Dissertations / Theses on the topic 'Fine weather'

This dissertation investigates the impact of 2000-2050 climate change on fine particulate matter \((PM_{2.5})\) air quality. We first applied a multiple linear regression model to study the correlations of total \(PM_{2.5}\) and its components with meteorological variables using the past decadal \(PM_{2.5}\) observations over the contiguous US. We find that daily variation in meteorology can explain up to 50% of \(PM_{2.5}\) variability. Temperature is positively correlated with sulfate and organic carbon (OC) almost everywhere. The correlation of nitrate with temperature is negative in the Southeast but positive in California and the Great Plains. Relative humidity (RH) is positively correlated with sulfate and nitrate, but negatively with OC. Precipitation is strongly negatively correlated with all \(PM_{2.5}\) components. We then compared the observed correlations of \(PM_{2.5}\) with meteorological variables with results from the GEOS-Chem chemical transport model. The results indicate that most of the correlations of \(PM_{2.5}\) with temperature and RH do not arise from direct dependence but from covariation with synoptic transport. We applied principal component analysis and regression to identify the dominant meteorological modes controlling \(PM_{2.5}\) variability, and showed that 20-40% of the observed \(PM_{2.5}\) daily variability can be explained by a single dominant meteorological mode: cold frontal passages in the eastern US and maritime inflow in the West. From 1999-2010 observations we further showed that interannual variability of annual mean \(PM_{2.5}\) in most of the US is strongly correlated with the synoptic period T of the dominant meteorological mode as diagnosed from a spectral-autoregressive analysis. We then used the observed local \(PM_{2.5}\)-to-period sensitivity to project \(PM_{2.5}\) changes from the 2000-2050 changes in T simulated by fifteen IPCC AR4 GCMs following the SRES A1B scenario. We project a likely increase of \(\sim 0.1 \mu g m^{-3}\) in annual mean \(PM_{2.5}\) in the eastern US arising from less frequent frontal ventilation, and a likely decrease of \(\sim 0.3 \mu g m^{-3}\) in the northwestern US due to more frequent maritime inflows. These circulation-driven changes are relatively small, representing only a minor climate penalty or benefit for \(PM_{2.5}\) regulatory purpose.
Engineering and Applied Sciences

Urban wet weather discharge impairs the receiving water and sediment quality. Among other factors, particulate matter plays a role. It increases the suspended sediment load of the receiving water and may thus enhance the clogging of the bed sediment which serves as an important river habitat. This thesis investigates how much urban areas may contribute to the fine sediment and associated element load which is retarded by the bed sediment. It is based on an extensive field study. The study area was the Bode River, a mid-sized stream in Central Germany. About 10 km upstream of the river mouth, the sampling campaign took place close to Staßfurt, a town of 20’000. During the sampling campaign, the intrusion of fine sediment into the bed sediment was captured by sediment traps. Furthermore three possible sources of this fine sediment were sampled. Within the Town of Staßfurt, we sampled urban wet weather discharge at three sites to capture urban areas. As second source naturally occurring fine sediment was considered. Therefore we took sediment cores upstream of the Town of Staßfurt. As third source, the impact of the upstream catchment was captured by taking suspended sediment samples. For all sample types, particle-bound element contents were determined to establish element patterns of the receptor and the source sites. The rationale thereby is that the element pattern at the receptor sites results from the element patterns of the sources. Consequently the contribution of the sources can be calculated by mixing models. In the study area, particulate matter from urban areas is distinct from river borne fine sediment due to elevated copper, zinc, nitrogen and phosphorus contents. We conducted an in-depth analysis of this element pattern by a cluster analysis. It revealed that the particle-bound element pattern is source specific whereby nitrogen, phosphorus and carbon are related to sewage and behave differently than most metals such as copper which mainly originate from surface runoff. The degree to which element patterns agree from site to site is limited by the variability encountered within sample sets from individual sites. Thereby the variability of the element pattern depends on the complexity of the catchment. The contribution of urban areas to fine sediment and associated elements which were captured by sediment traps was calculated by a mixing model. Based on this mixing model, about 10% of the fine sediment originate from urban areas. Thereby the impact of the Town of Staßfurt could not be detected leading to the conclusion that upstream urban areas contribute most. Because of the elevated content of e.g. copper and zinc, urban areas contribute up to 40% and thus disproportionally high to particle-associated copper and zinc load. The source apportionment of the fine sediment is little influenced by the elements considered in the mixing model. Different element patterns showed that the median contribution of urban areas ranges from 0 – 20%. This lies within the interquartile range of the initial mixing model. Another result of the measurement campaign ist that sediment traps over-estimated the anthropogenic impact because they did not resemble the surrounding bed sediment. When they were exposed, they were completely free from fine sediment and hence served as sink of suspended sediment. During the sampling campaign, one source was not directly taken into account. It was possible, though, to delineate this source by nonnegative matrix factorization. Within the Town of Staßfurt, a soda ash production site discharges into the Bode River. The nonnegative matrix factorization uncovered that the soda ash production site is a major source of particulate matter and contributes up to 30% of the fine sediment captured by the traps downstream of the Town of Staßfurt. This source dilutes most element contents as it mainly consists of carbonates. This was revealed by studying the element binding according to the BCR extraction scheme. This thesis shows that urban areas may be a major source of particulate matter and especially associated elements retarded by the bed sediment. It shows that the element contents form a viable pattern to calculate how much urban areas contribute to fine sediment by mixing models. The thesis further shows that nonnegative matrix factorization is a viable tool to delineate such a distinct source as soda ash production site
Misch- und Regenwasserentlastungen beeinträchtigen die Qualität von Vorflutgewässern. Unter anderem gelangt Feinsediment während Entlastungsereignissen in Vorflutgewässer. Dieses erhöht die Fracht an suspendiertem Sediment und verstärkt die Kolmatierung der Gewässersohle. Damit ist das hyporheische Interstitial, das ein wichtiges Fließgewässerhabitat ist, vom Eintrag von Feinsediment betroffen. Diese Arbeit untersucht, wie sehr urbane Flächen zur Feinsedimentfracht und zur Fracht von partikulär gebundenen Elementen beitragen können, die im Bettsediment zurückgehalten werden. Sie beruht auf einer umfangreichen Messkampagne. Das Untersuchungsgebiet dafür war die Bode, ein mittelgroßer Fluss in Mitteldeutschland. Etwa 10 km flussaufwärts der Mündung fand die Messkampagne nahe der Kleinstadt Staßfurt statt. Im Rahmen dieser Messkampagne haben wir den Eintrag von Feinsediment in das Bettsediment durch Sedimentkörbe erfasst. Drei Quellen dieses Feinsediments haben wir berücksichtigt. In Staßfurt wurden eine Regen- und zwei Mischwassereinleitungen beprobt, um urbane Flächen zu erfassen. Als zweite Quelle wurde natürlich vorkommendes Feinsediment berücksichtigt. Dafür haben wir Sedimentkerne flussaufwärts von Staßfurt genommen. Als dritte Quelle haben wir das stromaufwärts liegende Einzugsgebiet erfasst, indem wir das suspendierte Sediment beprobt haben. Für alle Proben wurde der Elementgehalt bestimmt, um das Elementmuster des Feinsediments, das ins Bettsediment eingetragen wurde, und der Quellen zu ermitteln. Der Grund für diese Messstrategie war, dass das Elementmuster des Feinsediments in den Körben aus den Elementmustern der Quellen, Regen- bzw. Mischwassereinleitungen, natürlich vorkommendes Feinsediment und suspendiertes Sediment aus dem Einzugsgebiet, resultieren sollte. Damit ist es möglich, den Beitrag über Mischungsmodelle zu berechnen. Im Untersuchungsgebiet unterscheidet sich das Feinsediment, das von urbanen Flächen stammt, von dem flussbürtigen Feinsediment aufgrund erhöhter Kupfer-, Zink-, Stickstoff- und Phosphorgehalte. Wir haben das Elementmuster der urbanen Flächen mit einer Clusteranalyse genauer untersucht. Dies ergab, dass das partikulär gebundene Elementmuster quellenspezifisch ist, wobei sich Stickstoff, Phosphor und Kohlenstoff Abwasser zuordnen lassen, während die meisten Metalle wie Kupfer und Zink hauptsächlich aus dem Oberflächenabfluss stammen. Das Maß, zu dem die Muster von Messpunkt zu Messpunkt übereinstimmen, wird durch die Variabilität beschränkt, die die Proben eines Messpunktes aufweisen. Diese Variabilität hängt dabei von der Komplexität des Einzugsgebiets ab. Über eine Mischungsrechnung konnten wir berechnen, wie viel urbane Flächen zur Fracht von Feinsediment und daran gebundenen Elementen in den Sedimentkörben beitrugen. Im Untersuchungsgebiet stammen etwa 10 % des Feinsediments, das durch die Sedimentkörbe aufgefangen wurde, von urbanen Flächen. Der Beitrag der Stadt Staßfurt konnte dabei aber nicht von dem Beitrag weiter flussaufwärts gelegener urbaner Gebiete getrennt werden. Daraus folgt, dass weiter stromaufwärts liegende Gebiete mehr beitragen als Staßfurt. Wegen des erhöhten Gehalts an z.B. Kupfer und Zink tragen urbane Flächen ca. 40 % und damit überproportional hoch zur partikulär gebundenen Kupfer- und Zinkfracht bei. Für die Berechung des Quellenbeitrags zum Feinsediment spielt es keine große Rolle, welche Elemente in der Mischungsrechnung berücksichtigt werden. Verschiedene Elementmuster ergeben, dass der Medianbeitrag urbaner Flächen zwischen 0 und 20 % liegt. Dies entspricht dem Interquartilsabstand der ursprünglichen Mischungsrechnung. Ein weiteres Resultat der Untersuchungen ist, dass die Sedimentkörbe den anthropogenen Einfluss überschätzten, weil sie das umgebende Bettsediment nicht exakt abbildeten und als Falle funktionierten. Innerhalb Staßfurts gibt es ein Sodawerk, das seine Produktionsabwässer in die Bode einleitet. Während der Messkampagne wurde diese Quelle nicht direkt erfasst. Es war trotzdem möglich, diese Quelle durch nicht-negative Matrix-Faktorisierung zu identifizieren. Die nicht-negative Matrix-Faktorisierung ergab, dass das Abwasser des Sodawerks eine Hauptquelle des Feinsediments der Bode ist. Bis zu 30 % des Feinsediments in den Sedimentkörben flussabwärts von Staßfurt lassen sich dem Sodawerk zuordnen. Dieses Feinsediment besteht hauptsächlich aus Karbonaten und verdünnt die meisten Elementgehalte. Dies wurde deutlich, indem die Elementbindungen nach dem BCR Extraktionsschema untersucht wurden. Diese Arbeit zeigt die Relevanz, die urbane Flächen als Quelle von Feinsediment und daran gebundener Elementfracht haben, die ins Interstitial eingetragen werden. Sie zeigt, dass die Elementgehalte ein Muster bilden, mit dem es möglich ist, über eine Mischungsrechnung zu klären, wie viel urbane Flächen zum Feinsediment beitragen. Die Arbeit zeigt ferner, dass nicht-negative Matrix-Faktorisierung ermöglicht, eine so charakteristische Quelle wie ein Sodawerk zu identifizieren

An experiential thesis, this document begins at dawn, travels through storms and calm air and ends at night in Argentina. It details the circumstances and influences leading to my thesis exhibition at the Anderson Gallery, including an artist’s statement told through a creative reading of Ray Bradbury’s “All Summer in a Day” and the excitement I found in an out-of-print text on scuba diving.

