Wildfires across northern Australia are a growing problem with more than 2.5 million hectares being burnt each year. Accordingly, remote sensing has been used as a tool to routinely monitor and map fire histories. In northern Western Australia, the Department of Land Information Satellite Remote Sensing Services (DLI SRSS) has been responsible for providing and interpreting NOAA-AVHRR (National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer) data. SRSS staff utilise this data to automatically map hotspots on a daily basis, and manually map fire affected areas (FAA) every nine days. This information is then passed on to land managers to enhance their ability to manage the effects of fire and assess its impact over time. The aim of this study was to develop an algorithm for the near real-time automatic mapping of FAA in the Kimberley and Pilbara as an alternative to the currently used semimanual approach. Daily measures of temperature, surface reflectance and vegetation indices from twenty nine NOAA-16 (2001) passes were investigated. It was firstly necessary to apply atmospheric and BRDF corrections to the raw reflectance data to account for the variation caused by changing viewing and illumination geometry over a cycle. Findings from the four case studies indicate that case studies 1 and 2 exhibited a typical fire response (visible and near-infrared channels and vegetation indices decreased), whereas 3 and 4 displayed an atypical response (visible channel increased while the near-infrared channel and vegetation indices decreased). Alternative vegetation indices such as GEMI, GEMI3 and VI3 outperformed NDVI in some cases. Likewise atmospheric and BRDF corrected NDVI provided better performance in separating burnt and unburnt classes. The difficulties in quantifying FAA due to temporal and spatial variation result from numerous factors including vegetation type, fire intensity, rate of ash and charcoal dispersal due to wind and rain, background soil influence and rate of revegetation. In this study two different spectral responses were recorded, indicating the need to set at least two sets of thresholds in an automated or semi-automated classification algorithm. It also highlighted the necessity of atmospheric and BRDF corrections. It is therefore recommended that future research apply atmospheric and BRDF corrections at the pre-processing stage prior to analysis when utilising a temporal series of NOAAAVHRR data. Secondly, it is necessary to investigate additional FAA within the four biogeographic regions to enable thresholds to be set in order to develop an algorithm. This algorithm must take into account the variation in a fire’s spectral response which may result from fire intensity, vegetation type, background soil influence or climatic factors.

No description available.

No description available.

La pollution des eaux est une préoccupation majeure relayée par la Communauté Européenne. Cette problématique s'accentue avec les particules métalliques et l'émergence de produits nanostructurés tels les Nano-objets, leurs Agrégats et leurs Agglomérats (NOAA). Ces NOAA constituent un cas particulier de polluants du fait de leurs propriétés physicochimiques. La surveillance et le contrôle de ces polluants dans les eaux, nécessite le développement d'instruments de mesure aptes à répondre à ce fléau environnemental. Dans ce contexte, la technique de spectroscopie de plasma induit par laser ou Laser-Induced Breakdown Spectroscopy (LIBS) a été retenue à l'INERIS. Elle permet l'identification chimique élémentaire des polluants sous forme particulaire dans la matrice liquide et la détermination de leurs concentrations in-situ et en temps réel. Ce travail de thèse a permis d'optimiser l'analyse des suspensions par LIBS avec deux modes d'échantillonnage. La première partie de l'étude a porté sur le couplage LIBS avec un jet liquide et les limites de détection du titane ont été évaluées à 0.5 mg/L. Dans la deuxième partie, les suspensions ont été aérosolisées avec un nébuliseur et analysées par LIBS. Les résultats obtenus en comparant ces deux modes d'échantillonnage montrent que le jet liquide peut être avantageux pour l'analyse de particules dans les liquides. Cependant le mode aérosol présente un intérêt pratique à condition d'avoir un rendement d'aérosolisation supérieur à 50%. Au final, ce travail de thèse démontre l'applicabilité de la LIBS comme