Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-09-28T20:00:01Z No. of bitstreams: 1 JOEL SILVA DOS SANTOS - TESE (PPGRN) 2011.pdf: 5220762 bytes, checksum: 35f8c4b7ea7bb6b3e7c706a4b11bea0d (MD5) / Made available in DSpace on 2018-09-28T20:00:01Z (GMT). No. of bitstreams: 1 JOEL SILVA DOS SANTOS - TESE (PPGRN) 2011.pdf: 5220762 bytes, checksum: 35f8c4b7ea7bb6b3e7c706a4b11bea0d (MD5) Previous issue date: 2011-12-19 / As alterações ocorridas no sistema climático urbano das grandes cidades são processos relacionados ao adensamento urbano e às diferentes formas de uso e cobertura do solo. O objetivo deste trabalho foi analisar o campo térmico urbano e a sua relação com as diversas formas de uso e cobertura do solo em cidade tropical úmida, especificamente a cidade de João Pessoa, PB. As medições da temperatura do ar e umidade relativa foram realizadas em dois períodos distintos de três meses (seco e chuvoso), utilizando-se termo-higrômetro da marca Hobos em nove pontos representativos da malha urbana de cidade. O nível de estresse térmico foi avaliado com base no índice de desconforto de Thom (IDT) para regiões tropicais, ajustado através de questionários de avaliação da sensação térmica das pessoas nos pontos monitorados. O teste de Mann-Kendall foi utilizado para avaliar a tendência temporal das séries climatológicas de temperatura, umidade relativa do ar e do IDT no período de 1963 a 2011. Os tipos de cobertura de solo de cada ponto monitorado foram classificados dentro de nove classes de acordo com a percentagem de vegetação e de materiais permeáveis e impermeáveis utilizando métodos quantitativos e qualitativos. Os resultados do trabalho indicam que a faixa de classificação do índice de desconforto de Thom não é apropriada para regiões tropicais úmidas. A ilha de calor urbano é um fenômeno que ocorre preferencialmente durante o período noturno enquanto a intensidade máxima dos gradientes de temperatura e umidade relativa do ar são fenômenos essencialmente diurnos. Os cenários dos níveis de conforto térmico indicam condições de forte desconforto ambiental para os anos de 2050 e 2060 durante o período seco e desconfortável para o período chuvoso no ano de 2060 em toda área de estudo. / The changes in the urban climate system in great cities are processes related to urban density and the different forms of use and land cover. The objective of this study was to analyze the thermal urban field and its relation to the various forms of use and land cover in a humid tropical city, specifically Joao Pessoa city, PB, Brazil. Measurements in air temperature and relative humidity were carried out in two distinct periods of three months (dry and wet seasons), using thermo-hygrometer Hobos located in nine representative areas of the city. The level of heat stress was evaluated based on Thom's discomfort index (IDT, in Portuguese), adjusted for tropical regions based on questionnaires for assessing the thermal sensation that people have in function to the parameters that determine the environment in which they live. Mann-Kendall test was used to assess the temporal trends of time series in temperature, relative humidity and IDT for the period from 1963 to 2011. The types of ground cover of each monitored point were classified into nine classes according to the percentage of vegetation coverage and permeable and impermeable materials by utilizing both qualitative and quantitative methods. The results of the study indicated that the classification range of the Thom’s discomfort index is not suitable for humid tropical regions. The urban heat island is a phenomenon that occurs preferentially during the night while the maximum intensity of the temperature and relative humidity gradients are essentially diurnal phenomena. The scenarios of the thermal comfort levels indicated a strong discomfort for the 2050 and 2060 years during the dry season and uncomfortable condition during the rainy season in the 2060 year throughout the study area.

