National Institute for Space Research
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Ajuste de bandas de modelos empíricos de estimativa de clorofila aplicados à região da planície de inundação do Lago Grande Curuai - PA
No full textEmpirical Models to estimate chlorophyll-a concentrations are among the most used in the remote sensing community. Historically, those models were applied to ocean monitoring, but in the last decade they were tested for Case II water types studies. In particular, in tropical water bodies characterized by highly complex mixture of optically active components. This complexity, based on high concentration of colored dissolved Organic Matter (CDOM), Total of Suspended Sediments (TSS) and Chlorophyll- (Chlo-a) that varies independently, one from each other, makes it necessary the search for a set of spectral bands able to improve the accuracy of chlorophyll estimates. This work uses a computational search method to find the best band set, for 295 samples distributed in 4 periods in a hydrological cycle. The samples are from the Curuai floodplain located in the Pará State in the Amazon Region. Results show good agreement to literature, but also shows some discrepancies, mostly because of tropical waters complexity. The new bands show better adjustments compared to standard bands intervals, found in literature. Models of Two and three band are adequate only for two periods with high degree of confidence. A discussion about the behavior of each period, and its empirical model best fit is also made.Pages: 8924-893
O uso de geotecnologias para a análise espaço-temporal da expansão urbana de Guarapuava-PR entre 1995 e 2011
No full textThe objective of this study was to identify and map the areas of urban expansion Guarapuava / PR, from 1995 to 2011, with the use of geotechnologies. Some studies have shown that since 1970 the city has seen an intense urbanization process, expressed in its horizontal growth. In the decades of 1990 and 2000, this expansion occurred in different directions throughout its periphery, often in areas susceptible to natural disasters. As of the use of aerial photographs and satellite images multitemporal, as well as construction of a relational database in a GIS environment, was possible to identify the increase in Guarapuava urban occupation, from 1995 to 2011. Utilizing methodologies for visual interpretation and field work was delimited the area of its urban perimeter. There was obtained as a result, the boundaries and size of urban occupation for the periods 1995, 2002, 2005 and 2011, which showed the urban sprawl, and also which directions to the urban growth occurred between a period and other. Was registered an increase in the urban area of Guarapuava of 54.23% from 1995 to 2011. In this way, we can state that the geotechnologies constitute an important tool for the studies aiming at subsidize the planning and management of urban territory.Pages: 898-90
Sistema Nacional de Dados Ambientais-SINDA- no monitoramento de animais
No full textThe main goal of this work is to evaluate the effectiveness of Brazilian Environmental Data Collection System (SINDA) to receive and distribute messages from low-power transmitters PTT, commonly used in satellite animal tracking, to users. We counted how many messages transmitted by low power transmitters were received by SCD and NOAA satellites when passing over Brazilian territory. Transmission experiments took place in four cities in Brazil - Belém-PA, Santa Maria-RS, Cuiabá-MT and Natal-RN, along the year of 2012. At each experiment a set of 10 transmitters, each one transmitting with 2 IDs, were kept running along 12 days, continually. Two power levels were used, 500 mW and 1.000mW. Another data source was a transmitter installed in a wild cougar, ranging near the city of Campinas, Sao Paulo State, transmitting with 500 mW power level. Results showed that both SCDs and NOAA satellites received less messages from 500 mW than from 1.000 mW transmissions, but NOAA were more sensitive and received more low-power messages than SCDs. Messages from animal transmitter were less received than that ones from fixed transmitters. Reception Stations nearest of transmitters were more efficient and received more messages than the other ones. Besides that, data distributed by Data Base Management Center SINDA were smaller than the real data collected from satellite overpasses. These results showed the importance of increasing the number of terrestrial reception stations spread over the Brazilian territory, the importance to improve transmitter antenna efficiency, and the necessity of improving data processing system, in order to receive and distribute the real mass of data to users.Pages: 9100-910
Análise de parâmetros morfométricos de geleiras derivados de diferentes modelos digitais de elevação da Península Antártica