outil potentiel pour l'analyse in situ de particules dans les liquides telle que la surveillance et le contrôle des eaux usées / Water pollution is a major concern, as noted by the European Community. This problem is accentuated with metallic particles and the emergence of nanostructured products such as Nano-Objects, their Aggregates and their Agglomerates (NOAA). These are the special types of pollutants owing their physicochemical properties. The monitoring and control of these pollutants in water require the development of measurement instruments which are capable to anwer this environmental problem. In this context, the technique of Laser-Induced Breakdown Spectroscopy (LIBS) has been developed at INERIS. It not only allows the chemical identification of these particles pollutants present in liquids, but also the determination of their concentrations in situ and in real time. This thesis has optimized the analysis of suspensions by LIBS with two sampling modes. The first mode focused on coupling LIBS with a liquid jet in which the detection limits of titanium dioxide were estimated at 0.5 mg/L. In the second mode, the suspensions were aerosolized with a nebulizer and analyzed by LIBS. The results obtained by comparing these two sampling modes show that the liquid jet may be advantageous for the analysis of suspensions. However, the aerosol mode has a practical interest if it has an aerosolization efficiency of over 50%. Finally, this work demonstrates the applicability of LIBS as a potential tool for in situ particle analysis of suspensions such as monitoring and control of wastewater

Desenvolveu-se nesse trabalho uma metodologia para identificar e quantificar quinzenalmente a área queimada na região contínua do Cerrado brasileiro a partir de imagens diárias do sensor AVHRR (Advanced Very High Resolution Radiometer) do satélite NOAA-14 (National Oceanic and Atmospheric Administration), utilizando as bandas 1 (0.6 um), 2 (0,9 um), 3 (3.7 um) e IVDN (Índice de Vegetação de Diferença Normalizada). A variação temporal de características das áreas queimadas e outras superfícies, obtida de mosaicos quinzenais das imagens AVHRR, foi a base para elaborar um algoritmo de identificação de \"cicatrizes\" de queimadas. Os resultados foram validados e ajustados com dados de alta resolução espacial obtidos em imagens TM/Landsat (Thematic Mapper). A análise estatística de regressão linear entre os dados de queimadas obtidos pela aplicação do algoritmo nos mosaicos AVHRR e aqueles das imagens TM gerou duas equações para estimar a área queimada no Cerrado com r2 = 0,8 e 0,7. Com a aplicação da metodologia desenvolvida, estimou-se em ~429.000 km2 a área queimada (entre 404.000 km2 e 455.000 km2 com intervalo de confiança a 95%) no período de 01/maio/98 a 30/abril/99, correspondendo a 19% (18 a 20%) da área total estudada. A relação entre focos de queimadas obtidos do AVHRR/NOAA-12 e área queimada permitiu cálculos preliminares de área queimada no Cerrado no período de 01/maio/99 a 31/outubro/00. Os dados TM mostraram que as queimadas pequenas, menores que 0,5 km2, embora muito numerosas (53% do total), respondem por apenas ~2 % da área queimada. Por outro lado, as queimadas grandes, maiores que 10 km2, são poucas (8%), mas responsáveis por cerca de 74% da área queimada no Cerrado. Os resultados desse trabalho mostraram pela primeira vez que é possível estimar regularmente a área queimada no Cerrado com erro inferior a 15% no cálculo anual a partir dos dados diários do AVHRR. Tais estimativas poderão subsidiar estudos sobre o papel ecológico do fogo no Cerrado, planejamento ambiental em nível regional, localização das áreas críticas com ocorrências mais freqüentes de queimadas, implantação de planos de uso, manejo e fiscalização do uso do fogo em escala regional, cálculos de emissões de queimadas, etc. / This work presents the development of a methodology to identify and quantify the surface burnt in the Brazilian contiguous Cerrado on a bi-weekly basis using daily images of the AVHRR (Advanced Very High resolution Radiometer) sensor on-board the NOAA-14 (National Oceanographic and Atmospheric Administration) satellite after its bands 1 (0,6 um), 2 (0,9 um) and 3 (3,7 um), as well as the NDVI (Normalized Difference Vegetation Index). The temporal variation of the burnt areas and of other surface covers in bi-weekly AVHRR mosaics was the basis for an algorithm to