Understanding climate change and variability at urban scale is essential for water resource management, land use planning, and development of adaption plans. However, there are serious challenges to meet these goals due to unavailability of observed and / or simulated high resolution spatial and temporal climate data. Recent efforts made possible the availability of high resolution climate data from non-hydrostatic regional climate model (RCM) and statistically downscaled General Circulation Models (GCMs). This study investigates trends in climate and urbanization and their impact on surface water supply for the city of Addis Ababa, Ethiopia. The methodology presented in this study focused on the observed and projected NIMRHadGEM2- AO model and Special Report on Emissions Scenarios (SRES) of B2 and A2 of HadCM3 model are also employed for rainfall, maximum temperature and minimum temperature data using for climate analysis. Water Evaluation and Planning (WEAP) modeling system was used for determination of climate and urbanization impacts on water. Land-Sat images were analyzed using Normalized Differencing Vegetation Index (NDVI). Statistical downscaling model (SDSM) was employed to investigate the major changes and intensity of the urban heat island (UHI). The result indicates monthly rainfall anomalies with respect to the baseline mean showing wet anomaly in summer (kiremt) during 2030s and 2050s, and a dry anomaly in the 2080s under A2 and B2 scenarios with exception of a wet anomaly in September over the city. The maximum temperature anomalies under Representative Concentration Pathways (RCPs) also show warming during near, mid and end terms. The mean monthly minimum temperature anomalies under A2 and B2 scenarios are warm but the anomalies are much lower than RCPs. The climate under the RCP 8.5 and high population growth (3.3 %) scenario will lead to the unmet demand of 462.77 million m3 by 2039. Future projection of urban heat island under emission pathway of A2 and B2 scenario shows that, the nocturnal UHI will be intense in winter or dry season episodes in the city. Under A2 scenario the highest urban warming will occur during October to December (2.5 ºC to 3.2 ºC). Under RCP 8.5 scenario the highest urban warming will occur during October to December (0.5 ºC to 1.0 °C) in the 2050s and 2080s. Future management and adaptation strategies are to expand water supply to meet future demand and to implement demand side water management systems of the city and UHI / Environmental Sciences / Ph. D. (Environmental Management)

As mudanças climáticas globais, regionais e locais representam, na atualidade, uma das maiores preocupações da humanidade. Essas mudanças podem ocorrer tanto a partir de causas naturais quanto a partir de causas antrópicas. As áreas das cidades se caracterizam por apresentarem temperaturas mais elevadas quando comparadas com as áreas rurais. Essa anomalia térmica causa a formação de ilhas de calor e esse fenômeno é reconhecidamente importante em estudos de clima urbano. O objetivo do presente trabalho foi, através de técnicas do sensoriamento remoto, identificar e analisar as ilhas de calor do Município de Piracicaba, SP verificando sua sazonalidade, intensidade e morfologia. Para tanto foi necessário realizar uma análise climática regional e verificar a possibilidade do uso do algoritmo de transformação termal do software IDRISI 3.2 nas imagens do satélite Landsat 7. Para validar o algoritmo foram aplicados dois métodos de transformação de temperatura aparente de superfície. Para a análise climática regional foram estudados os principais elementos climáticos do Município de Piracicaba, SP utilizando-se de dados da Estação Meteorológica da ESALQ/USP entre os anos de 1950 e 2005 e estes foram correlacionados com variáveis da urbanização. Concluiu-se, com os dados encontrados, que os elementos temperatura, precipitação, umidade relativa e evaporação tiveram tendência de aumento no período estudado e todos eles foram classificados como tendências climáticas. A temperatura apresentou tendência de aumento mais acentuada e se correlacionou positivamente com o aumento da urbanização. O algoritmo de transformação do software IDRISI 3.2 para o satélite Landsat 7 foi validado, sendo uma importante ferramenta para a utilização de imagens de melhor resolução. As ilhas de calor mais intensas do verão são representadas por locais com excesso de material de construção civil e pouca ou nenhuma área verde. A diferença entre a área urbana e a área rural da cidade ultrapassou 16°C no verão. O Parque da Rua do Porto é uma ilha de frescor e exerce um “efeito oásis” no centro e nos bairros vizinhos. O perfil das ilhas de calor do Município de Piracicaba não segue aquele delimitado por OKE (1974). As ilhas de calor variam sazonal e espacialmente e a intensidade destas, ao longo das estações do ano, está intimamente relacionada com a sazonalidade da cultura da cana-deaçúcar. As ilhas de calor da época da entressafra são, em média, 3.5°C mais intensas que as da época da safra. Por fim, pode-se afirmar que o uso e a cobertura do solo rural e urbano é um dos grandes agentes modificadores do clima local e regional. / Global, regional