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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Utilização de perfis multi-temporais do NDVI/AVHRR no acompanhamento da safra de soja no oeste do Parana / Use of NDVI/AVHRR time-series profiles for soybean crop monitoring in the west of Parana, Brazil

Esquerdo, Julio Cesar Dalla Mora, 1977- 16 February 2007 (has links)
Orientador: Jurandir Zullo Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-08T15:45:15Z (GMT). No. of bitstreams: 1 Esquerdo_JulioCesarDallaMora_D.pdf: 11640903 bytes, checksum: 682c94cd14226702d51cf54a7bd6387a (MD5) Previous issue date: 2007 / Resumo: O principal problema levantado nesta tese é que a ocupação do espaço rural para a produção agropecuária se efetiva sem a devida preocupação com os recursos naturais disponíveis, em especial o solo, e sem o conhecimento das características sócio-econômicas dos produtores. Uma das evidências para essa constatação é que ainda não há estudos suficientes sobre as dinâmicas ambientais e sociais do uso do solo, ocorrendo uma supervalorização da dimensão econômica na exploração dos mesmos. Objetivou-se realizar um estudo do meio físico, através de suas potencialidades e limitações, em sobreposição aos indicadores sócio-econômicos, com vistas a avaliar uma proposta metodológica de planejamento rural para o desenvolvimento sustentável. A partir daí procurou-se quantificar a adequabilidade do uso do solo dos municípios de Aguaí, Mogi Guaçú e Estiva Gerbi, Estado de São Paulo, para os anos de 1981, 1990 e 1997, compondo um banco de dados espaciais multitemporais. A avaliação sócio-econômica foi feita por meio da análise da dinâmica de ocupação e uso dos recursos naturais pelos agricultores, agrupados em setores censitários do IBGE, cujas variáveis e tipologia, georeferrenciadas, compuseram o banco de dados de atributos. A metodologia foi desenvolvida a partir da elaboração do Mapa de Adequabilidade do Uso do Solo dos municípios, empregando-se os Mapas de Aptidão Agrícola e de Uso e Cobertura do Solo, segundo o Método de Avaliação de Aptidão Agrícola, utilizando-se imagens dos satélites Landsat 2 (MSS) e Landsat 5 (TM). Foram também analisadas as transformações no uso dos solos pela tabulação cruzada e índices de exatidão global e Kappa, que indicam o grau de evolução nas mudanças ocorridas no espaço analisado. A caracterização sócio-econômica e tecnológica dos setores censitários foi efetivada por meio da Análise Fatorial de Correspondências Múltiplas (ACM) e da Classificação Hierárquica Ascendente, com os dados do Censo Agropecuário 1995/96. Os resultados da análise física multitemporal permitiram delimitar o histórico agroambiental do uso dos solos, representando a evolução e expansão agropecuária, em relação ao uso e adequabilidade dos mesmos. A análise espaço-temporal do uso intensivo do solo e da adequabilidade indicou uma forte evolução no sentido do aumento da ocupação dos solos, tanto para um uso adequado, quanto para uma sobreutilização. Nos três municípios, percebe-se que, com a intensificação da modernização da agricultura, as terras subutilizadas vão diminuindo, gradativamente de 1981 a 1997, apontando seu decréscimo na direção do desmatamento e/ou substituições das pastagens, para a introdução de culturas anuais e/ou permanentes, de maior valor comercial. Por outro lado, áreas que deveriam estar como reservas para preservação permanente acabam também sendo apropriadas por cultivos mais intensivos, ocorrendo, novamente, uma sobreutilização do solo. Foram definidos quatro tipos de agricultores nos municípios: modernos e diversificados citrícolas capitalizados, criadores descapitalizados de animais e familiares com produção vegetal diversificada. Como resultado final, obteve-se um conjunto de mapas, que traduzem o conhecimento integral dos espaços rurais e a ocupação do território. A metodologia proposta mostrou-se apropriada para o subsídio ao planejamento