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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

O campo térmico e a qualidade ambiental urbana em Chapecó/SC / The thermal field and quality environmental urban in Chapecó/SC / El campo térmico y calidad ambiental urbana en Chapecó/SC / Le champ thermique et qualité l'environnement urban en Chapecó/SC

Costa, Eduino Rodrigues da [UNESP] 14 December 2015 (has links)
Submitted by EDUINO RODRIGUES DA COSTA null (eduinocosta@gmail.com) on 2016-01-24T23:10:07Z No. of bitstreams: 1 tese_doutorado_versão_final_2016_4.pdf: 23957151 bytes, checksum: 7698593346da53efae4b6d352ff36ff2 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-01-25T16:07:41Z (GMT) No. of bitstreams: 1 costa_er_dr_prud.pdf: 23957151 bytes, checksum: 7698593346da53efae4b6d352ff36ff2 (MD5) / Made available in DSpace on 2016-01-25T16:07:41Z (GMT). No. of bitstreams: 1 costa_er_dr_prud.pdf: 23957151 bytes, checksum: 7698593346da53efae4b6d352ff36ff2 (MD5) Previous issue date: 2015-12-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Este trabalho teve como objetivo estudar o campo térmico e a qualidade ambiental urbana de Chapecó, cidade de porte médio localizada na região do Oeste Catarinense. Para estudar o campo térmico de Chapecó ao nível do dossel urbano, foi necessário estabelecer trajetos (transectos móveis) nos quais em condições de tempo especificas de cada mês do ano de 2014, e horários (06, 15 e 21 horas) foram realizadas coletas de dados climáticos (temperatura do ar), afim de identificar e espacializar a ocorrência de fenômenos climáticos urbanos como as ilhas de calor. Para a aquisição dos dados de temperatura do ar na zona urbana de Chapecó, utilizou-se a metodologia dos transectos móveis, a qual consiste na aquisição automática e simultânea de dados climáticos ao longo de trajetos preestabelecidos dentro de determinada malha urbana. Para avaliar e mapear a qualidade ambiental da zona urbana de Chapecó/SC foi utilizado uma adaptação da metodologia desenvolvida por Nucci (1996) ao estudar a qualidade ambiental e o adensamento urbano no distrito de Santa Cecília, localizado no município de São Paulo. Como resultados destaca-se que a ilha de calor atmosférica se definiu melhor no bairro Centro (horizontalizado e verticalizado) no horário das 15 e 21 horas em todos os episódios de tempo analisados. No horário das 06 horas não foi possível notar a influência da cidade sobre o campo térmico, visto que neste horário ocorre o resfriamento radiativo associado ao balanço negativo de radiação. A ilha de calor apresentou maior magnitude na estação de inverno e em episódios de tempo sob domínio de sistemas atmosféricos polares (Massa Polar Atlântica, Massa Polar Continental). Pelo tamanho da cidade e intensidade das alterações ambientais promovidas pela ação antrópica não foi registrada ilhas de calor de fraca magnitude. Em relação ao conforto térmico humano registrado em Chapecó, notou-se que a ilha de calor é responsável pelo desconforto térmico verificado nos tipos de tempos associados a sistemas atmosféricos tropicais no verão e pelo conforto térmico nos episódios de tempo associados a sistemas polares no inverno, principalmente no seu horário de máxima intensidade e aquecimento (15 horas). Em relação a qualidade ambiental, verificou-se que as áreas de baixa qualidade corresponderam as áreas centrais da cidade onde foram identificados e mapeados atributos negativos que reduzem a qualidade do ambiente. As ilhas de calor de média, forte e muito forte magnitude se estabeleceram justamente nas áreas centrais da cidade onde a qualidade ambiental é baixa. Conclui-se que a cidade de Chapecó por seu porte médio e dinâmicas espaciais da sua urbe, tem a capacidade de gerar um clima local; e as alterações ambientais nela verificadas contribuem para reduzir a qualidade do ambiente favorecendo assim o surgimento das ilhas de calor e o desconforto térmico. / This work aimed to study the thermal field and urban environmental quality of Chapecó, medium-sized city located in the western region of Santa Catarina. To study the thermal field of Chapecó in urban canopy level had to be established paths (mobile transects) where in specific weather conditions of each month of the year 2014, and times (06, 15 and 21 hours) samples were taken from climate data (air temperature) in order to identify and spatialize the occurrence of climatic phenomena such as urban heat islands. To acquire the air temperature data in the urban area of Chapecó, we used the methodology of mobile transects, which is the automatic and simultaneous acquisition of climate data along predetermined paths within a given urban area. To assess and map the environmental quality of the urban area of Chapecó / SC was used a methodology developed by adapting Nucci (1996) to study the environmental quality and the urban density in the Santa Cecilia district, located in São Paulo. As a result, it is emphasized that the atmospheric heat island defined better in the Centro neighborhood (horizontalized and vertical) in the time of 15 and 21 hours in all episodes rabbits. On time of 06 hours, it was not possible to note the influence of the city on the thermal field, since this time is the radiative cooling associated with the negative balance of radiation. The heat island showed greater magnitude in the winter season and episodes of time under the control of polar weather systems (Polar Atlantic Mass, Polar Continental Mass). The size of the city and intensity of environmental changes brought about by human action was not recorded weak magnitude of heat islands. Regarding the human thermal comfort registered in Chapecó, it noted that the heat island is responsible for the observed thermal discomfort in the types of associated time tropical weather systems in the summer and the thermal comfort in episodes of time associated with polar systems in the winter, especially in its maximum intensity and heating time ( 15 hours). For environmental quality, it was found that low-quality areas corresponded central city areas, which have been identified and mapped negative attributes that reduce the quality of the environment. The average heat islands, strong and very strong magnitude is precisely established in inner-city areas where environmental quality is low. We conclude that the city of Chapecó for its midsize and space of a dynamic metropolis, has the ability to generate a local climate; and environmental changes occurring in it contribute to reducing the quality of the environment favoring the emergence of heat islands and thermal discomfort. / FAPESP: 2012/01631-1
102