La pollution atmosphérique est le produit de fortes émissions de polluants (et de leurs précurseurs) et de conditions météorologiques défavorables. Les particules fines (PM2.5) sont l'un des polluants les plus dangereux pour la santé publique. L'exposition répétée ou prolongée à ces particules entraîne chaque année des maladies respiratoires et cardio-vasculaires chez les personnes exposées ainsi que des morts prématurées. L'évolution du climat dans les années à venir aura un impact sur des variables météorologiques (température, vents, précipitations, ...). Ces variables influencent à leur tour divers facteurs, qui affectent la qualité de l'air (émissions, lessivage par les précipitations, équilibre gaz/particule, ...). Si de nombreuses études ont déjà projeté l'effet du changement climatique sur les concentrations d'ozone, peu se sont intéressées à son effet sur les concentrations de particules fines, en particulier à l'échelle du continent européen. C'est ce que cette thèse se propose d'étudier. La circulation atmosphérique de grande échelle est étroitement liée aux variables météorologiques de surface. Par conséquent, il est attendu qu'elle ait également un impact sur les concentrations de PM2.5. Nous utilisons dans cette thèse une approche statistique pour estimer les concentrations futures de PM2.5 à partir d'observations présentes de PM2.5, de quelques variables météorologiques pertinentes et d'outils permettant de représenter cette circulation atmosphérique (régimes et types de temps). Le faible nombre d'observations journalières de PM2.5 et de ses composants en Europe nous a conduit à créer un jeu de données pseudo-observées à l'aide du modèle de qualité de l'air Polyphemus/Polair3D, puis à l'évaluer de façons opérationnelle et dynamique, afin de s'assurer que l'influence des variables météorologiques sur les concentrations de PM2.5 est reproduite de manière satisfaisante par le modèle. Cette évaluation dynamique d'un modèle de qualité de l'air est, à notre connaissance, la première menée à ce jour.Les projections de PM2.5 sur les périodes futures montrent une augmentation systématique des concentrations de PM2.5 au Royaume-Uni, dans le nord de la France, au Benelux et dans les Balkans, et une diminution dans le nord, l'est et le sud-est de l'Europe, en Italie et en Pologne. L'évolution de la fréquence des types de temps ne suffit pas toujours à expliquer l'évolution de ces concentrations entre les périodes historique et futures, car les relations entre circulation atmosphérique de grande échelle et types de temps, entre types de temps et variables météorologiques, et entre variables météorologiques et concentrations de PM2.5 sont amenées à évoluer dans le futur et contribuent à l'évolution des concentrations de PM2.5. L'approche statistique développée dans cette thèse est nouvelle pour l'estimation de l'impact du climat et du changement climatique sur les concentrations de PM2.5 en Europe. Malgré les incertitudes qui y sont associées, cette approche est facilement adaptable à différents modèles et scénarios, ainsi qu'à d'autres régions du monde et d'autres polluants. En utilisant des observations pour définir la relation polluant-météorologie, cette approche serait d'autant plus robuste
Air pollution is the result of high emissions of pollutants (and pollutant precursors) and unfavorable meteorological conditions. Fine particulate matter (PM2.5) is one of the pollutants of great concern for human health. Every year, a repeated or continuous exposure to such particles is responsible for respiratory and cardiovascular diseases among the concerned populations and leads to premature deaths. Climate change is expected to impact meteorological variables (temperature, wind, precipitation,...). Those variables will influence numerous factors, which will affect air quality (emissions, precipitation scavenging, gas/particle equilibrium,...). A large body of studies have already investigated the effects of climate change on ozone, whereas only a few have addressed its effects on PM2.5 concentrations, especially over Europe. This is the subject we investigate in this thesis. Large-scale circulation is closely linked to surface meteorological variables. Therefore, it is expected that it will impact PM2.5 concentrations too. In this thesis, we develop a statistical algorithm to estimate future PM2.5 concentrations from present PM2.5 observations, selected meteorological variables and tools to represent this circulation (weather regimes and weather types). The lack of daily observations of PM2.5 and its components over Europe prevents us to used observations. Consequently, we have created a pseudo-observed PM2.5 data set, by using the Polyphemus/Polair3D air quality Chemical-Transport Model. Both operational and dynamic evaluations were conducted against EMEP measurements, to ensure that the influence of meteorological variables on PM2.5 concentrations is correctly reproduced by the model. As far as we know, this dynamic evaluation of an air quality model with respect to meteorology is the first conducted to date.Future PM2.5 concentrations display an increase over the U.K., northern France, Benelux, and in the Balkans, and a decrease over northern, eastern, and southeastern Europe, Italy, and Poland compared to the historical period. The evolution of weather type frequencies is not sufficient to explain the PM2.5 changes. The relationships between the large-scale circulation and the weather types, between the weather types and meteorological variables, and between meteorological variables and PM2.5 concentrations evolve with future meteorological conditions and also contribute to PM2.5 changes. The statistical method developed in this thesis is a new approach to estimate the impact of climate and climate change on PM2.5 concentrations over Europe. Despite some uncertainties, this approach is easily applicable to different models and scenarios, as well as other geographical regions and other pollutants. Using observations to establish the pollutant-meteorology relationship would make this approach more robust

WEATHERED is a means to give back and say thanks to all who have helped me through life and offer similar aid to anyone willing to listen. Presented within the CRAIVE Lab at the Rensselaer Polytechnic Institute's Technology Park on March 4^th, 4pm to 8pm, it depicts an allegorical journey of survival, change, and rediscovery as people are reunited with their identity after separating themselves from it as a means of survival.

In the Thesis, the autobiographical forces behind WEATHERED are defogged, revealing a personal past of birth, growth, abuse, survival, and healing. It will further unravel and look deeper into the artwork's use of allegory, its development process, and conceptual decisions and symbolism, all in conjunction with the artist's creative growth and metamorphosis.

Thesis (Ph. D.)--University of Oregon, 2006.
Typescript. Includes vita and abstract. Includes appendices with Foy Lake pollen and charcoal data and fire atlas metadata. Includes bibliographical references (leaves 233-244). Also available for download via the World Wide Web; free to University of Oregon users.

Wildland fires are a type of vegetation fire that burn in a rural or wild landscape and affect many countries worldwide. They are an important mechanism in ecosystem maintenance, although in certain cases wildland fires can adversely affect both people and the environment. A wildland fire can interact with the surrounding topography, vegetation and weather in a complex manner, which makes microscale prediction of wildland fire behaviour difficult in many situations. This thesis focused on the application of the Weather Research and Forecast (WRF) numerical weather prediction (NWP) and WRF-Fire coupled atmosphere-fire models to investigating aspects of atmospheric interactions with wildland fire. The research covered a wide range of atmospheric scales, from a seasonal mesoscale analysis of fire weather conditions across New Zealand to a microscale analysis of complex atmosphere-fire interactions over idealised terrain. The first study investigated the suitability of WRF modelling of fire weather conditions for the 2009/10 wildland fire season in New Zealand. The WRF model horizontal grid spacing was 8 km and the model output was directly compared with near-surface fire weather conditions meaured and derived at 23 weather stations located throughout New Zealand. The analysis considered the air temperature, relative humidity, wind conditions, rainfall and the New Zealand Fire Weather Index (FWI) and Continuous Haines Index (CHI) on observed high-end fire weather days. WRF typically underpredicted the air temperatures and relative humidities, whereas it typically overpredicted the wind speeds, CHI and the number of high-end fire weather days. WRF was assessed to be unsuitable for accurately modelling particular aspects of fire weather, such as the wind speed and direction, in mountainous terrain and near complex coastlines. Further research is needed to investigate how varying the horizontal resolution in WRF affects the assessed accuracy of modelled fire weather conditions. The second study investigated the behaviour of the Haines Index (HI), CHI and FWI, and their associated atmospheric properties for the 2009/10 wildland fire season in New Zealand. The analysis demonstrated that there was a large degree of spatial variability in fire weather conditions throughout New Zealand, particularly in or near mountainous terrain. The fire weather severity was highest in the eastern South Island and appeared to be closely associated with mesoscale atmospheric processes over mountainous terrain, although the relationship between these atmospheric processes and fire weather condi- tions requires further investigation. The HI and CHI were both limited in their utility at measuring aloft fire weather conditions in high altitude regions. Finally, the fire weather conditions associated with the 36 largest wildland fires of the fire season were evaluated, although no statistical relationships were found between the wildland fire size and either the CHI or FWI. The third study investigated the fire weather conditions across the South Island associated with an extreme foehn event on 6 February 2011. Mountain waves developed in the northwesterly synoptic flow over the Southern Alps and were found to directly influence the fire weather conditions near the surface and aloft in the lee of the mountains. A hydraulic jump along the foothills of the Canterbury Plains resulted in a downslope windstorm with wind speeds exceeding 80 km/h. Further south, large amplitude mountain lee waves directly influenced the near-surface wind speeds and atmospheric stability aloft. The foehn winds were associated with peak air temperatures over 35˚C in the eastern South Island, which are significantly higher than the climatological average. The FWI indicated widespread extreme near-surface fire weather conditions in the lee of the mountains. The subsequent passge of a cold front on 7 February brought a marked reduction in fire weather severity across the South Island. The fourth study investigated atypical wildland fire behaviour on steep leeward slopes through a series of idealised WRF-Fire simulations. The analysis considered both the leeward flow characteristics over a triangular ridge line and the fire spread from an ignition point at the base of the leeward slope. The fire spread was modelled for two different fuel types and with two-way atmosphere-fire coupling both enabled and disabled. The modelled fire spread in the heavy fuel type with coupling enabled closely resembled the fire channelling wildland fire behaviour phenomenon. The initial fire spread was initially dominated by upslope fire spread to the mountain ridge line at an average rate of around 2.0 km/h. This was followed by a phase of intermittent rapid lateral fire spread close to the ridge line at a maximum rate of around 3.6 km/h. The intermittent rapid lateral fire spread was driven by strongly circulating horizontal near-surface winds that were associated with updraft-downdraft interfaces. These updraft-downdraft interfaces formed due to an interaction between the strong pyro-convection and terrain-modified winds. The presented research collectively demonstrated the versatility and effectiveness of NWP and coupled atmosphere-fire modelling for studying various aspects of atmospheric interactions with wildland fire. The research further highlighted the effects of atmospheric processes over complex terrain on fire weather conditions and wildland fire behaviour. Although three of the studies in the thesis had a regional focus on New Zealand, the research outcomes should benefit end users in fire management worldwide.

