National Institute for Space Research
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Nivelamento das estações linimétricas dos rios Negro, Uraricoera e Branco com dados altimétricos
No full textThe basic hydrological monitoring is an activity that aims to generate information to support studies and projects that require knowledge of water availability and hydroelectric potential of the basins. In this context, the reference altitude common for gauged stations is needed to better conducting hydrological and hydrodynamic studies (Moreira, 2010). To solve these problems, in part, an alternative to complement the hydrological monitoring is the use of satellite radar altimetry (Calmant and Seyler, 2006). The present study aims to level the gauges of the Negro, Uraricoera and Branco through altimetry data space. In this study were leveled a total of thirteen gauged stations twelve of these gauges were leveled by the indirect method wich is obtained by the difference in level between two stations altimetric to get the slope of that part of the river, and this slope is calculated to zero ruler which is between those two stations, one altimetric and was leveled by the method directly, in which the gauge is imaged within the range of the satellite, then performs a simple linear regression to obtain the zero level of the ruler. The results showed that it was possible to level the rules with altimetric data, but if the distance between the station and the ruler altimetry data are too large have a bigger margin of error.Pages: 5643-565
Aplicação de parâmetro morfomêtrico na identificação de anomalias em sub-bacias inseridas nas bacias hidrográficas do Gramame e Abiaí, localizadas na porção sul da borda oriental do estado da Paraíba
No full textThe objective of this paper is to present possible evidence of recent successful neotectonics performances in the study area, which comprises nine sub-basins included in the watersheds of Gramame and Abiaí, located in the southern portion of the eastern edge of the state of Paraíba, more precisely in the south of Paraiba river. The method adopted to uncover these potential evidence was the geomorphic index of asymmetry factor of drainage basin (AFDB), which by the results obtained from their measurements, which can indicate a basin or sub-basin has some type of diving block. The software used was ArcGIS, where it was responsible for all procedures, this extraction drainage image Shuttle Radar Topography Mission (SRTM) to the delineation of sub-basins and measuring their respective areas. The results from the application of this parameter allowed the identification of anomalies present in the sub-basins, as well as identify those with little or no displacement of the block. These values have an important morphometric information so that further research aimed at understanding the genesis of this geomorphological setting this compartment, possibly derived from tectonic reactivation, may already have a direction in applying a particular study. Is worth mentioning that this area has peculiarities from a possible neotectonic performance, as expeditious retreat headwater drainage, inflection watercourses and strong notches watercourses that do not have competence to notch verified. These characteristics observed in the SRTM image, motivated the application of FABD in this area.Pages: 5331-533
Base digital com imagens SPOT 5 e RapidEye, subsídio para o Cadastramento e Licencimento Ambiental Rural no Estado do Pará
No full textThis article proposes a method for optimizing and standardizing georreferenced digital bases for registering rural properties for environmental licensing in the state of Pará. The study produced a digital base map of forest cover and land use in the scale 1: 25.000, for the city of Santana do Araguaia. After geometrical evaluation and validation of SPOT 5 images , the digital data base was built using visual interpretation edited in the scale 1:10.000 showing villages, transport network, rivers, permanent protection areas (APP) and city limits and presenting them in the scale 1:25.000 for guaranteeing mapping quality . Forest cover map was based on RapiEye images from 2011, with 5 m spatial resolution and registered based on SPOT 5 through supervised classification. Noises were corrected with spatial filters and matricial edition. The final product was validated through aerial survey. Santana do Araguaia had lost 52% of forest cover by 2011 highlighting the fact that degraded lands represented 9% of this area. APPs are present in 6% of the city and 41% of them were degraded in 2011. This study has demonstrated more efficient methods for producing more precise digital data base to be used by municipal public managers.Pages: 1250-125
Identifying optimal classification rules for geographic object-based image analysis
