National Institute for Space Research
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Utilização de aeronaves remotamente pilotadas para extração de mosaico georreferenciado multiespectral e modelo digital de elevação de altíssima resolução espacial
No full textIn the last decade the use of UAVs in the world increased considerably both for military and for civilian applications. This paper presents an overview of UAVs and discusses the use of small UAVs to carry out airborne.The paper describes the operation of a multirotor rotary wing vehicle and its applications in remote sensing using conventional digital cameras and converted digital cameras to extract high quality data. The methods used in the acquisition and processing of UAV imagery were described with special attention to critical points, such as the use of two different sensors and the compatibilization process of these data. At the end the results was a multispectral georeferenced orthomosaic with 0,01m of spatial resolution in all four bands and a digital elevation model with 0,06m of pixel resolution. From these results were processed one NDVI index and a semiautomatic procedure for features extraction. The main goal of this paper is to determine the quality of the data acquired and it`s applications compared to conventional methods for acquire data.Pages: 9308-931
Análise das áreas queimadas no Estado do Acre nos anos de 2010 e 2011
No full textAnnually, anthropogenic fires consume large areas of grasslands and forests over the world with local, regional and global impacts, related to biochemical cycles and atmospheric processes. In Brazil, especially in Amazon region, fires occur due to agriculture expansion, deforestation and pasture renewals. In this context, the objective of this work is to estimate 2010 and 2011 burned areas for Acre State, correlating it with the public ministry action, annual precipitation and with radiative energy released in combustion process. Data from Thematic Mapper sensor aboard Landsat 5, Tropical Rainfall Measuring Mission (TRMM), Fire Radiative Power (FRP) and the Program of Amazon Deforestation Calculation (PRODES) was utilized. Also, a fieldwork was performed in September 2011 to validate burned areas maps. The results indicate that the estimated burned areas were approximately 2,000 km2 and 643 km2 in 2010 and 2011, respectively, a reduction of 68%. The values of fire radiative power decreased in 2011 and the higher consumption of biomass is located near to the deforestation polygons mapped by PRODES, indicating that the forest vegetation is cleared in the dry season before burning. Among the factors responsible for the decrease of fires, we can mention the highest volume of rainfall occurred in 2011, a fact that becomes the vegetation more humid, and especially due to the implementation of public policies, such as the increased of surveillance, the certification of properties and alternative techniques replacing the use of fire.Pages: 7257-726
Variabilidade interanual dos perfis temporais de NDVI/MODIS de áreas agrícolas cultivadas com cereais de estação fria para produção de grãos no Rio Grande do Sul
No full textThis study aimed to analyze the temporal NDVI/MODIS profiles variability in winter cereals cropping areas to establish relationship with wheat yield in Rio Grande do Sul State, Brazil. The data set comprised 17 NDVI/MODIS images, from April to December of the 2000-2008 series. Firstly, crop masks were elaborated by subtracting the minimum NDVI image (April to May) from the maximum NDVI image (June to October). Then, an unsupervised classification of NDVI/MODIS images was carried out, considering the crop masking areas. The class that temporal NDVI/MODIS profiles were in agree with crop calendar was named as winter cereals to grain production and the interannual variability was analized. The results showed that NDVI values were low (0,40) early in the crop cycle and increased up to August, September and first fortnight of October, according to the region. Maximum NDVI value and major interannual variability occurred in period before the flowering stage. It was possible to indicated difference between temporal NDVI/MODIS profiles in years of low and high wheat yield. The maximum yield in the series was associated with temporal NDVI/MODIS profile with more plant biomass accumulation.Pages: 23-3
Utilização de radar de abertura sintética em banda X para apoio a gestão territorial na produção de biocombustíveis na Amazônia