Wildfires are a natural phenomenon that strongly impacts the environment. Many terrestrial ecosystems depend on fire to maintain their ecological equilibrium and biodiversity, but new destructive fire patterns, often associated with land management practices and rapid climate change, have been degrading soil and water resources, increasing erosion by wind, precipitation and floods, decreasing biodiversity and contributing to desertification. Furthermore, pyrogenic emissions from biomass burning are an important source of atmospheric pollution and they impact the radiative balance of the troposphere, strongly contributing to the greenhouse effect. The objective of this research was to investigate the impact of climate variability on geographic, ecological, seasonal and inter-annual distributions of fires and correspondent pyrogenic emissions, across a variety of ecosystems. With this purpose, 10 years of world, monthly, 1°x1° gridded data, from the Global Fire Emissions Database, were compared with land-cover data, from the Goddard Institute of Space Studies, and with weather data, from the European Centre for Medium Range Weather Forecasting, the Global Precipitation Climatology Centre and the Global Hydrology Resource Centre. Overall, the climate parameters significantly correlated with carbon emissions were air and soil temperature, air and soil humidity, rainfall, wind speed and lightning density during the fire season, and also precipitation and snow cover up to 6 months before the fire season. Good statistical quantitative models of carbon emissions (correlations above 70%, and up to 95%, between estimated and predicted values, with residuals normally distributed) using humidity, temperature or lagged rainfall as predictors, were found almost exclusively in tropical grasslands, shrublands and woodlands, especially in Africa, where fire behaviour was more regular. In boreal and temperate forests and woodlands, where fire patterns were irregular and fire returning periods were larger, there were not enough fires, in 10 years of data, to obtain useful predictive statistical models. The fire models presented here, together with the quantitative statistical relationships found between climate and fire patterns, in different land ecosystems, are apt to be used in predictive climate models, land management, fire risk assessment and mitigation of climate change.

Includes bibliographical references (leaves 68-76).
This study assessed the spatial and temporal patterns of wildfires in the Cape Floristic Region (CFR). It focused on the factors that influence fire frequency; namely vegetation age, ignition sources and weather conditions. This work was done to aid decisions on fire management in fynbos nature reserves. Fire intervals were extracted from historical fire records in four reserves in the CFR. The study sites were the Cederberg and Hottentots-Holland (western) reserves and the Swartberg and Outeniqua (eastern) reserves, and fire records were used from 1970 to 2007. A non-parametric technique and smoothing methods were used to highlight patterns in the extracted fire intervals. Comparisons of fire frequency were made between the study sites to analyse spatial patterns of burning. The impact of anthropogenic ignitions on fire frequency was analysed to explore the effect of people on fire patterns. The relationship between fuel age and fire size was analysed to determine the influence of vegetation age on fire patterns. Two novel methods were described in this thesis. The first method developed a technique to analyse temporal patterns in fire frequency while avoiding the impacts of temporal autocorrelation. The second method analysed the relationship between weather condition and fire events by utilising self-organising maps of synoptic states. A temporal change in the frequency of these synoptic states was tested for over the recording period. Synoptic states were used to produce two regional fire risk indicators for the CFR. I found that fire intervals in western study areas of CFR were shorter than fire intervals in eastern study areas. The effect of anthropogenic ignition sources shortened fire intervals in all study sites; however, this was relative to the natural fire frequency of each study site. Prescribed burning as a form of fire management contributed relatively little to the total area burned in all study sites. Fuel age has a significant correlation to fire size in only the drier (Swartberg) study site. A decreasing trend in fire return intervals was found in three study sites; Cederberg, Hottentots-Holland and Outeniqua. Synoptic states characteristic of the southern-most extent of a tropical easterly wave low were correlated to frequency fire events in the western study areas. Fires in the eastern study areas were correlated to a synoptic state characteristic of a tropical temperate trough. Easterly wave lows are associated with strong atmospheric convection whereas tropical temperate troughs are associated with pre-frontal conditions and strong, hot and dry winds. The frequencies of these synoptic states were shown to have increased in recent decade. The factors influencing fire frequency in the western CFR are predominantly sources of ignition, while the availability of fuels and suitable weather conditions restrict fires in the eastern CFR. Fire frequency has increased in the study sites where weather exerts the dominant control and this is due to the increase in synoptic states that promote wildfires. Historical records show that fire management has had little impact on the total area burned, thus fire management under climate change is unlikely to influence fire frequency.

The El Niño/ Southern Oscillation (ENSO) is known to influence the weather in western North America through teleconnections. Several studies have established a relationship between ENSO and forest fire occurrence. However, a recently discovered variant of ENSO, called Central Pacific El Niño, may cause a different teleconnection and forest fire pattern. Investigating and classifying past El Niño events and their possible influence on weather and forest fire patterns in western North America from 1981-2010 was the objective of this study. The analysis revealed that current El Niño classification methods are suboptimal and that a binary distinction leads to misclassification of events. It, however, confirms that the two types show a different warming pattern as well as different wind and precipitation patterns. These characteristics of the Central Pacific El Niño can cause different extra tropical teleconnections in western North America than the canonical El Niño. Variation of teleconnections within the events and the limited amount of events, however, complicate a clear conclusion. Further, other oscillations such as the Arctic Oscillation play a major role in impacting the climate in western North America. Exploratory analysis of natural forest fires of North America identified hot spots of annual area burned in central Alaska, north-west and central Canada and western United States. Further, singular value decomposition and spatial correlation analysis revealed a different teleconnection response in summer drought patterns over western North America related to the two types of El Niño. The drought pattern is significantly related with forest fire frequency and area burned in certain regions across western North America. A clear connection between the different El Niño types and the forest fire pattern however remains inconclusive.

Diarrheal disease has long been known to be a burden to children worldwide. Although child mortality rates as a result of diarrhea have decreased over the past two decades, overall diarrhea incidence has remained relatively stable. In Cambodia, diarrhea was the third most prevalent outpatient diagnosis for children under five in 2012, with a reported incidence rate of 12 per 100 children, up from 7 per 100 children in 2008 (Ministry of Planning Cambodia, 2012). Cambodia is an agricultural country with 80% of the population living in rural areas (National Institute of Statistics Ministry of Planning, 2013). Many are also poor, with 20.5% of the population living at or below the poverty line (Sobrado et al., 2014). As a result, a large portion of the population is vulnerable to changing climate patterns and seasonal rainfalls. These patterns have been shown to have an effect on the incidence of diarrhea in regions throughout the world. This research evaluated the relationship between seasonality and the incidence of diarrheal disease in children under five years old in the Rumduol district, Svay Rieng province of Cambodia. Using monthly under-five diarrhea data from a local health center and meteorological data from the Ministry of Water Resources and Meteorology (MoWRAM), Spearman’s Correlation was used to find associations between monthly rainfall, heavy rainfall (defined by the 90th percentile), maximum average monthly temperature, and minimum average monthly temperature. Additionally, household surveys, interviews, and observations were used to understand how seasonal behavior, age/gender, household practices, and caregiver perception of the disease affect decisions surrounding diagnosis and treatment of childhood diarrhea throughout the year. Based on the results of the analysis, the number of heavy rainfall days had a weak negative association with monthly under-five diarrhea incidence in the initial month and following month, referred to as lag 0 and lag 1 (rs(96) = -.216, p = .035 and rs(95) = -.219, p = .033). Minimum average monthly temperature was also shown to have weak negative association with monthly under-five diarrhea incidence at lag 0 and lag 1 (rs(96) = -.208, p = .042 and rs(95) = -.212, p = .039). The negative correlation between heavy rainfall and under-five diarrhea indicates that heavy rain can have a washing effect on the environment at lag 0 and lag 1 months. Higher diarrhea incidence in the cooler months suggest a possible link to rotavirus, however more research must be done to make confirm this. Monthly rainfall was seen to have a positive association with diarrhea within the lag 3 and lag 4 months (rs(93) = .250, p = .015; rs(92) = .222, p = .034). This indicates that increased rainfall could have a delayed effect on diarrhea by three or four months. Maximum temperature did not have statistically significant results. These results show that heavy rainfall and minimum temperature likely play role in under-five child diarrhea in the study area at shorter lags times, while monthly rainfall has a greater effect at longer lag times. Results of survey and interview data showed participants had sufficient knowledge on personal and food hygiene practices but often practiced improper environmental hygiene behavior, especially as it related to the handling of child and animal feces. Additionally, there were statistically significant results when looking at the relationship between environmental hygiene knowledge and practice and households where mothers migrate for work. Households with migrant mothers was common within the study area, with 51.9% of households having a mother who was currently working away from home or had plans to return to work soon. More data is needed to further investigate this relationship; however, this result suggests that hygiene knowledge and practice could suffer in households where the mother is absent, as added burden is placed on grandmothers to do domestic and childcare work.

