National Institute for Space Research
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Modelagem da Qualidade da Água na Bacia Hidrográfica do Rio Coisa Boa - Igatu - Chapada Diamantina - Bahia
No full textThis research aims at modeling the Good thing Basin (BCB), region Igatu, Chapada Diamantina - Bahia, especially as the physico-chemical quality of surface waters. The study area lies within the limits of the National Park of Chapada Diamantina (PNCD) and listed as a Historic, belonging to the municipality of Andaraí. Regarding the methodological procedures was used: principal components analysis (PCA), application of IQABa, spatial analysis methods by the inverse square of the distance and line graphs. The months were as follows: April, July and October 2010 and January 2011, covering twenty (20) sampling sites upstream and downstream of the BCB. The physicochemical parameters used to implement IQABa are those representing the Principal Component Analysis (PCA), which further explain how the quality of the waters of BCB: turbidity, total solids, pH, phosphate, nitrate, BOD and conductivity. From the results obtained during the sampling campaign, did the calculations Index Water Quality of Bascarán (IQABa) (Bascarán, 1979 apud Rizzi, 2001). The analysis of water quality of the BCB was performed in twenty collection points, contemplating headwater areas with little human interference, primary contact recreation, sewage discharge and areas around the mouth. It is observed that the quality of water in BCB decreases from upstream to downstream, as it is the entry of effluent generated by the anthropogenic Village Igatu. The amount of the BCB, has an area with springs, with little human interference and with good water quality, even in the dry season, reflecting the natural water of the study area. As for surface maps for the area studied, the technique called inverse square of the distance was visually satisfactory to the spatial data.Pages: 6526-653
Quantificação da exportação de fósforo numa bacia do semiárido cearense
No full textIn small rural communities cearenses small dams are the main sources of supply being used for many activities. These dams has been suffering a fast process of eutrophication with the degradation of water quality through point and diffuse sources of phosphorus. This work aimed to quantification of the phosphorus loads in the catchment of Paus Branco, Madalena-CE, in the semiarid northeast. It was used satellite images LIS3, bands 2, 3 and 5 for the survey of the use and occupation of land by using GIS programs, following application of unit load model for quantification of phosphorus per class land use. Have been found six types of class, where the class "livestock" area occupies 49%, followed by class "preserved forest" (41%). The production of phosphorus released into the reservoir is 1371kg per year, and the main contribution of nutrients to the reservoir are the areas of livestock, contributing about 665 kg of phosphorus per year, representing 49% of full load affluent. And then, the contributions of exposed soil that are responsible for 43% of the total value of nutrients contributed. Remote sensing techniques and application of nutrient export models are an important instrument of management of reservoirs in semiarid.Pages: 4632-463
Clasificación de imágenes ETM+ y ASTER GDEM por el método árbol de decisiones para la detección de agua subterránea en Perú. Caso Estudio: Lambayeque
No full textCon el propósito de complementar las diferentes técnicas de prospección geofísica aplicada a la exploración del agua subterránea de acuíferos libres se propone el uso de imágenes satelitales ETM+ y ASTER. El área de estudio es la Región Lambayeque que está ubicada en la costa norte del Perú, entre las coordenadas geográficas 5\ub0 28' 36'' y 7\ub0 14' 37'' de latitud Sur y 79\ub0 41' 30'' y 80\ub0 37' 23'' de longitud Oeste. Los datos utilizados son las imágenes registradas por el sensor ETM+ del satélite Landsat-7, ortorectificadas del 31-10- 2000 y las imágenes del modelo de elevación digital ASTER GDEM. Con los datos imágenes ETM+ se calculan los componentes principales con las bandas 1, 2, 3, 4, 5 y 7 y con el componente principal tres (CP3) se estiman los valores que corresponden a la red de drenajes de la Región Lambayeque. Adicionalmente con las bandas 3 y 4 se calcula el índice de vegetación diferencial normalizado (NDVI) y con la banda 6 se estima la temperatura del suelo (TS). Con los datos imágenes ASTER GDEM se determina el modelo de pendiente (PEN) del área de estudio. Finalmente mediante un árbol de decisiones, basados en los valores de CP3, NDVI, TS y PEN se caracterizan las zonas potencialmente con agua subterránea de acuiferos libres. Para medir la confiabilidad de la metodología se verificó que 153 pozos de agua subterránea inventariados cuyas coordenadas se conocen 112 (73,2%) pertenecen a las zonas clasificadas como potencialmente con agua subterránea.Pages: 5689-569
Uso do Quantum GIS e Google Earth para delimitação e análise de áreas de preservação permanentes da sub-bacia do córrego Água Branca em Goiânia