identify the \"scars\" from vegetation fires. The results were validated and adjusted with high resolution data from TM-Landsat (Thematic Mapper). The statistical analysis of linear regression between the fire data obtained with the use of the algorithm and those of the TM produced two equations to estimate burnt area in the Cerrado, with r2 = 0.8 and 0.7. Applying the methodology developed, ~429,000 km2 burned in the period of May/01/98 to April/04/99 (range of 404,000 to 455,000 km2 for the 95% confidence interval), corresponding to 19% (18 to 20 %) of the total study area. The relation between active fires obtained with AVHRR/NOAA-12 and the burnt area supplied preliminary estimates of burnt area in the Cerrado from May/01/99 to Oct/31/00. The TM data showed that small scars, with less than 0.5 km2, although numerous (53 % of the total), account for just ~2 % of the burnt area. Large scars, with more than 10 km2, correspond to a small number (8 %), but to 74 % of the Cerrado burnt area. The results of this work showed for the first time that it is possible to estimate on a regular basis the Cerrado yearly burnt area with an error smaller than 15 %, using daily AVHRR data. These estimates should provide important information to understand the ecological role of fire in the Cerrado, identify areas with higher fire frequency, help environmental planning at regional levels, and plan soil use and control, as well as provide subsidies in biomass burning emission studies. Data from new sensors in satellites to be made available in 2001 should improve even further the methodology developed.

Desenvolveu-se nesse trabalho uma metodologia para identificar e quantificar quinzenalmente a área queimada na região contínua do Cerrado brasileiro a partir de imagens diárias do sensor AVHRR (Advanced Very High Resolution Radiometer) do satélite NOAA-14 (National Oceanic and Atmospheric Administration), utilizando as bandas 1 (0.6 um), 2 (0,9 um), 3 (3.7 um) e IVDN (Índice de Vegetação de Diferença Normalizada). A variação temporal de características das áreas queimadas e outras superfícies, obtida de mosaicos quinzenais das imagens AVHRR, foi a base para elaborar um algoritmo de identificação de \"cicatrizes\" de queimadas. Os resultados foram validados e ajustados com dados de alta resolução espacial obtidos em imagens TM/Landsat (Thematic Mapper). A análise estatística de regressão linear entre os dados de queimadas obtidos pela aplicação do algoritmo nos mosaicos AVHRR e aqueles das imagens TM gerou duas equações para estimar a área queimada no Cerrado com r2 = 0,8 e 0,7. Com a aplicação da metodologia desenvolvida, estimou-se em ~429.000 km2 a área queimada (entre 404.000 km2 e 455.000 km2 com intervalo de confiança a 95%) no período de 01/maio/98 a 30/abril/99, correspondendo a 19% (18 a 20%) da área total estudada. A relação entre focos de queimadas obtidos do AVHRR/NOAA-12 e área queimada permitiu cálculos preliminares de área queimada no Cerrado no período de 01/maio/99 a 31/outubro/00. Os dados TM mostraram que as queimadas pequenas, menores que 0,5 km2, embora muito numerosas (53% do total), respondem por apenas ~2 % da área queimada. Por outro lado, as queimadas grandes, maiores que 10 km2, são poucas (8%), mas responsáveis por cerca de 74% da área queimada no Cerrado. Os resultados desse trabalho mostraram pela primeira vez que é possível estimar regularmente a área queimada no Cerrado com erro inferior a 15% no cálculo anual a partir dos dados diários do AVHRR. Tais estimativas poderão subsidiar estudos sobre o papel ecológico do fogo no Cerrado, planejamento ambiental em nível regional, localização das áreas críticas com ocorrências mais freqüentes de queimadas, implantação de planos de uso, manejo e fiscalização do uso do fogo em escala regional, cálculos de emissões de queimadas, etc. / This work presents the development of a methodology to identify and quantify the surface burnt in the Brazilian contiguous Cerrado on a bi-weekly basis using daily images of the AVHRR (Advanced Very High resolution Radiometer) sensor on-board the NOAA-14 (National Oceanographic and Atmospheric Administration) satellite after its bands 1 (0,6 um), 2 (0,9 um) and 3 (3,7 um), as well as the NDVI (Normalized Difference Vegetation Index). The temporal variation of the burnt areas and of other surface covers in bi-weekly AVHRR mosaics was the basis for an algorithm to identify