Thesis (Ph. D.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

The primary objectives of this study are to understand if and how cities are adapting to heat and water stress and to characterize their understanding of the potential tradeoffs associated with vegetation-based strategies. I address these objectives using two approaches: a comparative analysis of climate adaptation and sustainability planning documents in cities vulnerable to heat and water stress and an in-depth case study of the response to heat and water threats in Los Angeles. The comparative analysis of city plans builds a broad understanding of how cities are planning to adapt to heat and water stress and the degree to which they articulate an understanding of, and mitigate the potential for, maladaptive measures. The Los Angeles case study provides the opportunity to more deeply trace how the process of adapting to heat and water stress has unfolded in a single city. To do so, I locate the city’s contemporary policies in an historical continuum with previous municipal environmental policy efforts, in local patterns of urban development and their entailing political and economic foundations, and in regional, state, national, and international environmental policy hierarchies.

Urban heat island is a phenomenon of different temperatures in cities compared to temperatures in the surrounding landscape. The intensity of this phenomenon can be influenced by the presence of vegetation in cities. There is evaluated the effect of vegetation on microclimate in various parts of the city České Budějovice in this thesis. The assessment is based on the evaluation of multispectral Landsat satellite images and thermal images, which were taken in-situ using thermal camera, and their statistical processing. The results show statistically significant differences in surface temperatures in the different areas of the city with a different amount of vegetation. Surface temperatures are significantly lower in areas with a large amount of vegetation than in areas without vegetation. Equally, selected vegetation surfaces have lower temperatures compared to anthropogenic surfaces, at least about 9 ° C.

O padrão de desenvolvimento das cidades brasileiras nas últimas décadas, com acelerada urbanização, tem mostrado resultados prejudiciais sobre a forma das cidades, a qualidade de vida nelas e o consumo dos recursos naturais. Para promover a sustentabilidade no planejamento urbano é importante adequar o ambiente construído ao clima local, permitindo ao homem viver em conforto e reduzir o consumo dos recursos naturais. Uma das maneiras apontadas para melhorar a qualidade das cidades e o conforto térmico nelas é através da criação de parques verdes. Este trabalho tem por objetivo analisar a influência dos parques verdes no conforto térmico urbano, através de estudo de caso em Porto Alegre/RS. A pesquisa parte da revisão bibliográfica, para explicar como as áreas verdes podem contribuir para o conforto térmico urbano. Para o estudo de caso foi analisada a influência dos parques Farroupilha, Moinhos de Vento e Germânia nos seus entornos, através de medições in loco de temperatura e umidade do ar, principais variáveis de conforto térmico, e de análises de dados de sensoriamento remoto. Utilizando índices que consideram apenas estas duas variáveis, um com base da carta de Givoni e outro no cálculo da Temperatura Efetiva, não foi possível observar correlação entre o conforto térmico e a presença e proximidade dos parques. Entretanto, analisando as variáveis, é possível observar que os parques aumentaram entre 3,54 e 13,94% a umidade relativa do ar e reduziram a temperatura do ar em até 2,3°C. As análises de sensoriamento remoto vão ao encontro destes resultados, chegando 8,6°C as diferenças de temperaturas de superfície obtidas no interior e no entorno dos parques. Os três parques estudados influenciaram nas variáveis de conforto nos seus entornos, sendo o efeito de oásis mais significativo nos parques maiores e com áreas mais arborizadas e superfícies de água. Assim sendo, até mesmo os parques menores contribuem para a redução das ilhas de calor urbano, evitando que as temperaturas dos centros das cidades aumentem ainda mais. / The pattern of development of Brazilian cities in recent decades, with rapid urbanization, have shown harmful results on the morphology of the cities, the quality of life in them and the consumption of natural resources. To promote sustainability in urban planning it is important to adapt the built environment to the local climate, allowing to live in comfort and to reduce the consumption of natural resources. One of the ways aimed at improving the quality of cities and the thermal comfort in them is by creating green parks. This work aims to analyze the influence of green parks in the urban thermal comfort a case study in Porto Alegre / RS. The study of the literature review can explain how green areas can contribute to the urban thermal comfort. For the case study we analyzed the influence of three parks (Farroupilha, Moinhos de Vento and Germânia) with their surroundings by measurements, in situ, of temperature and humidity, the main variables of thermal comfort, and remote sensing data analysis. Using indexes treating only these two variables, one based on the chart of Givoni and the other in the calculation of Effective Temperature, was not observed correlation between thermal comfort and the presence and proximity of the parks. However, analyzing the variables we can observe that the parks have increased of relative air humidity between 3.54 and 13.94% and reduced air temperature of 2.32°C. Remote sensing analysis are in agreement with these results, reaching 8.56°C differences in surface temperatures obtained inside and around the parks. The three parks studied influenced variables the comfort of in their surroundings, with the oasis effect very significant on the largest parks and more wooded areas and water surfaces. Even the smallest parks contribute to the reduction of urban heat islands, preventing temperatures from urban centers to increase further.