No full textThe use of GIS technologies and remote sensing work has efficacy in the identification and monitoring of special areas, it can be implemented in the short term and on different scales. This makes it possible to analyze the changes occurring in a given time interval, enabling the decision-making. This study aims to use these technologies to identify environmental impacts in Permanent Preservation Areas (PPA) of the watershed of the Água Branca Creek, located in the eastern of the city of Goiânia. It were used data from the Urban Basic Digital Map of Goiania (UBDMG v.22) which was manipulate using the software Quantum GIS. Images provided by Google Earth were also used in this study. PPAs have been drawn from the springs 100 meters and 50 meters of water sources along the watershed of that stream. The track was defined according to Complementary Law No. 171 of May 29, 2007, the Master Plan of Goiânia. The results obtained allowed to identify and evaluate points of degradation of the PPA of the Água Branca Creek and the watercourses of it sub basin, impacts resulting from direct and indirect human action. The use of GIS tools and remote sensing made it possible to study the sub basin of the creek Água Branca which is located in a region with high housing. In addition, the watershed is part of Meia Ponte River basin, a source of extreme importance because it is used for water supply part of the metropolitan region of Goiânia-GO.Pages: 1175-118
BayNeRD: inferência baseada em observações
No full textUnderstanding the behaviour and the interaction among the complex phenomena in the field of Earth sciences is an active challenge to the predictive science. Interactions of probabilities are pointed out as the most promising basis to allow a computer to have a plausible reasoning. When the number of variables increases or even when the complexity of the relationships among the variables and also between the variables and the phenomenon rises, the Bayesian Network (BN) is a representation suited to model and handle the task. Thus, the objectives of this paper are to develop and implement a computer aided BN method that is able to incorporate experts knowledge handling with raster data: Bayesian Networks for Raster Data (BayNeRD). A case study under the context of soy identification and mapping in Mato Grosso State, Brazil, was used to test the methodology and the implemented algorithms. BayNeRD algorithm was implemented on R software and allow the understanding of complex phenomena through plausible reasoning based on data observation. Based on observation of a vegetation index, terrain slope, road and water body distances and soil aptitude, BayNeRD was able to compute the probability of soy occurrence. Results showed that BayNeRD can be used in several applications.Pages: 2369-237
O uso de técnicas de geoprocessamento na prospecção de áreas para aproveitamento de energia eólica
No full textThis paper presents the use of GIS techniques in the identification and selection of areas that have potential for use of renewable energy resources from wind, to develop projects of power generation, considering the adoption of restrictive and inclusive conditions, such as existing local infrastructure (power grid and transport routes), proximity to residences and possible environmental factors based on the laws and regulations. For allowing the integrated analysis of a substantial amount of spatial geographic information, the computational geographic tools of geographic information systems, enable the expansion of areas of research in identifying areas favorable to the use of renewable natural resources, from prospective studies, quantitative criteria have been established that allowed to list those areas in degree of attractiveness. This technique allows us to identify and rank the most promising areas and eliminate the areas that have a number of restrictions that would unfeasible projects development, avoiding actions that modify the environment and unnecessary expenditure of resources.Pages: 4821-482
Extensão e distribuição de derrubadas por vento na Amazônia, associados a uma única linha de instabilidade em janeiro de 2005
No full textA large number of blowdowns occurred in Amazonia in mid-January of 2005 when a squall line traversed 4.5 million km2 of forest, propagating from SW to NE. This paper describes the spatial distribution of forest damage across Amazonia for that event, considering disturbance patches > ~3 ha in size. Damage was found to be highly concentrated near Manaus, not widespread. Nonetheless, blowdowns attributed to this single squall line contributed over half of all annual blowdown area detected in 30 samples across Amazonia for that year. Leaving a single Landsat scene out of the sample would cause a large difference in the estimate of total damage. Methods: In Landsat images, blowdowns associated with the January 2005 squall line exhibit a distinct geometry. They are either diffuse or have SW to NE directed lineaments. Thirty sample polygons were allocated across the Amazon region, each containing 15,000 km2 of continuous forest. These were visually inspected at 1:80,000 scale in Landsat TM RGB images (bands 5-4-3) from the 2005 dry season. All blowdown footprints ~3 ha were recognized by spectral pattern and geometry. After linear spectral unmixing with CLASLite, the disturbed pixels were identified within each blowdown by a threshold of the pure vegetation fraction (<85%) then summed within each 15,000 km2 sample. The percent of forest damaged and attributed to this single squall line was then interpolated between the 30 sample centroids.Pages: 3352-335
