Dissertations / Theses on the topic 'Pollution events'

This research uses air pollution data, information about the locations of the air quality monitoring stations, and political events data from 2016 to 2017 to investigate the possible existence and characteristics of China’s routine short-term environmental policies aimed for ambient air quality. The results of multiple difference-in-difference suggest that air quality in the urban area, where ambient air pollution levels are usually higher due to population density, is lower on diplomatic events dates, while there is limited evidence that air quality is better in the urban area on domestic events dates. Therefore, this research reveals that there are short-term policies taking place on diplomatic events dates.

Ce travail de thèse vise à améliorer notre connaissance des sources proches et lointaines contrôlant le dépassement des seuils réglementaires de qualité de l’air, tels qu’ils peuvent être appréciés par les réseaux de mesure existants, sur le site fortement industrialisé et urbain du Grand Dunkerque. Il s’agit notamment de s’appuyer sur le calcul d’un indice d’état de mélange des particules, prenant en compte l’hétérogénéité de leur composition élémentaire, celle-ci étant liée à leur temps de séjour dans l’air et à la distance entre les sources et le site récepteur étudié. Pour répondre à cette problématique, il a fallu dans un premier temps développer un impacteur séquentiel de particules à haute résolution temporelle, nommé TRAPS, qui répondait au besoin de suivre les changements rapides observés au sein des particules atmosphériques lors d’épisodes de pollution. Couplé à un granulomètre et après analyse individuelle des particules prélevées par microscopie électronique (MEB-EDX), le TRAPS permet de rendre compte de l’évolution physico-chimique des particules atmosphériques au cours du temps. Dans la première partie de cette thèse, des expériences menées en laboratoire et une campagne de terrain ont permis de valider notre prototype, de rendre compte de la dynamique de dépôt des particules sur les zones d’impaction et de vérifier les diamètres de coupure des étages grossier et fin du TRAPS, déterminés respectivement à 1.32µm et 0.13µm. Une étude statistique des épisodes de pollution aux PM₁₀ survenus sur le grand dunkerquois a ensuite été réalisée sur 3 ans, entre 2018 et 2020. Elle nous a permis d’identifier 12 principaux types d’épisodes sur la base de leur étendue spatiale, mais aussi des conditions locales de dispersion des polluants. On a pu ainsi identifier des épisodes locaux et des épisodes régionaux observés, soit en conditions atmosphériques stationnaires ou au contraire en conditions de dispersion des pollutions à plus grande échelle. Alors que 78 % des jours de dépassement du seuil réglementaire des PM₁₀ correspondent à des épisodes locaux, les 22.4% restant correspondent à des panaches de pollution d’étendue au moins régionale, avec une proportion égale des jours de dépassements en condition de dispersion et en conditions stationnaires. Hormis les épisodes très localisés, une étude fine de la variabilité temporelle des concentrations en particules fines (PM₂.₅) montre la présence systématique d'une période d'accumulation progressive des polluants, pouvant atteindre une dizaine d'heures et caractérisée par une contribution importante de ces particules. La dernière partie de ce travail a consisté en l'étude de la composition et l'état de mélange des particules individuelles collectées lors d'évènements de pollution sur la zone du Grand Dunkerque en 2021. La campagne a permis l'échantillonnage et la caractérisation de 5 épisodes de pollution durant lesquels le TRAPS était déployé en parallèle d'autres instruments fournissant des informations complémentaires sur la granulométrie des aérosols, la météorologie ou la dynamique atmosphérique. Près de 28000 particules individuelles ont été caractérisées par MEB-EDX. Avec plus de 90% des échantillons associés à des valeurs de l'indice d'état de mélange chimique supérieures à 0.5, il est possible d'affirmer que les particules collectées sur la zone du Grand Dunkerque, durant ces épisodes de pollution, sont, en général, de composition très hétérogène à l'échelle de la particule individuelle (particules dites "en mélange interne"). Les résultats obtenus montrent en outre une influence de l'origine, locale ou transportée, des particules sur leur composition chimique et par là même sur l'indice d'état de mélange chimique de la population de particules échantillonnées. Une évolution croissante de l'indice d'état de mélange avec le temps de résidence des particules dans l'atmosphère lors de ces évènements est notamment observée
This thesis aims at improving our knowledge of the near and distant sources controlling the exceedance of the regulatory thresholds of air quality, as detected by the air quality monitoring networks, at the strongly industrialized and urban site of Great Dunkirk Area (GDA). This appreciation is notably based on the calculation of a mixing state index of the particles, taking into account the heterogeneity of their elementary composition, this one being related to their residence time in the atmosphere and the distance between the sources and the studied receptor site. To do that, it was firstly necessary to develop a time resolved cascade impactor with high temporal resolution, named "TRAPS", which answered the need to follow the rapid changes observed within the atmospheric particles during pollution episodes. Coupled with a particle size analyser and after individual analysis of the collected particles by electron microscopy (SEM-EDX), TRAPS allows to report the physicochemical evolution of atmospheric particles over time. In the first part of this thesis, laboratory experiments and a field campaign allowed to validate our prototype, to report the dynamics of particle deposition on the impaction stages and to verify the cut-off diameters of the coarse and fine stages of TRAPS, determined respectively at 1.32µm and 0.13µm. A statistical study of PM₁₀ pollution episodes occuring over the GDA was then carried out over 3 years, between 2018 and 2020. It allowed us to identify 12 main types of episodes based on their spatial extent, but also on the local conditions of pollutant dispersion. We were able to identify local episodes and regional episodes observed, either in stationary or dispersive atmospheric conditions. While 78% of the PM₁₀ exceedance days correspond to local episodes, the remaining 22% correspond to pollution plumes with at least a regional extent, with an equal proportion of exceedance days in dispersion and stationary conditions. Except for very localized episodes, a detailed study of these pollutions episodes shows the systematic presence of a period of pollutant accumulation, of about 10 hours, characterized by an important contribution of fine particles (PM₂.₅) except for episodes of limited spatial coverage. The last part of this work consisted in the study of the composition and mixing state of the individual particles collected during pollution events in the GDA in 2021. The campaign allowed the sampling and characterization of 5 pollution episodes, during which TRAPS was deployed in parallel with other instruments providing complementary information on aerosol granulometry, or atmospheric dynamics. Nearly 28000 individual particles were characterized by SEM-EDX. With more than 90% of the samples associated with values of the mixing state index higher than 0.5, it can be said that the particles collected in the GDA during pollution episodes are in general of very heterogeneous composition at the particle scale (internal mixing). Nevertheless, the results show an influence of the local or transported origin of the particles on their chemical composition, but also on the mixing state index. An increasing evolution of this index with the particles residence time during these events is observed

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (M.S.)--Joint Program in Marine Environmental Systems, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1998.
Includes bibliographic references (p. 79).
by Charles E. Rawson.
M.S.

Le mercure est un composé toxique. En zone polaire, au printemps, une chimie extrêmement particulière est à l'origine, après oxydation, de son dépôt en surface du manteau neigeux. Ces phénomènes appelés « Atmospheric Mercury Depletion Events » (AMDEs) ou « pluies de mercure » sont à la base d'une contamination encore mal renseignée des écosystèmes polaires. Lors de campagnes de terrain en Arctique, nous avons observé sept AMDEs, et avons étudié les paramètres physico-chimiques susceptibles de gouverner l'apparition de ces événements. Le rôle des basses températures et l'implication des nuages glacés parmi les surfaces gelées actives sont évoqués. L'impact de ces AMDEs en terme de teneurs en mercure dans la neige de surface a également été examiné. Les dépôts résultant de ces phénomènes n'aboutissent pas forcément à une contamination marquée de la neige de surface, et nos connaissances sont aujourd'hui trop limitées pour pouvoir quantifier l'apport toxique des AMDEs sur l'Arctique.

Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains viii, 70 p. : ill., maps. Vita. Includes abstract. Includes bibliographical references.

Sustainable urban Drainage Systems (SuDS) present a ‘blue-green’ method of urban stormwater management that is increasingly implemented in the UK and worldwide. SuDS mimic natural vegetated flow paths and are designed to manage the increase in stormwater quantity and degradation of stormwater quality resulting from development (urbanisation). They have been widely implemented across the UK over the last 15 years, to aid compliance with the EU Water Framework Directive (2000) standards for river water quality. Given the increasing maturity of UK SuDS, there is growing concern over the long-term performance efficiencies of these assets/networks, particularly the variability of treatment efficiency over multiple flow events. Providing the field monitoring evidence base to address this concern forms the aim of the present thesis. Emphasis is placed upon understanding SuDS asset/network sediment detention efficiency, as the majority of urban pollution is adsorbed to sediment material rather than transported and treated as solute. A novel tracer method is, therefore, developed and employed to identify and quantify sediment processes for mature UK case study SuDS. SuDS design manuals (CIRIA 2015, Water by Design 2006, USEPA 2009) present expected or reported sediment detention and pollution mitigation levels for specific SuDS assets. For example, the expected Total Suspended Solids (TSS) removal for a swale has been defined as 90% in the WSUD (Water Sensitive Urban Design) technical manual (Leisenring et al. 2013). Yet, these treatment efficiencies are based on a single ‘design’ rainfall-runoff event through the system; hence, fail to consider the sensitivity of SuDS performance to non-design and multiple repeat events over the long term design life of the SuDS asset. As natural variability in rainfall affects pollutant washoff, shear stress for entrainment, conveyance, deposition, loss of treatment capacity etc., the research presented in the present thesis intensively monitored four established UK SuDS networks for 6-12 month timeframes. Bulk sampling data highlight that TSS treatment is highly variable, ranging from highly effective (>80%) to inefficient (< 20%). Similar variability is found in sediment deposition rates (on average: 0.4-1.1 kg/m2/yr), providing insight on temporal and asset dependency of fine sediment detention, including related treatment efficiency and long term loss of capacity. Wetlands illustrate the most effective (mass) sediment detention per area (>1kg/m2) while the swales detain the least (< 0.8kg/m2). To advance the volumetric data noted above, source-sink routing of diffuse fine sediment pollution required development of tracer methodology appropriate to use in SuDS. This dictated use of Rare Earth Oxides (REO) as fine sediment tags; although their use in an urban environment is new, it provides long term trace and experimental replicability results without loss of provenance, signature degradation or loss of tag material. Thus, unique time-stamped and source-specific identifiers have been used monitor their movement into and through each SuDS over a 6-12 month period. Use of REO tagged sediment data permits mass balance analysis of fine sediment through the monitored SuDS assets and networks. Data clearly illustrate that sediment is not fully detained (as assumed in SuDS design); rather, sediment is re-entrained and re-deposited multiple times over multiple flow events. Residence time of sediment within a full SuDS network is found to be as short as 12 weeks, raising concern over treatment capability. Reviewing this at finer asset-based resolution, detention efficiency and conveyance rates appear unique to each asset. Generally linear wetland and swale assets demonstrate the greatest (tagged) sediment detention efficiency (>70%) while (the monitored) wetland assets decline to below 50% efficiency over the first 12 months and ponds demonstrated negligible sediment detention efficiency (< 10%). As 80% of urban pollution is conveyed adsorbed to fine sediment, the sediment conveyance pattern through SuDS assets has been analysed to define the pollutant concentration levels and trends of detained sediment. Pollutant levels show no consistent trend across SuDS assets. Results illustrate that sediment pollutant contamination shows an influence from particle size distribution and mass deposition as well as asset design. Analysis shows the most numerous significantly elevated sediment pollutant concentrations within the linear wetland, with Fe, Ba, Cr, Cu, Zn, K and P demonstrating average concentrations above contaminated land thresholds. Enrichment and geoaccumulation indexing of pollutants illustrates Fe, Zn, Cr, Ba, Cu and P to be pollutants of concern, with Fe, Pb, Ni, Cr, Mn, Zn, Ba, Cu, Ni and P identified as hotspot pollutants in one or multiple SuDS assets. Cross-correlation of rainfall and flow characteristics with asset/network detention efficiencies were used to define key drivers of multi-event sediment conveyance. Outcomes highlight three variables of strong influence: the number of rainfall and flow occurrences; the antecedent dry days; rainfall clustering characteristics. Weaker correlations are found with flow characteristics (number of flow events, depth and velocity – leading to Fr and Re values) and modal particle size. These influential forcings have then been considered with respect to a selected standard SuDS pollution treatment process (MUSIC k-C*) to identify the compatibility for multiple rainfallrunoff event SuDS fine sediment and pollutant simulation. The research provides multiple event SuDS stormwater treatment efficiencies that can inform improved SuDS design and maintenance planning by engineering consultants, Local Authorities, environmental regulators and SuDS asset managers.