sócio-ambiental, propiciando elementos para um diagnóstico atualizado e eficaz, no estabelecimento de políticas públicas voltadas ao desenvolvimento rural sustentado / Abstract: The main problem raised in this thesis is that the occupation of the agricultural space for the farming, effectives production without the proper concern with the available natural resources, in special the ground, and without the knowledge of the social and economical characteristics of the producers. One of the causes for this confirmation is that it does not have enough studies yet on the environmental and social dynamic of the use of the land, occurring a supervaluation of the economic dimension in the exploration of agricultural ground. It was aimed to carry through a study of its potentialities and limitations, in overlapping to the social and economical index, with sights to evaluate a methodological proposal of agricultural planning for the sustainable development. Since then, it was tried to quantify the adequateness of the use of lands of the cities of Aguaí, Mogi Guaçú and Estiva Gerbi, State of São Paulo, for the years of 1981, 1990 and 1997, composing a multisecular space data base. The social and economical evaluation was made by the analysis of the dynamics of occupation and use of the natural resources for the agriculturists, grouped in tax sectors of the IBGE, whose georeferenced variable and typology had composed the bank of attributes. The methodology had as base the elaboration of the Map of Adequateness of the Use of Lands of the cities, using the Maps of Agricultural Aptitude and the Use and Covering of the Ground, according to Method of Classification of Agricultural Aptitude, using images of the satellites Landsat 2 (MSS), Landsat (5 TM) and Landsat 7 (ETM+). Also the transformations in the use of lands for the cross tabulation and index of global exactness and Kappa had been analyzed, that indicate the degree of evolution in the occured changes in the analyzed space. The social, economical and technological characterization of the tax sectors was accomplished by means of the Factorial Analysis of Correspondence (ACM) and the Ascending Hierarchic Classification, with the data of 1995/96 Farming Census. The results of the multisecular physical analysis had allowed to delimit the agro-environmental description of the use of the land, being represented the evolution and farming expansion in relation to the use and adequateness of lands. The analysis space-weather of the intensive use of the ground and the adequateness, indicated one strong evolution in the direction of the increase of the occupation of lands, as much for an adjusted use as for an over-use. In the three cities, it was perceived gradually that, with the intensification of the modernization of agriculture, the underutilized lands diminished, from 1981 to 1997, pointing its decrease in the direction of the deforestation and/or substitutions of the pastures with respect to the introduction of annual and/or permanent cultures of higher commercial value. On the other hand, lands that would have to remain as reserves for permanent preservation also finishing being appropriate for more intense cultivation, occurring, again, an over-use of the lands. Four types of agriculturists in the cities had been defined: modern and diversified, capitalized citrus producers, undercapitalized animal breeders, diversified familial vegetal production. As final result, a set of maps was gotten, aiming at the integral knowledge of the agricultural spaces and the occupation of the territory. The methodology proposal revealed appropriate for the subsidy to the spcial and environmental planning, propitiating elements for a fast, brought up to date and efficient diagnosis, in the establishment of directed public politics to the supported agricultural development / Doutorado / Planejamento e Desenvolvimento Rural Sustentável / Doutor em Engenharia Agrícola
42