and local climate changes represent one of the greatest concerns of humanity. Climate changes can occur through natural or anthropogenic causes. Urban areas usually present higher temperatures than rural areas. This thermal effect is called “heat-island phenomenon” and has great importance on urban climate studies. In the present work, we identified and analyzed the heat-islands from Piracicaba, São Paulo using remote sensing techniques. The heat-islands were analyzed according to its seasonality, intensity and morphology using images from Landsat 7 satellite. We performed analysis on regional climate changes and investigated the use of the IDRISI thermal algorithm to convert Landsat 7 infrared thermal data on land surface temperature (LST). In order to transform Landsat 7 infrared thermal data we used two mathematical methods. Climate changes were analyzed by monitoring the climate elements for long periods of time, enabling the visualization of directional or periodical regional changes. The main climate elements were studied using data from ESALQ meteorological station for the last 55 years (1950-2005). Temperature, relative humidity, evaporation and precipitation variation were found to be correlated with urban growth parameters. The results indicated that temperature, precipitation, relative humidity and evaporation increased during the studied period and have been classified as “climate trends”. The temperature presented the more accentuated trend of increase and was positively correlated with the growing urbanization. The software IDRISI 3.2 can be used with Landsat 7 high resolution images, being a useful and rapid tool to study urban heat islands. The most intense summer heatislands were represented by regions with higher amounts of constructed areas and almost any green area. In fact, during the summer the difference between the urban and rural areas was greater than 10°C. The Rua do Porto park was identified as a fresh-island and showed the “oasis effect” to the Center and neighbouring regions. Heat-islands varied according to the season and space and its intensity is intimately related to the sugar-cane seasonality. During the intercrop period the heat-islands were 3.5°C more intense than during the crop period. In conclusion land cover and land use affect local and regional climates.

The systemic relationship between the human entity and its environment, under the constraint of its function, were used as the perfect example to design and create the systemic relationship of an urban regenerative building with its economical, environmental and social context in the Inner City of Pretoria. / Dissertation (MArch (Prof))--University of Pretoria, 2005. / Architecture / unrestricted

Les projections climatiques prévoient une amplification du réchauffement climatique, potentiellement exacerbée en milieu urbain du fait du phénomène d’îlot de chaleur urbain. La recrudescence d’évènements extrêmes comme les canicules peut avoir des conséquences écologiques, sanitaires, et économiques dramatiques à l’échelle des villes qui concentrent la population. Parmi les mesures d’adaptation visant à améliorer le confort climatique et la demande énergétique, la climatisation et le verdissement urbain constituent deux leviers d’action aux effets parfois antagonistes. Ce travail de thèse – mené dans le cadre des trois projets de recherche CLIM2, MUSCADE et VegDUD, propose d’évaluer ces effets par des simulations du climat urbain à l’échelle de l’agglomération parisienne. La modélisation repose en particulier sur le modèle de canopée urbaine TEB qui permet de simuler les échanges de chaleur, d’eau et de quantité de mouvement entre les surfaces urbaines et l’atmosphère, et depuis peu l’énergétique des bâtiments et des indices de confort thermique dans les bâtiments et dans les rues. Afin d’améliorer la prise en compte de la végétation urbaine dans TEB, un modèle de toitures végétalisées extensives a tout d’abord été développé et évalué. Différentes pratiques d’arrosage de la végétation urbaine au sol ou sur les toits ont également été paramétrées. Les scénarios d’adaptation de la ville de Paris par la climatisation, évalués dans le cadre de CLIM2 pour la canicule 2003 par des simulations couplées de TEB avec un modèle atmosphérique, ont mis en évidence que toutes les formes de climatisation qui rejettent de la chaleur dans l’atmosphère (sèche ou humide) génèrent une augmentation de la température des rues au niveau des piétons. Ce réchauffement, proportionnel à la puissance des rejets de chaleur sensible dans l’atmosphère, est en moyenne de 0.5 à 2°C, selon le niveau de déploiement de la climatisation. Différentes stratégies de verdissement ont ensuite été mises en œuvre et évaluées toujours sur Paris, en faisant varier soit la végétation au sol (plusieurs taux et types de végétation testés), soit celle en toiture (avec ou sans arrosage), soit les deux. Ces simulations, réalisées dans la configuration générale du projet MUSCADE, i.e. en mode forcé avec une version de TEB disposant d’un générateur dynamique d’îlot de chaleur urbain, ont montré que l’augmentation de la couverture végétale au sol a un pouvoir rafraîchissant plus efficace