The following thesis project has been done in direct collaboration with Autokaross i Floby AB Rescue Vehicle Department, in Sweden.  The report contains the design development of a protective cover against weather conditions for the extendable ladder in a fire vehicle.   The aim of the report has been to develop a functional and low cost solution cover for the FEL on a fire truck, which is allocated on the roof, with the express intention of providing adequate access and protection against weather conditions in Nordic countries, so as to prevent premature deterioration of the FEL unit. The company has set the technical and conceptual boundaries, with the help of the two previous concepts currently used, the BMC and the ACP.   The initial requirements laid out by the company were expressed through a number of specific demands which can be categorized in two main points:   Cost: Designing a solution keeping in mind cost limits, assembly cost and time, and space optimization. This was done by taking into account the two existing solutions, particularly the BMC, which represents the lowest, cost wise and function wise. Therefore it was used as the basis on which to apply improvements, rather than trying to lower the high cost on the overqualified function of the ACP.   Function: Providing the adequate protection and access to the FEL. In this case, the problem was solved by establishing the correct degree of protection relevant to the Nordic weather conditions and FEL needs, and regarding the access, this was assured by fully automating the opening/closing process with the existing extraction operating system of the FEL.     The result of this report is a concept solution which meets the company’s demands, obtained by creative detailing, together with an analysis regarding possible considerations that could improve the creative detailing result in this report in the form of future work.     The report documents the process that has taken place in exploration, concept generation, concept evaluation, concept selection, and detailed CAD development. Each section shows the requirements and adjustments taken to fulfil the company’s needs.

Extreme-temperature events are known to favor large wildland fires and have consequences for human health and mortality, forest disturbance patterns, agricultural productivity, and the economic repercussions of these consequences combined. To gain insight into whether extreme-temperature events are changing in light of global climate dynamics, the annual numbers of high-temperature days (those with temperatures higher than 20, 22.5, and 25 ºC at 850 hPa) were analyzed across southern Europe from the years 1978 to 2012. A significant increase in the frequency of these days was found in many areas over the time period analyzed, and patterns in the spatial distribution of these changes were identified. Additionally, this work analyzes the effects of high temperature days on medium and large fires from 1978 to 2010 in Spain and other areas (Sardinia, Italy). A high temperature day was defined as being when air temperature at 850 hPa was higher than the 95th percentile of air temperature at that elevation from June to September across the study period. Temperature at 850 hPa was chosen because it properly characterizes the state of the lower troposphere. The effects of high temperature on forest fires were remarkable and significant in terms of fire number (15 % of total large fires occurred under high temperature days), burned area (25 % of the total burned area occurred under high temperature days). Fire size was also significantly higher under 95th percentile air temperature at 850 hPa and a large part of the largest fires in the past 20 years were under these extreme conditions. Additionally, both burned area and fire number only decreased under non-high temperature days in the study period and not under high temperature conditions. The worst consequence of wildland fires is the loss of human lives, a regular phenomenon over the last few decades worldwide. This work analyzes all recorded wildland fires in Spain with victims between 1980 and 2010. We classified causality causes during wildland fires to study the most frequent causes of fatalities and how they were related to regions, fire size, and extreme weather conditions (i.e., high temperature days). Trends in number of both injured and killed individuals were analyzed. We observed that the annual number of victims did not decrease in the study period. Entrapment is the most frequent cause of death within the fire suppression employees. Fire size is a key factor in the occurrence of victims because 95% of fatalities in wildland fires (not counting aerial casualties) happened in fires larger than 100 ha. High temperature days also were important because 60% of entrapments were produced in this kind of days.
Los eventos con temperaturas extremas favorecen la ocurrencia de grandes incendios forestales y tienen consecuencias en la salud y mortalidad humana, los patrones de perturbación forestal, la productividad agrícola y las repercusiones económicas de estas consecuencias combinadas. Para conocer si los eventos de temperaturas extremas están cambiando bajo la dinámica de cambio global, se analizaron las cifras anuales de días de alta temperatura (aquellos con temperaturas superiores a los 20, 22,5 y 25 ºC a 850 hPa) en el sur de Europa en el periodo 1978-2012. Un aumento significativo en la frecuencia de este tipo de días se encontró en muchas áreas durante el período de tiempo analizado, y se identificaron patrones en la distribución espacial de estos cambios. Además, este trabajo analiza los efectos de días de alta temperatura en incendios forestales medianos y grandes en España desde 1978, así como en otras áreas (Cerdeña, Italia). Un día de alta temperatura se define cuando la temperatura del aire a 850 hPa es mayor que el percentil 95 de la temperatura del aire a 850 hPa de junio a septiembre en todo el período de estudio. Elegí la temperatura a 850 hPa porque caracteriza adecuadamente el estado de la baja troposfera. Los efectos de las altas temperaturas sobre los incendios forestales fueron notables y significativos en términos de número de incendios (el 15% del total de los grandes incendios ocurrieron bajo días de alta temperatura) y área quemada (25% del total de área quemada se produjo bajo días de alta temperatura). El tamaño de los incendios también fue significativamente mayor en condiciones de alta temperatura y gran parte de los incendios más grandes en los últimos 20 años fueron en este tipo de condiciones extremas. Además, tanto el número de incendios como el área quemada solamente disminuyeron bajo días de no alta temperatura en el período de estudio. La peor consecuencia de los incendios forestales es la pérdida de vidas humanas, un fenómeno que se ha producido con regularidad durante las últimas décadas en todo el mundo. Este trabajo analiza todos los incendios forestales en España con víctimas registradas entre 1980 y 2010. Los incendios se clasificaron por la causa que provocó la muerte de las víctimas durante los incendios forestales con el objetivo de estudiar las causas más frecuentes en accidentes mortales y cómo se relaciona con distintas regiones geográficas, el tamaño de los incendios, y las condiciones climáticas extremas (es decir, días de alta temperatura). Se analizaron tendencias temporales en el número de individuos heridos y muertos en el periodo de estudio. Se observa que el número anual de víctimas no disminuyó en el período de estudio. El atrapamiento es la causa más frecuente de muerte dentro de los empleados de extinción de incendios. El tamaño de los incendios es un factor clave en la aparición de las víctimas ya que el 95% de las muertes en incendios forestales (sin contar las bajas aéreas) ocurrió en incendios mayores de 100 ha. Los días de alta temperatura también fueron claves debido a que el 60% de atrapamientos se produjo en este tipo de días.
Els esdeveniments amb temperatures extremes afavoreixen l’aparició de grans incendis forestals amb conseqüències en la salut i mortalitat humana, els patrons de pertorbació forestal, la productivitat agrícola i les repercussions econòmiques d’aquestes conseqüències combinades. Per conèixer si els esdeveniments de temperatures extremes estan canviant amb la dinàmica de canvi global, es van analitzar les xifres anuals de dies amb altes temperatures (aquells dies amb temperatures superiors als 20, 22.5 i 25ºC a 850hPa) al sud d’Europa en el període 1978-2012. Un augment significatiu en la freqüència d’aquest tipus de dies es va trobar en moltes àrees durant el període de temps analitzat, i es van identificar patrons en la distribució espacial d’aquests canvis. A més, aquest treball analitza els efectes de dies d’alta temperatura en incendis forestals mitjans i grans a Espanya des de 1978, així com en altres àrees (Cerdenya, Itàlia). Es defineix un dia d’alta temperatura quan la temperatura de l’aire a 850hPa és més gran que el percentil 95 de la temperatura de l’aire a 850hPa de juny a setembre en tot el període d’estudi. Vaig triar la temperatura a 850hPa perquè caracteritza adequadament l’estat de la baixa troposfera. Els efectes de les altes temperatures sobre els incendis forestals van ser notables i significatius en termes de nombre d’incendis (el 15% del total dels grans incendis es van produir en dies d’alta temperatura) i àrea cremada (el 25% del total d’àrea cremada es va produir en dies d’alta temperatura). Les dimensions dels incendis també van ser significativament més grans en condicions de temperatura i gran part dels incendis més grans en els últims 20 anys van ser en aquest tipus de condicions extremes. A més, tant el nombre d’incendis com l’àrea cremada només van disminuir en dies de no alta temperatura en el període d’estudi. La pitjor conseqüència dels incendis forestals és la pèrdua d’éssers humans, un fenomen que s’ha produït amb regularitat durant les últimes dècades a tot el món. Aquest treball analitza tots els incendis forestals d’Espanya amb víctimes registrades entre els anys 1980 i 2010. Els incendis es van classificar per la causa que va provocar la mort de les víctimes durant els incendis forestals amb l’objectiu d’estudiar les causes més freqüents en accidents mortals i la seva relació amb les diferents regions geogràfiques, les dimensions dels incendis, i les condicions climàtiques extremes (és a dir, dies d’alta temperatura). Es van analitzar tendències temporals en el nombre d’individus ferits i morts en el període d’estudi. L’atrapament és la causa més freqüent de mort dins dels empleats d’extinció d’incendis. Les dimensions dels incendis són un factor clau en l’aparició de les víctimes, ja que el 95% de les morts en incendis forestals (sense tenir en compte les baixes aèries) es van produir en incendis que afectaven més de 100 ha. Els dies d’alta temperatura també van ser claus pel fet que el 60% d’atrapaments es van produir en aquest tipus de dies.