Les cycles couplés des aérosols, de la vapeur d’eau et des nuages sont à l’heure actuelle un domaine de recherche dynamique au cœur d’enjeux climatiques et météorologiques. Une meilleure compréhension des interactions entre ces différents cycles atmosphériques doit permettre de mieux appréhender les processus conduisant à des évènements météorologiques extrêmes et également de diminuer les incertitudes des projections climatiques, en grande partie liées aux interactions aérosols – nuages. Contribuant à ces efforts, les travaux présentés dans cette thèse sont fondés sur l'analyse d'observations expérimentales de terrain autour d’un instrument de télédétection émergent. Il s’agit d’un lidar Raman météorologique transportable capable de mesurer simultanément la température thermodynamique, le contenu en vapeur d'eau et les propriétés optiques des aérosols, dans la colonne atmosphérique. Cet instrument, développé au LSCE et nommé WALI, permet des observations continues dans la basse et moyenne troposphère avec une précision et des résolutions verticale et temporelle en adéquation avec les objectifs de ruptures énoncés par l’OMM. En premier lieu, le bilan de liaison de la chaîne d’acquisition de la température basée sur la spectroscopie Raman rotationnelle, nouvellement implémentée sur le lidar, a été obtenu à l’aide d’une modélisation directe – inverse. Les premières mesures de température par lidar, conduites durant une période très contrastée en température marquée par l’occurrence d’une vague de froid, ont permis une comparaison avec les sorties de modèles de prévisions météorologiques à méso-échelle (AROME/Météo-France) et globale (ERA5/ECMWF) et l'instrument IASI embarqué sur les satellites de la série METOP. Lors d’une configuration météorologique hivernale analogue ayant induit des épisodes de pollution majeurs en Île-de-France, un suivi des propriétés optiques des aérosols a été effectué. Enfin, une campagne de mesure multi-instruments incluant un volet aéroporté a été conduite aux abords du lac d’Annecy, avec une stratégie originale couplant la télédétection et l'observation in situ. Elle a permis une analyse préliminaire du cycle de l'eau dans un environnement montagneux complexe, incluant les liens entre la vapeur d'eau atmosphérique, les nuages, les aérosols et le lac. Le lidar Raman météorologique s’avère être un outil idoine pour étudier ces processus
The coupled cycles of aerosols, water vapor and clouds are currently a dynamic field of research at the heart of climate and weather challenges. A better understanding of the interactions between these atmospheric cycles should allow to perceive the processes leading to extreme weather events and to reduce the uncertainties of climate projections, largely related to aerosol-cloud interactions. In line with these efforts, the work presented in this thesis are based on the analysis of experimental field observations, around a new tool for remote sensing. It is a transportable meteorological Raman lidar capable of simultaneous measurements of the thermodynamic temperature, water vapor content and optical properties of aerosols in the atmosphere. This instrument, developed at LSCE and called WALI, allows continuous observations in the lower and middle troposphere with a precision, and vertical and temporal resolutions in line with the breakthrough requirements set by the WMO. Firstly, the link budget of the temperature acquisition channel based on rotational Raman spectroscopy, newly implemented on the lidar, has been obtained using direct - inverse modeling. The first temperature measurements by lidar, carried out during a very contrasted period in terms of temperature marked by the occurrence of a cold spell, allowed a comparison with the outputs of mesoscale (AROME/Météo-France) and global (ERA5/ECMWF) weather prediction models and the IASI instrument onboard the METOP series satellites. During a similar winter meteorological configuration that induced major pollution events in Île-de-France, the optical properties of aerosols were monitored. Finally, a multi-instrument measurement campaign, involving aircrafts, was carried out on the shores of the Annecy lake, with an original strategy coupling remote sensing and in situ observations. They allowed preliminary analyses of the water cycle in a complex mountainous environment, including the links between atmospheric water vapor, clouds, aerosols and the lake. A meteorological Raman Lidar turns out to be a suitable tool to study these processes

L'objectif de cette thèse est de développer des méthodes statistiques basées sur la théorie des valeurs extrêmes pour estimer des probabilités d'évènements rares et des quantiles extrêmes conditionnelles. Nous considérons une suite de variables aléatoires indépendantes X_{t_1}$, $X_{t_2}$,...$,$X_{t_n}$ associées aux temps $0≤t_{1}< …
The objective of this PhD thesis is to develop statistical methods based on the theory of extreme values to estimate the probabilities of rare events and conditional extreme quantiles. We consider independent random variables $X_{t_1},…,X_{t_n}$ associated to a sequence of times $0 ≤t_1 <… < t_n ≤ T_{\max}$ where $X_{t_i}$ has distribution function $F_{t_i}$ and $F_t$ is the conditional distribution of $X$ given $T = t \in [0,T_{\max}]$. For each $ t \in [0, T {\max}]$, we propose a nonparametric adaptive estimator for extreme quantiles of $F_t$. The idea of our approach is to adjust the tail of the distribution function $F_t$ with a Pareto distribution of parameter $\theta {t,\tau}$ starting from a threshold $\tau$. The parameter $\theta {t,\tau}$ is estimated using a nonparametric kernel estimator of bandwidth $h$ based on the observations larger than $\tau$. We propose a sequence testing based procedure for the choice of the threshold $\tau$ and we determine the bandwidth $h$ by two methods: cross validation and an adaptive procedure. Under some regularity assumptions, we prove that the adaptive estimator of $\theta {t, \tau}$ is consistent and we determine its rate of convergence. We also propose a method to choose simultaneously the threshold $\tau$ and the bandwidth $h$. Finally, we study the proposed procedures by simulation and on real data set to contribute to the survey of aquatic systems

Concentrations of dissolved organic carbon (DOC) measured within water bodies have been increasing on a global scale over the last two decades. Changes in temperature and rainfall have been shown to increase the production and export of DOC from catchments with peat soils in the UK (Freeman et al., 2001). However it is not clear whether increases in DOC concentrations are caused by production increases induced by temperature changes or by a greater incidence of high flows induced by rainfall changes. Increases in both temperature and rainfall have been predicted in Scotland over the next few decades (Kerr et al., 1999) which may further increase current DOC concentrations and exports. The implications of this include both a decrease in water quality and an increase in mobility of metals in upland water bodies. The overall aim of the thesis is to determine if the relationship between dissolved organic carbon (DOC) concentrations and discharge has changed over a 20 year period in small stream catchments in Scotland, in order to better understand the role of hydrology, in driving changes in DOC concentration. To achieve this streams draining two coniferous forest sites and one moorland site were monitored intensively between June 2004 and February 2006. Analysis of the relationship between DOC and discharge, within the catchments, identified the importance of the amount of precipitation falling on the catchment, antecedent precipitation and season, on the concentration of DOC that was measured within the stream. Models were then developed using variables to represent these drivers in terms of both the production (seasonal sine values and 14 day average temperatures) and movement (log of discharge (log Q), days since previous storm event and rising or falling stage) of DOC. In the Ochil Hills catchment, the best predictive model, used 4 hour average discharge and 1 day average 30cm soil temperatures (R2= 0.88). In the Duchray and Elrig catchments, the best predictive models produced used discharge and seasonal sine values; the strength of the model was greater in the Elrig (R2= 0.80) than the Duchray (R2= 0.48) catchment. The strength of the regression models produced highlighted the importance of precipitation in the movement of DOC to the stream and temperature variables representing production in the surrounding catchment. To determine if dissolved organic carbon (DOC) concentrations had changed within the three study catchments, since previous research was conducted at the same sites in the early 1980s and 1990s (Grieve, 1984a; Grieve, 1994), then regression analysis conducted in the previous research was repeated, so changes in the DOC and discharge relationship could be identified. Analysis of the Ochil Hills regression equations identified higher log of discharge and lower temperature and seasonal sine values in the present study (2004-06), when compared to the previous study (1982-83). This suggests that more DOC is now available for movement from the soil, and that the difference between winter and summer DOC production has decreased, potentially because of increasing temperatures. This would explain the limited increase in DOC concentration within the Ochil Hills stream. In the Duchray and Elrig streams, a large increase in DOC was identified at all discharges when all the models produced were compared between the two sampling periods (1989-90 and 2004-06). The increasing trend in DOC concentrations is too large to have been produced by change in temperature alone and it is suggested that the measured reduction in acidic deposition has resulted in the increased DOC concentrations measured in the Duchray and Elrig. The results from this research have identified that concentrations of DOC have increased in Scottish streams over the last 20 years and that the increases in DOC have been induced, potentially by temperature changes in climate. However, changes in temperature are not the only driver of this change as the reduction in acidic deposition is potentially more important, specifically in areas with base poor geology such as the Duchray and Elrig catchments.