the \"scars\" from vegetation fires. The results were validated and adjusted with high resolution data from TM-Landsat (Thematic Mapper). The statistical analysis of linear regression between the fire data obtained with the use of the algorithm and those of the TM produced two equations to estimate burnt area in the Cerrado, with r2 = 0.8 and 0.7. Applying the methodology developed, ~429,000 km2 burned in the period of May/01/98 to April/04/99 (range of 404,000 to 455,000 km2 for the 95% confidence interval), corresponding to 19% (18 to 20 %) of the total study area. The relation between active fires obtained with AVHRR/NOAA-12 and the burnt area supplied preliminary estimates of burnt area in the Cerrado from May/01/99 to Oct/31/00. The TM data showed that small scars, with less than 0.5 km2, although numerous (53 % of the total), account for just ~2 % of the burnt area. Large scars, with more than 10 km2, correspond to a small number (8 %), but to 74 % of the Cerrado burnt area. The results of this work showed for the first time that it is possible to estimate on a regular basis the Cerrado yearly burnt area with an error smaller than 15 %, using daily AVHRR data. These estimates should provide important information to understand the ecological role of fire in the Cerrado, identify areas with higher fire frequency, help environmental planning at regional levels, and plan soil use and control, as well as provide subsidies in biomass burning emission studies. Data from new sensors in satellites to be made available in 2001 should improve even further the methodology developed.

The role of remote sensing data for monitoring different parameters in the study of ecosystems has been increasing. Particularly the development of different indices has played a great role to study the properties of vegetation and vegetation dynamics in large countries. In addition to this, satellite rainfall estimate data has been used to study the pattern of precipitation in areas where station rain-gauge data is not available. The Normalized Difference Vegetation Index (NDVI) and rainfall estimates data from the National Oceanic and Atmospheric Administration (NOAA) satellites were used to investigate the spatio-tempotal pattern of precipitation and the response of vegetation to precipitation in Ethiopia from 1996 to 2008. The patterns were studied in different land cover classes using data from the Global Land Cover Network (GLCN). The spatial patternof NDVI and precipitation showed that vegetation responded directly to precipitation. The seasonal patterns showed that there was between 0 to 3 months lag between precipitationand vegetation. However it was not possible to draw conclusion regarding the annual trendsof precipitation and NDVI because of the nature of the NDVI data, which was produced using the 10 day maximum composite values.

Made available in DSpace on 2016-06-02T19:29:43Z (GMT). No. of bitstreams: 1 TeseACP.pdf: 5193455 bytes, checksum: 5bc13e84b2705d44928f3d7b974a269a (MD5) Previous issue date: 2002-11-14 / Universidade Federal de Sao Carlos / At the present, the Cerrado (a type of the Brazilian savannas) is burned on about 20 to 30% of its area during the dry season mainly owing to anthropic causes. Three simultaneous factors are needed for the burnings to happen: favourable meteorological conditions; availability of vegetation fuel; existence of an ignition source. This work studied the susceptibility of the Cerrado vegetation to fire with respect to parameters linked to the three factors: rainfall, relative air humidity and air temperature with respect to the meteorological conditions; vegetation coverage classes with respect to the biomass fuel; proximity to the roads and fire spots from previous days with respect to the ignition source. Location data for the fire spots obtained from the AVHRR/NOAA-12 channel 3 (3,7 mm) images were used as field truth. The study period was between May and October 1998. The study area was divided into 50 km x 50 km cells. The meteorological conditions occurring in 95% of the cells presents fire spots were: rainfall lower than 2 mm; 5-day cumulative precipitation lower than 25 mm; relative air humidity lower than 60%; air temperature higher than 28oC; more than one rainless day before the burning. More than 80% of the Cerrado were susceptible to the fire occurrence, with both locations with and without fire spots presented