133 research outputs found
La pensée disciplinaire à la Socìetas Raffaello Sanzio : le choix de l’exclusion
L’histoire du théâtre est une histoire d’exclusion. L’élément qui unit à jamais certains réformateurs du théâtre du XVIIIe siècle — appelés à limiter l’ingérence des désordres qui accompagnaient les séances des spectacles — et des artistes contemporains qui souhaitent s’opposer aux pratiques bourgeoises du théâtre, est ce que nous avons appelé la pensée disciplinaire. Cette figure de pensée se situe aux croisements entre les écritures de la pratique et les écritures de la théorie lors de la naissance d’une nouvelle esthétique. Or, que l’esthétique en question ait comme but la recherche d’une intégration sociale ou, au contraire, un travail de rupture avec les codes en vigueur, elle s’accompagne toujours d’un nouveau système de contraintes, d’un nouvel ordre, paradoxalement demandeur d’une nouvelle exclusion. L’aperçu historique que nous proposons autour de la notion de pensée disciplinaire touchera à des interrogations fondamentales : le vertige de l’aliénation et ses monstres, les tensions entre texte et matière, la relation entre art et culpabilité, la crainte de la punition liée à l’exposition publique qui sont autant de lieux de la pensée et de la pratique artistique qu’on retrouvera aussi bien au XVIIIe siècle que dans le travail de redéfinition de l’art théâtral de la Socìetas Raffaello Sanzio, au XXe siècle.The history of theatre is one of exclusion. What we have designated here as disciplinary thought is that which unites certain theatre reformers of the 18th century called to limit the intrusion of disorders which accompanied representations and contemporary artists who wished to oppose bourgeois practices of theatre. This thought figure is found at the crossroads between practical and theoretical writings when a new aesthetic is born. That this aesthetic aims at social acceptability or on the contrary to break away from existing codes, it is always accompanied by a new system of constraints—a new order—that is paradoxically in need of new exclusions. The historical overview that we propose around the notion of disciplinary thought will concern itself with fundamental interrogations—the vertigo of alienations and its monsters, the tensions between text and matter, the relationship between art and culpability, the fear of punishment in regards to public exposure: all places of thought and artistic practices which we find during the 18th century but also, during the 20th century, in Socìetas Raffaello Sanzio's efforts in redefining theatre
Detecção de cicatrizes de incêndios florestais utilizando a técnica de análise por vetor de mudança na terra indígena sete de setembro - Rondônia Forest fire scars detection using change-vector analysis in the sete de setembro indigenous land Rondonia
A Terra Indígena Sete de Setembro (TISS) localiza-se no arco do desmatamento, caracterizada por ser uma região de grande pressão antrópica. Esta condição a torna susceptível às ameaças da degradação florestal por incêndios, exploração madeireira ilegal e corte raso para uso agropecuário. Assim, esse estudo teve por finalidade mapear áreas de floresta afetadas pela ação do fogo no período de 2010 a 2011, utilizando imagens TM/Landsat e a técnica de detecção por análise de vetor de mudança. Os resultados mostraram uma área total de 4.187 hectares de florestas afetadas pelo fogo no interior da TISS, correspondendo a cerca de 1,7 % da área total da terra indígena. O monitoramento de terras indígenas por técnicas de sensoriamento remoto é fundamental para avaliar a vulnerabilidade dessas áreas às pressões humanas.Abstract The Sete de Setembro Indigenous Land is situated in Brazil’s “arc of deforestation,” which is a region characterized by high anthropic pressure. This makes the reserve susceptible to forest degradation by fires, illegal logging and clearcutting for agriculture and ranching. The purpose of the present study was to map forest areas affected by fire from 2010 to 2011 using TM/Landsat images and the changevector analysis detection technique. The results showed a total area of 4187 hectares of forest affected by fire in the indigenous reserve, or about 1.7% of the total reserve area. Monitoring of indigenous lands by remote sensing techniques is essential in order to evaluate the vulnerability of these areas to pressures from human activities