que les toitures végétalisées, et ce d’autant plus que le taux de verdissement et que la proportion d’arbres sont importants. Les toitures végétalisées quant à elles constituent le moyen le plus efficace de réduire la consommation d’énergie, non seulement estivale mais aussi à l’échelle annuelle, essentiellement grâce à leur pouvoir isolant. / Climate projections predict an amplification of global warming, potentially exacerbated in urban areas by the urban heat island effect. More frequent extreme events such as heat waves may have severe public health, ecological, and economic consequences as cities concentrate population. Among the measures aiming at improving thermal comfort or energy demand, air conditioning and urban greening are measures that may have antagonistic effects. This PhD work is undertaken within the framework of three research projects, CLIM2, MUSCADE and VegDUD. Its objective is to evaluate the respective effects of air conditioning and urban greening based on urban climate simulations across the Paris area. The modelling relies on the Town Energy Balance (TEB) model, which simulates the exchange of heat, water and momentum between the urban surface and the atmosphere. It has been recently improved to simulate building energetics, as well as indoor and outdoor thermal comfort indices. To improve the description of urban vegetation within TEB, a green roof model has been developed and evaluated. In addition, watering practices have been implemented to model the watering of urban vegetation at ground or roof level. Within CLIM2, the air conditioning scenarios tested for adapting Paris city to the extreme temperatures of the 2003 heatwave have been evaluated based on simulations using TEB coupled with an atmospheric model. Results shows that all forms of conditioning that release waste heat (dry or wet) into the atmosphere generate a temperature increase in the streets. This warming is proportional to the power of the sensible heat releases in the atmosphere and is on average 0.5 to 2_C, depending on the level of deployment of the air conditioning. Then, the greening of Paris city has been evaluated based on simulations carried out with the general configuration of the MUSCADE project, i.e. with climate forcings and a dynamic urban heat island generator. The scenarios tested consisted in an increase in ground-base vegetation or an implementation of green roofs on compatible buildings, or the two combined, with the option of watering green roofs or not in summer. Results show that increasing the ground cover has a stronger cooling effect than implementing green roofs, and even more so when the greening rate and the proportion of trees are important. The green roofs are however the most effective way to reduce energy consumption, not only in summer but also on an annual basis, mainly due to their insulating properties.

De par ses caractéristiques, l’environnement urbain influe significativement sur le climat observé dans et à la périphérie des villes. Il est communément admis que le centre des villes présente fréquemment des températures d’air plus élevées que celles mesurées dans les zones rurales environnantes. Ce phénomène appelé îlot de chaleur urbain intéresse les enjeux relatifs à la santé publique, au confort urbain et à la demande énergétique. Ce travail de thèse propose de caractériser le phénomène d’îlot de chaleur à partir de l'association d'un zonage climatique et de mesures mobiles à haute résolution spatiale dans la canopée urbaine. Il repose sur une approche méthodologique en trois temps. Une classification climatique ("Local Climate Zones" (LCZ)) est tout d'abord appliquée à l'agglomération de Nancy. Ce découpage climatique du territoire sert de support à la réalisation de mesures embarquées effectuées en période estivale à l'aide d'un véhicule instrumenté. Celles-ci ont pour but d'observer in situ les spécificités climatiques des LCZ recensées dans l'agglomération. L'association d'une base de données de relevés météorologiques et de la classification LCZ permet de caractériser le comportement climatique du milieu urbain et de comparer le comportement de différentes typologies de quartiers en présence d'un îlot de chaleur urbain. Cette démarche propose également un cadre théorique pour le développement d'un modèle de diagnostic à partir d'indicateurs urbains et climatiques, avec la perspective de construction d'un outil de prise en compte de l'îlot de chaleur dans le processus de planification urbaine / Urban environment impacts significantly the climate observed within and around cities. In this context, city centers frequently present higher air temperatures than those measured in the rural areas nearby. This phenomenon called urban heat island impacts major issues such as public health, urban comfort and energy demand. This Ph.D. thesis proposes to characterize the urban heat island phenomenon based on the combination of a climatic zoning and high spatial density mobile measurements performed within the urban canopy layer. This study is divided into three steps. A climate classification ("Local Climate Zones" (LCZ)) is first applied to the conurbation of Nancy, France. This climatic zoning is used in order to perform mobile measurements thanks to an instrumented vehicle. These measurements target to observe the climatic patterns of the LCZ built in this conurbation. The combination of meteorological database and LCZ classification scheme allows to characterize the urban climate behavior and to compare the thermal behavior of different neighbourhood types. This approach provides a theoretical framework for the development of a diagnosis model based on urban and climatic indicators. It also brings outlooks regarding the building of a decision-support tool that aims to supply information about urban heat island adapted to the urban planners needs

