National Institute for Space Research
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Mapeamento de mudança de uso e cobertura da terra no bioma Cerrado entre 1975 e 2010 a partir da classificação de imagens Landsat
No full textLand cover and land use in the Brazilian savanna (Cerrado biome) has been intensively modified since the early 70s. Nevertheless, the analysis of such rapid transformations has been very limited due to the inexistence of historical mappings. In this work we present the methodology utilized for mapping, at every two years (from 1975 to 2010), four Landsat (MSS, TM, and ETM+) located over consolidated converted areas and along expanding agricultural frontiers. Image segmentation and the Bhattacharya classification were performed on the Spring GIS / Image Processing plataform and relied on field validation, followed by extensive visual interpretation. Our results, which indicate distinct spatial-temporal occupation patterns in the Cerrado, corroborate our multiple sensors, interpretation (i.e. automated processing, visual interpretation, and ground-truthing), and cumulative (i.e. previous year interpretation constrains the following years mapping) approaches, as well as the ability of biannual Landsat like imagery for capturing rapid changes in the Cerrado landscapes.Pages: 1626-163
Aplicación de SIG en el estudio de la evolución geomorfológica de las lagunas de la Lomada Norte, Corrientes, Argentina
No full textGeomorphology focuses on the knowledge of characteristics and dynamics of a particular area, given that it is of major significance in determining impacts, both actual and potential, that can be generated by human action and / or by the same natural progression. The Lomada Norte is located in the northwestern triangle of Corrientes province (Argentina). It holds an area of about 5 km wide and 80 km long, having 925 lentic bodies of water, either temporary or permanent. The aim of this work is to explain the geomorphologic processes involved in the study area using tools for spatial analysis. All water bodies were digitalized to generate a digital elevation model of the region (DEM). For the spatial analysis, the expansion Spatial Analyst Tools Hydrology from ArcGis 10 was used. As a result, a diagram showing the runoff system on Lomada Norte was generated that coincides with the erosion processes observed on satelital images. The analysis performed evidenced the convenience of using this tool for the spatial analysis of low-altitude areas suggest. All these results suggest that the geomorphologic dynamic of the Lomada Norte responds to topographic conditions.Pages: 5591-559
Indicativo de fatores econômicos ligados ao desmatamento em Goiás
No full textSecond largest biome in South America is the Cerrado. The Cerrado is considered a global diversity hotspots. With the technology of soil correction and relief it suitable for agriculture, the Savannah area has became economic attractive. Due to the historical occupation of the Cerrado, as: the coffee industry in the '30s, the march to the West, began the process of deforestation was more intense in the southern of the state. By the year of 2002, Goiás was the region with the largest area of human action among the states that make up the Cerrado. With the 9 th largest gross domestic product (GDP), Goiás has an activity driving economic growth in agriculture. However, the largest deforested areas of the state were in average low income of municipalities, 5 cities with the largest deforested areas count together 1.4% for the economy in the state of Goiás while participating with 18.7% in Goiás deforestation between 2002 and 2009. The Gini index calculates income, deforestion and savanna in area the state and it generated the following results: 0.8, 0.67 and 0.55, respectively. Therefore, the concentration of wealth among municipalities is greater than the distribution of deforestation. In agriculture, the relationship between deforestation and acreage is weak with an index of 0.06, as in the livestock index of 0.70 between deforestation and cattle, corroborates the influence of deforestation with planted pastures. Therefore, with the clash of economic indicators and data logging was possible to identify relationships and characteristics linked to environmental destruction.Pages: 7563-757
Mapeamento participativo e uso do SIG: FLONA de Tefé-AM
No full textThis paper have as goal to analyze the mapping work done along the National Forest of Tefé/AM. This mapping, in particular, is about the land use and has been done in order to, along with other necessary maps, subsidize the management plan of the conservation unit. The Tefés FLONA is located in the geographical regions of Tefé and Juruá, that have similar socio-economic aspects, as the source of income of the resident population, mainly based on family agriculture, with emphasis on cassava production, artisanal fishing and the extraction of açai, andiroba and copaiba. Currently approximately 500 families living in FLONA, distributed in small communities along the rivers Bauana, Tefé and low Curumitá. The methodological procedures used for this work are divided into: a) obtaining satellite images from Google Earth program and making a map image for the study area, b) realize the first expedition to the field and participatory mapping by the overlay of tracing paper in satellite's images and supported by dialogue with the community, c) elaboration of thematic maps within ArcGIS software d) realize the second expedition to confirm the generated maps. Because the project is in progress we can only present preliminary results on the features, uses, conflicts, environmental problems and needs of these populations, besides the systematization of their demands. The spatialized information reveal a knowledge generated by the community, and assists in social transformation as representations that enable understand the space and its use forms by those communities.Pages: 7532-753
Mapeamento e análise da capacidade de carga antrópica nas trilhas do Campus da Universidade Federal do Amazonas
No full textThe aim of this study was to analyze the arrangement of tracks of Federal University Amazonas - UFAM, Brazil, from receiving the flow of people, not to compromise its physical structure and the ideal conditions of fauna and flora. We conducted field work and laboratory research, survey data on length, width of the tracks, areas with flooding, erosion, and rainfall, solar brightness and accessibility. The ability to load the tracks of Campus is very diverse among the 29 tracks studied ranged from 2 per day to nearly 50 people. The results of this study contribute to support the planning of the physical and educational trails. The procedures used were effective to identify key indicators to determine the load capacity of the manmade trails. There must be constant monitoring and maintenance of the trails, so as not to accelerate erosion and control the deposition of waste, not to alter ecological processes in Campus UFAM.Pages: 5032-503