the minimum meteorological conditions favourable to the vegetation burning described in the literature: rainfall lower than 5 mm; 5-day cumulative precipitation lower than 20 mm; relative air humidity lower than 60%; air temperature higher than 25oC; A method for classifying the Cerrado vegetation coverage to fire susceptibility was also developed. This method was based on 2-weekly mosaics of the AVHRR/NOAA-14 Normalized Difference Vegetation Index (NDVI) and of the channel 3 images. Seven classes of vegetation coverage were discriminated and associated to four degrees of susceptibility: very low, low, medium and high. It was verified that 72% of the burning occurred in the high and medium susceptibility classes, which indicated satisfactory results on the preliminary development of this method. Lastly, the distance between the fire spots and two indicators of anthropic activity was analysed. The indicators were: roads and fire spots previously occurred. About a quarter of the fire spots occurred at up to 10 km from the roads in a area of 582,000 km2 surrounding the roads, which is about 27% of the Cerrado´s total area. On the same way, a quarter of the spots occurred at up to 10 km from the fire spots of the previous day, in an average area of 33,000 km2 at the burning spots surroundings. This area is about 2% of the total area of the Cerrado. In conclusion, the indicators of anthropic activity analysed here area good tools for studying the vegetation susceptibility to fire. / Anualmente, o Cerrado é queimado em 20 a 30% de sua área durante a estação seca, principalmente devido a causas antrópicas. Três fatores simultâneos são necessários para que as queimadas ocorram: condições meteorológicas propícias; disponibilidade de combustível vegetal; existência de fonte de ignição. Este trabalho estudou a susceptibilidade da vegetação do Cerrado ao fogo em relação a parâmetros desses três fatores: precipitação, umidade relativa e temperatura do ar, em relação às condições meteorológicas; classes de cobertura vegetal, em relação ao combustível vegetal; proximidade de malha viária e de focos de queimadas dos dias anteriores, em relação à fonte de ignição. Como verdade de campo foram utilizados os dados de localização dos focos de queimadas obtidos de imagens do canal 3 (3,7 mm) do Advanced Very High Resolution Radiometer / National Oceanic and Atmospheric Administration - 12 (AVHRR/NOAA-12). O período de estudo foi de maio a outubro/1998. A área de estudo foi dividida em células de 50 km por 50 km. As condições meteorológicas em 95% das células com queimadas foram: precipitação inferior a 2 mm; precipitação acumulada de 5 dias inferior a 25 mm; umidade relativa do ar inferior a 60%; temperatura do ar superior a 28oC; mais de um dia sem chuva antecedendo a queimada. Mais de 80% do Cerrado estavam susceptível a ocorrência de fogo, com os locais com e sem focos de queimadas apresentando as condições meteorológicas mínimas propícias à combustão da vegetação relatadas na literatura: precipitação inferior a 5 mm; precipitação acumulada de 5 dias inferior a 20 mm; umidade relativa do ar inferior a 60%; temperatura do ar superior a 25oC. Um método para classificar a cobertura vegetal do Cerrado quanto à susceptibilidade ao fogo também foi desenvolvido, baseado em mosaicos quinzenais do Índice de Vegetação por Diferença Normalizada (IVDN) e do canal 3 gerados com base em imagens AVHRR/NOAA-14. Sete classes de cobertura vegetal foram discriminadas, as quais foram associadas a quatro graus de susceptibilidade: muito baixo, baixo, médio e alto. Foi verificado que 72% dos focos de queimadas ocorreram nas classes de susceptibilidade alta e média, indicando resultados satisfatórios no desenvolvimento preliminar desse método. Por último, foi analisada a distância entre focos de queimadas e dois indicadores de atividade antrópica: malha viária e focos de queimadas recentemente ocorridos. Cerca de um quarto dos focos de queimadas ocorreram até 10 km da malha viária, em uma área ao longo das vias de 582 mil km2, cerca de 27% da área total do Cerrado. Do mesmo modo, um quarto dos focos ocorreu até 10 km dos focos de queimadas ocorridos no dia anterior, em uma área média no entorno dos focos de 33 mil km2, cerca de 2% do Cerrado. Portanto, a proximidade de indicadores de atividade antrópicas pode ser um bom instrumento para avaliação da susceptibilidade da vegetação ao fogo.