No full textThis paper presents results from the analysis of some basic morphometrical parameters derived from Digital Elevation Models (DEMs), used in the Global Land Ice Measurements from Space (GLIMS) project, such as: minimum, maximum and mean elevations, mean slope and glacier aspect. We derived these parameters for 14 glaciers located in the northern tip of the Antarctic Peninsula, from the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM) versions 1 and 2 (spatial resolution of 30 m), the Radarsat Antarctic Mapping Project (RAMP) DEM (200 m) and one ASTER Digital Terrain Model - DTM (15 m) generated in this study from images of bands 3N and 3B, acquired on 15/11/2005. Glacier basins were manually delimitated, following suggestions of the GLIMS project. DEM analysis showed the existence of some outliers in the ASTER GDEM 1 and 2, and ASTER DTM, that were not eliminated even by using a double-pass 5x5 median filter. We observed the RAMP DEM has more consistent values and thus it is better to represent topographical features of study area than the other DEMs analyzed. Therefore, the RAMP DEM was considered the most efficient model for topographical analysis of the Antarctic Peninsula in small and medium scales.Pages: 8782-878
Comparação entre temperatura de superfície e presença de vegetação viária em dois bairros de Campinas-SP
No full textThermal infrared remote sensing techniques have been applied in urban climate and environmental studies as an instrument to urban planning for improving quality of life. This study analyze the influence of urban trees on microclimate in two different areas of Campinas-SP, a densely urban forestry and another with limited presence of trees characterized by population density concentration and high levels of built-up areas. To understand the energy exchange between the surface and the atmosphere, knowledge of climatic factors as temperature along the features of the landscape is fundamental for surface urban heat island studies. Thus was analyzed land surface temperature (LST) by using data from Landsat Thematic Mapper (TM). To estimate LST were used data of relative humidity, pressure and air temperature from a meteorological station and Geographic Information System (GIS. The results showed that the density and distribution of the trees had an influence on the air temperature. The sets of trees had the greatest influence on a larger scale in places where there were no green spaces around. According to the arrangement of the elements, a reduction of the air temperature was higher. In addition, new models in the Urban Canopy Layer (UCL) about relationship between surface energy exchange and air temperature could improve remote sensing researches in studies of LST associations.Pages: 850-85
Análisis de los patrones de deforestación en México con regresiones ponderadas geográficamente
No full textMexico is a megadiverse country, however environmental sustainability is threatened by the loss of native vegetation due to the high rates of deforestation. In this study, a nationwide multidate GIS database was generated in order to carry out the quantification and spatial characterization of deforestation during the last decades. Digital land use/land cover maps at scale 1:250,000 from three different dates (1993, 2002 and 2007) were revised and integrated into a GIS database along with ancillary data (road network, settlements, topography, land tenure and socio-economical parameters). Drivers of deforestation were identified by applying geographically weighted regression (GWR) analysis to these data. The regression model highlighted the spatial variation of the relationship between the percentage of land deforested and its proximate causes. Preliminary results show that although rates of deforestation have decreased during the most recent period, deforestation still represents a serious problem. Factors identified as having a major impact on deforestation are related to topography, accessibility and fragmentation. However the analysis also shows that the most important drivers explaining deforestation vary over space. Based upon the results of this analysis, regions presenting similar patterns of deforestation were defined. A model of deforestation for the entire country will be developed using these regions as model sub-regions with different rates of deforestation and drivers.Pages: 6292-629
Estudo da dispersão de partículas em reservatórios a partir de derivadores rastreados por satélite
No full textSatellite tracked drifters were deployed in order to study the horizontal transport and dispersion in the epilimnion of a large hydroelectric reservoir. Our study was motivated by the dispersion implications on the reservoir surface process, such as larval dispersion, turbulent mixing, point-source fertilizer, dispersion of pollutants, and many others. Our results have demonstrated the effectiveness of the drifter in estimating differential kinematic properties and horizontal dispersion. A discussion of how these parameters can be useful for the safe and efficient management of the waterway is carried out. The diffusivity observed in this study was comparable with those observed in others lakes. The average value of diffusivity coefficient (K = 2 m2s-1) was very close to the mean value observed by Stocker and Imberger (2003) (K = 2.5 m2s-1) in the Lake Kinneret. Comparing the diffusivity coefficient for the identical releases of drifters at the same time but from two slightly different locations a pronounced difference is observed. This indicates that the dispersion is sensitive to the location of the release.Pages: 9048-905