Adaptação de um modelo simplificado para verificação da influência da geometria urbana na formação de ilha de calor noturna

Nakata Osaki, Camila Mayumi 19 January 2016 (has links)
Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-09-14T12:46:38Z No. of bitstreams: 1 TeseCMNO.pdf: 7498079 bytes, checksum: f4a2b7e655a7e6fb0d19d9ed7a9144b1 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-15T13:59:13Z (GMT) No. of bitstreams: 1 TeseCMNO.pdf: 7498079 bytes, checksum: f4a2b7e655a7e6fb0d19d9ed7a9144b1 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-15T13:59:18Z (GMT) No. of bitstreams: 1 TeseCMNO.pdf: 7498079 bytes, checksum: f4a2b7e655a7e6fb0d19d9ed7a9144b1 (MD5) / Made available in DSpace on 2016-09-15T13:59:24Z (GMT). No. of bitstreams: 1 TeseCMNO.pdf: 7498079 bytes, checksum: f4a2b7e655a7e6fb0d19d9ed7a9144b1 (MD5) Previous issue date: 2016-01-19 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Nocturnal heat island formation is a prominent phenomenon in research of urban planning and thermal comfort. This phenomenon is the result of the influence of urbanization characteristics, which alter the energy balance of the cities, and is characterized by an increase in air temperature, from the periphery to the center of cities. The heat island has as a major cause, the urban geometry. In this context, the model proposed by Oke, in 1981, became a reference in the area because of its importance in analytical studies of relation between urban geometry and the formation of heat islands. This research aims to determine the role of urban geometry in the formation of nocturnal heat islands, from the adaptation of a simplified model for a computational simulation tool GIS (Geographic Information System). The methodological procedures have steps: study of theoretical and numerical base, developing a calculation algorithm and its incorporation into the GIS platform, data monitoring for calibration (validation) and simulation. The measured data for the tool validation demonstrated an increasing trend of heat island with increasing H/W ratio (height/width) canyon, but there are different behavior for different ranges of roughness length (Z0). The developed tool, THIS (Tool for Heat Island Simulation), was used in simulation of different scenarios, which showed that urban canyons of greater roughness result in heat island values twice lower compared to the canyons of lower roughness, for the same H/W ratio. The development of THIS tool expands the possibilities of simulations to forecast heat islands to different climatic conditions and suggests further discussion on the influence of different urban geometry settings in the formation of heat island. / A formação de ilha de calor noturna é um fenômeno de destaque em pesquisas de planejamento urbano e conforto térmico. Esse fenômeno é resultado da influência das características da urbanização, que alteram o balanço energético das cidades, e caracteriza-se pelo aumento da temperatura do ar, da periferia para o centro das cidades. A ilha de calor tem como uma das principais causas, a geometria urbana. Nesse contexto, o modelo proposto por Oke, em 1981, se tornou referência na área por sua importância em estudos de análise de relação entre a geometria urbana e a formação de ilhas de calor. Esta pesquisa tem como objetivo verificar o papel da geometria urbana na formação de ilhas de calor noturna, a partir da adaptação de um modelo simplificado para uma ferramenta de simulação computacional SIG (Sistema de Informação Geográfica). Os procedimentos metodológicos contam com as etapas de: estudo da base teórico-numérica, desenvolvimento de um algoritmo de cálculo e sua incorporação à plataforma SIG, monitoramento de dados para calibração (validação) e simulação. Os dados medidos para a validação da ferramenta demonstraram uma tendência crescente da ilha de calor com o aumento da relação H/W (altura/largura) do cânion, mas há comportamentos distintos para diferentes faixas de comprimento de rugosidade (Z0). A ferramenta desenvolvida, THIS (Tool for Heat Island Simulation), foi utilizada em simulação de diferentes cenários, que demonstrou que cânions urbanos de maior rugosidade resultam em valores de ilha de calor duas vezes menor em relação aos cânions de menor rugosidade, para um mesmo valor de relação H/W. O desenvolvimento da ferramenta THIS amplia as possibilidades de simulações para previsão de ilhas de calor para diferentes condições climáticas e sugere uma discussão mais aprofundada sobre a influência de diferentes configurações de geometria urbana na formação de ilhas de calor.
103