<div><br></div><div>Extreme heat is one of the deadliest health hazards that is projected to increase in intensity and persistence in the near future. Temperatures are further exacerbated in the urban areas due to the Urban Heat Island (UHI) effect resulting in increased heat-related mortality and morbidity. However, the spatial distribution of urban temperatures is highly heterogeneous. As a result, metrics such as UHI Intensity that quantify the difference between the average urban and non-urban air temperatures, often fail to characterize this spatial and temporal heterogeneity. My objective in this thesis is to understand and characterize the spatio-temporal dynamics of UHI for cities across the world. This has several applications, such as targeted heat mitigation, energy load estimation, and neighborhood-level vulnerability estimation.</div><div><br></div><div>Towards this end, I have developed a novel multi-scale framework of identifying emerging heat clusters at various percentile-based thermal thresholds T_thr and refer to them collectively as <i>intra-Urban Heat Islets</i>. Using the Land Surface Temperatures from Landsat for 78 cities representative of the global diversity, I have showed that the heat islets have a fractal spatial structure. They display properties analogous to that of a percolating system as T_thr varies. At the percolation threshold, the size distribution of these islets in all cities follows a power-law, with a scaling exponent = 1.88 and an aggregated Area-Perimeter Fractal Dimension =1.33. This commonality indicates that despite the diversity in urban form and function across the world, the urban temperature patterns are different realizations with the same aggregated statistical properties. In addition, analogous to the UHI Intensity, the mean islet intensity, i.e., the difference between mean islet temperature and thermal threshold, is estimated for each islet, and their distribution follows an exponential curve. This allows for a single metric (exponential rate parameter) to serve as a comprehensive measure of thermal heterogeneity and improve upon the traditional UHI Intensity as a bulk metric.</div><div><br></div><div><br></div><div>To study the impact of urban form on the heat islet characteristics, I have introduced a novel lacunarity-based metric, which quantifies the degree of compactness of the heat islets. I have shown that while the UHIs have similar fractal structure at their respective percolation threshold, differences across cities emerge when we shift the focus to the hottest islets (T_thr = 90^th percentile). Analysis of heat islets' size distribution demonstrates the emergence of two classes where the dense cities maintain a power law, whereas the sprawling cities show an exponential deviation at higher thresholds. This indicates a significantly reduced probability of encountering large heat islets for sprawling cities. In contrast, analysis of heat islet intensity distributions indicates that while a sprawling configuration is favorable for reducing the mean Surface UHI Intensity of a city, for the same mean, it also results in higher local thermal extremes. </div><div><br></div><div>Lastly, I have examined the impact of external forcings such as heatwaves (HW) on the heat islet characteristics. As a case study, the European heatwave of 2018 is simulated using the Weather Research Forecast model with a focus on Paris. My results indicate that the UHI Intensity under this HW reduces during night time by 1^oC on average. A surface energy budget analysis reveals that this is due to drier and hotter rural background temperatures during the HW period.</div><div>To analyze the response of heat islets at every spatial scale, power spectral density analysis is done. The results show that large contiguous heat islets (city-scale) persist throughout the day during a HW, whereas the smaller islets (neighborhood-scale) display a diurnal variability that is the same as non-HW conditions. </div><div><br></div><div>In conclusion, I have presented a new viewpoint of the UHI as an archipelago of intra-urban heat islets. Along the way, I have introduced several properties that enable a seamless comparison of thermal heterogeneity across diverse cities as well as under diverse climatic conditions. This thesis is a step towards a comprehensive characterization of heat from the spatial scales of an urban block to a megalopolis.</div><div><br></div>

Indiana University-Purdue University Indianapolis (IUPUI)

No description available.