Sur le site minier orphelin de Sentein (Pyrénées), la dynamique de Zn, Pb et Cd est étudiée à l'échelle du bassin versant amont du Lez, en couplant des approches géochimiques et minéralogiques. A partir de la minéralisation, primaire et naturelle, l'exploitation minière a redistribué les métaux en plusieurs sources secondaires (sols contaminés, résidus d'extraction et de traitement). Les résidus de traitement constituent le principal réservoir de métaux. Dans ce contexte carbonaté, l'exportation des métaux sous forme dissoute est limitée par la formation de phases minérales secondaires. L'érosion mécanique est le mécanisme majeur de mobilisation des métaux. A l'exutoire du bassin, la dispersion particulaire des métaux est dominante, notamment lors des crues. La contribution de ce site minier au flux de métaux transportés par la Garonne est estimée
On the orphan Sentein mining district (Pyrénées), the Zn, Cd and Pb dynamics is studied at the scale of the Lez upstream catchment, with geochemical and mineralogical approaches. From the primary and natural mineralization, mining exploitation has lead to the redistribution of metal into several secondary sources (contaminated soils, extraction wastes and tailings). Tailings are the main storage compartment of metals. Submitted to erosion, they constitute the principal source. In this carbonated context, the metal exportation under dissolved form is limited by the formation of secondary minerals. Runoff and erosion are dominant processes for metal mobilization. At the catchment outlet, particulate dispersion is dominant specially, during storm events. The contribution of this mining site to Garonne metal fluxes is assessed

The point and nonpoint source pollution released in rivers are the main responsible for the deterioration of the surface water quality. This study aimed to evaluate the water quality of the Vacacai – Vacacai Mirim watershed, in sub-basins located in the city of Santa Maria – RS. In the Vacacai Mirim River, the quality of the water and surface runoff were evaluated through the monitoring of five precipitation events in Joao Goulart sub-basin. The surface runoff negatively influenced the water quality of this water body. The EMC for the analysed parameters, as well as for the transported pollutants masses varied considerably among events. The average EMC for the BOD variable (51.3 mg∙L-1) stands out. The limit established for this variable for class 2 of CONAMA Resolution 357/2005 is only 5 mg∙L-1. Furthermore, the variability of the nonpoint source pollution in Vacacai Mirim River was evaluated in five sub-basins: João Goulart, Rancho do Amaral, Alto da Colina, Menino Deus II, and Menino Deus IV through cluster and principal components analysis using data from current and previous monitoring performed in this watershed. The five sub-basins were grouped according to the water quality and predominant land use and occupation. The BOD variable was essential in the water quality characterization of all sub-basins, and for the majority of them the total coliforms, E. coli, total solids, nitrogen and phosphorus variables were also essentials. In the Vacacai and Vacacai Mirim Rivers the presence of pharmaceutical and hormonal residues was studied in two urban sub-basins with large percentage of impermeable area. In Cancela-Tamandai sub-basin, the hormone etisterone and ibuprofen and paracetamol drugs were detected. The equivalent of 30 tablets of ibuprofen and 15 of paracetamol were released in this water body, on average per day. In the João Goulart sub-basin only the drugs ibuprofen and paracetamol were detected, hence the equivalent daily average load released in this water body is 52 tablets of ibuprofen and 14.5 of paracetamol. The hormones 17β-estradiol, estriol, estrone and megestrol acetate were not detected in the studied watersheds. Therefore, there is the necessity of investments to ensure the improvement of the sewage networks and treatment of domestic effluents, as well as the solid waste collection services. Together these sources contribute to the poor water quality confirmed in this study.
As fontes de poluição pontuais e difusas lançadas nos rios são as principais responsáveis pela degradação da qualidade da água superficial. Este estudo teve como objetivo avaliar a qualidade da água da bacia hidrográfica Vacacaí – Vacacaí Mirim, em sub-bacias localizadas no município de Santa Maria, RS. No rio Vacacaí Mirim, foi avaliada a qualidade da água e do escoamento superficial através do monitoramento de cinco eventos de precipitação na sub-bacia denominada João Goulart. O escoamento superficial impactou negativamente a qualidade da água desse corpo hídrico. As concentrações médias dos parâmetros analisados variaram consideravelmente entre os eventos, assim como as massas poluentes transportadas no curso hídrico. Destaca-se a concentração média do evento para a variável DBO, que foi 51,3 mg∙L-1, sendo que o limite estabelecido para a classe 2 da Resolução CONAMA 357/2005 é de apenas 5 mg∙L-1. Ainda no rio Vacacaí Mirim, foi avaliada a variabilidade da poluição difusa em cinco sub-bacias: João Goulart, Rancho do Amaral, Alto da Colina, Menino Deus II e Menino Deus IV por meio das análises estatísticas de agrupamento e componentes principais utilizando dados de monitoramento atual e realizados anteriormente nesta bacia. As cinco sub-bacias foram agrupadas conforme a qualidade da água e o uso e ocupação do solo predominante. A variável DBO foi importante na caracterização da qualidade da água de todas as sub-bacias, e para a maioria delas, as variáveis CT, E.coli, ST, nitrogênio e fósforo também foram importantes, pois são variáveis que descrevem a qualidade da água com elevada significância. Nos rios Vacacaí e Vacacaí Mirim foi investigada a presença de resíduos farmacêuticos e hormonais em duas sub-bacias urbanas e com grande porcentagem de área impermeável. Na sub-bacia Cancela-Tamandaí foram detectados o hormônio etisterona e os fármacos ibuprofeno e paracetamol. A partir das concentrações analisadas, estima-se que foi lançado nesse corpo hídrico, em média por dia, o equivalente a 30 comprimidos de ibuprofeno e 15 de paracetamol. Na sub-bacia João Goulart foram detectados apenas os fármacos ibuprofeno e paracetamol, sendo lançada a carga média diária equivalente a 52 comprimidos de ibuprofeno e 14,5 comprimidos de paracetamol nesse curso hídrico. Os hormônios 17 β-estradiol, estriol, estrona e acetato de megestrol nunca foram detectados nas bacias estudadas. Diante do exposto, verifica-se a necessidade de investimentos na melhoria de redes de coletas e tratamentos de efluentes domésticos, assim como os serviços de coleta de resíduos sólidos. Juntamente, essas fontes contribuem para má qualidade da água verificada nesse estudo.