abstract: Pavement surface temperature is calculated using a fundamental energy balance model developed previously. It can be studied using a one-dimensional mathematical model. The input to the model is changed, to study the effect of different properties of pavement on its diurnal surface temperatures. It is observed that the pavement surface temperature has a microclimatic effect on the air temperature above it. A major increase in local air temperature is caused by heating of solid surfaces in that locality. A case study was done and correlations have been established to calculate the air temperature above a paved surface. Validation with in-situ pavement surface and air temperatures were made. Experimental measurement for the city of Phoenix shows the difference between the ambient air temperature of the city and the microclimatic air temperature above the pavement is approximately 10 degrees Fahrenheit. One mitigation strategy that has been explored is increasing the albedo of the paved surface. Although it will reduce the pavement surface temperature, leading to a reduction in air temperature close to the surface, the increased pavement albedo will also result in greater reflected solar radiation directed towards the building, thus increasing the building solar load. The first effect will imply a reduction in the building energy consumption, while the second effect will imply an increase in the building energy consumption. Simulation is done using the EnergyPlus tool, to find the microclimatic effect of pavement on the building energy performance. The results indicate the cooling energy savings of an office building for different types of pavements can be variable as much as 30%. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2015

O padrão de desenvolvimento das cidades brasileiras nas últimas décadas, com acelerada urbanização, tem mostrado resultados prejudiciais sobre a forma das cidades, a qualidade de vida nelas e o consumo dos recursos naturais. Para promover a sustentabilidade no planejamento urbano é importante adequar o ambiente construído ao clima local, permitindo ao homem viver em conforto e reduzir o consumo dos recursos naturais. Uma das maneiras apontadas para melhorar a qualidade das cidades e o conforto térmico nelas é através da criação de parques verdes. Este trabalho tem por objetivo analisar a influência dos parques verdes no conforto térmico urbano, através de estudo de caso em Porto Alegre/RS. A pesquisa parte da revisão bibliográfica, para explicar como as áreas verdes podem contribuir para o conforto térmico urbano. Para o estudo de caso foi analisada a influência dos parques Farroupilha, Moinhos de Vento e Germânia nos seus entornos, através de medições in loco de temperatura e umidade do ar, principais variáveis de conforto térmico, e de análises de dados de sensoriamento remoto. Utilizando índices que consideram apenas estas duas variáveis, um com base da carta de Givoni e outro no cálculo da Temperatura Efetiva, não foi possível observar correlação entre o conforto térmico e a presença e proximidade dos parques. Entretanto, analisando as variáveis, é possível observar que os parques aumentaram entre 3,54 e 13,94% a umidade relativa do ar e reduziram a temperatura do ar em até 2,3°C. As análises de sensoriamento remoto vão ao encontro destes resultados, chegando 8,6°C as diferenças de temperaturas de superfície obtidas no interior e no entorno dos parques. Os três parques estudados influenciaram nas variáveis de conforto nos seus entornos, sendo o efeito de oásis mais significativo nos parques maiores e com áreas mais arborizadas e superfícies de água. Assim sendo, até mesmo os parques menores contribuem para a redução das ilhas de calor urbano, evitando que as temperaturas dos centros das cidades aumentem ainda mais. / The pattern of development of Brazilian cities in recent decades, with rapid urbanization, have shown harmful results on the morphology of the cities, the quality of life in them and the consumption of natural resources. To promote sustainability in urban planning it is important to adapt the built environment to the local climate, allowing to live in comfort and to reduce the consumption of natural resources. One of the ways aimed at improving the quality of cities and the thermal comfort in them is by creating green parks. This work aims to analyze the influence of green parks in the urban thermal comfort a case study in Porto Alegre / RS. The study of the literature review can explain how green areas can contribute to the urban thermal comfort. For the case study we analyzed the influence of three parks (Farroupilha, Moinhos de Vento and Germânia) with their surroundings by measurements, in situ, of temperature and humidity, the main variables of thermal comfort, and remote sensing data analysis. Using indexes treating only these two variables, one based on the chart of Givoni and the other in the calculation of Effective Temperature, was not observed correlation between thermal comfort and the presence and proximity of the parks. However, analyzing the variables we can observe that the parks have increased of relative air humidity between 3.54 and 13.94% and reduced air temperature of 2.32°C. Remote sensing analysis are in agreement with these results, reaching 8.56°C differences in surface temperatures obtained inside and around the parks. The three parks studied influenced variables the comfort of in their surroundings, with the oasis effect very significant on the largest parks and more wooded areas and water surfaces. Even the smallest parks contribute to the reduction of urban heat islands, preventing temperatures from urban centers to increase further.

