National Institute for Space Research
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Representação de dados e Modelos de Dados Espaço-Temporais em SIG
No full textThe Geographic Information Systems (GIS) constitute a technology able to address problems involving the temporal aspect of the data. However, the question of how to represent the spatio-temporal dynamic in GIS was ignored until the late 1980s. Since then, some models of spatio-temporal data that incorporate the temporal dimension in GIS have been proposed. This article aims to address and discuss the issue of modeling of spatio-temporal GIS. Initially, we present issues related to stages of development of GIS with spatio-temporal characteristics and data representation in GIS. Then, to address some of the major models of spatio-temporal GIS developed in the last decades.Pages: 3787-379
Estimativa e espacialização da erosividade para as bacias hidrográficas dos rios Guapi-Macacu e Caceribu
No full textSoil losses caused by rain events depend not only on the resistance that the soil offers to raindrop impact, but also on the rain kinetic energy, its intensity and duration. The influence of these factors on the rain capacity to cause erosion is estimated by the erosivity index -- the two most cited in the technical literature are EI30 and KE > 25. This study aims to estimate the erosivity indexes based on rainfall data of 19 stations and to present the spatial distribution on the watersheds of Guapi-Macacu and Caceribu rivers. The method applied allowed to analyse the distribution of the erosivity on this area and show that they are greater on the North of the area in all months. The results showed that, although both indexes have shown major differences in terms of their absolute values or their magnitude, they have similar behavior in terms of their relative values and their distribution in the study area.Pages: 4109-411
Estimativa da biomassa aérea de um fragmento de floresta estacional semidecidual por meio de imagens de satélite IKONOS II
No full textEstimates of biomass in forested areas can be obtained using direct (allometric equations) and indirect (high resolution remote sensing imagery) methods. This study aimed to estimate the above ground biomass of a natural forest fragment, classified as Forest Semideciduous Montana, located in the municipality of Viçosa, State of Minas Gerais, Brazil, on the campus of the Federal University of Viçosa (UFV). Based on data from forest inventory conducted in 15 sample plots of 1,000 m2 (20 m × 50 m) spread over the study area were obtained estimates of stocks of biomass from allometric equations, which were related to digital variables (reflectance in the four multispectral bands and in 12 transformed vegetation indices images), extracted from the 4 meters spatial resolution images of IKONOS II, using artificial neural networks (ANN). The main results indicate that the use of the four spectral bands of IKONOS II, as input variables, are sufficient to estimate biomass stocks for the study area, with their residual varying in the range of \ub1 1,3%. For the conditions of this study, the neural network technique has proved to be excellent for estimating above ground biomass from the digital data extracted from high resolution sensors aboard orbital platforms.Pages: 2786-279
Imagens de satélite de alta resolução espacial aplicadas na caracterização de áreas de preservação permanente de corpos d´água
No full textThe discussion about water and its protection and conservation has been broadened and deepened in last decades. From the observation that this is a finite natural resource and its being misused and, especially, contaminated and polluted, have sought ways to protect it efficiently in order to preserve their current use and later. One of the simplest and most effective ways to protect this natural resource is the maintenance of existing native vegetation on the margins of water bodies. This procedure, however, has not been adopted by many owners, both urban and rural, during the process of land occupation on Brazil. So many Permanent Preservation Areas (PPA) are currently occupied by productive activities, which goes against Brazilian environmental legislation. To evaluate and quantify the uses of land in large areas of PPA can be used satellite images of high spatial resolution, as the sensor PRISM of the Japanese satellite ALOS. In this study they were used to analyze land use in PPA Novo River, a sub-basin of the Paranapanema River. It was found that a total of 5596.87 hectares of PPA, 1477.29 (26.4%) are occupied by improper use, according to the legislation. This indicates areas that require interventions aimed at their adequacy and demonstrates the importance of studies with satellite images of high spatial resolution for the analysis, management and protection of water resources.Pages: 2928-293
Histórico do uso do solo do Distrito Federal (DF) nas micro-bacias
No full textThe Brazilian Constitution of 1946 had already determined the transfer of the countrys capital to the brazilian Center West. However, it was only in 1956 that the president Juscelino Kubitschek announced the shift. The new capital was developed and, consequently, problems arose due to its modern concept of architecture and innovative living. Nevertheless, the city has been struggling to keep its environmental quality dependant on the integrity of ecological processes and natural resources. This articles purpose is to show, through the use of maps, a history of soil use in Distrito Federal and to present the anthropic percentage of each regional watershed over a duration of time (1953 2006). To do so, shapefiles supplied by UNESCO (United Nations), originally from the public production Vegeteção no Distrito Federal: tempo e espaço, were used, as well as the software ArcGis (ESRI). The system of coordinates UTM, datum SAD 69, zona 23S was also used to all the shapefiles. The evidence suggests that the urban anthropic and the variation of the vegetation are strictly related to the watersheds quality; there are impacts in the soil and air, associated to the climate, biodiversity and flows in the ecosystem, emissions of greenhouse gases and lower carbon retention in the biota. Moreover, the loss of vegetation in the micro watersheds also leads to the degradation of the fauna and floras natural ecological habitats and to difficulties in the connection of the Conservation Units.Pages: 3230-323
Espacialização, quantificação e classificação das áreas verdes do município de Sete Lagoas, utilizando as ferramentas de modelagem (NDVI) e de técnicas matemáticas - estatística de componentes principais e a análise de agrupamento