As águas superficiais vêm sofrendo impactos em diversas cidades e o escoamento superficial tem sido uma das causas primárias de degradação dos recursos hídricos devido à poluição difusa, além das fontes pontuais, como efluentes domésticos e industriais. A Concentração Média do Evento (CME) tem sido muito utilizada para caracterizar a poluição difusa gerada no escoamento superficial durante o evento de precipitação, além de ser empregada como parâmetro de entrada na estimativa de carga de origem difusa por meio de modelos hidrológicos. Este estudo se dedicou especialmente à avaliação de como a CME influencia a estimativa de cargas difusas quando parâmetro de entrada para modelos hidrológicos. Para isso, além de atividades de campo visando à confecção de modelos de previsão da CME com base em dados reais de uma bacia hidrográfica urbana (Mineirinho, São Carlos, SP) em resposta a eventos chuvosos, buscou-se ajustar, à realidade brasileira, um modelo consagrado para estimativa de cargas difusas e aplicado principalmente em países com clima temperado. Os resultados desta pesquisa mostraram que, em geral, os valores de CME observados são de 2 a 12 vezes maiores que os encontrados na literatura internacional. Em comparação com estudos nacionais, observou-se uma variação nos dados encontrados dependendo das características da bacia hidrográfica monitorada. Além disso, ao adequar o modelo hidrológico L-THIA às características locais, verificou-se um aumento na estimativa da carga de origem difusa quando se utilizavam dados locais. Por fim, com base nas análises realizadas neste estudo, foi possível verificar que os valores de CME que melhor representam as características da bacia hidrográfica do Mineirinho são: nitrogênio total Kjeldahl 6,19 mg.L-1, fósforo total 1,00 mg.L-1, sólidos suspensos totais 870 mg.L-1, chumbo 0,78 mg.L-1, cobre 0,09 mg.L-1 e zinco 0,34 mg.L-1. Reforça-se, portanto, a necessidade de estudos locais para análise da poluição difusa para o planejamento de ações de mitigação de poluição difusa no Brasil.
Surface water has been impacted in several cities and surface runoff has been one of the primary causes of degradation of this resource due to nonpoint source pollution besides the point sources, like domestic effluents and industries. The Event Mean Concentration (EMC) has been widely used to characterize the diffuse pollution generated in the surface runoff during the precipitation event, and it is still used as input parameter in hydrological models that seek to estimate diffuse load. This study focused particularly on the evaluation of how the EMC influences the estimation of diffuse loads as input parameter for hydrological models. To that end, in addition to field activities for the preparation of EMC forecast models based on real data from a river basin in response to rainy events, we attempted to adjust to the Brazilian reality a well-established model for estimating diffuse loads and mainly applied in countries with temperate climate. The results of this research showed that, overall, the EMC observed values are from 2 to 12 times higher than those found in the international literature. Compared with national studies, a variation was observed in the data found depending on the characteristics of the monitored watershed. In addition, when adapting the L-THIA hydrological model to local characteristics, there was an increase in the diffuse source load estimate when using local data. Finally, based on the analyzes carried out in this study, it was possible to verify that the EMC values which best represent the characteristics of the Mineirinho river basin are: Total Kjeldahl Nitrogen 6.19 mg.L-1, Total Phosphorous 1.00 mg.L-1, Total Suspended Solids 870 mg.L-1, Lead 0.78 mg.L-1, Copper 0.09 mg.L-1 and Zinc 0.34 mg.L-1. Therefore, it is necessary to carry out local studies to analyze diffuse pollution in order to create a more solid basis for the planning of mitigation actions to control diffuse pollution in Brazil.

Les écosystèmes d’eau douce sont très vulnérables face aux perturbations anthropiques. Ils peuvent en effet subir de multiples pollutions via entre autres le lessivage des sols des bassins versants mais aussi la remobilisation des sédiments des lits des rivières et des réseaux d’assainissement, phénomènes accentués lors des épisodes pluvieux, particulièrement intenses et fréquents dans les régions au climat méditerranéen. Lors d’un épisode méditerranéen étudié précédemment, il a été démontré que des déversements de mélanges de polluants se produisaient, coïncidant avec le pic de débit et du débordement des déversoirs d’orage (DDO) qui l’ont précédée. Au cours de cette thèse, nous avons pu vérifier que ces multipollutions sont récurrentes, se produisant à chaque DDO et pic de débit lors de deux autres crues. Nous avons donc émis l’hypothèse que les communautés microbiennes fluviatiles, qui constituent le seul compartiment biologique capable de dégrader les polluants, pourraient être largement impactées par ces multipollutions récurrentes en méditerranée. Cette thèse visait ainsi à déterminer l'évolution du microbiome fluviatile au cours d’événements pluvieux extrêmes, et ce, à travers la modélisation statistique combinant des données de séquençage haut débit à une large panoplie de paramètres environnementaux. Les résultats obtenus démontrent une relation significative entre les multipollutions et l’apport de microorganismes liés à la matière fécale, aux milieux urbains et résistants aux polluants et/ou pathogènes. Ces microorganismes exogènes pourraient affecter fortement les communautés résidentes. Compte tenu de la réaction rapide du microbiome fluviatile face aux multipollutions, nous avons également mis en évidence des microorganismes clés de stress multiple, qui pourraient servir comme nouveaux biomarqueurs à incorporer dans un outil de détection de multipollutions pour le suivi de la qualité des eaux
Freshwater ecosystems are highly vulnerable to anthropogenic disturbances. Indeed, they can be subject to multiple forms of pollution via, among other things, the leaching of soil from catchment basins but also the remobilisation of sediment from river beds and sewerage networks, phenomena that are accentuated during rainy episodes, which are particularly intense and frequent in regions with a Mediterranean climate. In a Mediterranean event studied previously, it was shown that discharges of pollutant mixtures occurred, coinciding with the water discharge peak and combined sewer overflows (CSO) that preceded it. During this thesis, we were able to verify that these multipollutions are recurrent, occurring at each CSO and water discharge peak along two other floods. We hypothesised that fluvial microbial communities, which constitute the only biological compartment able to degraded pollutants, could be largely impacted by these recurrent multipollutions in Mediterranean. This thesis aimed to determine the impact of pollutant mixtures on the evolution of the fluvial microbiome during extreme rainfall events via statistical modelling coupling high throughput sequencing data to a wide range of environmental parameters. Results showed a significant relationship between multipollutions events at CSOs and water discharge peak and the appearance of microorganisms linked to faecal matter, urban environments and resistant to pollutants and/or pathogens, which could strongly affect riverine resident communities. Given the rapid response of the fluvial microbiome to multi-pollutants, we were able to identify key multi-stress microorganisms, that could be used as new biomarkers to be incorporated into a multi-pollutant detection tool for water quality monitoring

碩士
國立高雄第一科技大學
環境與安全衛生工程系碩士班
105
The frequency, duration and severity of exposure to air pollutants are important factors in exposure assessment. Exposures long – term and extreme air pollution events have been examined widely with respect to their potential effects, but repeated exposures at moderate levels received little attention. The purpose of this study was to establish a method to evaluate characteristics of their air pollution events. Fine particulate matters (PM2.5) between 2006 and 2016 at Nanzih station were obtained from Taiwan Environmental Protection Agency. Hourly monitoring data were converted to running 24-hour average concentrations. The criterial limit (35 µg/m3) was used to screen for air pollution status. Consecutive hours with 24-hour average concentrations above the limit were treated as the same pollution event. For each identified event, the time of first occurrence, total event hours, average and maximum concentrations were recorded. Between 2006 and 2016, the criterial limit was exceeded 54% of the time, and a pollution event last 92 hours on average, with event average concentration ranging between 35.1 and 83.4 µg/m3, which was substantially higher than the regulatory limit. The duration, frequency and severity of the PM2.5 events showed a strong seasonal pattern. The concentration and duration of pollution events were highest in dry season (October to February) and lowest in rainy season (April to August), with transient season (March and September) in between. The seasonal variation were more pronounced in event frequency and duration. A decreasing trend was observed in event duration, average and maximum concentration in the dry season. The regulatory limit (35 µg/m3) for 24-hr average concentration was used for screening air pollution events in this study. The method may also be applied with different screening value for other pollutants to better characterize intermittent air pollutant exposures.