Evaluating Multitemporal Sentinel-2 data for Forest Mapping using Random Forest

Nelson, Marc January 2017 (has links)
The mapping of land cover using remotely sensed data is most effective when a robust classification method is employed. Random forest is a modern machine learning algorithm that has recently gained interest in the field of remote sensing due to its non-parametric nature, which may be better suited to handle complex, high-dimensional data than conventional techniques. In this study, the random forest method is applied to remote sensing data from the European Space Agency’s new Sentinel-2 satellite program, which was launched in 2015 yet remains relatively untested in scientific literature using non-simulated data. In a study site of boreo-nemoral forest in Ekerö mulicipality, Sweden, a classification is performed for six forest classes based on CadasterENV Sweden, a multi-purpose land covermapping and change monitoring program. The performance of Sentinel-2’s Multi-SpectralImager is investigated in the context of time series to capture phenological conditions, optimal band combinations, as well as the influence of sample size and ancillary inputs.Using two images from spring and summer of 2016, an overall map accuracy of 86.0% was achieved. The red edge, short wave infrared, and visible red bands were confirmed to be of high value. Important factors contributing to the result include the timing of image acquisition, use of a feature reduction approach to decrease the correlation between spectral channels, and the addition of ancillary data that combines topographic and edaphic information. The results suggest that random forest is an effective classification technique that is particularly well suited to high-dimensional remote sensing data.
43

Dynamiques morpho-sédimentaires des avant-plages et impact sur les stocks sableux : vers une meilleure stratégie de gestion des risques côtiers / Nearshore morpho-sedimentary dynamics and stocks impacts : improving strategies of coastal risks management