No full textIn Geographic Object-based Image Analysis (GEOBIA), remote sensing experts benefit from a large spectrum of characteristics to interpret images (spectral information, texture, geometry, spatial relations, etc). However, the quality of a classification is not always increased by considering a higher number of features. The experts are then used to define classification rules based on a laborious "trial-and-error" process. In this paper, we test a methodology to automatically determine an optimal subset of features for discriminating features. This method assumes that a reference land cover map (or at least training samples) is available. Two approaches were considered: a rule-based approach and a Support Vector Machine approach. For each approach, the method consists in ranking the features according to their potential for discriminating two classes. This task was performed thanks to the Jeffries-Matusita distance and Support Vector Machine-Ranking Feature Extraction (SVM-RFE) algorithm. Then, it consists in training and validating a classification algorithm (rule-based and SVM), with an increasing number of features: first only the best-ranked feature is included in the classifier, then the two best-ranked features, etc., until all the N features are included. The objective is to analyze how the quality of the classification evolves according to the numbers of features used. The optimal subset of features is finally determined through the analysis of the Akaike information criterion. The methodology was tested on two classes (urban an non urban areas) on a Spot5 image regarding a study area located in the La Réunion island.Pages: 2290-229
Uso da Terra no entorno do Reservatório da UHE Passo Real - RS
No full textOne of mankinds greatest worries relates to environmental problems which are accentuated more and more, we highlight water bodies, because these denounce local realities that occur indiscriminately in the distinct geographical scenarios. From satellite images and geoprocessing techniques it is possible to generate and analyze terrestrial and aquatic ecosystem information in a synoptic way that permits an integrated vision of the protection and/or degradation processes of these. The objective of this research is investigating and analyzing the changes that occurred in the spatial organization of Passo Real HydroelectricalPowerplant Reservoir (UHE) 100 meters around it, from 2001 to 2009. Initially, we created a geo-referred database using the software Spring version 4.3.3 and after we elaborated maps of use and coverage around the reservoir, corresponding to the areas of permanent preservation, from the supervised classification of Landsat/TM images. For the identification of terrestrial use and coverage alterations in the period we used Spatial Language for Algebraic Geoprocessing (LEGAL). The methodological approach used permitted to identify areas around the reservoir which do not present the use of land according to Environmental Legislation. In the studied period, we observed two important effects; one related to the forest decrease in 5.6% and other to the increase of agricultural cultivation and exposed soil in 9.3%.Pages: 7289-729
Estimativa do saldo de radiação à superfície em área de cerrado amazônico utilizando imagem Landsat 5-TM
No full textRemote sensing may be used to identify changes that occur in land use of Earth, resulting from natural and/or anthropic processes. Many of these changes can be diagnosed from the monitoring of radiative exchanges that take place at the surface. Net radiation is an important component of the surface energy balance in hydrological studies. In spite of existing weather stations in Brazil, equipped with pyranometers, we cannot forget its size and that the measures of solar radiation are representative of a limited area. Because of that, the use of techniques of remote sensing to complement meteorological information on a certain place becomes indispensable. In this sense, this study aims to determine the net radiation at surface, by means of satellite image covers part of the amazon cerrado, State of Amapá, Brazil. A Landsat 5 - TM image obtained in October 26, 2006 was used to generate map of instantaneous net radiation (Rn) based on algorithm SEBAL. The instantaneous Rn values varied between 222.73 and 530.0 Wm-2, with average of 376.37 W.m-2. The anthropic areas showed decrease in net radiation, while forests areas showed increase. According to the results, it may be concluded that the methodology used for net radiation determination presented coherence when compared to other studies in the literature.Pages: 1712-171
Índice de Qualidade da Água do córrego Vicente Pires-DF, sua relação com o uso e ocupação do solo e influência sobre o córrego Riacho Fundo-DF