Detecção de corte seletivo de madeira por técnica de rotação radiométrica na floresta amazônica / Detecting selective logging using radiometric rotation techniques in the amazon forest
Este estudo teve por objetivo desenvolver uma metodologia para detectara exploração seletiva de madeira na Amazônia. Para alcançar este objetivoutilizou-se a técnica de detecção de mudanças baseada na rotaçãoradiométrica controlada por eixo de não mudança (RCEN) acoplada a umclassifi cador temático probabilístico. Esta técnica tem como vantagem dispensar a necessidade de correções radiométricas prévias para asimagens analisadas. Os resultados encontrados revelam que as áreas de florestas afetadas pela extração madeireira ultrapassaram a extensão das áreas de fl orestas convertidas para fi ns agrícolas na região de Cláudia, Mato Grosso. O desempenho do mapeamento da atividade madeireira foi satisfatório, apresentando um Kappa condicional de 0,72. Esforços futuros para o aprimoramento de um sistema operacional automatizado utilizando esta técnica serão envidado
Detecção de corte seletivo de madeira por técnica de rotação radiométrica na floresta amazônicaDetecting selective logging using radiometric rotation techniques in the amazon forest
Este estudo teve por objetivo desenvolver uma metodologia para detectar a exploração seletiva de madeira na Amazônia. Para alcançar este objetivo utilizou-se a técnica de detecção de mudanças baseada na rotação radiométrica controlada por eixo de não mudança (RCEN) acoplada a um classificador temático probabilístico. Esta técnica tem como vantagem dispensar a necessidade de correções radiométricas prévias para as imagens analisadas. Os resultados encontrados revelam que as áreas de florestas afetadas pela extração madeireira ultrapassaram a extensão das áreas de florestas convertidas para fins agrícolas na região de Claudia, Mato Grosso. O desempenho do mapeamento da atividade madeireira foi satisfatório, apresentando um Kappa condicional de 0,72. Esforços futuros para o aprimoramento de um sistema operacional automatizado utilizando esta técnica serão envidados.Abstract The purpose of this study was to develop a methodology for detecting selective logging in the Amazon. To achieve this objective we used a change detection technique based on radiometric rotation controlled by the no-change axis (RCEN) coupled with a probabilistic thematic classifier. The advantage of this technique that is dispenses with radiometric corrections prior to the images analysis. The results show that Claudia, in the state of Mato Grosso. The performance of the method of mapping for logging activity was satisfactory, with a conditional Kappa value of 0.72. Future efforts to develop a system for automated operational detection using this technique will be undertaken
Efeito da topografia na resposta polarimétrica de floresta tropical em imagens PALSAR/ALOS Effect of topography on the polarimetric response of tropical forest in PALSAR / ALOS
A dependência do coeficiente de retroespalhamento (σ°) para diferentes alvos florestais não tem sido investigada quanto às variações topográficas, conforme se observa na literatura. Assim, o objetivo desse estudo é avaliar o efeito da topografia sobre o retroespalhamento derivado de áreas de floresta tropical em imagens PALSAR/ALOS (banda L). Para tal, foi realizada uma análise das respostas polarimétricas de áreas florestais, parcelas situadas em relevo plano, ondulado e fortemente ondulado. As respostas polarimétricas revelaram comportamento característico do efeito da topografia sobre o sinal do radar através da altura do pedestal, que indica a intensidade da despolarização da onda incidente. Observouse uma maior frequência de ocorrência e de intensidade da despolarização nas parcelas de terrenos ondulados a forte ondulado, com acentuada despolarização como comportamentos típicos nesta última condição.Abstract The dependence of backscatter coefficient (σ°) on different targets forest has not bee deeply investigated as affected by topographic variations, as seen in the literature. The objective of this study is to evaluate the effect of topography on backscatter derived from rainforest areas in PALSAR / ALOS (L-band) images. An analysis of the polarimetric responses of forest plots located in flat, gentle and undulated terrain was performed. The polarimetric responses showed a typical behavior of the topography effect on the radar signal through the height of the pedestal, which indicates the intensity of depolarization of the incident wave. There was a higher frequency of occurrence and intensity of depolarization in the plots on gentle and undulated terrains, with a marked depolarization as a typical pattern for the last condition