Jabbar, Marie 12 December 2016 (has links)
Le phénomène global d’érosion côtière, notamment sur les rivages d’accumulation, tend à accroître les risques côtiers (érosion et submersion) dans les secteurs à enjeux. Dans ce contexte, les stratégies visant à la gestion des stocks sableux côtiers au sein même des cellules hydro-sédimentaires apparaissent comme une réponse potentielle à la gestion locale de l’érosion des accumulations littorales, et au-delà à la gestion de ces risques. Ces perspectives se heurtent encore à une insuffisance de connaissance des dynamiques géomorphologiques des avant-plages (partie immergée de la cellule). Pour autant, la connaissance des échanges au sein de la cellule et avec le large sont au coeur de la compréhension du fonctionnement des systèmes littoraux sableux. Les objectifs de cette thèse sont de renforcer les connaissances géomorphologiques des stocks sableux et de leur mobilité au sein des cellules littorales et, par l’amélioration de cette connaissance, de contribuer à l’élaboration de stratégies de gestion des risques côtiers.La comparaison de levés bathymétriques multi-temporels sur le temps long (séculaire) et court (annuel) à une échelle régionale et locale met en évidence les évolutions des avant-plages sur les côtes bretonnes du début du XXème siècle à nos jours. Ainsi, un des résultats majeurs est une inversion des tendances d’évolutions au milieu du XXème siècle. Une situation d’accrétion ou de stabilité relative laisse place à une érosion généralisée des avant-plages sur les côtes bretonnes. L’interprétation et la discussion de ces résultats permettent d’avancer des facteurs explicatifs de ces évolutions tels que les forçages météo-marins et anthropiques et les contraintes structurales. / The global phenomenon of coastal erosion, occurring especially on sandy coasts, tends to increase coastal risks in areas with key issues and concerns. In this context, stocks management strategies within sandy hydro-sedimentary coastal cells have appeared to be potential solutions to the local management of coastal erosion and their associated risks. However, despite their importance to determine management strategies, the dynamics of nearshore (submerged part of the cell) geomorphology remain poorly studied and partially understood. This PhD thesis aims to provide a better understanding of nearshore geomorphology in some specific sites and to contribute to the development of coastal risk management strategies.The study of multi-temporal bathymetric surveys at century-scale and annual-scale highlights significant evolution of the Brittany nearshore morphology from the beginning of the 20th century until today.In particular, a striking result is the reversal of the morphological evolution tendency in the mid-20th century. During the first half-century, the situation is steady, though nearshore morphology has a slight tendency toward accumulation. During the second half-century, we measured a net erosion tendency for all the survey sites. Interpretation and discussion of these results allow to determine the forcing of the nearshore morphodynamics, among which are climatic (coupled ocean-atmosphere) events, anthropogenic impacts and structural constraints.
44

Methods for the analysis of time series of multispectral remote sensing images and application to climate change variable estimations

Podsiadło, Iwona Katarzyna 08 November 2021 (has links)
In the last decades, the increasing number of new generation satellite images characterized by a better spectral, spatial and temporal resolution with respect to the past has provided unprecedented source of information for monitoring climate changes.To exploit this wealth of data, powerful and automatic methods to analyze remote sensing images need to be implemented. Accordingly, the objective of this thesis is to develop advanced methods for the analysis of multitemporal multispectral remote sensing images to support climate change applications. The thesis is divided into two main parts and provides four novel contributions to the state-of-the-art. In the first part of the thesis, we exploit multitemporal and multispectral remote sensing data for accurately monitoring two essential climate variables. The first contribution presents a method to improve the estimation of the glacier mass balance provided by physically-based models. Unlike most of the literature approaches, this method integrates together physically-based models, remote sensing data and in-situ measurements to achieve an accurate and comprehensive glacier mass balance estimation. The second contribution addresses the land cover mapping for monitoring climate change at high spatial resolution. Within this work, we developed two processing chains: one for the production of a recent (2019) static high resolution (10 m) land cover map at subcontinental scale, and the other for the production of a long-term record of regional high resolution (30 m) land cover maps. The second part of this thesis addresses the common challenges faced while performing the analysis of multitemporal multispectral remote sensing data. In this context, the third contribution deals with the multispectral images cloud occlusions problem. Differently from the literature, instead of performing computationally expensive cloud restoration techniques, we study the robustness of deep learning architectures such as Long Short Term Memory classifier to cloud cover. Finally, we address the problem of the large scale training set definition for multispectral data classification. To this aim, we propose an approach that leverages on available low resolution land cover maps and domain adaptation techniques to provide representative training sets at large scale. The proposed methods have been tested on Sentinel-2 and Landsat 5, 7, 8 multispectral images. Qualitative and quantitative experimental results confirm the effectiveness of the methods proposed in this thesis.
45