No full textThe increase of urban occupation intensifies on the Distrito Federal-DF, enlarging the water and sewer demand and affecting the environmental in consequence of use and occupation of the drainage basin. Therewith, natural resources, mainly the hydric ones suffer pressure, this kind of resource has a delicate situation on the DF region, it all assists questions related to basic sanitation. The objective of this study is to classify in a spatial diagnostic the water of Vicente Pires-DF stream, according to the Index of Water Quality (IWQ)-CETESB, demonstrating the contamination by pollutants generated by the use and occupation of near areas. The results according to the Resolução CONAMA 357/05 indicates class 2 of freshwater. The interference of Vicente Pires stream on Riacho Fundo stream and it on Lago Paranoá was verified, considering that in the future it may be used for public water catchments. Five samples were collected for the characterization of water quality. The parameters analyzed were required by CETESB. The results with maps were made in the Geoprocessing Laboratory-UCB. The Dissolved Oxygen had one sample above the limit, the Biochemical Oxygen Demand (BOD) exceeds maximum values on one sample and Thermotolerant Coliforms had high concentrations on two samples. The other parameters analyzed have some restrictions according to the resolution cited or do not present values out of the allowed. At last it is possible to conclude that the stream suffer with the clandestine sewer, agricola waste and urban drains, making necessary treatment measures, preservation and protection for these hydric resources.Pages: -92
Uso combinado de dados NDVI/MODIS dos satélites Terra e Aqua no monitoramento multi-temporal de áreas agrícolas
No full textThe temporal analysis of vegetation indices has shown a great potential application of land surface monitoring, especially in areas with high spectral-temporal dynamics, such as agricultural crops. Not always the maximum value compositions, which synthesize the daily information obtained by sensors with high temporal resolution, are cloud-free. Moreover, the methods of time-series filtering may deform the spectral information and mask some phenological features of the crops. Therefore, the objective of this study was to analyze the combined use of NDVI/MODIS data obtained from Terra and Aqua satellites, in order to increase the frequency of the spectral information and assess its application in agricultural monitoring activities. Despite the age and time pass differences of these two satellites, the combined use of these two datasets was useful in activities of crop monitoring. Visual analysis of NDVI temporal profiles, produced by the combination of these two datasets, showed a significant improvement in the representation of agricultural cycles. The results also presented advantages in combining these two datasets in an activity of annual agriculture mapping in a region with frequent cloud cover.Pages: 431-43
Comparação de Modelos Digitais de Elevação gerados com dados oriundos de levantamentos de voçorocas com laser scanner
No full textDigital elevation models are data structures that present a numerical spatial coordinates x, y and z terrain. These models can be divided into vector, by means of dots or lines or raster feature values that cover the surface regularly without overlapping and full coverage. The main source of data for most common MDEs are still developing the contours mainly provided by the Brazilian Institute of Geography and Statistics (IBGE), which in many cases do not attend some studies by the lack of detail, making each are used more data from remote sensors. The laser scanner is a tool that makes it possible to obtain three-dimensional information of the study area, with high accuracy and speed in the survey. The system generates and emits laser pulses that reach the surface of the scanned object at various points. These objects reflect the pulses of these and return to the system, thus enabling the calculation of the distance between the sensor and the object by the time of emission and reflection of the pulse. This study aimed to evaluate the effectiveness of three software for generating digital elevation models with data from scans of gullies located in the municipality of Brooms (RJ). The softwares were backed ArcGIS 10.0 (ESRI), with the the top to raster tool, FUSION 3.10 (Forest Service of the United Stated Department of Agriculture) and Microstation 08:09 (Bentley Systems).Pages: 6502-650
Calibração da geometria interna das imagens do sensor AWFI/AMAZONIA-1
No full textThis article presents a methodology for guarantee the internal geometry calibration of images from the AWFI sensor, on board of the AMAZONIA-1 satellite. The main objective of this methodology is to fix the non-linearity of the arrays from the three different optical systems. The array non-linearity is caused by the irregular construction of the optic systems in the instrument and, therefore, a line in the output image can contain data from different lines of the three arrays. In the presented methodology, this issue is addressed through matching portions of the images of the arrays using the register by correlation process, and applying a filter to refine the result. The experiments and some results are presented at the end of this text.Pages: 8056-806