Suscetibilidade da vegetação ao fogo no sul do amazonas sob condições meteorológicas atípicas durante a seca de 2005
Weather conditions play an important role in the behavior of fires both in agricultural and pasture management and in forest wildfires in Amazonia. In severe drought years, the fires used for the management of land can escape from human control and burn large areas of vegetation. Meteorological parameters and hotspot locations were used to evaluate the susceptibility of the vegetation to fire in the southern portion of the state of Amazonas in a year without drought (2004) and a year with severe drought (2005). The number of cells susceptible to fire was 84% higher in 2005 (72%) compared with 2004 (39%). In 2005, the number of cells with hotspots increased by 66% and the number of hotspots by 121%. In 2004, 65% of the hotspots occurred in locations with 40 and 90 mm precipitation, 96% with an average temperature of 26 to 28 º C, and 89% with less than 65% humidity. In 2005, 83% of the hotspots occurred when rainfall was less than 70 mm, 96% with average temperature between 24 and 28 º C and 99% with air humidity below 65%. The meteorological parameters differed between years but not between areas with and without hotspots (PC1 = 84%). There was a higher amplitude variation in these meteorological parameters in the severe drought year, providing hotter and drier weather, thus increasing the susceptibility of vegetation to fire. © 2015, Sociedade Brasileira de Meteorologia. All rights reserved
Carbon stocks and losses to deforestation in protected areas in Brazilian Amazonia
By 2014 approximately 2.2 million km2 (~43%) of Brazil’s Legal Amazonia region had been incorporated into an extensive network of 718 protected areas, which are comprised by 372 indigenous lands, 313 federal, state and municipal (county) conservation units, and 33 Maroon territories (Quilombos). Although protected areas occupy vast expanses in Amazonia, their importance as carbon reserves needs to be better understood. In this study, we estimate the total carbon in 2014 held in protected areas in Brazil’s “Legal Amazonia” and “Amazonia biome” regions, and the carbon loss in the portions of these protected areas that were cleared by 2014. In 2014, a total of 33.4 Pg C or 57.0% of all carbon stored in Legal Amazonia was held in protected areas and 32.7 Pg C or 58.5% of all the carbon stored in the Amazonia biome was held in protected areas. By 2014, carbon lost due to clearing in protected areas in Legal Amazonia and the Amazonia biome totaled, respectively, 0.787 (or 2.3%) and 0.702 (or 2.1%) Pg C if one assumes that previously each protected area was entirely covered by native vegetation. If the protection of these areas is effective, about half of the carbon in Brazilian Amazonia will be maintained. Carbon in protected areas has strategic value for environmental conservation and for mitigation of climate change because these areas are under lower risk of being emitted to the atmosphere than carbon stored in vegetation located outside of protected areas, although the effectiveness of protected areas varies. © 2017, The Author(s)
Land use/land cover characterization in Amazonia using COSMO-SkyMed multitemporal images
The use of radar imagery is an alternative source of information to support the monitoring of the Amazon region, since the optical images have imaging limitations in tropical areas due to the occurrence of clouds. Therefore, the goal of this study is to analyze the radar images in X-band multi-temporal polarized obtained by COSMO-SkyMed satellite (COnstellation of small Satellites for Mediterranean basin Observation), in the intensity mode, isolated and/or combined with textural information, to thematic characterization of land use/land cover in the Humaitá, Amazonas State region. The methodology used includes: analysis of the dual images obtained during two subsequent acquisitions, in order to explore the potential of the dataset as a quad-pol intensity; extraction of textural attributes from the co-occurrence matrix (Gray Level Co-occurrence Matrix) and subsequent contextual classification; statistical assessment of the thematic performance of the intensity and textural images, isolated and in polarized groups. Within the