The Ecological Dynamics of a Coastal Lagoon

Nandi, Nandi 17 February 2015 (has links) (PDF)
A coastal lagoon is a landform that is influenced by natural processes and human activities. All human activities at the upstream, particularly agriculture and cultivation bring soil, waste, and other materials to the downstream area through the river drains into the lagoon. Even though its position is inland of water bodies, the lagoon is still affected by waves and winds from the sea. Additionally, coastal lagoon will be the depository place for sedimentation from the upland area. Segara Anakan (SA), which is located in Indonesia, is an example of a coastal lagoon area, which has a unique biophysical characteristic. The region has a great natural ability to ensure the sustainability of the interrelationships between terrestrial, estuarine and marine ecosystems in harmony and balance as a habitat for flora and fauna. The region is an area of migration of various types of protected animals and it is a place of breeding for diverse species of the shrimp and fish, which have a highly economical value. Segara Anakan lagoon (SAL), currently experiencing acceleration narrowed on its area due to a very intensive sedimentation from the mainland. The research aims to answer the question of how ecological dynamic occurs in the SAL area due to sedimentation. Achieving the objectives of this study required examining the morphology and land use changes with multitemporal remote sensing approaches. While, to assess the role of community participation and planning management strategies is using qualitative descriptive methods and SWOT analyze. The using of multitemporal remote sensing Landsat images is possible to analyze the morphological and land use changes with different time and sensors. These Landsat has image accuracy about 92.66%. It can be used for image interpretations resulting 13 classes of land use. The morphodynamics of SAL indicated by the changes of area of lagoon and accreted land and also the distance of coastlines during the periods 1979-2013. In addition, the land use or land cover also changes during that time. The bigger portions of land use changes are in the tropical and mangrove\'s forests. There are distinctive forms of participation in conservation efforts. The upstream community involvement in conservation tends to be different participating in the way of ideas, money, materials, properties, skills and expertise or social activities. In addition, the community at downstream area has a sufficiently high level of participation in environmental conservation. There are also strong relationships between the level of education and level of income and basic knowledge in conservation with the participation of SA conservation. The ecological dynamics of the SAL area are described with a historical time line. It is divided into three time periods: the 1970s - 1980s, the 1990s and from 2000 onwards. Each of these has occurrences that can lead to changes in the environment. The implementation of appropriate conservation technique can reduce the sedimentation rate. Hence, the synergic coordination measures between upstream and downstream regions are necessary in the future. Increasing community awareness and participation in the conservation by improving educational sector, providing information, and applying sustainable development land use are the ways to match human activities with the temporal and spatial dynamics of the coastal resources.
46

ANÁLISE MULTITEMPORAL DO USO DA TERRA E COBERTURA FLORESTAL COM DADOS DOS SATÉLITES LANDSAT E ALOS / MULTITEMPORAL ANALYSIS OF LAND USE AND FOREST COVERAGE WITH DATA FROM LANDSAT AND ALOS SATELLITES

Torres, Daniela Ricalde 29 July 2011 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The monitoring of the use and coverage is very important when studying determined regions, just because it helps knowing the environmental reality and contributes to solve problems that can probably appear. This research was done from the images of ALOS and LANDSAT satellites. Its main objective was to have a multi-temporal analysis of Arroio Grande micro watershed, central region of Rio Grande do Sul. The specific purposes were to identify and to quantify the different classes of land use found in this micro watershed along the 1987, 1998, 2002, 2005, 2007 and 2009 periods, as well as cross the land use information to show the forest coverage changes during the 22 years of analysis. The software SPRING 5.1.7 was employed to classify the supervised images through Bhattacharya, a sorter algorithm, and the map spatial analysis was done through the Spatial Language of Algebraic Geoprocessing program with the same computational application. The classes of land use as forest, field, agriculture, irrigated agriculture, exposed soil and water layer were observed in the images of each year in this analysis. These classes were utilized in the spatial analysis of the forest coverage in which forest monitoring parameters have been defined (forest maintenance and regeneration, deforestation). In this research the principal results that have been noticed were the increase of 17,98% on the distributed forest coverage, mainly in the areas of bigger declination, and the reduction of 16,32% on the field area. The analysis of the spatial forest coverage has presented stability with the landscape, in a gradual progression, because the area of forest maintenance, found in these 22 years, was 12.252,60ha, the forest regeneration was 4.389,12ha and only 1.853,82ha of deforested area. / O monitoramento do uso e cobertura da terra faz-se importante no estudo de determinadas regiões, pois auxilia no conhecimento da realidade ambiental e contribui na busca por soluções de problemas que possam se apresentar. A partir do uso de imagens dos satélites, ALOS e LANDSAT, foi realizada esta pesquisa com o objetivo principal de fazer uma análise multitemporal na microbacia do Arroio Grande, região central do Rio Grande do Sul, cujos objetivos específicos foram: Identificar e quantificar as diferentes classes de uso da terra encontradas na microbacia nos períodos de 1987, 1998, 2002, 2005, 2007 e 2009; além de cruzar as informações de uso da terra, evidenciando a cobertura florestal que sofreu alterações no decorrer dos 22 anos de análise. Para tanto, foram utilizados o software SPRING 5.1.7 para a classificação supervisionada das imagens, com a adoção do algoritmo classificador Bhattacharya, e a análise espacial dos mapas com a programação LEGAL do mesmo aplicativo computacional. Para esta análise, foram observadas as classes de uso do solo: floresta, campo, agricultura, agricultura irrigada, solo exposto e lâmina d água, nas imagens de cada ano. Estas classes foram empregadas na análise espacial da cobertura florestal em que foram definidos parâmetros para o monitoramento florestal (manutenção florestal, regeneração florestal e desmatamentos). Os principais resultados notados, nesta pesquisa, foram o aumento de 17,98% na cobertura florestal distribuída, principalmente, nas áreas de maiores declividade, e a redução de 16,32% sobre a área de campo. Quanto à análise espacial da cobertura florestal, esta mostrou-se em estabilidade com a paisagem, e em gradual progressão, pois a área de manutenção florestal encontrada, nestes 22 anos, foi de 12.252,60 ha, a regeneração florestal foi de 4.389,12 ha e apenas 1.853,82 ha de área desmatada.
47