No full textThe medium cities are in Minas Gerais regions of spatial transformations, growing and profound changes in the built environment, showing, on the other hand, a decrease and almost total lack of green areas within cities, the result of profound changes in the social-space, obeying the laws of capitalist expansion of the city, which appears to be a fragmented social product, articulate and engendered by social agents. This research aimed spatialize, quantify and classify the green areas of the city of Sete Lagoas, Minas Gerais. The basic tools were modeling the high-resolution image of the German RapidEye satellite, census data and the use of mathematical techniques statistical of principal component and cluster analysis for the validation of this model. Through the three analyzes in this article, it was observed that the socio-economic activity in the principal components analysis had a very low correlation relative to NDVI. Cluster analysis in relation to NDVI was more satisfactory compared to urban density and green areas. The result shows that deforestation of areas intended for preservation or recreation independent of socioeconomic status, but the growth acceleration that is disordered in the city of Sete Lagoas, where the municipal government is the lack of record, quantify and preserve areas environmental and social interest.Pages: 6658-666
O uso do geoprocessamento como instrumento de análise morfométrica da microbacia do rio capivara, município de Lençóis-BA
No full textThis article aims to analyze the morphometrics of the river watershed capybara, in the city of Lençóis, region of Chapada Diamantina-BA, in northeastern Brazil from geoprocessing techniques applied and the use of remote sensing. The variables measured and characterized were area, perimeter, length of the river, extension of rivers, number of rivers, fluvial hierarchy, density of rivers, drainage density, index of circularity, compactness coefficient, drainage pattern, altitude and altimetric amplitude, all of them appropriately based on the scientific literature of fluvial landforms. The materials and methods used previously have relied on the use of topographic sheet and in the definition of system geodetic suitable of geographic projection in order to make the results more accurate. Posteriorly, the analysis of the parameters was made possible by the creation of a database that have been manipulated through the software ArcGis 10.1 and BaseCamp Garmin that generated a digital elevation model of the terrain from data project topodata-INPE derived of imagery SRTM-NASA, outside, hypsometric map, map of location, the boundaries of the river basin and river network. The results indicate that the watershed of the river capybara has an elongated shape, steeper slopes, is sparse and has a deep dissection river, with a drainage system little branched and dendritic, showing that geoprocessing is a tool very useful for studies of watersheds.Pages: 4555-456
Análise das mudanças no uso e cobertura vegetal ao longo da paisagem da bacia do vale do rio Itapecerica, alto São Francisco, em Minas Gerais
No full textThis study aimed to investigate the changes in the soil use and vegetation cover in the basin of Itapecerica river valley in Minas Gerais, Brazil, between the years 1992 to 2012, using vegetation indices extracted from TM (Thematic Mapper) / Landsat 5 images, and by subtraction between pairs of images SAVI (Soil Adjusted Vegetation Index). The results show the efficiency of subtraction SAVI technique to detect patterns of changes in vegetation cover in the basin. The diagnosis generated revealed a reduction of about 44.58% on cover, 27.13% relating to regeneration and even 28.29% of the area of use without change or presenting no significant changes. By one side, the rate of regeneration suggests a high degree of resilience related to the anthropic pressure and modification of natural space in recent times. However, the conservation of the region is worrisome because the suppression rate in just 20 years is extremely high, so the basin may face serious conflicts and problems of water supply. These results indicate the need for a specific policy on environmental education for conservation, ecosystem functioning and balance in order to avoid future problems and greater attention to the multiple use of natural resources with emphasis on more sustainable farming methods.Pages: 1649-165
Análise do padrão de ocupação urbana e sua relação com a regularização fundiária: uma abordagem utilizando imagens CBERS fusionadas
No full textThis paper aims to verify the relationship between pattern of urban settlement and legal registration of urban property in a small Amazonian city, Ponta de Pedras, located at Marajó Island, state of Pará. We defined the pattern of urban settlement using fusion image produced with CBERS satellite images that have high spatial resolution (HRC) and high spectral resolution (CCD), to produce this hybrid image with a better characterization of urban structures. The results confirmed that both data (pattern of urban settlement and legal registration of urban property) are high related. For instance, the number of registered properties is much higher in areas where there is better infrastructure and urban services, such as paved streets, low flood risk, far from the forest and close to commercial area.Pages: 960-96
Mining, deforestation and conservation opportunities: A case study of the Quadrilátero Ferrífero land use change dynamics
No full textMining and mineral processing operations fundamentally oppose the objectives of conservation programs. Environmental compensation (or biodiversity offset) policies, however, present a unique opportunity to expand conservation reserves within mining regions. In this study, we quantified the land use change dynamics that have occurred within Minas Gerais intensive iron ore mining region, the Quadrilátero Ferrífero. Specifically, the objectives of the study were to: 1) quantify the direct impact of mining operations on native vegetation extent and compare this to that caused by other land uses, and 2) to investigate the conservation effectiveness of previously established environmental compensation areas in preventing vegetation loss. To do this we quantified the land use change in the region at four time points over 20 years using Landsat images. Results illustrate that the region has undergone rapid and extensive change. In 2010 only 46% of native (unproductive) vegetation remained. Deforestation was the result of multiple pressures that emerged from multiple land users in the region. Mining accounted for 14% of vegetation loss since 1990, with the remainder caused by a combination of expanding cattle pastures, Eucalyptus plantations and urbanization. In 2010, only 20% of the region was under some form of conservation tenure, with less than 0.05% of native vegetation protected for the purposes of environmental compensation. Within these compensation reserves, however, almost no vegetation loss was observed. If all mining companies in the region had been required to compensate for the deforestation caused by their operations at least an additional 15,000 ha of native vegetation would be protected. We conclude that while the direct impacts of mining on deforestation is relatively small, mining companies can play a much larger role in regional dynamics as there is a great opportunity to expand the protected area network in the Quadrilátero Ferrífero through the use and implementation of environmental compensation policies.Pages: 6300-630