No full textThis paper describes a case of a Petrobras Biocombustivel pilot project thats have a primary scope of test tools to environmental research. The focus was in use Synthetic Aperture Radars to support environmental management of biofuels production in Amazon Region. There are deadlines for past deforestation (provided by international roundtables, Agroecological Zoning of Pará State, etc.), few spatial data about environmental dynamics of the region, the limits for vegetation removal and others. The first step was to classify the types of land uses using the MTC images as a foundation to more complex analysis. The definition of keys patterns to classify the types of land uses was the one of the main goals of the project. These key patterns specify types of textures, shape of features, intensity, tone and context for each class. The land use maps stared the following classes: Primary Forest, Secondary Forest, Pasture, Natural Fields, Crop, Bare Soil, Water bodies, Infrastructure and the built environment (urban / Buildings / villages). After that, the project envisioned the following outbreaks of analysis: evolution of deforestation; compliance of legal reserves and APPs; growth areas of secondary vegetation ("Juquira", "Capoeira"); monitoring the stages of oil palm; evolution of other cultures; changes in land use, mapping areas of general civil construction (road, houses, etc.) or any urban or rural; hydrological dynamic; The data generated provided a level of information that led to the improvement of business processes, such as identifying types of vegetation in the partners farms, that was not possible with the resources previously used.Pages: 8421-842
Cuantificación de la pérdida potencial de suelos para evaluar la susceptibilidad del suelo a la erosión cuenca hidrográfica quebrada "el mochuelo"
No full textThe main purpose of the present study is the quantification of loss of soils in the basin of the Mochuelo creek, using the Universal Soil Loss Equation USLE, to calculate and evaluate the susceptibility from the soils to the erosion. It was carried out a Stratified Sampling and, the prediction models were analyzed under the concept of fuzzy logic with DEM image, thematic and base maps. In the laboratory the contents of humidity, apparent density, real density, structural stability, consistency, grain size, pH, and organic carbon were determined. Due to the erosion factor between 100 and 626 Mj.mm/ha.hr.; to the high susceptibility of the soils; to the steep gradient between 26 and 30 m.; to the slopes of the hillside between 0.18 and 70% and the increasingly deficiency of the vegetable covering as well as the realization of practical of handling, the potential loss of soils of the hydrographic basin of the Mochuelo creek, was considered between 50 ton/ha/year and 500 ton/ha/year. Besides the physical and biotic characteristics and of the basin, it is considered that the actual erosion process is due to the wrong and inappropriate land use, to the deforestation carried out in the 40-50 decade; to the introduction of farming of cereals in intense way, and the extraction of clays for the manufacture of bricks. Also, the soils are very susceptible can be degraded by any external force (threatens), this bears to increase the risk for erosion and the movement of mass will be bigger. Key words: DEM processing, Erosive, Erodability, GIS, Fuzzy Logic.Pages: 171-17
Uso de imagens de satélite para identificação de áreas queimadas para uso em laudos periciais de incêndios florestais
No full textForest fires have the potential of destruction of biodiversity, water resources, soil and air quality, and offer hazard to property and bodily integrity of rural populations. Thus, preventing and fighting fires are essential to minimize such losses. In this context, the use of remote sensing data is essential to provide data for temporal and spatial resolutions required for monitoring and analysis of burned areas. The objective of this study is to evaluate the use of satellite images for the quantification and identification of burned areas aiming to calculate the extent of damage, by means of multispectral indexes, NDVI (Normalized Difference Vegetation index) and NBR (Normalized Burn Ratio) and also the classification method using Gaussian Maximum Likelihood (GML). The region analyzed encompasses the Parque Nacional da Serra do Cipo (National Park) - PNSCi and the Área de Proteção Ambiental (Environmental Protection Area) do Morro da Pedreira APAMP, points of occurrence of several wildfires in recent years in Minas Gerais state. Images of TM / Landsat 5 were used for quantification and identification of fires in those areas. The results obtained by those methods were effective in reaching the calculation of burned areas, with advantages and limitations which are discussed in conclusion.Pages: 2809-281
Comparação de modelos digitais de elevação de SRTM e ASTER com modelo de elevação de grande escala do município de Lages - SC
No full textThe digital elevation models today are a great help in planning and projects. But get them is very expensive by conventional surveys. There is the willingness EDM prepared using satellite sensors such as ASTER and SRTM. The objective of this study was to analyze the behavior of altimetric SRTM and ASTER products, compared to an EDM data generated from photogrammetry of the urban area of the municipality of Lages, Santa Catarina State, Brazil, in thousand points random sample processed in a GIS. With the base map of the city hall was generated an EDM software and imported the files corresponding to the area analyzed SRTM and ASTER. After thousand points were created by random sampling tool HawthsTools and were used for extracting the altitudes of the three layers of EDM. The data were