Táto diplomová práca sa zaoberá novým prístupom k zhlukovaniu časových rád na základe dynamického faktorového modelu. Dynamický faktorový model je technika redukujúca dimenziu a rozširuje klasickú faktorovú analýzu o požiadavku autokorelačnej štruktúry latentných faktorov. Parametre modelu sa odhadujú pomocou EM algoritmu za použitia Kalmanovho filtra a vyhladzovača a taktiež sú aplikované nevyhnutné podmienky na model, aby sa stal identifikovateľným. Po tom, ako je v práci predstavený teoretický koncept prístupu, dynamický faktorový model je aplikovaný na skutočné pozorované časové rady a práca skúma jeho správanie a vlastnosti na jednomesačných meteorologických dátach požiarneho indexu (Fire Weather Index) na 108 požiarnych staniciach umiestnených v Britskej Kolumbii. Postup výpočtu modelu odhadne záťažovú maticu (loadings matrix) spolu so zodpovedajúcim malým počtom latentných faktorov a kovariačnou maticou modelovaných časových rád. Diplomová práca aplikuje k-means zhlukovanie na výslednú záťažovú maticu a ponúka rozdelenie meteorologických staníc do zhlukov založené na redukovanej dimenzionalite pôvodných dát. Vďaka odhadnutým priemerom zhlukov a odhadnutým latentným faktorom je možné získať aj priemerné trendy každého zhluku. Následne sú dosiahnuté výsledky porovnané s výsledkami získanými na dátach z rovnakých staníc avšak iného mesiaca, aby sa stanovila stabilita zhlukovania. Práca sa taktiež zaoberá efektom varimax rotácie záťažovej matice. Diplomová práca naviac navrhuje metódu detekovania odľahlých časových rád založenú na odhadnutej kovariačnej matici modelu a rozoberá dôsledky odľahlých hodnôt na odhanutý model.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
Ao mesmo tempo em que foram desenvolvidos no Brasil programas com a meta de racionalização do sistema energético nacional, motivados principalmente pelas crises enfrentadas pelo país, como o racionamento de 2001, estudos a respeito do comportamento do clima em escala mundial apresentaram avanços expressivos, acilitados pela evolução tecnológica e computacional. Entre as estratégias para contenção do desperdício da energia produzida está o consumo pelas edificações, uma vez que a adoção de sistemas construtivos adequados pode reduzir o consumo final de eletricidade. Tal constatação constitui um dos preceitos da arquitetura bioclimática, que preconiza a necessidade de adaptação do edifício ao clima local, sendo, para isso, imprescindível a compreensão dos fenômenos climáticos. Desta forma, o princípio que conduziu esta pesquisa foi o comportamento variável do clima, consenso para grande parte dos climatologistas, e suas consequências para as demandas energéticas futuras, particularmente durante o ciclo de vida planejado para cada edifício. Investigar o impacto das mudanças projetadas para o clima ao longo do século XXI no desempenho termoenergético de edificações comerciais artificialmente climatizadas localizadas em diferentes cidades do Brasil foi o principal objetivo deste estudo. Os procedimentos metodológicos foram divididos em quatro etapas, iniciando-se por uma ampla revisão bibliográfica sobre a temática central mudanças climáticas bem como os temas correlacionados, com especial ênfase para a associação entre conforto térmico e a questão energética. Na segunda etapa foram estabelecidos os mecanismos para preparação de arquivos climáticos futuros, incluindo-se a seleção de cidades para representação das diferentes condições geográficas do território brasileiro. Posteriormente foi efetuado o recorte do objeto, com a indicação dos parâmetros de controle e das variáveis em análise, designandose as características do edifício que não serão afetadas por intervenções futuras: percentual de abertura nas fachadas, dispositivos de proteção solar e orientação das maiores fachadas. A etapa final foi dedicada às simulações, realizadas no programa DesignBuilder a partir da configuração dos 192 modelos paramétricos. Os resultados da aplicação da metodologia, analisados quantitativa e qualitativamente, reproduziram, de forma generalizada, um aumento no consumo de 10,7% em 2020, 16,9% em 2050 e 25,6% em 2080, em relação ao consumo atual. Apesar da significância desse aumento, inclusive para o planejamento energético nacional, aumentos mais expressivos foram registrados em estudos internacionais, reforçando a necessidade de consideração dos fenômenos regionais na preparação de dados climáticos futuros neste tipo de pesquisa. Em Recife, a variação de parâmetros construtivos não provocou diferenças tão significativas nas taxas de aumento do consumo quanto nas outras cinco localidades, sendo que Brasília apresentou as maiores taxas de aumento. Considerando-se os edifícios de todas as cidades, a presença de dispositivos de proteção solar foi a variável com maior impacto para diminuição do consumo, e o edifício orientado a Leste e Oeste, com grandes aberturas desprotegidas, apresentou consumo significativamente superior aos outros modelos, atual e futuramente. Por fim, ao contrário da maioria dos resultados mensais observados, em Porto Alegre ocorreu uma diminuição no consumo em alguns meses de 2020 e 2050, ocasionada possivelmente pela diminuição dos períodos de utilização da climatização artificial para aquecimento
At the same time that programs were developed in Brazil with the goal of the national energy system rationalization, mainly motivated by the crisis faced by the country as in the rationing of 2001 studies of the climate s behavior on a global scale showed significant advances, facilitated by technological and computational development. One of the strategies for containment the waste energy produced is the energy consumption by buildings, since the adoption of appropriate constructive systems can reduce the final electricity consumption. This was a principle of bioclimatic architecture, which recommends an adaptation of the building to the local climate conditions, and for that, it is essential to understand the climate system. Therefore, the principle that guided the development of this research was the variable behavior of the climate, which is consensus for most climatologists, and its consequences for the future energy demands of buildings, particularly along the planned life cycle for each building. The main objective of this study was to investigate the impact of projected changes to the climate over the twenty-first century in the thermo energetic performance of commercial buildings artificially acclimatized located in different cities of Brazil. The methodological procedures were divided into four stages, initiating with an extensive literature review on the central theme climate change as well as related topics, with special emphasis on the relationship between thermal comfort and energy issue. In the second step mechanisms for preparing future climate files were established, including the selection of cities for representation of different geo-climatic conditions of the Brazilian territory. After that the definition of the object was performed, indicating the control parameters and variables in the analysis, assigning the characteristics of the building that will not be affected by future interventions window wall ratio, solar shading and orientation of the largest facades. The final step was dedicated to the simulations, performed in the program DesignBuilder from the configuration of the 192 parametric models. The results of applying the methodology, analyzed quantitatively and qualitatively, reproduced in generalized way an increase in energy consumption in buildings by 10.7% in 2020, 16.9% in 2050 and 25.6% in 2080, compared to current consumption. Although the significance of this increase, including the national energy planning, most significant increases were recorded in international studies, reinforcing the need for consideration of regional climate events in the preparation of future climate data in this type of research. In Recife, the variation of constructive parameters did not cause as significant differences in the rates of increase in consumption as the other five locations, and Brasilia had the highest rates of increase. Considering the buildings of all the cities, the presence of solar shading was the variable with the greatest impact on reducing energy consumption, and the building oriented east and west, with large unprotected openings, showed energy consumption significantly superior to other models, in all cities and periods. Finally, unlike most of monthly results observed, in Porto Alegre occurred a decrease in energy consumption in some months of 2020 and 2050, possibly caused by the reduction in time use of artificial air conditioning heating

Au cours des dernières décennies, le nombre d'occurrences de catastrophes naturelles a augmenté sensiblement. Cette augmentation a des conséquences catastrophiques sur les espaces verts, les propriétés et les êtres vivants. L'énorme quantité de dommages a attiré l'attention des chercheurs, des organisations et des secteurs gouvernementaux et non-gouvernementaux vers l'analyse de ces phénomènes, leurs causes et leurs effets. Le but est de pouvoir reconnaître leurs comportements et prédire leur occurrence pour mieux aborder la phase de gestion des risques qui contribue à empêcher leur incidence ou limiter les conséquences. Le risque de d'incendie existe souvent et la présence de dangers est également possible. D'où l'importance de tout effort pour lutter contre de telles crises. Dans cette contribution, le phénomène des incendies de forêt est étudié. Au Liban, les espaces verts ont considérablement diminué au cours des dernières années, ce qui impose une intervention urgente des politiques et le soutien des organisations gouvernementales et non gouvernementales. L'orientation globale est d’aller vers des techniques qui permettent de prédire les risques élevés d'incendie permettant ainsi de prendre des précautions pour empêcher les occurrences d'incendie ou tout au moins limiter leurs conséquences. La prévision des incendies de forêt contribue à prévenir d'une part la fréquence des incendies et d'autre part, à réduire ses impacts sur les êtres vivants, les propriétés et la richesse forestière
During the last decades, the number of occurrences of natural disasters has increased noticeably which lead to catastrophic results on human as well as properties and green areas. But despite the huge amount of damages, this helps to draw the attention of researchers, organizations and the various governmental and non-governmental sectors towards analyzing these phenomena, their causes & effects, allowing to recognize their behaviors and the methods to predict their occurrence and thus reaching the phase of risk management contributing to prevent their incidence or limit the consequences. As the risk of happening often exists, the instantaneous presence of dangers is also possible. Here appears the importance of any effort that serves to tackle such crises. In this contribution, the phenomenon of forest fires is studied. In Lebanon, green areas declined dramatically during the last decades, what imposes an urgent intervention with strict governmental policies and support of non-governmental organizations. The global orientation is towards techniques that predict high fire risks, allowing for precautions to preclude fire occurrences or at least limit their consequences. Forest fire prediction proves to contribute in preventing fire occurrence or reducing its catastrophic impacts in worst cases on human lives, properties and green forestry

