostics, predictions and simulations, as well as communicating scientific results clearly. Dynamic modeling of landscapes had an intense development in recent decades, along with the growing availability of remote sensing data, the popularization of GIS and the creation of methods for spatial analysis and simulation. This study compares the performance, flexibility and usability of two platforms for dynamic land-use modeling widely used, Dinamica EGO and Land Change Modeler. The comparison is based on a case study of deforestation in the Brazilian Amazon. The softwares were calibrated for the period 1997 to 2000, with the same input data and similar parameters, and were used to simulate deforestation for the year 2003. We performed a compared validation of the results, using Kappa pixel-by-pixel indices, fuzzy reciprocal similarity and landscape metrics. The simulation performed by LCM showed better results for the first two validation methods, while DINAMICA EGO presented spatial metrics closer to the ones of the observed landscapes. It is concluded that both modelers generate coherent results, although with medium performance for the case studied. The softwares may serve to distinct purposes, being LCM best for end users who want a simplified tool for simulation, while DINAMICA EGO demands more knowledge from the user, but allows modification of the model structure, adapting it to specific needs.Pages: 6379-638
Avaliação de diferentes tipos de manejo de pastagem natural utilizando valores de reflectância coletados com espectrorradiômetro
No full textThis study aims to evaluate the potential of reflectance and vegetation index (NDVI) data, collected in plots of native grasslands for identification of different types of grazing management. The study area includes paddocks of 0.5 ha, located in the experimental area of the Federal University of Santa Maria (UFSM). These paddocks are managed with intervals between cattle grazing according to the accumulated heat sum according to the duration of leaf expansion of two groups of grasses, in classes called as 375 or 750 degrees day (GD). Reflectance measurements were collected with the FieldSpec HandHeld portable spectroradiometer which produced data for the 400 to 900nm range. Five paddocks of the UFSM experimental area were studied - 15, 23, 51, 58 and the paddock with no grazing (exclusion). Paddocks 15 and 23 were managed with thermal sum of 375 GD and 51 and 58 managed by thermal sum of 750 GD. At the same time spectral reflectance was measured, digital photos of the points were acquired using GPS Oregon Garmin 550t. The spectral response of vegetation considered for the study showed differences in the amount of the reflected radiation depending on the region visible and near-infrared of the electromagnetic spectrum. Paddock 15 and 23 exhibited higher reflectance in the green wavelengths. The 750 GD paddocks (51 and 58) had similar behavior to the paddock with no grazing, dominated by tall grass species, with a large portion of dry biomass.Pages: 8822-882
Diferentes modelos de estimativa da radiação de onda longa a partir de dados MODIS/TERRA
No full textThe objective of this study is to analyze the accuracy of different methods to estimate the surface downwelling and upwelling longwave radiation (LWR) using data from Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the satellite Terra. For downwelling LWR three methods were used which is conventionally called SEBAL (S), METRIC (M) and Bisht (B). For application of the methods SEBAL and METRIC need only data for air temperature, which is easily obtained from the weather station. The method proposed by Bisht was processed in a completely autonomous form because the air temperature, as well as the dew temperature, were obtained from MODIS/ TERRA data. The upwelling LWR was estimated from a single mode, only with remote sensing data. The SEBAL method demonstrated greater accuracy, followed by METRIC, with standard deviations of 19 and 20 Wm-2, respectively. Finally, the Bisht method showed that errors introduced were above the acceptable precision (36 Wm-2). It was also examined the emissivities estimated by each method, as well as their impact on the accuracy of longwave radiation data. It is observed that the performance not so satisfactory of the Bisht methodology is due to estimate of the atmosphere emissivity, whose performance was not as good as the others. This is due to the fact of that the air temperature data obtained of the MODIS sensor were 2 3° higher than air temperature measured on the meteorological towers.Pages: 8698-870