results achieved, the group formed only by the intensity images presented a better performance if compared to those containing the textural attributes. In this discrimination, the classes involved were forest, alluvial forest, reforestation, savannah, pasture and burned areas, yielding 66% overall accuracy and a Kappa value of 0.55. The results showed that X band images, from COSMO-SkyMed, StripMap mode (Ping-Pong), multi-polarized, presents a moderate potential to characterize and monitor the dynamics of land use/land land cover in the Brazilian Amazon.A utilização de imagens de radar é fonte alternativa de informações para subsidiar o monitoramento da região amazônica, visto que as imagens ópticas têm limitações de imageamento em zonas tropicais face a ocorrência de nuvens. Por conseguinte este trabalho teve como objetivo analisar a capacidade das imagens-radar de banda X multitemporais e polarizadas obtidas pelo satélite COSMO-SkyMed (COnstellation of small Satellites for Mediterranean basin Observation), no modo intensidade, isoladamente e agregados às informações texturais, na caracterização temática de uso e cobertura da terra no município de Humaitá/AM. A metodologia empregada consistiu daanálise das imagens duais obtidas em duas aquisições subsequentes, de forma a explorar a potencialidade do conjunto de dados na forma quad-pol intensidade; extração dos atributos texturais a partir da matriz de coocorrência (Gray Level Co-occurrence Matrix) e posterior classificação contextual; avaliação estatística de desempenho temático das imagens intensidade e texturais, isoladas e em grupos polarizados. Dentre os vários resultados alcançados, foi verificado que o grupo formado somente pelas imagens intensidade apresentou o melhor desempenho, comparado àqueles contendo os atributos texturais. Nesta separabilidade, estavam envolvidas as classes de floresta, floresta aluvial, reflorestamento, savana, pasto e queimada, obtendo-se 66% de acurácia total e valor Kappa de 0,55. Os resultados mostraram que as imagens de banda X do COSMO-SkyMed, modo StripMap (Ping-Pong), multipolarizadas, têm potencial moderado para a caracterização e monitoramento da dinâmica de uso e cobertura da terra na Amazônia brasileira
Estimating aboveground biomass in tropical forests: Field methods and error analysis for the calibration of remote sensing observations
Mapping and monitoring of forest carbon stocks across large areas in the tropics will necessarily rely on remote sensing approaches, which in turn depend on field estimates of biomass for calibration and validation purposes. Here, we used field plot data collected in a tropical moist forest in the central Amazon to gain a better understanding of the uncertainty associated with plot-level biomass estimates obtained specifically for the calibration of remote sensing measurements. In addition to accounting for sources of error that would be normally expected in conventional biomass estimates (e.g., measurement and allometric errors), we examined two sources of uncertainty that are specific to the calibration process and should be taken into account in most remote sensing studies: the error resulting from spatial disagreement between field and remote sensing measurements (i.e., co-location error), and the error introduced when accounting for temporal differences in data acquisition. We found that the overall uncertainty in the field biomass was typically 25% for both secondary and primary forests, but ranged from 16 to 53%. Co-location and temporal errors accounted for a large fraction of the total variance (<65%) and were identified as important targets for reducing uncertainty in studies relating tropical forest biomass to remotely sensed data. Although measurement and allometric errors were relatively unimportant when considered alone, combined they accounted for roughly 30% of the total variance on average and should not be ignored. Our results suggest that a thorough understanding of the sources of error associated with field-measured plot-level biomass estimates in tropical forests is critical to determine confidence in remote sensing estimates of carbon stocks and fluxes, and to develop strategies for reducing the overall uncertainty of remote sensing approaches. © 2017 by the authors; licensee MDPI, Basel, Switzerland
Biomass estimation in a tropical wet forest using Fourier transforms of profiles from lidar or interferometric SAR
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