Le risque feu de forêt en France est actuellement localisé pour l'essentiel dans le Sud du territoire métropolitain, principalement en Méditerranée et en Aquitaine. Les projections climatiques sur le territoire français pour le 21ème siècle posent la question de l'effet du réchauffement climatique sur l'aléa d'incendie de forêt. Nous considérons en particulier deux questions : Comment le niveau de danger et le régime de feux (fréquence, saisonnalité) pourraient évoluer dans les régions déjà confrontées au risque ? Quelle pourrait être l'extension de la zone à risque dans le futur ?L'effet du changement climatique a d'abord été déterminé à partir de projections sous climat futur d'un indice empirique de danger climatique d'incendie (le FWI), calculées selon cinq modèles climatiques contrastés et deux scénarios d'émission de gaz à effet de serre. Ces projections montrent une augmentation très importante du danger dans les zones déjà concernées par les incendies de forêt, en particulier la Méditerranée, avec un bon accord entre modèles climatiques. L'amplitude de l'augmentation du danger au Nord et à l'Ouest, bien qu'existante, est plus difficile à quantifier, compte-tenu des incertitudes des modèles climatiques.Cette première approche est limitée par le fait que le FWI ne représente qu'imparfaitement l'activité des feux de forêts. Nous avons donc développé un modèle probabiliste d’activité d'incendie dans le but de projeter le nombre de feux et les surfaces brûlées sous climat futur. L'approche considère les feux comme résultant de processus aléatoires sous-jacents qui déterminent l'occurrence et la taille des feux, en fonction du FWI et de différents facteurs spatio-temporels. Le modèle a été ajusté selon une approche bayésienne à partir de la base de données Prométhée, qui recense les observations de feux en région méditerranéenne. Les projections de ce modèle sur la période historique et dans le futur ont permis de montrer que les différents facteurs de la relation feu-climat (localisation, saison, continuité de la forêt) affectent fortement les patrons spatio-temporels d'activité des feux. Par ailleurs, nous avons montré que les projections de FWI sous-estiment les augmentations d'activité de feu, principalement du fait de la non-linéarité de la relation feu-climat. Ainsi, les augmentations attendues en période estivale en Méditerranée en 2080 (scénario pessimiste) sont nettement moins importantes pour le niveau de danger climatique (FWI, de 25 à 59%), que pour les surfaces brûlées (de 48 à 202%).Cette approche ne permet pas d'aborder l'évolution de l'activité des feux dans les régions où les incendies sont aujourd'hui peu nombreux et ne bénéficient pas d'un suivi fiable (moitié Nord de la France). Nous avons cependant réussi à extrapoler le modèle établi pour la région méditerranéenne au reste de la moitié Sud, où les données sont suffisantes. Parmi les difficultés liées à l'extrapolation à l'échelle du territoire national, se pose notamment la question des variations de structure du combustible. Ce facteur n'a pour l'instant pas été intégré dans les projections, mais ses implications sont discutées
Wildfires impacting French forests are currently concentrated in the South, especially in the Mediterranean and Aquitaine regions. Climate projections for the 21st century in France question the impact of climate change on wildfire hazard. We focus on two particular issues: the evolution of the fire danger and fire regime in regions already facing frequent wildfires today, and the potential extension of the risk to new regions in the future.Climate change effect was first determined using projections of an empirical fire danger index (FWI) under future climate, computed for five contrasted climatic models under two greenhouse gases emission scenarios. These projections highlight a very strong increase in fire danger levels in the areas already facing wildfires, especially in the Mediterranean, with a very good agreement between climate models. The range of the increase in the North and the West, though existing, is more challenging to quantify, because of climate model uncertainties.This first approach was limited by the ability of FWI to represent fire activity. Therefore, we developed a probabilistic model for fire activity, aiming at projecting fire numbers and burnt areas under future climate. The approach considers that fires result from underlying random processes that determine the occurrence and the fire size based on the FWI and various spatiotemporal factors. The model was fitted following a Bayesian approach using the Promethee database, which records fire observations in the Mediterranean area. Model projections under historical and future conditions demonstrated that FWI projections underestimated projected fire activity increases, mainly due to the non-linearity of the fire-climate relation. Thus, fire danger increases projected in summer in the Mediterranean in 2080 (pessimistic scenario) are considerably lower (25 to 59%) than those for burnt areas (48 to 202%).This approach does not apply to regions where wildfires are currently sparse, and unreliably recorded, especially in Northern France. Yet we extrapolated the model, established over the Mediterranean area, to the rest of Southern France where data were sufficient. Among the difficulties encountered while extrapolating to the national scale, the variation of fuel structure is a critical issue. It was not included in the projections, but its implications are discussed

In the current study, we have presented a systematic analysis of the diurnal cycle of rainfall over the Indian region using satellite observations, and evaluated the ability of the Weather Research and Forecasting Model (WRF) to simulate some of the salient features of the observed diurnal characteristics of rainfall. Using high resolution simulations, we also investigate the underlying mechanisms of some of the observed diurnal signatures of rainfall. Using the Tropical Rain-fall Measuring Mission (TRMM) 3-hourly, 0.25 ×0.25 degree 3B42 rainfall product for nine years (1999-2007), we extract the finer spatial structure of the diurnal scale signature of Indian summer monsoon rainfall. Using harmonic analysis, we construct a signal corresponding to diurnal and sub-diurnal variability. Subsequently, the 3-hourly time-period or the octet of rain-fall peak for this filtered signal, referred to as the “peak octet,” is estimated with care taken to eliminate spurious peaks arising out of Gibbs oscillations. Our analysis suggests that over the Bay of Bengal, there are three distinct modes of the peak octet of diurnal rainfall corresponding to 1130, 1430 and 1730 IST, from north central to south Bay. This finding could be seen to be consistent with southward propagation of the diurnal rainfall pattern reported by earlier studies. Over the Arabian sea, there is a spatially coherent pattern in the mode of the peak octet (1430 IST), in a region where it rains for more than 30% of the time. In the equatorial Indian Ocean, while most of the western part shows a late night/early morning peak, the eastern part does not show a spatially coherent pattern in the mode of the peak octet, owing to the occurrence of a dual maxima (early morning and early/late afternoon). The Himalayan foothills were found to have a mode of peak octet corresponding to 0230 IST, whereas over the Burmese mountains and the Western Ghats (west coast of India) the rainfall peaks during late afternoon/early evening (1430-1730 IST). This implies that the phase of the diurnal cycle over inland orography (e.g., Himalayas) is significantly different from coastal orography (e.g., Western Ghats). We also find that over the Gangetic plains, the peak octet is around 1430 IST, a few hours earlier compared to the typical early evening maxima over land. The second part of our study involves evaluating the ability of the Weather Research and Fore-casting Model (WRF) to simulate the observed diurnal rainfall characteristics. It also includes conducting high resolution simulations to explore the underlying physical mechanisms of the observed diurnal signatures of rainfall. The model (at 54km resolution) is integrated for the month of July 2006 since this period was particularly favourable for the study of diurnal cycle. We first evaluate the sensitivity of the model to the prescribed sea surface temperature (SST) by using two different SST datasets, namely Final Analyses (FNL) and Real-time Global (RTG). The overall performance of RTG SST was found to be better than FNL, and hence it was used for further model simulations. Next, we investigated the impact of different parameterisations (convective, microphysical, boundary layer, radiation and land surface) on the simulation of diurnal cycle of rainfall. Following this sensitivity study, we identified the suite of physical parameterisations in the model that “best” reproduces the observed diurnal characteristics of Indian monsoon rainfall. The “best” model configuration was used to conduct two nested simulations with one-way, three-level nesting (54-18-6km) over central India and Bay of Bengal. While the 54km and 18km simulations were conducted for July 2006, the 6km simulation was carried out for the period 18-24 July 2006. This period was chosen for our study since it is composed of an active period (19-21 July 2006), followed by a break period (22-24 July 2006). At 6km grid-spacing the model is able to realistically simulate the active and break phases in rainfall. During the chosen active phase, we find that the observed rainfall over central India tends to reach a maximum in the late night/early morning hours. This is in contrast to the observed climatological diurnal maxima of late evening hours. Interestingly, the 6km simulation for the active phase is able to reproduce this late night/early morning maxima. Upon further analysis, we find that this is because of the strong moisture convergence at the mid-troposphere during 2030-2330 IST, leading to the rainfall peak seen during 2330-0230 IST. Based on our analysis, we conclude that during both active and break phases of summer monsoon, mid-level moisture convergence seems to be one of the primary factors governing the phase of the diurnal cycle of rainfall. Over the Bay of Bengal, the 6km model simulation is in very good agreement with observations, particularly during the active phase. The southward propagation observed during 19-20 July 2006, which was not captured by the coarse resolution simulation (54km), is exceedingly well captured by the 6km simulation. The positive anomalies in specific humidity attain a maxima during 2030-0230 IST in the north and during 0830-1430 IST in the south. This confirms the role of moisture convergence in the southward propagation of rainfall. Equally importantly we find that while low level moisture convergence is dominant in the north Bay, it is the mid-level moisture convergence that is predominant in the south Bay.