abstract: In recent years, an increase of environmental temperature in urban areas has raised many concerns. These areas are subjected to higher temperature compared to the rural surrounding areas. Modification of land surface and the use of materials such as concrete and/or asphalt are the main factors influencing the surface energy balance and therefore the environmental temperature in the urban areas. Engineered materials have relatively higher solar energy absorption and tend to trap a relatively higher incoming solar radiation. They also possess a higher heat storage capacity that allows them to retain heat during the day and then slowly release it back into the atmosphere as the sun goes down. This phenomenon is known as the Urban Heat Island (UHI) effect and causes an increase in the urban air temperature. Many researchers believe that albedo is the key pavement affecting the urban heat island. However, this research has shown that the problem is more complex and that solar reflectivity may not be the only important factor to evaluate the ability of a pavement to mitigate UHI. The main objective of this study was to analyze and research the influence of pavement materials on the near surface air temperature. In order to accomplish this effort, test sections consisting of Hot Mix Asphalt (HMA), Porous Hot Mix asphalt (PHMA), Portland Cement Concrete (PCC), Pervious Portland Cement Concrete (PPCC), artificial turf, and landscape gravels were constructed in the Phoenix, Arizona area. Air temperature, albedo, wind speed, solar radiation, and wind direction were recorded, analyzed and compared above each pavement material type. The results showed that there was no significant difference in the air temperature at 3-feet and above, regardless of the type of the pavement. Near surface pavement temperatures were also measured and modeled. The results indicated that for the UHI analysis, it is important to consider the interaction between pavement structure, material properties, and environmental factors. Overall, this study demonstrated the complexity of evaluating pavement structures for UHI mitigation; it provided great insight on the effects of material types and properties on surface temperatures and near surface air temperature. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2013

abstract: Rapid urbanization in Phoenix, Arizona has increased the nighttime temperature by 5°C (9 °F), and the average daily temperatures by 3.1°C (5.6 °F) (Baker et al 2002). On the macro scale, the energy balance of urban surface paving materials is the main contributor to the phenomenon of the Urban Heat Island effect (UHI). On the micro scale, it results in a negative effect on the pedestrian thermal comfort environment. In their efforts to revitalize Downtown Phoenix, pedestrian thermal comfort improvements became one of the main aims for City planners. There has been an effort in reformulating City zoning standards and building codes with the goal of developing a pedestrian friendly civic environment. Much of the literature dealing with mitigating UHI effects recommends extensive tree planting as the chief strategy for reducing the UHI and improving outdoor human thermal comfort. On the pedestrian scale, vegetation plays a significant role in modifying the microclimate by providing shade and aiding the human thermal comfort via evapotranspiration. However, while the extensive tree canopy is beneficial in providing daytime shade for pedestrians, it may reduce the pavement surfaces' sky-view factor during the night, thereby reducing the rate of nighttime radiation to the sky and trapping the heat gained within the urban materials. This study strives to extend the understanding, and optimize the recommendations for the use of landscape in the urban context of Phoenix, Arizona for effectiveness in both improving the human thermal comfort and in mitigating the urban heat island effect. / Dissertation/Thesis / Ph.D. Design 2014