Improving Urban Cooling in the Semi-arid Phoenix Metropolis: Land System Science, Landscape Ecology and Urban Climatology Approaches

January 2018 (has links)
abstract: The global increase in urbanization has raised questions about urban sustainability to which multiple research communities have entered. Those communities addressing interest in the urban heat island (UHI) effect and extreme temperatures include land system science, urban/landscape ecology, and urban climatology. General investigations of UHI have focused primarily on land surface and canopy layer air temperatures. The surface temperature is of prime importance to UHI studies because of its central rule in the surface energy balance, direct effects on air temperature, and outdoor thermal comfort. Focusing on the diurnal surface temperature variations in Phoenix, Arizona, especially on the cool (green space) island effect and the surface heat island effect, the dissertation develops three research papers that improve the integration among the abovementioned sub-fields. Specifically, these papers involve: (1) the quantification and modeling of the diurnal cooling benefits of green space; (2) the optimization of green space locations to reduce the surface heat island effect in daytime and nighttime; and, (3) an evaluation of the effects of vertical urban forms on land surface temperature using Google Street View. These works demonstrate that the pattern of new green spaces in central Phoenix could be optimized such that 96% of the maximum daytime and nighttime cooling benefits would be achieved, and that Google Street View data offers an alternative to other data, providing the vertical dimensions of land-cover for addressing surface temperature impacts, increasing the model accuracy over the use of horizontal land-cover data alone. Taken together, the dissertation points the way towards the integration of research directions to better understand the consequences of detailed land conditions on temperatures in urban areas, providing insights for urban designs to alleviate these extremes. / Dissertation/Thesis / Doctoral Dissertation Geography 2018
104