Extraction d'informations de changement à partir des séries temporelles d'images radar à synthèse d'ouverture / Change information extraction from Synthetic Aperture Radar Image Time Series

Lê, Thu Trang 15 October 2015 (has links)
La réussite du lancement d'un grand nombre des satellites Radar à Synthèse d'Ouverture (RSO - SAR) de nouvelle génération a fourni régulièrement des images SAR et SAR polarimétrique (PolSAR) multitemporelles à haute et très haute résolution spatiale sur de larges régions de la surface de la Terre. Le système SAR est approprié pour des tâches de surveillance continue ou il offre l'avantage d'être indépendant de l'éclairement solaire et de la couverture nuageuse. Avec des données multitemporelles, l'information spatiale et temporelle peut être exploitée simultanément pour rendre plus concise, l'extraction d'information à partir des données. La détection de changement de structures spécifiques dans un certain intervalle de temps nécessite un traitement complexe des données SAR et la présence du chatoiement (speckle) qui affecte la rétrodiffusion comme un bruit multiplicatif. Le but de cette thèse est de fournir une méthodologie pour simplifier l'analyse des données multitemporelles SAR. Cette méthodologie doit bénéficier des avantages d'acquisitions SAR répétitives et être capable de traiter différents types de données SAR (images SAR mono-, multi- composantes, etc.) pour diverses applications. Au cours de cette thèse, nous proposons tout d'abord une méthode générale basée sur une matrice d'information spatio-temporelle appelée Matrice de détection de changement (CDM). Cette matrice contient des informations de changements obtenus à partir de tests croisés de similarité sur des voisinages adaptatifs. La méthode proposée est ensuite exploitée pour réaliser trois tâches différentes: 1) la détection de changement multitemporel avec différents types de changements, ce qui permet la combinaison des cartes de changement entre des paires d'images pour améliorer la performance de résultat de détection de changement; 2) l'analyse de la dynamicité de changement de la zone observée, ce qui permet l'étude de l'évolution temporelle des objets d'intérêt; 3) le filtrage nonlocal temporel des séries temporelles d'images SAR/PolSAR, ce qui permet d'éviter le lissage des informations de changement dans des séries pendant le processus de filtrage.Afin d'illustrer la pertinence de la méthode proposée, la partie expérimentale de la thèse est effectuée sur deux sites d'étude: Chamonix Mont-Blanc, France et le volcan Merapi, Indonésie, avec différents types de changements (i.e. évolution saisonnière, glaciers, éruption volcanique, etc.). Les observations de ces sites d'étude sont acquises sur quatre séries temporelles d'images SAR monocomposantes et multicomposantes de moyenne à haute et très haute résolution: des séries temporelles d'images Sentinel-1, ALOS-PALSAR, RADARSAT-2 et TerraSAR-X. / A large number of successfully launched and operated Synthetic Aperture Radar (SAR) satellites has regularly provided multitemporal SAR and polarimetric SAR (PolSAR) images with high and very high spatial resolution over immense areas of the Earth surface. SAR system is appropriate for monitoring tasks thanks to the advantage of operating in all-time and all-weather conditions. With multitemporal data, both spatial and temporal information can simultaneously be exploited to improve the results of researche works. Change detection of specific features within a certain time interval has to deal with a complex processing of SAR data and the so-called speckle which affects the backscattered signal as multiplicative noise.The aim of this thesis is to provide a methodology for simplifying the analysis of multitemporal SAR data. Such methodology can benefit from the advantages of repetitive SAR acquisitions and be able to process different kinds of SAR data (i.e. single, multipolarization SAR, etc.) for various applications. In this thesis, we first propose a general framework based on a spatio-temporal information matrix called emph{Change Detection Matrix} (CDM). This matrix contains temporal neighborhoods which are adaptive to changed and unchanged areas thanks to similarity cross tests. Then, the proposed method is used to perform three different tasks:1) multitemporal change detection with different kinds of changes, which allows the combination of multitemporal pair-wise change maps to improve the performance of change detection result;2) analysis of change dynamics in the observed area, which allows the investigation of temporal evolution of objects of interest;3) nonlocal temporal mean filtering of SAR/PolSAR image time series, which allows us to avoid smoothing change information in the time series during the filtering process.In order to illustrate the relevancy of the proposed method, the experimental works of the thesis is performed on four datasets over two test-sites: Chamonix Mont-Blanc, France and Merapi volcano, Indonesia, with different types of changes (i.e., seasonal evolution, glaciers, volcanic eruption, etc.). Observations of these test-sites are performed on four SAR images time series from single polarization to full polarization, from medium to high, very high spatial resolution: Sentinel-1, ALOS-PALSAR, RADARSAT-2 and TerraSAR-X time series.
48