Mineração de dados e adaptação de modelos de classificação de cobertura e uso da terra para imagem Worldview 2
No full textThe studies about forest fragmentation have increased since the past 3 decades, together with the increase of the discussion about conservation and preservation. In this way, the landscape and land use maps are important tools for this analysis, as well as other remote sensing techniques. The object oriented analysis classifies the image according to patterns as texture, color, shape, and context. To identify which value and attribute is necessary to the classification, data mining technique has been used, because it looks for patterns inside the data. This technique helps to accelerate the process; however, it was necessary to adapt the model. In this way, the land use and land cover classification was made using the values that data mining software has provided. Afterwards, this classification was analyzed, and the verification was made by the confusion matrix, which was generated through the creation of random points shapefile in ArcGis 9.3, trough this it was possible to evaluate the classification accuracy (58,89%). From these results, the model has been adapted. However, these adaptations have been done in the classes water and forest. As result, 2 new classes have been created: shadow and forest2. Also, some values were changed and some attributes added, for example, brightness, to identify dark areas. In the end, the accuracy was 89,33%, however this result doesnt show some errors which are still on the model.Pages: 2345-235
Mapeamento automático de áreas de preservação permanente em topos de morros no município de Santa Maria - RS
No full textThe uncontrolled advance of the urban and agricultural areas on Permanent Preservation Areas - PPAs has spurred laws as the Brazilian Forest Code, which aims to prevent the overthrow of the native vegetation of these places, thus preserving the ecosystems in general. The demarcation of PPAs in hilltops is a process considered complex, making it difficult the monitoring these regions by environmental agencies. To assist this procedure, are used geoprocessing techniques with the help of satellite images. This method consists in to map the APPs on hilltops automatically, through the generation of Hydrologically Consistent Digital Elevation Models and of algebra functions of maps, saving time and labor. This study aimed to map the PPAs in hilltops in Santa Maria-RS through the use of Geografic Information System - GIS and of LANDSAT 5 sattelite image. In Spring 5.0.6 GIS, was made a thematic classification of the image. The delimitation of PPAs, and the land use conflict map was made in the ArcGIS 9.3 software. It was found that Santa Maria has 57,28 Km² of PPAs on hilltops, and of this total, 21.68% are in the area of conflict with the law. Finally, it is emphasized that the mapping obtained good results because ensured the effectiveness of the methodology developed for the scale of work.Pages: 4123-412
Determinação do fator topográfico utilizando Modelos Digitais de Elevação de diferentes fontes e resoluções para a Bacia Hidrográfica do Rio Conceição - RS
No full textKnowledge of sediment delivery to and from rivers and streams is essential evaluate the impact of land use on water quality. The impact of current and alternative land use needs to be investigated in order to determine appropriate land management strategies to maintain or obtain good water quality. The influence of relief at the erosion risk is usually calculated by the LS topographic factor from the Universal Soil Loss Equation USLE and its derivations. This work evaluates the influence of the grid spacing in Digital Elevation Models (DEMs) on the determination of the LS topographic factor for the Rio Conceição hydrographic basic RS. The DEMs employed in this study are those from the STRM mission (90 m) and TOPODATA project (30 m) and one generated from the topographic charts published by the Geographic Service Directorate of the Brazilian Armed Forces with a 1:50.000 scale (20 m). The DEMs generated from both the STRM and TOPODATA sources are found to be inadequate for the determination of the LS topographic factor with a tendency to underestimate erosive potential in the undulating areas and overestimate the erosive potential for the planar areas. The DEM generated by the topographic charts gives the best estimate of declivity values, especially the areas with high declivity, and gives the best estimate of the erosive potential for land forms in the hydrographic basin studied.Pages: 5291-529