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-05-03T15:18:12Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) FERREIRA, H. S._Dissertação_FINAL.pdf: 9243519 bytes, checksum: f2021a9042905cd6559a1e42abc0aa57 (MD5) / Made available in DSpace on 2017-05-03T15:18:12Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) FERREIRA, H. S._Dissertação_FINAL.pdf: 9243519 bytes, checksum: f2021a9042905cd6559a1e42abc0aa57 (MD5) Previous issue date: 2016-02-29 / FACEPE / O planejamento urbano atrelado às perspectivas de desenvolvimento sustentável podem minimizar os riscos socioambientais urbanos que se consolidaram na maioria das grandes cidades brasileiras, dentre eles, os ricos à saúde. As repercussões locais das alterações climáticas observadas na atualidade têm provocado mudanças nos padrões dos elementos atmosféricos, potencializando ainda mais os riscos à saúde, especialmente a expansão e a persistência de surtos epidêmicos de arboviroses como a dengue. O objetivo deste trabalho foi analisar a relação entre a dinâmica do clima urbano e a ocorrência de surtos e formação de epidemias de dengue na cidade do Recife – PE. Foram analisadas as características do clima urbano do Recife – variáveis atmosféricas – temperaturas e umidade relativa do ar, as influencias dos elementos atmosféricos sobre a formação das epidemias e o padrão de distribuição espacial das notificações em relação à indicadores socioeconômicos e físicoambientais. Conforme resultados encontrados verificou-se que os surtos epidêmicos mais expressivos na cidade estão relacionados com as ocorrências de precipitações no primeiro semestre do ano, especialmente durante a quadra chuvosa, sendo possível a identificação de bairros mais e menos suscetíveis aos surtos da doença em períodos com condições atmosféricas favoráveis a reprodução e proliferação do mosquito vetor da dengue. As áreas de morros das zonas norte e sul apresentaram maior problemática em relação a situação da dengue no município, com persistência importante de surtos epidêmicos. A ligação entre os surtos de dengue e as condições climáticas locais, faz das condições atmosféricas um fator digno de vigilância e monitorização como parte das estratégias de combate e controle das epidemias de dengue na cidade. / Urban planning linked to sustainable development prospects can minimize the environmental risks that have been consolidated in most of the Brazilian cities. One of these risks are the health risks. Nowadays, local effects of climate change can be observed, and they are leading to changes in atmospheric elements patterns, which in turn enhance health risks even more. Among these risks, we highlight the expansion and persistence of arboviral diseases outbreaks, such as dengue episodes. The objective of this study was to analyze the relationship between urban climate dynamics and occurrences of dengue epidemics outbreaks in the city of Recife, PE. We analyzed the characteristics of the urban climate of Recife (temperature and relative humidity), the influence of atmospheric elements on formation of epidemic outbreaks and its spatial distribution regarding socioeconomic, physical and environmental indicators. Results indicated that the most significant outbreaks in the city are related to the occurrence of rainfall in the first half of the year, especially during the rainy season. In addition, it is possible to identify more or less susceptible neighborhoods to disease outbreaks in the periods of favorable weather conditions to reproduction and proliferation of the mosquito. The areas of hills in the northern and southern areas have greater problems regarding the situation of dengue than other areas in the city, showing recurrence of outbreaks. The connection between the dengue outbreaks and the local weather conditions makes weather conditions a decent factor of surveillance and monitoring as part of combat strategies and control of dengue epidemics in the city.