Denna rapport utforskar effekterna av värmeböljor i urbana miljöer och utforskar användningen av olika stadsplaneringsverktyg för att mildra dessa effekter. Värmestress och värmerelaterade sjukdomar är betydande risker som orsakas av stigande temperaturer i städer, därmed analyseras gröna, blå och gråa lösningar i syfte att minska uppkomsten av värmeböljor i stadsmiljöer och därmed även minska dessa risker. Studien bygger på en omfattande litteraturstudie samt en fallstudie av Hornsbergskvarteren i Stockholm där en intervju även genomfördes med viktiga nyckelpersoner. Resultaten från studien pekar på att en kombination av gröna, blåa och gråa lösningar kan samverka för att minska temperaturen i stadsmiljöer. Gröna lösningar som parker, trädplanteringar, gröna tak och väggar kan bidra till att sänka temperaturen men också förbättra luftkvaliteten i städer, vilket skapar hälsosammare levnadsmiljöer. Blåa lösningar inkluderar olika vattenfunktioner i städer där denna studie främst fokuserat på effekterna av sjöar, dammar, kanaler och bäckar. Blåa lösningar har visat sig ha varierande effekter för temperaturregleringen i urbana miljöer, vilket indikerar att ytterligare undersökning är nödvändig för att förstå dess fulla effekt. Två aspekter som inte togs i beaktning under litteraturstudien men som uppkom som potentiella blåa lösningar under fallstudien var fontäner samt potentiella lösningar för fördröjning av regnvatten. Effekterna av dessa kan vidare utforskas i framtida studier för att ge en helhetsbild av blåa lösningars effekter i urbana miljöer. Gråa lösningar, såsom användningen av reflekterande material har visat sig bidra till att skapa svalare städer. Sammantaget pekar resultaten på att en tillämpning av gröna, blåa och gråa lösningar är viktiga för att hantera värmeböljor och mildra dess effekter, främst risken för hälsorelaterade problem. Dessa planeringsverktyg är viktiga för att främja hållbar utveckling och skapa resilienta städer. / This report explores the effects of heatwaves in urban environments and examines the use of various urban planning tools to mitigate these effects. Heat stress and heat-related diseases are significant risks caused by rising temperatures in cities, therefore, green, blue, and gray solutions are analyzed to reduce these risks in urban areas. The study is based on a literature review and a case study of the Hornsberg area in Stockholm, on which an interview was also conducted. The results from the study suggest that a combination of green, blue, and gray solutions can work together to reduce temperatures in urban environments. Green solutions such as parks, trees, green roofs and walls can help to lower temperatures but also improve air quality in cities, creating healthier living environments. Blue solutions include various water features in cities, where this study primarily focused on the effects of lakes, ponds, canals and streams. Blue solutions have shown varying effects on temperature regulation in urban environments, which means that further investigation is necessary to understand their full impact. Two aspects not considered during the literature review but which emerged as potential solutions during the case study, were fountains and rainwater retention basins. For these solutions, further studies need to be reviewed. Gray solutions, such as the use of reflective materials, have proven to contribute to cooler cities. Overall, the results indicate that the integration of green, blue, and gray solutions is important for managing heatwaves and mitigating their effects, primarily the risk of health-related issues. These planning tools are important for sustainable development and creating resilient cities.