A SOCIO-ECOLOGICAL UNDERSTANDING OF EXTREME HEAT VULNERABILITY IN MARICOPA COUNTY, ARIZONA

January 2013 (has links)
abstract: This dissertation explores vulnerability to extreme heat hazards in the Maricopa County, Arizona metropolitan region. By engaging an interdisciplinary approach, I uncover the epidemiological, historical-geographical, and mitigation dimensions of human vulnerability to extreme heat in a rapidly urbanizing region characterized by an intense urban heat island and summertime heat waves. I first frame the overall research within global climate change and hazards vulnerability research literature, and then present three case studies. I conclude with a synthesis of the findings and lessons learned from my interdisciplinary approach using an urban political ecology framework. In the first case study I construct and map a predictive index of sensitivity to heat health risks for neighborhoods, compare predicted neighborhood sensitivity to heat-related hospitalization rates, and estimate relative risk of hospitalizations for neighborhoods. In the second case study, I unpack the history and geography of land use/land cover change, urban development and marginalization of minorities that created the metropolitan region's urban heat island and consequently, the present conditions of extreme heat exposure and vulnerability in the urban core. The third study uses computational microclimate modeling to evaluate the potential of a vegetation-based intervention for mitigating extreme heat in an urban core neighborhood. Several findings relevant to extreme heat vulnerability emerge from the case studies. First, two main socio-demographic groups are found to be at higher risk for heat illness: low-income minorities in sparsely-vegetated neighborhoods in the urban core, and the elderly and socially-isolated in the expansive suburban fringe of Maricopa County. The second case study reveals that current conditions of heat exposure in the region's urban heat island are the legacy of historical marginalization of minorities and large-scale land-use/land cover transformations of natural desert land covers into heat-retaining urban surfaces of the built environment. Third, summertime air temperature reductions in the range 0.9-1.9 °C and of up to 8.4 °C in surface temperatures in the urban core can be achieved through desert-adapted canopied vegetation, suggesting that, at the microscale, the urban heat island can be mitigated by creating vegetated park cool islands. A synthesis of the three case studies using the urban political ecology framework argues that climate changed-induced heat hazards in cities must be problematized within the socio-ecological transformations that produce and reproduce urban landscapes of risk. The interdisciplinary approach to heat hazards in this dissertation advances understanding of the social and ecological drivers of extreme heat by drawing on multiple theories and methods from sociology, urban and Marxist geography, microclimatology, spatial epidemiology, environmental history, political economy and urban political ecology. / Dissertation/Thesis / Ph.D. Environmental Social Science 2013
105

O clima da cidade de Caucaia-CE sob uma perspectiva termodinÃmica / Climate of Caucaia city under the perspective thermodynamics

Jorge Ricardo Felix de Oliveira 05 December 2014 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / The relationship of the dynamics of the lower atmosphere to urban settlements becomes influence the thermal exchanges between the Sun and the Earth producing transformations of energy often perceived negatively. In this sense we propose a study of urban climate, a thermodynamic perspective, the municipal headquarters of Caucaia, CearÃ, located in the Metropolitan Region of Fortaleza. In order to check the thermal differences in two periods of Cearà rainy season and the influence of land use and occupation in the climatic attributes of different spaces intraurbanos The survey basically follows the theoretical and conceptual proposal of the Urban Climate System-SCU, with the thermodynamic subsystem (perception channel thermal comfort) of MONTEIRO (1976, 2003). In association with the analysis of active weather systems, measurements were performed with the mobile and fixed transect mini-shelters in a 48hrs profile in representative days of January and May 2014. Furthermore, it was ascertained through satellite imaging Landsat 8 ( Band 10) behaves surface temperature city. One can show that the weather systems influence the characteristics of climatic attributes considered. It was found that temperatures of greater value surface were found in the central area of the city, in an industry characterized by the absence of vegetation, with fiber cement roofs. The measurements with the mini-shelters installed in the yards of homes, showed the influence of building materials in conditioning temperatures and humidities. In the experiments with the mobile transects, in general, we find a small variation of the temperatures and humidities of air, ranging between 1.3  C and 5% in summer; and 2,1ÂC with 13% in autumn, and the center the location with the highest values. / A relaÃÃo da dinÃmica da baixa atmosfera com os assentamentos urbanos passa a influenciar as trocas tÃrmicas entre o Sol e a Terra produzindo transformaÃÃes de energias muitas vezes percebidas de maneira negativa. Nesse sentido propomos um estudo do clima urbano, numa perspectiva termodinÃmica, da sede municipal de Caucaia-CE, situada na RegiÃo Metropolitana de Fortaleza. Com objetivo de verificar as diferenÃas tÃrmicas em dois perÃodos da quadra chuvosa cearense e a influÃncia do uso e ocupaÃÃo do solo nos atributos climÃticos dos diferentes espaÃos intraurbanos A pesquisa basicamente segue a proposta teÃrico-conceitual do Sistema Clima Urbano-SCU, com o subsistema termodinÃmico (canal de percepÃÃo do conforto tÃrmico) de MONTEIRO (1976, 2003). Em associaÃÃo com a anÃlise dos sistemas atmosfÃricos atuantes, foram realizadas mediÃÃes com o transecto mÃvel e miniabrigos fixos em um perfil de 48hrs em dias representativos de Janeiro e Maio de 2014. AlÃm disso, foi averiguada atravÃs de tratamento de imagem do satÃlite Landsat 8 (banda 10) como se comporta a temperatura de superfÃcie para cidade. Pode-se evidenciar que os sistemas atmosfÃricos influenciem as caracterÃsticas dos atributos climÃticos considerados. Verificou-se que as temperaturas da superfÃcie de maior valor foram encontradas na Ãrea central da cidade, em uma indÃstria, caracterizada pela ausÃncia de vegetaÃÃo, com telhados de fibrocimento. As mediÃÃes com os miniabrigos instalados nos quintais das residÃncias, mostraram a influÃncia dos materiais construtivos no condicionamento das temperaturas e umidades. Nos experimentos realizados com os transectos mÃveis, de forma geral, encontramos uma pequena variaÃÃo das temperaturas e umidades do ar, variando entre 1,3ÂC e 5% no verÃo; e 2,1ÂC com 13% no outono, sendo o centro o local com os maiores valores.
106