Urban wet weather discharge impairs the receiving water and sediment quality. Among other factors, particulate matter plays a role. It increases the suspended sediment load of the receiving water and may thus enhance the clogging of the bed sediment which serves as an important river habitat. This thesis investigates how much urban areas may contribute to the fine sediment and associated element load which is retarded by the bed sediment. It is based on an extensive field study. The study area was the Bode River, a mid-sized stream in Central Germany. About 10 km upstream of the river mouth, the sampling campaign took place close to Staßfurt, a town of 20’000. During the sampling campaign, the intrusion of fine sediment into the bed sediment was captured by sediment traps. Furthermore three possible sources of this fine sediment were sampled. Within the Town of Staßfurt, we sampled urban wet weather discharge at three sites to capture urban areas. As second source naturally occurring fine sediment was considered. Therefore we took sediment cores upstream of the Town of Staßfurt. As third source, the impact of the upstream catchment was captured by taking suspended sediment samples. For all sample types, particle-bound element contents were determined to establish element patterns of the receptor and the source sites. The rationale thereby is that the element pattern at the receptor sites results from the element patterns of the sources. Consequently the contribution of the sources can be calculated by mixing models. In the study area, particulate matter from urban areas is distinct from river borne fine sediment due to elevated copper, zinc, nitrogen and phosphorus contents. We conducted an in-depth analysis of this element pattern by a cluster analysis. It revealed that the particle-bound element pattern is source specific whereby nitrogen, phosphorus and carbon are related to sewage and behave differently than most metals such as copper which mainly originate from surface runoff. The degree to which element patterns agree from site to site is limited by the variability encountered within sample sets from individual sites. Thereby the variability of the element pattern depends on the complexity of the catchment. The contribution of urban areas to fine sediment and associated elements which were captured by sediment traps was calculated by a mixing model. Based on this mixing model, about 10% of the fine sediment originate from urban areas. Thereby the impact of the Town of Staßfurt could not be detected leading to the conclusion that upstream urban areas contribute most. Because of the elevated content of e.g. copper and zinc, urban areas contribute up to 40% and thus disproportionally high to particle-associated copper and zinc load. The source apportionment of the fine sediment is little influenced by the elements considered in the mixing model. Different element patterns showed that the median contribution of urban areas ranges from 0 – 20%. This lies within the interquartile range of the initial mixing model. Another result of the measurement campaign ist that sediment traps over-estimated the anthropogenic impact because they did not resemble the surrounding bed sediment. When they were exposed, they were completely free from fine sediment and hence served as sink of suspended sediment. During the sampling campaign, one source was not directly taken into account. It was possible, though, to delineate this source by nonnegative matrix factorization. Within the Town of Staßfurt, a soda ash production site discharges into the Bode River. The nonnegative matrix factorization uncovered that the soda ash production site is a major source of particulate matter and contributes up to 30% of the fine sediment captured by the traps downstream of the Town of Staßfurt. This source dilutes most element contents as it mainly consists of carbonates. This was revealed by studying the element binding according to the BCR extraction scheme. This thesis shows that urban areas may be a major source of particulate matter and especially associated elements retarded by the bed sediment. It shows that the element contents form a viable pattern to calculate how much urban areas contribute to fine sediment by mixing models. The thesis further shows that nonnegative matrix factorization is a viable tool to delineate such a distinct source as soda ash production site.
Misch- und Regenwasserentlastungen beeinträchtigen die Qualität von Vorflutgewässern. Unter anderem gelangt Feinsediment während Entlastungsereignissen in Vorflutgewässer. Dieses erhöht die Fracht an suspendiertem Sediment und verstärkt die Kolmatierung der Gewässersohle. Damit ist das hyporheische Interstitial, das ein wichtiges Fließgewässerhabitat ist, vom Eintrag von Feinsediment betroffen. Diese Arbeit untersucht, wie sehr urbane Flächen zur Feinsedimentfracht und zur Fracht von partikulär gebundenen Elementen beitragen können, die im Bettsediment zurückgehalten werden. Sie beruht auf einer umfangreichen Messkampagne. Das Untersuchungsgebiet dafür war die Bode, ein mittelgroßer Fluss in Mitteldeutschland. Etwa 10 km flussaufwärts der Mündung fand die Messkampagne nahe der Kleinstadt Staßfurt statt. Im Rahmen dieser Messkampagne haben wir den Eintrag von Feinsediment in das Bettsediment durch Sedimentkörbe erfasst. Drei Quellen dieses Feinsediments haben wir berücksichtigt. In Staßfurt wurden eine Regen- und zwei Mischwassereinleitungen beprobt, um urbane Flächen zu erfassen. Als zweite Quelle wurde natürlich vorkommendes Feinsediment berücksichtigt. Dafür haben wir Sedimentkerne flussaufwärts von Staßfurt genommen. Als dritte Quelle haben wir das stromaufwärts liegende Einzugsgebiet erfasst, indem wir das suspendierte Sediment beprobt haben. Für alle Proben wurde der Elementgehalt bestimmt, um das Elementmuster des Feinsediments, das ins Bettsediment eingetragen wurde, und der Quellen zu ermitteln. Der Grund für diese Messstrategie war, dass das Elementmuster des Feinsediments in den Körben aus den Elementmustern der Quellen, Regen- bzw. Mischwassereinleitungen, natürlich vorkommendes Feinsediment und suspendiertes Sediment aus dem Einzugsgebiet, resultieren sollte. Damit ist es möglich, den Beitrag über Mischungsmodelle zu berechnen. Im Untersuchungsgebiet unterscheidet sich das Feinsediment, das von urbanen Flächen stammt, von dem flussbürtigen Feinsediment aufgrund erhöhter Kupfer-, Zink-, Stickstoff- und Phosphorgehalte. Wir haben das Elementmuster der urbanen Flächen mit einer Clusteranalyse genauer untersucht. Dies ergab, dass das partikulär gebundene Elementmuster quellenspezifisch ist, wobei sich Stickstoff, Phosphor und Kohlenstoff Abwasser zuordnen lassen, während die meisten Metalle wie Kupfer und Zink hauptsächlich aus dem Oberflächenabfluss stammen. Das Maß, zu dem die Muster von Messpunkt zu Messpunkt übereinstimmen, wird durch die Variabilität beschränkt, die die Proben eines Messpunktes aufweisen. Diese Variabilität hängt dabei von der Komplexität des Einzugsgebiets ab. Über eine Mischungsrechnung konnten wir berechnen, wie viel urbane Flächen zur Fracht von Feinsediment und daran gebundenen Elementen in den Sedimentkörben beitrugen. Im Untersuchungsgebiet stammen etwa 10 % des Feinsediments, das durch die Sedimentkörbe aufgefangen wurde, von urbanen Flächen. Der Beitrag der Stadt Staßfurt konnte dabei aber nicht von dem Beitrag weiter flussaufwärts gelegener urbaner Gebiete getrennt werden. Daraus folgt, dass weiter stromaufwärts liegende Gebiete mehr beitragen als Staßfurt. Wegen des erhöhten Gehalts an z.B. Kupfer und Zink tragen urbane Flächen ca. 40 % und damit überproportional hoch zur partikulär gebundenen Kupfer- und Zinkfracht bei. Für die Berechung des Quellenbeitrags zum Feinsediment spielt es keine große Rolle, welche Elemente in der Mischungsrechnung berücksichtigt werden. Verschiedene Elementmuster ergeben, dass der Medianbeitrag urbaner Flächen zwischen 0 und 20 % liegt. Dies entspricht dem Interquartilsabstand der ursprünglichen Mischungsrechnung. Ein weiteres Resultat der Untersuchungen ist, dass die Sedimentkörbe den anthropogenen Einfluss überschätzten, weil sie das umgebende Bettsediment nicht exakt abbildeten und als Falle funktionierten. Innerhalb Staßfurts gibt es ein Sodawerk, das seine Produktionsabwässer in die Bode einleitet. Während der Messkampagne wurde diese Quelle nicht direkt erfasst. Es war trotzdem möglich, diese Quelle durch nicht-negative Matrix-Faktorisierung zu identifizieren. Die nicht-negative Matrix-Faktorisierung ergab, dass das Abwasser des Sodawerks eine Hauptquelle des Feinsediments der Bode ist. Bis zu 30 % des Feinsediments in den Sedimentkörben flussabwärts von Staßfurt lassen sich dem Sodawerk zuordnen. Dieses Feinsediment besteht hauptsächlich aus Karbonaten und verdünnt die meisten Elementgehalte. Dies wurde deutlich, indem die Elementbindungen nach dem BCR Extraktionsschema untersucht wurden. Diese Arbeit zeigt die Relevanz, die urbane Flächen als Quelle von Feinsediment und daran gebundener Elementfracht haben, die ins Interstitial eingetragen werden. Sie zeigt, dass die Elementgehalte ein Muster bilden, mit dem es möglich ist, über eine Mischungsrechnung zu klären, wie viel urbane Flächen zum Feinsediment beitragen. Die Arbeit zeigt ferner, dass nicht-negative Matrix-Faktorisierung ermöglicht, eine so charakteristische Quelle wie ein Sodawerk zu identifizieren.

碩士
國立中興大學
森林學系
91
This paper which including the forest fire situation analyzed, fuel factor, people factor, and weather factor is concentrating on the forest fire basic situation and fire weather index. By the fire situation analyzed and the research of the fuel, energy, and weather we can provide the information of forest fire rescue. The summary of obtained result is as follows : Luanta forest fire situation have clear and obvious seasonal change. The fire type is always ground fire which burning light fuel. Almost forest fire were caused with people and the most reason were smoking. Finally we make the Wet Coefficient to know the forest fire potential in the forestry. Through the index we can adjust the method about forest fire rescuer. The findings will provide detailed information for forest fire and make some help with forest fire rescuer in the future.

碩士
吳鳳科技大學
消防研究所
105
Most of the fires in the windbreak areas of Taichung Harbor were concentrated in the northeast monsoon beginning from September to February of the following year. During this period, the precipitation in the forest area was low, and the litter in the forest area was dry. In this paper, based on the daily metrological data (temperature, preeipitation, relative humidity, and wind speed), and the Canadian forest fire weather index system was introduced, and the meteorological data and forest fire data from 1991 to 2015 in Taichung Harbor were used to study the correlation between forest fire index and forest fire. The results showed that the DSR continued to increase from the beginning of 1990 (DSR = 10.48), but in the past 10 years has shown a lower value(DSR = 1.54), and found that the surface ignition susceptibility or ignition probability of windbreak forest area in Taichung Harbor is increasing continuously from 1990 to 1995 (FFMC=78.76）, but is decreasing from 2010 to 2015（FFMC=74.76）.

碩士
國立雲林科技大學
環境與安全衛生工程系碩士班
99
The study is on photochemical station and the main station at Taihsi county in Yunlin, using the monitoring data and making the volatile organic compounds ( VOCs ) species mass ratio, and choosing the lower reaction Benzene ( referred to as B ). The major of VOCs species includes Toluene,( referred to as T ), m/p-Xylene,( referred to as X ) , 1,2,4-Trimethylbenzene, ( referred to as 124-TMB ), 1,3,5-Trimethylbenzene, ( Referred to as 135-TMB ). The characteristic species of the petrochemical industry of Styrene, ( referred to as S ) and Isopropylbenzene, ( referred to as IPB ). The species mass ratio can avoid the different layer of atmosphere and make the atmosphere space’s mass variation. By OH free radical method can estimate the photochemical age, and verify the species ratio and have the normal relationship of photochemical age. The higher ratio indicates the fresh air. The whole month data is so gigantic and can’t control the variational condition. For prominent and estimated the possible pathway. The study used each species’ top 5% mass ratio and top 3 major species mass ratio to proceed researching. When concluded and analyzed the data of temperature, humidity, wind direction and speed, and Principal Component Analysis ( referred to as PCA ) method is applied to analyze the top 5% species ratio out form the May-December 2010 at Taihsi station. When the mass of species, wind speed and wind direction are the main factor, it explain reaching to 83.6% variance volume of the top 5% average ratio ( T/B ,124-TMB/B, S/B, IPB/B ). First the air mass aging characteristic, photochemical half-life, sea-land wind effect and transport distance methods to proceed the top 5% species ratio( such as T/B, X/B, 124-TMB/B, 135-TMB/B, S/B, and IPB/B ) and the top three of species ratio of the month. Then proceeding of 6th cracking plant petrochemistry’s fire, date of typhoon event researching, and finally capitalize on backward trajectory path and T/B, S/B and IPB/B ratio to support the different relationships between time and wind information of pollution. Summary, it has the significant effect of sea and land wind. Because the species ratio with S/B and IPB/B ratio mainly come from the southwest winds, it is caused a higher ratio of species on May to December. About northeast wind it would cause the increase of the T/B, X/B ratio of species. While the northwest wind axis is caused by the shorter half-life 1,3,5-TMB may be increased, and increasing to top 5% 135-TMB/B ratio (circa 0.78). The main emitted resource of species may be concern with the industrial combustion. Finally we can figure out the species ratio with fire and typhoon are no significant connected with 6th cracking plant petrochemistry. Typhoon events are associated with different axis wind and bring the different species increasing. For example, the northeast monsoon, which cause that S/B species ratio relative about half of July and August (circa 0.55). Therefore, it should compare that different types of species ratio effect and coordinated with sea-land wind transport distance comparison. By the 8 hours’ backward trajectory path estimation, track at the station when the prevailing sea-land wind effect on May to August. The land wind is more significant on the top three of S/B ratio (Between 2.4~3.5), but the sea wind is more significant on the top three of IPB/B ratio (between 0.4~0.7). The northeast wind is the main axis wind effected on October to December. It is made T/B, S/B and IPB/B the top 3 ratio appeared in the northeast monsoon path. This study’ contribution are applied to the integrated with station wind direction, speed, temperature and emission source ratio data. The statistics method to analyze and judge the VOCs emission that source on the nearby area (Air Quality inspecting station). Especially petrochemical industry specific species to S/B and IPB/B ratio research. And screen each month’ top 5 % data to control the fresh air mass’s VOCs audit value, and to decrease specific species affected by photochemical reaction, after sifting data we can proceed another analysis. The study of VOCs data screen and analytical method are coordinated photochemical year estimation, sea-land wind effect research backward trajectory analysis, that can search under the industrial area’s normal and abnormal emittion condition to the neihborhood contribution or search the typhoon etc. climate condition to industrial area peripheral density’s affect, investigated the pollutant reason and can judge the pollutant source. The study can supply some easier data analysis and the evalution of emission source.