O presente trabalho teve por objetivo caracterizar as circulações locais que se formam na região central do Chile (RCC). Uma análise sinótica para o ano 2004 mostrou que durante o verão a condição de tempo dominante foi de céus claros associados à presença do Anticiclone Subtropical do Pacífico Sul com o deslocamento de baixas pressões litoral que mudam o regime de ventos. Dados da Armada do Chile mostraram que, no litoral da Região de Valparaíso, a amplitude anual de temperatura é de aproximadamente de 8 ºC. Os extremos de temperatura ocorrem entre as 09 e 12 UTC para as mínimas e 18 e 21 UTC para as máximas. O vento apresenta um ciclo anual com domínio da componente oeste no verão e componente leste no inverno. Maiores intensidades estão associadas à passagem de sistemas frontais no inverno. A brisa marítima é melhor caracterizada nos valores médios horários do vento no período de verão, sendo observada a partir das 12 UTC, com ventos de maior intensidade entre 18 e 21 UTC. A brisa terrestre é observada a partir das 00 UTC com ventos de menor intensidade que na brisa marítima. Dados da CONAMA-RM mostraram um ciclo diurno de temperatura bem definido na Região Metropolitana de Santiago com as temperaturas mínimas ocorrendo entre 06 e 09 HL e valores máximos entre 14 e 16 HL. Ao agrupar as estações localizadas dentro e fora dos limites urbanos foi possível identificar o efeito da ilha de calor (IC). Para o período de verão a IC apresentou intensidades positivas e no inverno uma maior freqüência de valores negativos. A intensidade do vento sofre também os efeitos da cidade, observando-se uma redução desta nas estações que se localizam no centro da Grande Santiago. Valores mínimos de intensidade do vento por períodos prolongados levaram a um incremento nas concentrações de material particulado. A diminuição nas concentrações está associada à passagem de frentes e ao incremento na intensidade do vento. Os efeitos da cidade na atmosfera foram estudados com mais detalhamento mediante a utilização do BRAMS. A análise sinótica mostrou uma região de vento fraco e baixo gradiente barométrico na região de estudo para a maior parte do período. Foi possível identificar a brisa marítima com maior intensidade do vento entre 18 e 19 UTC. A brisa terrestre foi identificada na maior parte das noites, com intensidade de vento maior próximo das 04 UTC. As cidades localizadas na RCC apresentam a tendência de resfriar o ar próximo da superfície e modificam a intensidade do vento e os padrões de umidade relativa. Embora os efeitos das cidades tenham sido encontrados, os efeitos da topografia no escoamento são ainda mais importantes, gerando circulações sobre a região central do Chile que não são completamente modificadas pela presença das cidades. / The objective of this work was to characterize the local circulations that are generated in the Central Chile (CC) region. A synoptic analyze for 2004 show that clear sky weather conditions associated to the Subtropical Anticyclone of South Pacific (SASP) was dominant during the summer. Coastal lows moving from north to CC interacts with SASP changing the wind regime. Meteorological data from Armada do Chile showed that on the coast of Valparaíso, the annual temperature amplitude was approximately 8 ºC. Temperature extremes occur between 09 and 12 UTC for minimum and 18 and 21 UTC for maximum values. The wind showed an annual cycle, with dominant direction to west during summer, while in wintertime, wind dominant direction is to the east. Higher values of wind speed are associated with frontal passages during winter. The sea breeze was better seen in the wind mean hourly values between 12 UTC and 21 UTC with higher wind speeds at 18 UTC. Land breeze was observed around 00 UTC, with lower wind speeds than in the sea breeze case. Meteorological data form CONAMA-RM showed a well defined diurnal cycle of temperature in the Metropolitan Region of Santiago with minimum temperatures occurring between 06 and 09 LT and maximum values between 14 and 16 LT. The urban heat island effect was seen grouping urban and non urban meteorological stations. The urban heat island is, in general, positive during the summer but, during the winter, negative values of intensity are frequent. The wind speed also shows the urban effects, with a wind speed decrease in the meteorological station inside the city. Long periods of low wind speed are associated with an increase in the particulate matter concentrations. The decrease in these concentrations is associated with the passage of frontal systems, as well as wind speed increase. The city effects on the atmosphere were studied in more details through the use of BRAMS. The synoptic analysis showed a weak wind region and low pressure gradient in the study region for most part of the period. The sea breeze was identified with higher wind speeds between 18 and 19 UTC. The land breeze was identified in the most part of the nights, with higher wind speeds near 04 UTC. The cities situated in CC have a tendency to cool down the air near to the surface and modify the wind speed and relative humidity patterns. Although the effects of the cities have been found, the topography effects on the wind flow are even more important, generating circulations over Central Chile that are not completely modified by the presence of the cities.