Estudo do campo térmico urbano de São Carlos (SP): análise da intensidade da ilha de calor urbano em episódio climático de verão / Study of urban thermal field of São Carlos (SP): analysis of the intensity of urban heat island in summer climatic episode

Ricardo Victor Rodrigues Barbosa 09 December 2009 (has links)
A modificação das condições iniciais do clima é conseqüência inerente da substituição da cobertura natural do solo pelo ambiente construído. Nesse processo, um dos mecanismos do sistema cidade-atmosfera mais afetado pela mudança do uso e da cobertura do solo é o campo térmico urbano. Assim, esta pesquisa objetivou estudar a configuração do campo térmico da cidade de São Carlos nas suas dimensões espaços-temporais, com vistas a conhecer a intensidade da ilha de calor urbano no período de verão, dentro de suas variações diurnas e das condições impostas pelos diferentes tipos de tempo habituais, com o aporte da abordagem dinâmica do clima. A análise da intensidade do campo térmico urbano foi feita a partir de registros de dados climáticos contínuos tomados em superfície por quatro estações automáticas instaladas em diferentes regiões da malha urbana. Os resultados obtidos denotaram que a maior intensidade da ilha de calor urbano, no período de verão, ocorreu na atuação da massa Tropical Atlântica sobre a região, cujo tipo de tempo habitual foi caracterizado por cenário atmosférico com predominância de céu claro, alta incidência de radiação solar direta e valores de temperatura do ar elevados com máxima diária acima da média das máximas indicadas pelas normais climatológicas. Sob essas condições, observou-se que as características do entorno construído exerceram maior influência no comportamento térmico urbano, na qual as diferenças térmicas entre diferentes regiões dentro da malha urbana de São Carlos foram superiores a \'5 GRAUS\' Celsius. Observou-se, ainda, que a maior expressão da ilha de calor urbano ocorreu após o pôr-do-sol, nos horários entre 21:30h e 22:00h. / The initial conditions of the climate are consequence of replacing the natural ground cover by the built environment. In this process, one of the most affected mechanics of the city-atmosphere system due to the change of use and land cover is the urban thermal field. Thus, this research aim to study the configuration of the thermal field of São Carlos in the spatial and temporal dimensions for understanding the intensity of urban heat island in the summer, taking into account its diurnal temperature variations and imposed conditions by different weather types, guided by the climate dynamics approach. The analysis of the intensity of urban thermal field is made from records of climatic data observed in solid ground for four automatic weather stations placed in different areas of the city. The obtained results denote that the highest intensity of urban heat island in summer occurs in the activity of Tropical Atlantic air mass over the region, where the habitual weather was clear skies with high incidence of direct solar radiation and values of air temperature with high daily maximum above the average of the levels indicated by the climate normals. Under these weather conditions, it is observed that the characteristics of the built environment have a greater influence on urban thermal behavior, in which the temperature variations between different regions within the urban area of San Carlos were above 5 Celsius \'DEGREES\'. It is also observed that the highest intensity of urban heat island occurred after sunset, at times between 21:30 and 22:00h.
107