Uso integrado de dados de sensoriamento remoto para o estudo da geologia e geomorfologia da área da foz rio Tapajós, Santarém, Pará

Sousa, Enilson da Silva 03 April 2009 (has links)
Made available in DSpace on 2015-04-22T21:58:36Z (GMT). No. of bitstreams: 1 Dissertacao Final Enilson.pdf: 11943140 bytes, checksum: a78a8a02c9bcb5f788febff73efa8524 (MD5) Previous issue date: 2009-04-03 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / The Amazon plain is an important and strategic region of the world for scientific-technological development of Brazil. The scientific research point of view it knows little of the geology and geography of the region. The use of satellite images can be regarded as an indispensable tool to boost progress in this direction. In this context, the main objective of this paper is to present the details of geomorphology and geology of the mouth of the Tapajós River, between the 2nd 20 S to 40 S 2nd and meridians of 54, 35 W to 55 05 W and make a temporal analysis of the depositional history of this complex river system, located in the city of Santarém, Pará, In general, the methodological approach implemented was characterized by intense literature review, steps pre image processing, lifting steps field, a more significant step processing and multi-temporal analysis of satellite images. The data used in this research include images from the Landsat series, orthorectified Landsat images obtained at the University of Maryland site, topographical data Radar interferometry Shuttle Radar Topography Mission (SRTM), and radar mosaic picture JERS-1 SAR. Treatment and digital processing of orbital images were performed in 10.1 and PCI Software Arc GIS (Arc Map 9.2). In the western part of Pará emerge few lithostratigraphic units of regional distribution, essentially these are representatives of the rocks of the land Alter do Chão formation of Meso-Cenozoic age, and younger sedimentary terrains of Cenozoic plain of the Amazon and Tapajos rivers, modern alluvial deposits and detrital-lateritic covers. Among these regional geomorphological units only two matters within the study area: the Amazon Plain and Plateau relegated from Amazon. The visual interpretation of the set of images generated in this study allowed to obtain more detailed information than those available regionally, including some physiographic features, geomorphological and geological study of the area. In this study it was possible the delineation and characterization of at least three (03) distinct geomorphological areas: the Amazon floodplain / Tapajós, the River Valley area Dissected Tapajós and the Tablelands Pediplanizados. The analysis of all the associated information directly to systematic field surveys enabled the recognition, individualization and characterization of three (03) distinct geological units: the study area dominate lithologies associated Alter do Chão Formation and deposits of unconsolidated Cenozoic sedimentary (old and new) and modern alluvium. There are also less common-materials associated with the lateritic deposits-coverages debris. The information field and the numerous geological caminhamentos and visited spots, allowed the organization and presentation of the general stratigraphy of the study area and the stratigraphic correlation between the various profiles of rocks belonging to Alter do Chão Formation. With regard to the results achieved in the multi-temporal analysis of Landsat images , aimed at establishing the depositional evolution ( accretion rate and erosion) of the study area , in the study period (1975 and 2007) and respecting the limitations presented it was possible to state the region of the Tapajos bar showed dominance of erosion (positive erosion rate ) , and on the other hand, the fluvial islands on the Amazon River show depositional process of growth ( accretion ). / A planície Amazônica é uma importante região do planeta e estratégica para o desenvolvimento científico-tecnológico do Brasil. Do ponto de vista da pesquisa científica se conhece pouco da geologia e geografia da região. A utilização de imagens de satélite pode ser considerada como ferramenta indispensável para dinamizar o avanço nesta direção. Neste contexto, o objetivo principal deste trabalho é de apresentar o detalhamento da geomorfologia e da geologia da foz do rio Tapajós, entre os 2º 20 S a 2º 40 S e os meridianos de 54º, 35 W a 55º 05 W e fazer uma análise temporal da história deposicional deste complexo sistema fluvial, localizado no município de Santarém-Pará, De um modo geral, a abordagem metodológica executada caracterizou-se por intensa revisão bibliográfica, etapas de pré processamento das imagens, etapas de levantamento de campo, uma etapa mais significativa de processamento e análise multitemporal das imagens de satélite. Os dados utilizados nesta pesquisa incluem imagens da série LANDSAT, imagens LANDSAT ortorretificadas obtidas no site da Universidade de Maryland, dados topográficos do radar interferométrico do Shuttle Radar Topography Mission (SRTM), além de imagens mosaico de radar do SAR JERS-1. O tratamento e processamento digital das imagens orbitais foram realizados no Software PCI 10.1 e Arc Gis (Arc Map 9.2). Na porção oeste do Estado do Pará afloram poucas unidades litoestratigráficas de distribuição regional, essencialmente trata-se de terrenos representantes das rochas da Formação Alter do Chão, de idade Meso-cenozóica, além de terrenos sedimentares mais jovens da planície Cenozóica dos rios Amazonas e Tapajós, depósitos aluvionares modernos e coberturas detrítico-lateríticas. Dentre estas unidades geomorfológicas regionais somente duas tem importância no âmbito da área de estudo: a Planície Amazônica e o Planalto Rebaixado da Amazônia. A interpretação visual do conjunto de imagens geradas neste estudo permitiu a obtenção de informações mais detalhadas que as disponíveis regionalmente, que incluem alguns aspectos fisiográficos, geomorfológicos e geológicos da área de estudo. Neste estudo foi possível a delimitação e caracterização de pelo menos três (03) domínios geomorfológicos distintos: o da Planície de Inundação Amazonas/Tapajós, o da Zona Dissecada do vale do rio Tapajós e dos Planaltos Pediplanizados. A análise do conjunto de informações associada diretamente aos sistemáticos levantamentos de campo realizados permitiram o reconhecimento, individualização e caracterização de três (03) unidades geológicas distintas: na área de estudo dominam litologias associadas Formação Alter do Chão e aos depósitos de sedimentares inconsolidados cenozóicos (antigos e recentes) e aluviões modernas. Não menos freqüentes encontram-se também materiais associados a depósitos de coberturas detrito-lateríticas. As informações de campo e os inúmeros caminhamentos geológicos e pontos visitados, permitiram a organização e apresentação da estratigrafia geral da área de estudo e a correlação estratigráfica entre os vários perfis das rochas pertencentes a Formação Alter do Chão. No que se refere aos resultados alcançados na análise multitemporal das imagens LANDSAT, visando o estabelecimento da evolução deposicional (taxa de acresção e erosão) da área de estudo, no intervalo de tempo estudado (1975 e 2007) e respeitando as limitações apresentadas foi possível afirmar que a região da barra do Tapajós apresentou dominância de processos erosivos (taxa de erosão positiva), e, por outro lado, as ilhas fluviais no rio Amazonas mostram processo de crescimento deposicional (acresção).
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Change Detection Using Multitemporal SAR Images