Análise do zoneamento como um instrumento de preservação ambiental utilizando técnicas de Geoprocessamento e Sensoriamento Remoto
No full textThis study aims to analyze the environmental zoning as a tool to control urban expansion in environmentally protected areas using GIS techniques and remote sensing, taking as a test area the case of Itaipu Lagoon Region in Niterói (RJ). The present study was carried out in two parts: preparation of the database and spatial analysis of data in GIS. The first phase was the mapping of land use/land cover the in the years 2000 and 2007 in the region to analyze urban expansion, using aerial photographies and Quickbird data and visual interpretation, and the digitalization of the Environmental Zoning created for the Forest of Itaipu Lagoon by the Urban Plan for the Oceanic Region of Niterói and by the Municipal Decree 9060/03. Finally, in the step of spatial analysis, the intersect between land use/land cover maps and environmental zoning of Itaipu Lagoon Region was performed, creating urban occupation maps for the study area in 2000 and 2007. The environmental zoning of Itaipu Lagoon Region created areas with restrictions of occupation. In general, urban expansion in Itaipu Lagoon Region between 2000 and 2007 corresponds to a growth of 33.8%, of which 79.7% occurred in areas with restrictions, 3.1% occurred in protected areas, and 17.2% occurred in areas with parameters that restrict any type of urban occupation. It can be concluded that the methodology allowed the analysis of the urban occupation in the study area and of the environmental zoning.Pages: 1069-107
Baixo curso do rio Capibaribe, Recife-PE: Avaliação da desestruturação ambiental do manguezal, em área urbana
No full textThe mangrove ecosystem is a coastal, transitional between terrestrial and marine environments, characteristic of tropical and subtropical regions. It consists of woody plant species, called mangroves, which is associated with a characteristic flora, creating favorable conditions for food, protection and reproduction of many animal species. Soon, the mangroves that thrive in estuaries that are located in the Metropolitan Region of Recife are valuable ecosystems for the city of Recife, but are subjected to various types of stressors that come accelerating its degradation. The Capibaribe is one of the major rivers of Recife and the urban sprawl of recent decades has been responsible for the breakdown of their environmental resources, especially in areas consisting of mangroves, compromising the quality of life of coastal communities. In this context, this study aims to identify, quantify and assess the impacts of land use and occupation of the lower course of the river Capibaribe between the BR 101 and north of Tower Bridge, trying thus to understand the dynamics of the ecosystem and its environmental conditions. For a survey of human activities and their impacts were conducted on-site visits to applying checklists in seven selected sectors along the stretch considered. The level of degradation can be considered the mangrove high, since most of the sectors studied showed extreme rates (greater than -171). The data provide information for the development of actions aimed at monitoring and environmental conservation in the study area.Pages: 3148-315
Utilização de Support Vector Machine para classificação multiclasses de imagens Landsat TM+
No full textThe classification of images uses digital spectral information represented by digital values of each pixel, for example, at one or more spectral bands, classifying this pixel in a class, this can be considered spectral pattern recognition. Classification algorithms have been developed since the first Landsat image, acquired in 1972. Among the most popular and widely used is the maximum likelihood classifier, or proven as an alternative, the Artificial Neural Networks (ANN). Support Vector Machine (SVM) have also been proposed to improve the classification, and one of the main differences between RNA and SVM is that, while for RNA there can be many solutions, the SVM converges to a single optimal solution. SVM are binary classifiers that assign a given sample to a class, of only two possible classes. However, remote sensing applications involves multiple classes. There are some solutions to use SVM in the multiclass problem, and in this work, the methodology used in this work was 'one against all' for the six classes classification Landsat TM+ image of Ilha do Mel and Pontal do Paraná regions, Paraná - Brazil. For evaluating the performance of the classification algorithm, the results were analyzed based on the error matrix (or confusion matrix), giving a good results on the discrimination of similar targets, like mangroves and other vegetation, and with a total classification accuracy of 99.6%.Pages: 2322-232