Avaliação dos efeitos urbanos sobre circulações de mesoescala em função da expansão territorial da Região Metropolitana de São Paulo / Evaluation of urban effects on mesoscale circulations due to the territorial expansion of the Metropolitan Area of São Paulo

Camila Tavares Homann 13 November 2014 (has links)
A Região Metropolitana de São Paulo (RMSP) conta com mais de 20 milhões de habitantes em 7958 km², o que a caracteriza como uma megacidade. Este fato ocasiona o efeito de ilha de calor que pode resultar em interações complexas com circulações de mesoescala, tais como a brisa marítima, podendo influenciar nos padrões de circulação local e afetar diretamente o tempo e o clima da região. Dessa forma, através da modelagem numérica com o modelo de mesoescala WRF este trabalho se propôs a analisar e avaliar os possíveis efeitos da expansão da mancha urbana - passada e futura - na modificação destes padrões em duas estações do ano de 2007: inverno (18/08) e verão (07/03). Para isto introduziu-se diferentes manchas urbanas no modelo, supondo nenhuma urbanização, urbanização observada em 1952 e em 2007, bem como uma suposta urbanização prevista para o ano de 2030. O acoplamento de um modelo de dossel urbano junto ao WRF também foi avaliado, e os resultados mostraram que para o inverno a inclusão do mesmo se mostrou dispensável, enquanto para o verão as simulações em que o módulo esteve ativo se mostraram mais coerentes à realidade. Para as duas estações observou-se a influência da expansão da mancha urbana nos eventos de brisa marítima, sendo que quanto maior a área urbanizada maior o tempo de deslocamento da frente de brisa continente adentro, podendo a diferença chegar a 2 horas. Diferenças na temperatura também puderam ser vistas, principalmente à noite no período de inverno, de forma que algumas regiões chegaram a apresentar 6 °C a mais em 2007. Observou- se uma frente de umidade acompanhando a frente de brisa marítima e quanto maior a urbanização, menor a quantidade de umidade associada, chegando a uma redução de 22% durante o inverno e de 33% durante o verão. No inverno não foram observadas grandes diferenças na precipitação, enquanto que no verão foram encontradas diferenças significativas em praticamente todo o domínio de simulação, chegando a 50 mm em determinadas regiões (a mais ou a menos). Tais diferenças na precipitação não se mostraram lineares com a expansão da mancha urbana. Cortes verticais não evidenciaram circulações bem definidas associadas à ilha de calor, nem para o inverno nem para o verão, no entanto, claramente pôde-se observar a influência que a expansão urbana tem sobre os episódios de brisa marítima, em quaisquer das variáveis meteorológicas analisadas. / The Metropolitan Area of São Paulo (MASP) has over 20 million inhabitants over a 7958 km² area, which characterizes a megacity. This fact causes the heat island effect that can result in complex interactions with mesoscale circulations such as the sea breeze and can influence the local circulation and directly affect the weather and climate of the region. Therefore, through numerical modeling of the atmosphere using the WRF mesoscale model this work analyses and evaluates the possible effects of urban expansion - past and future on the modification of these patterns in two days representatives of the winter and summer (18/08 and 07/03, respectively). For that purpose we introduced different types of urban areas in the model, assuming no urbanization, using the urbanization observed in 1952 and 2007 as well as a hypothetical urbanization numerically predicted for the year of 2030. The coupling of an urban canopy model (UCM) along with WRF was also evaluated and the results showed that the inclusion of UCM proved to be unnecessary during wintertime. However, in the summer, the simulations where the module was activated were more consistent with reality. For the two seasons we observed the influence of urban expansion in the events of sea breeze, and the higher the urbanized area more increased was the travel time of the sea breeze front inland, being the time difference as high as 2 hours. Differences in temperature were also observed, especially at night in the winter, so that some regions were as high as 6 °C hotter in 2007. A moisture front accompanying the sea breeze front and the higher the urbanization the lower the amount of moisture associated, reaching a reduction of 22% during winter and 33% during the summer. During the winter no major differences were observed in precipitation, while in the summer significant differences were found almost over all simulation domain, reaching 50 mm in certain regions (positive or negative). Such differences in precipitation were not linear with the expansion of urban area. Vertical sections did not show well-defined circulations associated with urban heat island, neither for the winter nor for summer, however, we can clearly observe the influence that urban area extension has on episodes of sea breeze in any of the weather variables.
108