Yousif, Osama January 2013 (has links)
Multitemporal SAR images have been used successfully for the detection of different types of environmental changes. The detection of urban change using SAR images is complicated due to the special characteristics of SAR images—for example, the existence of speckle and the complex mixture of the urban environment. This thesis investigates the detection of urban changes using SAR images with the following specific objectives: (1) to investigate unsupervised change detection, (2) to investigate reduction of the speckle effect and (3) to investigate spatio-contextual change detection. Beijing and Shanghai, the largest cities in China, were selected as study areas. Multitemporal SAR images acquired by ERS-2 SAR (1998~1999) and Envisat ASAR (2008~2009) sensors were used to detect changes that have occurred in these cities. Unsupervised change detection using SAR images is investigated using the Kittler-Illingworth algorithm. The problem associated with the diversity of urban changes—namely, more than one typology of change—is addressed using the modified ratio operator. This operator clusters both positive and negative changes on one side of the change-image histogram. To model the statistics of the changed and the unchanged classes, four different probability density functions were tested. The analysis indicates that the quality of the resulting change map will strongly depends on the density model chosen. The analysis also suggests that use of a local adaptive filter (e.g., enhanced Lee) removes fine geometric details from the scene. Speckle suppression and geometric detail preservation in SAR-based change detection, are addressed using the nonlocal means (NLM) algorithm. In this algorithm, denoising is achieved through a weighted averaging process, in which the weights are a function of the similarity of small image patches defined around each pixel in the image. To decrease the computational complexity, the PCA technique is used to reduce the dimensionality of the neighbourhood feature vectors. Simple methods to estimate the dimensionality of the new space and the required noise variance are proposed. The experimental results show that the NLM algorithm outperformed traditional local adaptive filters (e.g., enhanced Lee) in eliminating the effect of speckle and in maintaining the geometric structures in the scene. The analysis also indicates that filtering the change variable instead of the individual SAR images is effective in terms of both the quality of the results and the time needed to carry out the computation. The third research focuses on the application of Markov random field (MRF) in change detection using SAR images. The MRF-based change detection algorithm shows limited capacity to simultaneously maintain fine geometric detail in urban areas and combat the effect of speckle noise. This problem has been addressed through the introduction of a global constraint on the pixels’ class labels. Based on NLM theory, a global probability model is developed. The iterated conditional mode (ICM) scheme for the optimization of the MAP-MRF criterion function is extended to include a step that forces the maximization of the global probability model. The experimental results show that the proposed algorithm is better at preserving the fine structural detail, effective in reducing the effect of speckle, less sensitive to the value of the contextual parameter, and less affected by the quality of the initial change map compared with traditional MRF-based change detection algorithm. / <p>QC 20130610</p>
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The Ecological Dynamics of a Coastal Lagoon: A Study of the Morphodynamics, Land Use Change, Community Participation, and Spatial Planning of the Segara Anakan Lagoon in Indonesia

Nandi, Nandi 04 February 2015 (has links)
A coastal lagoon is a landform that is influenced by natural processes and human activities. All human activities at the upstream, particularly agriculture and cultivation bring soil, waste, and other materials to the downstream area through the river drains into the lagoon. Even though its position is inland of water bodies, the lagoon is still affected by waves and winds from the sea. Additionally, coastal lagoon will be the depository place for sedimentation from the upland area. Segara Anakan (SA), which is located in Indonesia, is an example of a coastal lagoon area, which has a unique biophysical characteristic. The region has a great natural ability to ensure the sustainability of the interrelationships between terrestrial, estuarine and marine ecosystems in harmony and balance as a habitat for flora and fauna. The region is an area of migration of various types of protected animals and it is a place of breeding for diverse species of the shrimp and fish, which have a highly economical value. Segara Anakan lagoon (SAL), currently experiencing acceleration narrowed on its area due to a very intensive sedimentation from the mainland. The research aims to answer the question of how ecological dynamic occurs in the SAL area due to sedimentation. Achieving the objectives of this study required examining the morphology and land use changes with multitemporal remote sensing approaches. While, to assess the role of community participation and planning management strategies is using qualitative descriptive methods and SWOT analyze. The using of multitemporal remote sensing Landsat images is possible to analyze the morphological and land use changes with different time and sensors. These Landsat has image accuracy about 92.66%. It can be used for image interpretations resulting 13 classes of land use. The morphodynamics of SAL indicated by the changes of area of lagoon and accreted land and also the distance of coastlines during the periods 1979-2013. In addition, the land use or land cover also changes during that time. The bigger portions of land use changes are in the tropical and mangrove\''s forests. There are distinctive forms of participation in conservation efforts. The upstream community involvement in conservation tends to be different participating in the way of ideas, money, materials, properties, skills and expertise or social activities. In addition, the community at downstream area has a sufficiently high level of participation in environmental conservation. There are also strong relationships between the level of education and level of income and basic knowledge in conservation with the participation of SA conservation. The ecological dynamics of the SAL area are described with a historical time line. It is divided into three time periods: the 1970s - 1980s, the 1990s and from 2000 onwards. Each of these has occurrences that can lead to changes in the environment. The implementation of appropriate conservation technique can reduce the sedimentation rate. Hence, the synergic coordination measures between upstream and downstream regions are necessary in the future. Increasing community awareness and participation in the conservation by improving educational sector, providing information, and applying sustainable development land use are the ways to match human activities with the temporal and spatial dynamics of the coastal resources.

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