This study aimed to assess the relationships (if any) between air pollutant measurements in the Durban South Basin (DSB) and (i) local meteorology, (ii) community reports of pollution incidents in Durban, and (iii) air quality and meteorology in Cape Town on the days preceding the Durban South Basin events. With the use of daily synoptic charts and various meteorological variables at an hourly resolution, it was established that air pollution events were better associated with local meteorological events than a community complaint database. Visual analyses of graphed meteorological conditions during the course of air pollution events revealed three clear meteorological scenarios associated with these: 1. A pre-frontal scenario; 2. A scenario showing inversion conditions but no approaching front, and generally low wind speeds; and 3. A post-frontal scenario, likely to be associated with stack downwash under higher wind speeds with the passing of a front. ANOVA revealed significant differences between peak PM10 and average PM10 across scenarios, with Scenario 3 showing highest average and peak PM10. At the Wentworth monitoring station, 24.4% of pollution incidents fell under Scenario 1, 64.2% under Scenario 2, and 5.7% under Scenario 3 between 2006 and 2010. A further 5,7% of the air pollution incidents did not fall under these three scenarios. The latter were not associated with fronts, and did not show inversion conditions, and are likely to be associated with intermittent industrial pollution events. Further statistical analysis assessed the relationships (if any) between various meteorological variables, traffic levels and air pollution concentrations at the Wentworth station between 2006 and 2010. Findings show that delta temperature (change in temperature with height) is the strongest explanatory variable with respect to PM10, wind speed the second strongest, and traffic levels the third strongest. On average, PM10 concentrations increased with increasing delta temperature, decreasing wind speed, and increasing traffic levels. The pressure minimum at Durban associated with an approaching front showed a negative relationship with PM10 during pre-frontal events, but this variable was not significant at the 95% confidence level. This tentatively suggests that even when controlling for frontal influences on delta temperature, lower pressure minima (i.e. stronger frontal systems) are associated with higher pollution levels. Pollution maxima at various Cape Town stations and pressure minima in Cape Town prior to the incident in the DSB showed no relationships with incident PM10 levels at Wentworth. As such, pollution concentrations and meteorology in Cape Town as a front approaches do not appear to be effective predictors of pollution conditions in the DSB when the front approaches there.
Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2013.

碩士
國立陽明大學
環境與職業衛生研究所
105
Recently the issue of the air pollution was more concerned gradually by residents who living in Taiwan. Several chemical compounds were contained in PM2.5 (particle matter with an aerodynamic of less than or equal to 2.5 μm) such as water-soluble ion, trace metal and persistent organic pollutants (POPs). Especially for PCDDs (polychlorinated dibenzo-p-dioxins) and PCDFs (polychlorinated dibenzofurans) which known as the dioxin-like compound was one of the POPs announced by United Environment Programme (UNEP). The PCDD/Fs were accumulated in environment because of their semi-volatility and long half-life and transported to the vicinity cities. 　　Taiwan is located in eastern Asia which is between Siberian anticyclone and Pacific anticyclone and with the different monsoon and relative level of pollutants affect between summer and winter season. In this study, PM2.5 and atmospheric PCDD/Fs, ion and metal in particles were investigated during winter season in 2015 and 2016, respectively. The PM2.5 hourly data into LRT (Long-range transport event), LP (Local polluted evert) and normal period were classied by AGAGE method (Advanced Global Atmospheric Gases Experiment method) and the meteorological data. Furthermore, Positive Matrix Factorization (PMF), Potential Source Contribution Function (PSCF) and Source Regional Apportionment (SRA) were used in source apportionment of atmospheric PCDD/Fs at different areas. 　　During the winter monsoon period in 2015 and 2016, the PM2.5 concentration were 14.8 to 15.3 ( μg)⁄m^3 and 22.2 to 22.9 ( μg)⁄m^3 during baseline and polluted period, respectively. Compared with normal period, the wind speed, PM2.5, CO and O3 were increased with decreasing temperature during LRT event. However, the PM2.5, CO, O3 and SO2 were increased with decreasing wind speed during LP event. The significantly higher PCDD/F concentrations were measured during LP event and especially at urban site. Furthermore, the level of air pollution impact during winter monsoon was related with the trajectory of air masses transported and the level of pollutant emission. The result also shown the Zn, Pb and Mo were increased and urban site were effected obviously during both LRT and LP event. 　　The result of PMF analysis showed that around 46% PCDD/Fs in ambient air were provided from multiply industrial activity, 33% from coal-fired power plant and sinter plant, 8% from crematorium, 8% from traffic emission and 5% from waste incinerator in 2015 and 2016. However, the results of PSCF and SRA also indicated the atmospheric PCDD/Fs were provided from central China (35.4%) during LRT event and from Taiwan, city of southern China and south Asia (25.6%) during Taiwan during LP event. 　　In this study, the air quality in northern Taiwan was main significantly affected by the LRT event during winter monsoon. But about the deterioration of air quality was not only for LRT but also the local anthropogenic emission.

碩士
國立中山大學
環境工程研究所
96
The trends of PM10, O3, NOX and NMHC concentrations were analyzed by the Holland model (without meteorological-adjusted) and the MM-Regression model (with meteorological-adjusted) base on the data of eight EPA air quality stations from 1997 to 2006 in Kaohsiung. The aim of this study was to evaluate the influence of meteorological factors on the pollutants (PM10 and O3) trends. The trends of PM10 concentrations in Kaohsiung city analyzed without meteorological-adjusted were 7.18 % at Tzuo-Yin, 3.20 % at Chien-Chin and 9.72 % at Nan-Chie. After eliminating the meteorological factors, the percent of gradual trends were 1.91 % at Tzuo-Yin, 2.92 % at Chien-Chin and 2.02 % at Nan-Chie. The trends of O3 concentrations without meteorological-adjusted were 11.42 % at Tzuo-Yin, 20.92 % at Hsiung-Kong, 42.08 % at Chien-Chin and 13.69 % at Nan-Chie. The trends of PM10 concentrations in Kaohsiung County analyzed without meteorological-adjusted were 14.96 % at Lin-yuan and 3.24 % at Jen-wu. After meteorological factors eliminating, the trend was 3.15 % at Jen-wu but the trend was -2.53 % at Lin-yuan. Meteorological factor was a primary reason that influences the PM10 concentration in recent years. The trends of O3 in Kaohsiung County without meteorological-adjusted were 18.89 % at Da-liao, 4.40 % at Jen-wu, 35.16 % at Lin-yuan and 29.98 % at Mei-nung. After meteorological factors eliminating, the trends were 1.99 % at Da-liao, 2.23 % at Jen-wu, 1.16 % at Lin-yuan and -1.16 % at Mei-nung. The results show that the influence of meteorological factors for O3 trends was more sensitive in Kaohsiung county than in Kaohsiung city. The concentration of PM10 has no significant difference (64.8 – 92.3 %) in Kaohsiung city. For the concentration of O3, the similarity (78 – 100 %) was extensive in Kaohsiung city because O3 could diffuse easily. O3 episodes has no significant difference as PM10 episodes in Kaohsiung city. As above-mentioned, the results show that the contributions of ambient PM10 were individually but the contributions of ambient O3 were uniform extensively.

Recurrent data are widely encountered in many applications. This thesis work focuses on how the recurrent hospital admissions relate to the air pollutants. In particular, we consider the data for two major cities in Saskatchewan. The study period ranges from January 1, 2005 to December 30, 2011 and involves 20,284 patients aged 40 years and older. The hospital admission data is from the Canadian Institute for Health Information (CIHI). The air pollutants data is from the National Air Pollution Surveillance Program (NAPS) from Environment Canada. The data set has been approved by the Biomedical Research Ethics Board, University of Saskatchewan. The gaseous pollutants included in this study are carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), as well as particulate matter PM2:5 (tiny particles in the air that are 2:5 microns in width). In the data analysis, we applied three different existing models to all respiratory diseases and asthma, respectively. The three models are the Poisson process model (also called Andersen-Gill model), the Poisson process model with the number of previous events as a covariate and the Poisson process model with shared gamma distributed frailties (random effects). For all respiratory diseases, the Poisson process model with random effects provides the best t in comparison to the other two models. The model output suggests that the increased risk of hospital readmission is significantly associated with increased CO and O3. For asthma, the Poisson process model provides the best t in comparison to the other two models. We found that only CO and O3 have significant effects on recurrent hospital admissions due to asthma. We concluded this thesis with the discussion on the current and potential future work.