Análise da circulação de brisa marítima e seus impactos sobre a precipitação na Região Metropolitana de São Paulo por meio do modelo ARPS / Sea breeze circulation analysis ant its impacts over Metropolitan area of São Paulo precipitation using ARPS model

Felipe Vemado 11 May 2012 (has links)
Eventos de brisa marítima (BM) são comuns na Região Metropolitana de São Paulo (RMSP). No verão, em particular, estão associados com tempestades, chuvas, rajadas de vento, granizo e descargas atmosféricas intensas na RMSP. Utilizou-se o método de OLIVEIRA e SILVA DIAS (1982) para identificar os eventos de BM. Todos os eventos de BM entre 2005 e 2008 foram analisados por meio de medições de superfície, altitude, radares meteorológicos, satélite e modelagem numérica da atmosfera. Em geral, a penetração da frente de BM na RMSP ocorre entre o meio e o fim da tarde com aumento da temperatura do ponto de orvalho. Ainda, o ambiente urbano mais aquecido tende a intensificar as tempestades que podem produzir enchentes, alagamentos, queda de árvores, entre outros impactos socioeconômicos muito significativos. A partição anual pluviométrica devido a BM foi estimado com o radar meteorológico de São Paulo. Os resultados indicam um núcleo de máxima precipitação acumulada com pico de 600 mm sobre a RMSP, muito maior que no entorno dessa. A modelagem com o ARPS permitiu simular condições médias espaciais em baixos, médios e altos níveis de diversas variáveis dos eventos analisados. As simulações de controle e específicas com ARPS sugerem um impacto significativo da cobertura do solo na distribuição espacial da precipitação. As análises foram complementadas com medições do radar meteorológico MXPOL e demonstram a importância desse tipo de sensoriamento remoto na detecção e previsão a curtíssimo prazo da penetração de BM, com alta resolução espaço-temporal. / Sea breeze events (SB) are common in Metropolitan area at São Paulo (MASP). Particularly, in the summer, SB triggers over MASP deep convection, heavy rainfall, wind gusts, hail and lightning. OLIVEIRA and SILVA DIAS (1982) method was used to identify the SB events. SB events between 2005 and 2008 were analysed by means of surface and upper air measurements, weather radar, satellite and numerical modelling. In general, the SB front penetrates in MASP between midafternoon and evening increasing dew point. Moreover, the warmer urban environment tends to intensify storms that produce flooding, falling trees, among other large socioeconomic impacts. The annual rainfall partition due to SB was estimated using the São Paulo weather radar. The results indicate a core of maximum rainfall accumulation of 600 mm over MASP, much larger than that in the vicinity. The modelling with ARPS allowed simulate conditions spatial average in low, medium and upper levels of several variables of the analysed events. Moreover, the ARPS system was used to simulate SB with control and specific runs. Results suggest significant impact of surface cover on rainfall distribution. MXPOL weather radar measurements of SB were important in detecting and nowcasting SB inflow at very high spatial and temporal resolution.
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Observational and modelling approaches to study urban climate : application on Pakistan / Méthodes d'observation et de modélisation pour étudier le climat urbain : application sur le Pakistan