Au cours des dernières décennies, le nombre d'occurrences de catastrophes naturelles a augmenté sensiblement. Cette augmentation a des conséquences catastrophiques sur les espaces verts, les propriétés et les êtres vivants. L'énorme quantité de dommages a attiré l'attention des chercheurs, des organisations et des secteurs gouvernementaux et non-gouvernementaux vers l'analyse de ces phénomènes, leurs causes et leurs effets. Le but est de pouvoir reconnaître leurs comportements et prédire leur occurrence pour mieux aborder la phase de gestion des risques qui contribue à empêcher leur incidence ou limiter les conséquences. Le risque de d'incendie existe souvent et la présence de dangers est également possible. D'où l'importance de tout effort pour lutter contre de telles crises. Dans cette contribution, le phénomène des incendies de forêt est étudié. Au Liban, les espaces verts ont considérablement diminué au cours des dernières années, ce qui impose une intervention urgente des politiques et le soutien des organisations gouvernementales et non gouvernementales. L'orientation globale est d’aller vers des techniques qui permettent de prédire les risques élevés d'incendie permettant ainsi de prendre des précautions pour empêcher les occurrences d'incendie ou tout au moins limiter leurs conséquences. La prévision des incendies de forêt contribue à prévenir d'une part la fréquence des incendies et d'autre part, à réduire ses impacts sur les êtres vivants, les propriétés et la richesse forestière
During the last decades, the number of occurrences of natural disasters has increased noticeably which lead to catastrophic results on human as well as properties and green areas. But despite the huge amount of damages, this helps to draw the attention of researchers, organizations and the various governmental and non-governmental sectors towards analyzing these phenomena, their causes & effects, allowing to recognize their behaviors and the methods to predict their occurrence and thus reaching the phase of risk management contributing to prevent their incidence or limit the consequences. As the risk of happening often exists, the instantaneous presence of dangers is also possible. Here appears the importance of any effort that serves to tackle such crises. In this contribution, the phenomenon of forest fires is studied. In Lebanon, green areas declined dramatically during the last decades, what imposes an urgent intervention with strict governmental policies and support of non-governmental organizations. The global orientation is towards techniques that predict high fire risks, allowing for precautions to preclude fire occurrences or at least limit their consequences. Forest fire prediction proves to contribute in preventing fire occurrence or reducing its catastrophic impacts in worst cases on human lives, properties and green forestry

Tese de mestrado, Ciências Geofísicas (Meteorologia e Oceanografia), Universidade de Lisboa, Faculdade de Ciências, 2019
Os incêndios florestais são um risco que não é recente na Península Ibérica. No entanto, é inquestionável que alguns dos episódios mais dramáticos, tanto em termos de vítimas infligidas como de área total ardida, ocorreram durante este século, particularmente na região Oeste da Península Ibérica. A sua ocorrência é responsável, todos os anos, por uma grande quantidade de área ardida, traduzindo-se com frequência em impactos humanos e socioeconómicos significativos. Como tal, existe um reconhecimento crescente que a identificação de uma multiplicidade de padrões de circulação associados à ocorrência de fogos (Fire Weather Types, FWT) tem um interesse considerável em estudos de regimes de fogo, nomeadamente para 1) uma melhor compreensão da relação entre a meteorologia e a ocorrência de fogos; 2) explicar os padrões de severidade dos fogos; 3) melhorar as projeções/previsões e estratégias de combate aos fogos. Neste estudo propõe-se a identificação e a análise dos fatores meteorológicos que controlam as variações da atividade associada aos grandes incêndios na Península Ibérica. Para isso, procede-se à classificação dos grandes de incêndios (aqueles cuja área ardida é superior ao percentil 95) para uma estação de fogos estendida (maio a outubro) para quatro regiões com regimes de fogo semelhantes. A identificação dessas regiões é feita de acordo com as condições meteorológicas locais (temperatura, humidade relativa, velocidade do vento e índices representativos da secura dos combustíveis), recorrendo-se a uma análise de compósitos para diferentes escalas temporais e de forma a captar a variabilidade interanual, subsazonal e sinótica. Para além disso, pretende-se ainda utilizar a análise de clusters (K-means) para identificar um conjunto limitado de FWT, sendo cada um caracterizado por uma certa combinação de condições meteorológicas sinergéticas condutoras do fogo. A identificação dos limiares a partir dos quais um determinado fogo se considera um grande incêndio em cada uma das quatro regiões da Península Ibérica, permitiu a identificação de limiares distintos, sendo a região Este aquela que apresenta o valor mais elevado (171 ha). A análise de compósitos aplicada a uma escala diária para as anomalias standardizadas das variáveis meteorológicas e para os índices que funcionam como proxies de seca, tendo em conta os percentis 1, 85, 95, 98 calculados para as áreas queimadas associados aos eventos ocorridos em cada uma das regiões, permite verificar um aumento das anomalias (em módulo) com o aumento da área queimada dos incêndios. A uma escala de 12 dias, as variáveis meteorológicas são aquelas que têm maior importância na distinção da atividade associada aos grandes incêndios, embora com desfazamentos (lags) temporais diferentes para as quatro regiões. A uma escala mais longa (oito meses), os índices que traduzem a secura dos combustíveis a diferentes camadas do solo são aqueles que têm maior importância. A aplicação da análise de clusters permitiu identificar três FWT distintos para cada uma das regiões. O FWT_1 caracteriza-se por anomalias da velocidade do vento elevadas (acima de um desvio padrão). No caso do FWT_2, as anomalias das variáveis meteorológicas são bastante menores, situando-se abaixo de um desvio padrão. Por fim, o FWT_3 distingue-se por apresentar elevadas anomalias da temperatura e humidade relativa (acima de um desvio padrão). As quatro regiões apresentam, no entanto, resultados diferentes para cada um dos FWT identificados. Para além disso, verifica-se que o FWT_3 é aquele a que estão associadas as condições de secura dos combustíveis mais intensa para todas as regiões. A uma escala de 12 dias, verifica-se que: 1) para o caso do FWT_1 a influência do vento está restrita ao dia do fogo; 2) para o FWT_2 as anomalias variam em torno de zero sem nenhum padrão definido; 3). O FWT_3 não apresenta uma influência restrita ao dia do fogo, mas a sua influência varia nas quatro regiões. A análise do estado da secura dos combustíveis associados aos eventos caracterizados por cada um dos FWT permitiu identificar que o FWT_3 é aquele a que corresponde a uma situação em que os os índice representativos da secura dos combustíveis apresentam anomalias mensais mais elevadas quando comparadas com as anomalias do FWT_1 e FWT_2 para as quatro regiões. Esta análise permitiu identificar as condições climáticas associados à ocorrência dos grandes incêndios para quatro regiões da Península Ibérica tendo em conta as características meteorológicas das regiões, permitindo assim, diferenciar as condições meteorológicas e as diferentes escalas temporais entre a atividade que está na origem de todos os incêndios e aquela que está associada aos grandes incêndios.
The Mediterranean region is characterized by the frequent occurrence of summer wildfires representing an environmental and socioeconomic burden. Some Mediterranean countries (or provinces) are particularly prone to Large Fires (LF), namely Portugal, Galicia, Greece, and southern France. On the other hand, the Mediterranean basin corresponds to a major hotspot of climate change, and anthropogenic warming is expected to increase the total burned area due to fires in Mediterranean Europe. Here, we propose to classify summer large fires for four regions of Iberia (with similar fire regimes) according to their local-scale weather conditions (i. e. temperature, relative humidity, wind speed) and fire danger weather indices (Duff Moisture Code and Drought Code). The composite analysis was used to investigate the impact of local and regional climate drivers at different time scales, and to identify distinct climatologies associated with the occurrence of LF in Iberia for an extended fire season (May to October). A Principal Component Analysis (PCA) was applied to identify the variables with the highest variance explained for the fire day. Also, cluster analysis was used to identify a limited set of Fire Weather Types (FWT), each characterized by a combination of meteorological conditions leading to a better understanding of the relationship between meteorology and fire. For each of the regions, three FWTs were identified with different characteristics. The FWT_1 is characterized by high anomalies (above one std) of zonal wind velocity. The FWT_2 presents anomalies of the meteorological variables within the average (bellow one std). Finally, the FWT_3 is categorized by high positive temperature anomalies (above one std) and strong negative relative humidity anomalies (bellow one std). The methodology followed allowed to objectively identify for different regions of Iberia multiple fire climatologies associated with the occurrence of LF.

碩士
正修科技大學
電機工程研究所
106
Everyone can tell the weather nowadays is very unstable and often turns into extremely severe conditions. As a result, it often causes a lot of damage to our agriculture and loss. Especially when there is a typhoon slashing our island, not only does it make our life inconvenient, but also evaporates our farmers’ efforts in a short time so prices rise instantly. All of which have a significant impact to our life. In order to reduce the impacts, some related units and private enterprises are trying to find out the solutions for it. The government is also trying to promote the vegetable greenhouses for the reduction on the impact. However, its so pity that the promotion isn’t still being carried out practically. On the other side, the government also spares no efforts to promot the solar electric energy, so under all conditions we may integrate Photovoltaic Systems with Vegetables greenhouses to find out the best method to create a win-win situation for government, farmers and photovoltaic dealers.