extracted from altitudes in tables and statistical analysis was performed considering the altitude of the city hall of the EDM as an attestant. It was used the paired T-test to compare samples SRTM and ASTER data with city hall. Visually the EDM of SRTM was more like of the city EDM. Analyzing the values of sampled thousand points of comparison, the data showed 4.945 meters of mean difference between PML and ASTER and 3.345 meters between PML and SRTM. The confidence interval for the difference showed no significant differences between PML-SRTM for altimetric accuracies between 2.65 and 4.035 meters and PML-ASTER no difference in accuracies between 4.23 and 5.66 meters. The data comparison showed that the EDM has values closer to cartographic data base of the municipality of Lages, in relation to the values of the EDM of ASTER for isolated points sampled.Pages: 4647-465
Monitoramento ambiental de lagoas inseridas na planície de inundação do médio Araguaia, com base em imagens Landsat (MSS e TM)
No full textStudies to discriminate the land use and land cover changes in watershed tributaries have shown expressiveness due to the agro-pastoral activities influences on the quality of inland waters. In order to analyze this conversion rate around thirty ponds inserted in the Middle Araguaia watershed, during 1976 - 2011 period, we used a LANDSAT-TM and MSS sensor imagery to quantify the remaining vegetation, pasture and agriculture activities. Our results show an intensive conversion of the natural areas in disturbed areas (around the ponds) The rate of conversion of natural areas in disturbed (APPs within 100 m) ranged from 0.01% to 53.3% over the 35anos analysis (1976-2011), and converting the soil was checked using 22 to ponds and 8 remained intact. The grazing activity ranged from 0.21% to 21.1% for the same period, while the activity of agriculture had a significant increase of 0.01% will be 53.3%. The last period (2000 - 2011) was the most intense in terms of anthropic conversion, with more than half of the ponds presenting some disturbance, which coincides with the activities of agriculture and pasture in the Araguaia River basin (since 1970s), principally in Goias and Mato Grosso states.Pages: 7731-773
Dinâmica espaço-temporal da vegetação secundária no município de Apuí (AM)
No full textSecondary forests accounted for over one-third (266.000 km2) of the total deforested area in the Legal Amazon by 2008. This study analyzed the spatial and temporal dynamics of secondary forests in Apuí (AM), Brazil, municipality in which the expansion of cattle ranching has caused substantial increases in deforestation. A multi temporal series of 10 Landsat TM 5 satellite was classified by the maximum likelihood method in Envi 4.7 software. Mappings were analyzed by logical expressions using Dinamica EGO software, which allowed the extraction of information related to the land cover dynamics in the landscape. It also allowed the evaluation of the methodology employed in the images classification. The results pointed to the intensive land use system established in the region, where deforestation rates were above the average found in the whole Amazon in the last decade. The dynamics of secondary forest was associated temporally to the date of images acquisition and spatially to the local dynamics of pastures expansion and maintenance. The high land use dynamics in the region resulted in a high decrease of secondary forests; on average, only 10% of the secondary forests mapped in a year remain in the landscape after six years. The methodology employed in our study was useful for mapping land cover. The use of tools that allowed the overlay of classified images and the extraction of their quantitative information were essential to the refinement and analysis of data, minimizing errors associated with the process of classifying satellite imagery.Pages: 7639-764
Estudo da dinâmica de desmatamento do município de Cotriguaçu-Mato Grosso, Brasil
No full textThe northwestern region of Mato Grosso is increasingly being assisted by universities, government and non-governmental organizations, as this part of the state are the last large block of Amazon forest and also an important border region between Mato Grosso and Amazonas State . Thus, this paper aims to study the dynamics of deforestation in the municipality of Cotriguaçu in search of historical fact relating to deforestation and thus elucidate some of the main causes of this phenomenon. The quantification of deforestation and all intersections of polygons with Amazon, states and municipalities in the northwest were made using GIS techniques and remote sensing. In the discussion we present current data of all crossings, and to detail the polygons and deforestation hotspots of Cotriguaçu characterized by agrarian situation, ie, identify the region of occurrence. The data collected could be used for planning, municipal management and spatial planning. In the end we can see that Amazon does not follow a single pattern of deforestation, so each county or region must have a policy and management specific to their sustainable development.Pages: 7079-708