The deteriorating air quality in Cape Town (CT) is a threat to the social and economic development of the city. Although previous studies have shown that most of the pollutants are emitted in the city, it is not clear how the transport of pollutants from neighbouring cities may contribute to the pollution. This thesis studies the transport of atmospheric nitrogen oxides (NOx) and nitric acid (HNO3) pollutants over South Africa and examines the role of pollutant transport from the Mpumalanga Highveld on pollution in CT. The study analysed observation data (2001 - 2008) from the CT air quality network and from regional climate model simulation (2001 - 2004) over South Africa. The model simulations account for the influences of complex topography, atmospheric conditions, and atmospheric chemistry on transport of the pollutants over South Africa. Flux budget analysis was used to examine whether the city is a net source or sink for NOx and HNO3. The results show that north-easterly flow transports pollutants (NOx and HNO3) at low level (i.e., surface to 850 hPa) from the Mpumalanga Highveld towards CT. In April, a tongue of high concentration of HNO3 extends from the Mpumalanga Highveld to CT, along the southern coast. The flux budget analysis shows that CT can be a net sink for NOx and HNO3 during extreme pollution events. The study infers that, apart from the local emission of the pollutants in CT, the accumulation of pollutants transported from other areas may contribute to pollution in the city.
Environmental Sciences
M. Sc. (Environmental Science)

碩士
明志科技大學
環境與安全衛生工程系環境工程碩士班
103
According to the past air pollution events, specific pollution activities could cause the deterioration of the air quality. In this study, the impact on the air quality from emission particles had been investigated during the Yanshuei beehive firework and the agricultural waste burning. The sampling site is located on the roof of the building in the campus of the Yanshuei Junior High School in Tainan City. PM2.5, black carbon mass concentrations and particle number concentrations were measured continuing from February 10, 2014 to February 20, 2014. In addition, previous studies had found that the mass concentrations of the black carbon could be underestimated due to the loading artifacts on the filter when the Aethalometer was used. In order to overcome this loading artifact, two Aethalometers were used simultaneously to measure black carbon mass concentrations under different sampling flow rates in this study causing a different deposition rate of particles on the filter paper. Then, a correction model was used to determine the corrected mass concentrations of black carbon. Measurement results demonstrated that measured BC mass concentrations for 6 L/min were lower than those for 2 L/min. After BC correction, the difference for the levels between these two corrected BC mass concentrations was only 1.5%. Based on the measurement results in this study, PM2.5 mass hourly average concentrations during the Yanshuei beehive firework were 6 times higher than those at normal day. Otherwise, BC mass hourly average concentrations during the agricultural waste burning were 3 times higher than those at normal day. At the same time, the particles from the agricultural waste burning could bind with a lot of UV enhanced organic compounds due to UVBC mass hourly average concentrations during the agricultural waste burning were 11 times higher than those at normal day. Despite the Yanshuei beehive firework or agricultural waste burning, the high levels of particle number concentrations could be observed at these two events.

碩士
國立臺灣大學
國家發展研究所
101
Through the actor network and risk communication of the Aspire-Park air pollution event, to discuss the third phase of the residents who are in the face of the air smells, and how do they confront and solve the problem of air pollution? As well as through this cooperation model of actor network and risk communication, and the concept followed by this model whether as an another new way of the solution to the current environmental problems of Taiwan? This research analyzes air pollution event in the context of Aspire-Park, not only stresses the Actor -Network Theory’s angle of the course of the event, but also integrates the risk communication’s viewpoints to explore each period of context in the event with what risk characteristics and problems are, and how to turn the conflicts and the cooperation of the various actors in the process, so this research also emphasizes the various actors in the translation process and focuses on the risk communication in this group of actors, and the research will discuss what risk conflicts may arise after the Aspire-Park event in the future.

碩士
逢甲大學
環境工程與科學所
93
The purpose of this study is for investigating the relation between transformation and formation using the monitoring data of the air pollution event day in the 2004 in the Taichung area. The basin terrain and surface wind field effect the concentration distribution in the Taichung area. It shows that two kinds of transformation and formation are in the south and north parts in the Taichung area. Therefore, the transformation phenomenon of air pollution in the two parts was investigated separately. The unsteady and steady states and one-dimensional atmospheric transport difference equations were used to obtain the formation rate (R) and the disappear rate constant (L). In each ozone event day are: (1) the values of R and L change from positive to negative after 14:00 due to the photochemical smog formation; (2) the values of R and L are lower after 16:00 may be due to ozone react with particle or water; (3) the value of Rincreases with decreasing the value of L; (4) the wind speed (＞2.0m/s)and the values of R(＞100μg/m3-hr) and L (＞1.0 1/hr)are high in the day before ozone event day; (5) ozone easy cumulates in the Taichung area due to low wind speed(＜2.0m/s), high solar radiation, low humidity, and basin effect. In the PM10 event day, the phenomenon indicts that: (1) PM10 formation or disappearance depends on surface wind direction and terrain; (2) high PM10 concentration always is in the coastal (strong wind speed, ＞2.0m/s) and near the mountain (complex terrain), especially on the Changhwa and Tali cities; (3) the values of R and L shift from minus value onto plus value after 17:00 due to the traffic jam, maximum values of R(＞200μg/m3-hr) and L(＞1.5 1/hr) at 20:00~21:00; (4) the values of R (＞150μg/m3-hr) and L (＜-1.0 1/hr) keep high and low all the nighttime (18:00~06:00 next day), respectively, due to the mixing height down. The wind speed is fast (＞2.0m/s)in the O3 and PM10 pre- and/or later- event days, which enhance the dispersion of the pollutants. Therefore, the concentration of air pollutant always is low even the value of R is high. The Taichung area is a special area, which combines coast, basin and mountain topography. The high concentration of air pollution accumulates easily in the Taichung basin because of the basin effect and low wind speed.

碩士
國立臺灣大學
新聞研究所
100
In 2008, There were serious air pollutions event outbreak in Ciao Liao Village. Over 100 victims were sent to the hospital, some of them vomitted, felt naucous, or dizzy. But pollution event didn''t only happen once, it happened at least 5 times within a month. During the time, both Environmental Protection Administration Executive Yuan and Local Environmental Protection Bureau couldn''t identify the source of pollutions. Even worse, victims had to go on the street for protest and fight for their own rights. The event has pointed that something was wrong with the "Public Nuisance Disputes Mediation Act", and this thesis is about discovering the main problem of it. This report revealed the air pollution event by video report, because author believes that this is the most proper way to bring back the "Fact" and the "Past". By interviewing the victims, the official government, environmental groups and scholars, this report try to present opinions objectively.