Sajjad, Sajjad Hussain 16 April 2013 (has links)
L'objectif majeur de ce travail est d'étudier le climat urbain, principalement en mettant l'accent sur les tendances de la température. Il s’agit principalement de l’augmentation des températures grâce à des techniques d'observation et de modélisation. A cet effet, des données températures de 1950 à 2004 ont étudiées sur plusieurs stations de mesure au Pakistan. Les données de températures annuelles et saisonnières moyennes quotidiennes minimales (Tmin) et maximales (Tmax) de 37 observatoires météorologiques du Pakistan (17 urbain, 7 petite ville et 13 rurale) pour la période 1950-2004 ont d'abord été homogénéisées, puis analysées. Les résultats montrent qu’après les années 1980, Tmin et Tmax tendent à augmenter plus vite que la période d'avant 1980 sur les zones urbaines. Au cours de la période 1980-2004, l'augmentation annuelle de Tmin sur les stations urbaines est observée plus élevée que sur les stations des petites villes et les stations rurales. Pour comprendre l’effet de la taille de la ville, le changement du l’utilisation des sols et la hauteur du bâtiment sur l'évolution des températures minimales et maximales des zones urbaines a été étudié en utilisant le model FVM (Finite Volume Model) et des simulations ont faites pour trois jours à partir de 00:00 (GMT) le 19e jour de chaque mois et se terminant à 00:00 (GMT) le 22e jour de chaque mois. Pour chaque mois, 48 combinaisons possibles de scénarios de simulation sont exécutés (4*4*3) et au total, 576 simulations (48*12) sont exécutés pendant un an. Les résultats centre montrent que Tmin et Tmax augmente lorsque fraction urbaine u, taille de la ville r et hauteur du bâtiment h augmente. Mais on remarque que Tmax augmente plus que le Tmin quand u augmente, Tmin augmente plus que Tmax lorsque r augmente et Tmin augmente plus que Tmax lorsque h augmente. Parmi tous les facteurs urbains (fraction urbaine u, taille de la ville r et hauteur du bâtiment h), la taille de la ville est le facteur majeur qui contribue principalement à augmenter la température minimale plus que température maximale dans les zones urbaines. / The objective of this work is to study the urban climate, mainly by focusing on urban temperature trends. The specific focus is to understand the reasons of increase in minimum temperature through observational and modelling techniques. For this purpose, the temperatures data from 1950 to 2004 measured on several meteorological stations of Pakistan is studied and analyzed. Daily averaged annual and seasonal minimum (Tmin) and maximum (Tmax) temperature data of 37 meteorological observatories of Pakistan (17 urban, 7 town and 13 rural) from 1950 to 2004 is first homogenized and then analyzed. The results show that after 1980s Tmin and Tmax increase faster than the period before 1980s at urban areas. During 1980–2004, the increase in Tmin at major urban stations is observed higher than the smaller towns and rural stations. To understand, the effect of the size of the city, changing land use and the building height on the evolution of minimum and maximum temperatures in urban areas has been studied by using the FVM (Finite Volume Model) model and the simulations are run for three days starting at 00:00 (GMT) on 19th day of each month and ending at 00:00 (GMT) on 22nd day of each month. For each month, 48 possible combinations of simulation scenarios are run (4*4*3) and in total, 576 simulations (48*12) are run for a year. The main results show that Tmin and Tmax increase when urban fraction u, city size r and building height h increase. But it is noticed that Tmax increases more than the Tmin when u increases, Tmin increases more than the Tmax when r increases and Tmin increases more than the Tmax when h increases. Among all urban factors (urban fraction u, city size r and building’s height h), city size is the major factor that mainly contributes to increase the minimum temperature more than the maximum temperature in urban areas.
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A Landscape of Thermal Inequity: Social Vulnerability to Urban Heat in U.S. Cities

Mitchell, Bruce Coffyn 04 July 2017 (has links)
A combination of the urban heat island effect and a rising temperature baseline resulting from global climate change inequitably impacts socially vulnerable populations residing in urban areas. This dissertation examines distributional inequity of exposure to urban heat by socially disadvantaged groups and minorities in the context of climate justice. Using Cutter’s hazards-of-place model, variables indicative of social vulnerability and biophysical vulnerability are statistically tested for their associations. Biophysical vulnerability is conceptualized utilizing a urban heat risk index calculated from summer 2010 LANDSAT imagery to measure land surface temperature , structural density through the normalized difference built-up index, and vegetation abundance through the normalized difference vegetation index. A cross-section of twenty geographically distributed metropolitan statistical areas (MSAs) in the U.S. are examined using census derived variables at the tract level. The results of bivariate correlation analysis, ordinary least squares regression, and spatial autoregression analysis indicate consistent and significant associations between greater social disadvantage and higher urban heat levels. Multilevel modeling is used to examine the relationship of MSA-level segregation with tract-level minority status and social disadvantage to higher levels of urban heat. Segregation has a significant but varied relationship with the variables, indicating that there are inconsistent associations with urban heat due to differing urban ecologies. Urban heat and social vulnerability present a varying landscape of thermal inequity in different urban areas, associated in many cases with residential segregation.

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