Identificação de áreas aptas à implantação de irrigação por pivô central no município de Unaí-MG utilizando ferramental do SIG
No full textThe use of the method of analysis overlapping layers by weighting is considered one of the most efficient methods to support decision making. Thus the aim of this study was to characterize suitable areas for the deployment of center pivot irrigation systems. The processing and the spacial analysis were realized in GIS with ArcGIS 10. The work was performed for the city of Unaí, Minas Gerais. To construct the suitability map were considered three variables: slope, water availability and soil type and for each layer was assigned an importance percentage. Each layer was divided into classes with weights assigned to them being that the class more favorable received higher weight, while less favorable given less weight. At the thematic map generated from overlapping layers was added a vector of center pivots already installed in the region. As a result it was found that around 75% of the total area was classified as good or very good suitability, while only 25% were classified as medium or low suitability. Regarding the irrigated area, it was found that about 78% of the total irrigated area was classified into suitability classes good or very good, while only 2% is located in areas classified as low suitability. Thus we conclude that the GIS tools demonstrated good results being a viable alternative to study the suitability of areas for irrigation center pivot systems.Pages: 585-59
Quantificação do Grau de Severidade de Queimada em Unidades de Conservação no Distrito Federal por meio dos Índices Espectrais dNBR e RdNBR
No full textThe aim of this study was investigate the fire severity occurs in the conservation units in the Distrito Federal for 2010 and 2011. For this, we used the spectral indices normalized burn ratio - NBR, differenced normalized burn ratio - dNBR and relative differenced normalized burn ratio - RdNBR. The RdNBR presents the best results to quantify the burning biomass if it compares with the dNBR results. The dNBR overestimates the unburned area and underestimates the other classes. New studies must be encouraged aiming better understand the fire behavior to manage and monitor, as well as understanding the effects of fire on the Cerrado region.Pages: 6534-654
Uma abordagem híbrida e semi-automática para a remoção de nuvens e sombras de imagens de satélite
No full textThe main goal of this work is to propose an efficient, and so automatic as possible process for replace clouds and shadows regions from satellite images. The motivation comes from the problems caused by these elements, among them: hinder the identification of image objects, prejudice urban and environmental monitoring, and disfavor crucial steps of the digital image processing to extract information from the user, such as segmentation and classification. Through a hybrid approach, is proposed a method for decomposing regions using a nonlinear median low-pass filter, in order to map structure (homogeneous) regions, like vegetation, and texture (heterogeneous) regions, like urban, in the image. In these areas, was applied the restoration method called inpainting by smoothing based on Discrete Cosine Transform (DCT), and an exemplar based texture synthesis. It is important to highlight that the techniques were modified to be able to work with images of peculiar characteristics as those obtained by satellite sensors, such as the large size and the high.Pages: -802
Localização automática de pontos de controle utilizando correspondência por mínimos quadrados
No full textNowadays integrated GNSS/INS (Global Navigation Satellite Systems/Inertial Navigation System) systems are being used in Direct Sensor Orientation (DSO), improving automation in Photogrammetry. However, even with DSO some problems like camera calibration, stability and definition of reference systems cause effects on the results, requiring Ground Control Points (GCP) to assess the procedures and to correct these systematic effects. Although many photogrammetric tasks have been automated, the measurements of GCP in the aerial images are still performed manually, which introduce errors due to the limits of human vision. The aim of this paper is to assess the feasibility of automation and the precision in the matching of terrestrial images (named templates) with aerial images by using iterative LSM (Least Squares Matching) with 8 parameters (6 geometric and 2 radiometric). Using area-based matching, terrestrial templates (with the GCP identified) are matched with aerial images. Next, the best matches are refined by LSM. Experiments were performed using synthetic and real images to evaluate the effects and the conditions of LSM between terrestrial and aerial images. A procedure of aerial triangulation was used for assessment using GCP image coordinates and GCP measured stereoscopically. The analysis was performed with independent check points and the results showed that the image coordinates were automatically measured with sub-pixel precision. Considering that the LSM method is iterative, some experiments were performed to assess the number of iterations and it was verified that two iterations are enough to match terrestrial and aerial images. The results achieved with the proposed automatic location method were more accurate, when compared to the stereoscopic method.Pages: 1945-195
Aplicando filtro local máximo (LM) através dos métodos da janela fixa e variável em dados LIDAR para identificação de árvores individuais em um povoamentos de Eucalyptus sp
No full textThe identification of individual trees using LIDAR technology has lately been one of the latest innovations in remote sensing applied to forest inventory. In this paper, we aimed evaluate the performance of LiDAR data for individual tree detection in Eucalyptus sp plantation using filter of variable and fixed windows size applied by Local Maximum (LM) algorithm implemented in FUSION software. The results show that LiDAR has a good accuracy of tree individual tree detection, and that filter of fixed windows (FJF) size has a better performance than filter of variable windows size (FJV). The better accuracy to individual tree detection using fixed windows size was of the 98.57%, whereas in variable windows size was of the 17,07%. We conclude that FJF has a good performance when applied to individual tree detection in Eucalyptus sp plantation.Pages: 6081-608