The development of flexible and interpretable statistical methods is necessary in order to provide appropriate risk assessment measures for extreme events and natural disasters. In this thesis, we address this challenge by contributing to the developing research field of Extreme-Value Theory. We initially study the performance of existing parametric and non-parametric estimators of extremal dependence for multivariate maxima. As the dimensionality increases, non-parametric estimators are more flexible than parametric methods but present some loss in efficiency that we quantify under various scenarios. We introduce a statistical tool which imposes the required shape constraints on non-parametric estimators in high dimensions, significantly improving their performance. Furthermore, by embedding the tree-based max-stable nested logistic distribution in the Bayesian framework, we develop a statistical algorithm that identifies the most likely tree structures representing the data's extremal dependence using the reversible jump Monte Carlo Markov Chain method. A mixture of these trees is then used for uncertainty assessment in prediction through Bayesian model averaging. The computational complexity of full likelihood inference is significantly decreased by deriving a recursive formula for the nested logistic model likelihood. The algorithm performance is verified through simulation experiments which also compare different likelihood procedures. Finally, we extend the nested logistic representation to the spatial framework in order to jointly model multivariate variables collected across a spatial region. This situation emerges often in environmental applications but is not often considered in the current literature. Simulation experiments show that the new class of multivariate max-stable processes is able to detect both the cross and inner spatial dependence of a number of extreme variables at a relatively low computational cost, thanks to its Bayesian hierarchical representation. These innovative methods and models are implemented to study the concentration maxima of various air pollutants and how these are related to extreme weather conditions for a number of sites in California, one of the most populated and polluted states of the US. As a result, we provide comprehensive measures of air quality that can be used by communities and policymakers worldwide to better assess and manage the health, environmental and financial impacts of air pollution extremes.

Dissertação de mestrado em Estatística
O presente trabalho intitulado “Metodologias estatísticas aplicadas à relação entre Eventos Climáticos Extremos, Saúde e Desigualdades Socioeconómicas na Grande Área Metropolitana do Porto” funda-se no relatório de estágio curricular, sendo parte integrante e conclusiva do curso de Mestrado em Estatística, ministrado pela Escola das Ciências da Universidade do Minho. Este projeto foi desenvolvido no Departamento de Geografia da Faculdade de Letras da Universidade do Porto e está inserido no Projeto Ondas, um projeto financiado por Fundos FEDER e pela Fundação para a Ciência e a Tecnologia. O presente relatório está estruturado em cinco capítulos. No capítulo inicial faz parte a introdução, no qual é apresentado o tema de estudo e investigação, os objetivos com referência às metodologias estatísticas e ao software a utilizar. O segundo capítulo contextualiza os eventos climáticos extremos, os poluentes ozono (03) e as partículas de matéria até 10 micrómetros de diâmetro (PM10), referindo as suas origens e a relação destes fatores com a saúde humana. Refere, ainda, alguns estudos efetuados neste contexto. O terceiro capítulo está vocacionado para a descrição matemática das várias metodologias e modelos estatísticos utilizados neste estudo, designadamente, os modelos lineares generalizados, os modelos aditivos generalizados e os modelos de regressão de séries temporais para dados de contagem, com distribuição de Poisson. O capítulo quarto faz uma descrição dos dados e apresentação de resultados. É descrita a proveniência dos dados, é efetuada uma análise descritiva e seguidamente são apresentados e comparados os resultados obtidos através dos diferentes métodos estatísticos. O quinto capítulo corresponde à conclusão, na qual são efetuadas algumas referências aos capítulos anteriores e às suas principais conclusões, são ainda apresentadas algumas considerações sobre a concretização dos objetivos do projeto de estágio. Neste capítulo são também feitas algumas recomendações ou sugestões para trabalhos futuros.
The present report with the title “Statistical methods applied to the relationship between Extreme Weather Events, Health and Socioeconomic inequalities in the Greater Metropolitan Area of Porto” is based on the training period of two-year-degree of Master in Statistics at School of Sciences, University of Minho. This project was developed at Department of Geography of the Faculty of Arts of the University of Porto and is inserted in Waves Project, a project funded by Funds FEDER and the Foundation for Science and Technology. The present report is divided into five chapters. The first chapter includes the introduction, which presents the theme of study and the research objectives with reference to the statistical methodologies and software to be used. The second chapter contextualizes extreme weather events, the pollutants ozone (03) and the particular matter (PM10), referring to its origins and the relationship of these factors with human health. It also presents some studies conducted in this context. The third chapter is devoted to the mathematical description of the ok various methodologies and statistical models used in this study, namely, the generalized linear models, generalized additive models and the of time series regression models for count data, with Poisson distribution. The fourth chapter gives a description of the data and presents results. The data provenance is explained, a descriptive analysis is performed and the results obtained using different statistical methods are then presented and compared. The fifth chapter corresponds to the conclusion, in which some references are made to earlier chapters and their main conclusions. Moreover, some comments are made about these objectives which were reached as defined. This chapter also presents some recommendations and suggestions for future works.
Fundação para a Ciência e a Tecnologia (FCT) - Projeto Ondas com a referência: PTDC/SAU-ESA/73016/2006
FEDER através do Programa Operacional Factores de Competitividade - COMPETE

The evidence of a flood wave passing through a catchment remains visible even for a long time after it occurs. The morphological update in the channel and floodplains, together with the processes related to the mass transport within the aquatic environment, can be regarded as flood event evidence. The advancement in hydroinformatics brought the development of numerical modeling as a tool for the solution of broad hydrological tasks. Thanks to the scenario modeling, flood events with interconnected processes can be explored in detail. This thesis is broadly focused on the mass transport initialization issue both in the polluted and clear middle-European water environments. The aim of the thesis is the evaluation of the principal issues connected with the mass transport initialization based on complex and integrated numerical modeling. The thesis brings original datasets resulting from several case studies. The aim of the thesis is also to bring a comparative study of methodological approaches evaluating the possibilities and limits regarding the accuracy of inputs vs. outputs and computational time requirements. This thesis also brings several useful comparisons and innovative solutions design. The mass transport initialization issue is solved in both balance and event-scale processed- based models....

The study focuses on the role of government in the provision of environmental programmes, events and campaigns. South Africa is a signatory to a number of environmental treaties and protocols hence it is expected to celebrate environmental days annually, such as World Wetland Day, National Water Week, World Environmental Week, Arbor Day and many more. The study considered the community of Masibekela, a remote rural village in Mpumalanga Province under the Nkomazi Local Municipality as its study area. Both qualitative and quantitative methods were applied to gather the necessary data from the four sets of respondents to a questionnaire survey, namely: the Sector Manager of Tonga Environmental Centre, traditional leadership and community members, learners and educators. The study discovered that the provision of environmental programmes, events and campaigns to the study area by the government leaves much to be desired. It lays bare that the community members of Masibekela are neglected environmentally by the government as compared to schools. The study also revealed contrasting features both in the knowledge and celebration of some of the environmental days by both the schools (learners and educators) and the general community members. A high percentage of learners and educators expressed their knowledge and celebration of environmental days since they are frequently visited by government officials to promote environmental programmes, events and campaigns geared towards environmental education and awareness but the same cannot be said about the traditional leaders and community members. It is recommended, among other things, that the Tonga Environmental Centre, as a custodian of provision of environmental programmes, events and campaigns, should be capacitated both in terms of human resources and strategic planning so as to meet its expectations. It is also recommended vi that more funding for bursaries for environmental studies for the youth should be made available and also more capital should be injected into the actual promotion of environmental programmes, events and campaigns. The National Department of Education in collaboration with the Department of Environmental Affairs should consider including Environmental Education in the school curriculum as a compulsory subject in all grades
Geography
M. A. (Geography)