The earth was shown in the last century to have a surface layer composed of large plates. Plate tectonics is the study of the movement and stresses in the individual plates that make up the complete surface of the world's sphere. Two types of earthquakes are observed in the surface plates, interplate and intraplate earthquakes, which are classified, based on the location of the origin of an earthquake either between two plates or within the plate respectively. Limited work has been completed on the definition of the boundary region between the plates from which interplate earthquakes originate, other than the recent work on the Mid Atlantic Ridge, defined at two degrees and the subsequent work to look at the applicability of this degree based definition. Others suggested an alternative view of a constant width for the interplate region in recent work at Texas A&M University. The objective of the paper is to determine whether the assumption of a linear width of the region along the tectonic plate boundaries to classify earthquakes as interplate and intraplate earthquakes using accepted statistical criteria provides a better fit to the data than the constant degree definition. There are three types of interplate boundaries defined by the relative movement of the two plates to each other, which further complicates this study. The study used a nonrandom analysis of regions of the different types of boundary to compare the rate and decay of the intraplate earthquakes from a notional centerline for the known boundaries. The study used GIS software and EXCEL for the statistical analysis component of the research work. The results show that a constant width definition provides a number of advantages in determining the relative definition of interplate and intraplate earthquakes when compared to the constant degree definition developed for work on the Mid Atlantic Ridge. Further research is suggested on a randomly selected set of study sites to improve the reliability and quality of the statistical work for each type of the boundary of the tectonic plates.

Orientador: Hilton Silveira Pinto / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-06T03:42:16Z (GMT). No. of bitstreams: 1 Almeida_CarlosAlbertoSoaresde_D.pdf: 685356 bytes, checksum: 3eb22116a96bd0f7b5643e5620f19c26 (MD5) Previous issue date: 2001 / Resumo: Foram utilizadas séries de imagens diurnas e noturnas captadas pelos sensores AVHRR a bordo do satélite NOAA-14 para a obtenção dos valores finais de temperatura de superfície do dossel vegetativo. O processamento das imagens incluiu o geo-referenciamento e as correções quanto aos efeitos atmosféricos e de emissividade, para as quais se utilizou o método de correção split window. A equação de split window usada considerou o parâmetro de emissividade da superfície cultivada estimada diretamente no campo pelo método da caixa. Este método foi comparado a um método alternativo de estimativa de emissividade no campo baseado na proporção de cobertura vegetal e solo descoberto. Os dois métodos apresentaram resultados equivalentes quanto à estimativa de emissividade da superfície. A alta correlação entre a temperatura de superfície medida no campo e a obtida a partir das imagens indicou que as equações de split window usadas corrigiram satisfatoriamente as imagens quanto aos efeitos atmosféricos e de emissividade / Abstract: Diurnal and nocturnal image series have been used in this work. These images were processed on suitable software to the treatment of NOAA-AVHRR products, for Surface temperature final value obtaining. The processing work includes both the images geo-referencing and their atmospheric correction applying the "split window method". The split window equation used takes into account the crop surface emissivity parameter, estimated directly on the field by the "box method". This one was compared to an alternative emissivity estimate on the field method, which is based on the crop covering/bared soil relation. Both methods when compared presented similar results. A terrestrial radiometer was used to the surface temperature measurements carried out in situ, during the satellite passes. The correct surface temperature satellite data were submitted to a regression analysis against the terrestrial data about the same parameter. High association level between surface temperature measured at the field and the near air temperature was observed. The high correlation between surface temperature measured at the field and that one from the images shown that the split window equation corrected satisfactorily the atmosphere effects over the images / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola