Le milieu urbain est à l'origine de processus radiatifs, thermiques, dynamiques et hydriques qui modifient le climat de la ville. La couche superficielle du sol, avec la présence plus ou moins importante de surfaces végétales ou d’eau, les activités humaines qui induisent des rejets de chaleur et de polluants, et la structure urbaine, avec des matériaux de construction et une certaine morphologie du cadre bâti, sont les principaux facteurs de cette modification. Le bilan d'énergie thermique permet d'appréhender la majorité des perturbations générées par la ville. A l'aide du schéma Town Energy Balance, développé par Météo-France pour paramétrer les échanges en énergie et en eau entre les surfaces bâties et l'atmosphère, nous avons effectué des tests de sensibilité du bilan d'énergie à différents facteurs. Ces facteurs appartiennent à cinq domaines d'actions : le bâtiment, l'espace public, l'organisation urbaine, les activités industrielles et les transports. Nos différentes simulations ont permis de confirmer le rôle prédominant des paramètres radiatifs dans le bilan d'énergie de la ville en été. Durant l'hiver, ce sont d’autres paramètres thermiques (isolation) qui ont la plus grande influence. Les collectivités territoriales françaises ont à leur disposition plusieurs outils et moyens pour agir en faveur de leur environnement climatique et intégrer des facteurs influant sur le climat urbain : leurs domaines de compétence directe (voirie, bâtiments communaux, espaces verts, etc.), les documents stratégiques d'orientation (SCOT et PLU), les procédures d'aménagement (ZAC et lotissement), l'incitation et l'information de leurs citoyens et de leurs services (Agenda 21 local, Plan Climat Territorial, Approche Environnementale de l'Urbanisme). Elles ne peuvent cependant pas agir avec une liberté suffisante, compte tenu des limites contraignantes entre droit de l’urbanisme et droit de la construction et de l’habitat / Urbanization, with artificial surfaces replacing natural land, more anthropogenic heat and urban geometry, modifies the micro and meso scale climate. Such modifications do alter the radiative, thermal, moisture and aerodynamics properties of the urban environment. The study of energy balance could help understanding most of these changes. In this thesis, we used the urban surface exchange parameterization of Météo-France: Town Energy Balance, which computes water and energy exchanges between urban surfaces and atmosphere. In order to study the significance of different factors, we made a sensivity study. Factors are filed in five fields: building, public space, land use, industrial activities and transports. Our simulations showed that radiative parameters are the most influential during the summer. During winter, other thermal parameters (insulation) are the most influential. French local authorities could use several tools and means to act in favor of their climatic environment: their fields of direct jurisdiction (roads, parks, buildings which are owned by the community, etc.), guidance documents (SCOT and PLU), development procedures (urban development zone and building plotting), and incitement and pieces of information for their citizens and their agencies (local Agenda 21, Plan Climat, Approche Environnementale de l'Urbanisme). They can not work completely freely because of the boundary between urban planning law and building and dwelling law

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.

Submitted by SBI Biblioteca Digital (sbi.bibliotecadigital@puc-campinas.edu.br) on 2019-03-18T17:37:56Z No. of bitstreams: 1 MARCELO REZENDE CAL?A SOEIRA.pdf: 10669454 bytes, checksum: 0c817cd4715977e2f4677644509e8516 (MD5) / Made available in DSpace on 2019-03-18T17:37:56Z (GMT). No. of bitstreams: 1 MARCELO REZENDE CAL?A SOEIRA.pdf: 10669454 bytes, checksum: 0c817cd4715977e2f4677644509e8516 (MD5) Previous issue date: 2019-01-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The objective of this research was to estimate and compare the Sky View Factor (SVF) and Urban Heat Island Intensity (UHII) correlation across different Local Climate Zones (LCZs) situated in the city of Campinas, S?o Paulo, Brazil. The SVF consists of an non dimensional parameter which describes the ratio of visible sky from a given point in space. In the urban environment, SVF values are strongly related to buildings density and height. Also strongly related to the densification and verticalization of the urban tissue is the Urban Heat Island phenomenon, which is characterized by the elevation of air temperature in urban environments as a result of its impact on the surface energy balance. For this reason, research has been conducted in many countries to investigate the correlation between SVF and the UHII. To evaluate the effects of urban tissue composition on these correlations, however, systematic methods for detecting and reporting such composition are required. Employing the Local Climate Zones method, which classifies urban areas as climate zones according to their structural typology and surface cover, this research evaluated SVF-UHII correlation variations across different built up areas of the same city. Combining mobile measurements and stationary monitoring devices a map of the nocturnal UHII at the research site was obtained. According to seven parameters (H/W ratio; SVF; Built area; Permeable area; Impermeable area; Height of roughness elements; And roughness class), obtained by geoprocessing, eleven LCZs were identified at the site. Nocturnal UHII linear regressions were calculated for SVF values (point and 100m radius average values were used) at eight LCZs classes. At compact low, low-high, mid-low and high-mid rise LCZs (3, 31, 23 and 12), with SVF values between 0,20 and 0,45, the approximate air temperature increase ranged from 1,5 up to 2,2?C. At compact low and mid-low rise LCZs (3 and 23), with SVF values between 0,45 and 0,7, the approximate air temperature increase ranged from 0,7 up to 1,2?C. For sparsely built low rise LCZs (6), with SVF between 0,60 and 0,90, the approximate air temperature variation ranged from - 0,2 up to 0,0?C. From these results it was concluded that the correlation between SVF and UHII is influenced by the morphological and superficial composition of the urban tissue. Hence, to effectively utilize SVF in UHI mitigation strategies, these influences should be considered. / A presente pesquisa teve como objetivo estimar e comparar as correla??es entre o FVC e a varia??o da temperatura do ar encontradas em diferentes zonas clim?ticas situadas em um recorte da cidade de Campinas- SP. O fator de vis?o do c?u (FVC) ? um par?metro adimensional utilizado para descrever a propor??o de c?u vis?vel, em um determinado local, a partir do n?vel do solo. No ambiente urbano, seu valor est? fortemente relacionado ao grau de compacta??o e verticaliza??o da malha construtiva. Outro fen?meno relacionado ao grau de compacta??o e verticaliza??o da malha urbana ? o fen?meno da Ilha de Calor Urbana (ICU), caracterizado pela reten??o do calor absorvido no ambiente constru?do. Por este motivo, ? grande o n?mero de pesquisas que estudam a correla??o entre o FVC e o fen?meno da Ilha de Calor Urbana em diversas cidades do mundo. Atrav?s de m?todos sistem?ticos para o reconhecimento e documenta??o de heterogeneidades da malha urbana, como o m?todo das Zonas Clim?ticas Locais (LCZs), que classifica ?reas urbanas em zonas clim?ticas locais de acordo com sua tipologia construtiva e cobertura de superf?cies, tornou-se poss?vel avaliar a varia??o desta correla??o em um contexto intramunicipal. Atrav?s de campanhas de medi??es m?veis e de pontos fixos de monitoramento, a intensidade da ilha de calor urbana na ?rea de estudo foi avaliada. A ?rea de estudo foi classificada em onze LCZs de acordo com sete par?metros urban?sticos obtidos por geoprocessamento (rela??o altura-largura, FVC, ?rea edificada, ?rea imperme?vel, ?rea perme?vel, altura m?dia dos elementos de rugosidade e classe de rugosidade). Regress?es lineares foram estabelecidas entre a intensidade da ICU ?s 21:00 e valores de FVC (pontuais e m?dios para um raio de 100m) em ?reas de an?lise correspondentes a oito LCZs. Para valores de FVC entre 0,20 e 0,45, a eleva??o aproximada da temperatura do ar em LCZs de arranjo compacto e verticaliza??o baixa a m?dia-alta ? 1,5 a 2,2 ?C; para valores de FVC entre 0,45 e 0,7 em LCZs de arranjo compacto e verticaliza??o baixa e m?dia-baixa, a eleva??o aproximada da temperatura do ar foi de 0,7 a 1,5 ?C; e para valores de FVC entre 0,60 e 0,90 em LCZs de arranjo esparso e verticaliza??o baixa, a varia??o aproximada da temperatura do ar foi de 0,0 a -0,2 ?C. Assim, conclui-se que a influ?ncia do FVC na eleva??o da temperatura do ar em ?reas urbanizadas varia conforme a composi??o morfol?gica e superficial do tecido urbano. Para que o FVC seja utilizado efetivamente em estrat?gias de mitiga??o da ICU, essa rela??o deve ser considerada.

Modelling solar radiation data at a high spatiotemporal resolution for an urban environment can inform many different applications related to climate action, such as urban agriculture, forest, building, and renewable energy studies. However, the complexity of urban form, vastness of city-wide coverage, and general dearth of climatological information pose unique challenges doing so. To address some climate action goals related to reducing building emissions in the City of Victoria, British Columbia, Canada, applied geomatics and climatology were used to model solar radiation data suitable for informing renewable energy feasibility studies, including photovoltaic system sizing, costing, carbon offsets, and financial payback. The research presents a comprehensive review of solar radiation attenuates, as well as methods of accounting for them, specifically in urban environments. A novel methodology is derived from the review and integrates existing models, data, and tools – those typically available to a local government. Using Light Detection and Ranging (LiDAR), a solar climatology, Esri’s ArcGIS Solar Analyst tool, and Python scripting, daily insolation (kWh/m2) maps are produced for the city of Victoria. Particular attention is paid to the derivation of daily diffuse fraction from atmospheric clearness indices, as well as LiDAR classification and generation of a Digital Surface Model (DSM). Novel and significant improvements in computation time are realized through parallel processing. Model results exhibit strong correlation with empirical data and support the use of Solar Analyst for urban solar assessments when great care is taken to accurately and consistently represent model inputs and outputs integrated in a methodological approach. / Graduate

Se ha sintetizado la información de las temperaturas de emisión superficial obtenidas mediante 53 imágenes del satélite Terra MODIS, aplicando para ello promedios anuales y estacionales de las temperaturas estandarizadas, y reducción de las imágenes a factores complejos de los patrones espaciales usando Análisis de Componentes Principales (ACP); finalmente, se han realizado mapas de diferencias térmicas para conocer la intensidad de la isla de calor urbana de superficie (ICUs) estacional y anual. Los resultados muestran que la isla de calor tiende a localizar el máximo térmico en las comunas de Santiago, Providencia, Las Condes, Ñuñoa y Vitacura, conformando un núcleo cálido asociado a la mayor densidad construida; además, las comunas de Huechuraba y Quilicura conforman otro núcleo cálido, el que está asociado a viviendas de alto nivel de ingresos en el primer caso e industrias en el caso de Quilicura. El ACP revela cuatro patrones típicos, que explican el 90,6% de las situaciones, a saber: ICUs consolidada (44,5%), ICUs del piedmont y cuña de altos ingresos (22,3%), un tipo sin isla de calor urbana (20,2%) e ICUs más intensa al sur (3,6%). Finalmente, la intensidad de la isla de calor urbana de superficie es de mayor magnitud durante el otoño (7,4ºC), seguida de verano (5,9ºC), primavera (5,4ºC) e invierno (5,0ºC); incluso en verano y otoño supera los 7ºC en la zona oriente de la ciudad. De las situaciones sin isla de calor, se ha sugerido la hipótesis de efecto sumidero de calor o «urban heat sink», asociado a fuerte brisa de la Cordillera de Los Andes, que barre la ICUs y la desplaza al poniente de la ciudad, lo que en días de contaminación por material particulado (PM10) tendría efectos nocivos sobre la salud de la población de esa parte de la ciudad. Además, se modela la isla de calor urbana de superficie (ICUs) en función de una serie de variables geográficas y urbanas, con el propósito de plantear alternativas para la mitigación de los efectos negativos que las ICUs provocan a los habitantes de la ciudad de Santiago. Además, se entregan algunas directrices para una planificación territorial más sostenible. En total se utilizaron 42 mapas de isla de calor del año 2010, los cuales se generaron con imágenes satelitales Terra MODIS. Ellos fueron sintetizados en cinco cartografías, un mapa anual y cuatro correspondientes a las estaciones del año. Las variables explicativas para predecir la isla de calor fueron nueve: densidad de población y construida, elevación topográfica, NDVI, albedo, radiación solar y las distancias euclidianas al centro, la costa y los ríos y esteros. Los resultados de los modelos de regresión lineal múltiple por pasos indican coeficientes de determinación entre 47,39% y 80,08% (invierno y verano respectivamente). Las variables explicativas más influyentes son el albedo y el NDVI (relación negativa), y la densidad construida (relación positiva). Al modificar las variables que explican la ICUs se podría variar la intensidad de ella, por ejemplo: al aumentar de 10.000 m2 a 20.000 m2 construidos por hectárea la temperatura deberá aumentar entre 1ºC y 2ºC; implementando de áreas verdes un espacio sin vegetación, la isla de calor se verá reducida entre 1,2ºC y 5,5ºC; y al modificar el albedo de la ciudad desde un 10% a un 20% se consigue una reducción de la ICUs entre 1,1ºC y 2,7ºC.

林憲德等人於1999年提出台北夏季午夜之都市熱島強度為4.5℃，至2012年簡子翔等人所提出夏季白天最大熱島強度6.18℃、午夜4.38℃，可以發現台北市的高溫化現象並未有顯著的差異，甚至還新增加了多個新興熱區。 本研究以健康新城為研究對象，以實測方式、CFD電腦模擬方法，釐清社區建築環繞下，社區內的高溫化現象，並與社區外的街道環境比較溫度差異，評估熱舒適性。研究結果顯示，建築環繞下的社區內部(社區中庭)，在日落後的確有高溫化現象，白天時則會因為各社區的遮蔽條件、綠化條件不同，而有不同程度的差別。而模擬結果亦顯示，社區開口條件、通風道配置不同，也會影響社區中庭與外部周邊街道環境之舒適性差異。 建議未來社區的建築規劃設計，除了增加綠化措施之外，尚能適度增加開放空間，增加通風性能；而公部門在訂定法定容積時，應考量都市環境因素(增加遮蔽、通風)，酌以調整已達優良的都市實質環境。 / According to Urban Heat Island’s studies by Lin et al. (1999) and Chien et al. (2012), urban heat island intensity (UHIs) of Taipei didn’t get an obvious improvement from 1999 to 2012. UHIs of Taipei was 4.5℃ in the midnight in 1999, 4.38℃ in the midnight in 2012 and 6.18℃ in the daytimes in 2012. Obviously, there are several high temperature area appeared in the years. This study tries to measure the thermal comfort between the area inside Jian-Kang community and the streets’ environment around Jian-Kang community. Furthermore, this study utilize CFD simulation that can help the study knows the reason effects thermal comfort. As the result of the study, the area inside Jian-Kang community has higher temperature after sunset. In the morning, it will have difference due to the shadow and green situation. Also, the simulation results show that the draft condition of the community will influence the thermal comfort. In the future, this study suggests some strategy to have a better urban environment. First, increase much more greening measures. Second, preserve open spaces to improve the ventilation when deciding the community’s design. Third, consider the urban environmental factors when rule the building’s height.

This dissertation contains three independent essays relating energy economics. The first essay investigates price asymmetry of diesel in South Korea by using the error correction model. Analyzing weekly market prices in the pass-through of crude oil, this model shows asymmetric price response does not exist at the upstream market but at the downstream market. Since time-variant residuals are found by the specified models for both weekly and daily retail prices at the downstream level, these models are implemented by a Generalized Autoregressive Conditional Heteroskedasticity (GARCH) process. The estimated results reveal that retail prices increase fast in the rise of crude oil prices but decrease slowly in the fall of those. Surprisingly, retail prices rarely respond to changes of crude oil prices for the first five days. Based on collusive behaviors of retailers, this price asymmetry in Korea diesel market is explained. The second essay aims to evaluate the new incentive system for biodiesel in South Korea, which keeps the blend mandate but abolishes tax credits for government revenues. To estimate changed welfare from the new policy, a multivariate stochastic simulation method is applied into time-series data for the last five years. From the simulation results, the new biodiesel policy will lead government revenues to increases with the abolishment of tax credit. However, increased prices of blended diesel will cause to decrease demands of both biodiesel and blended diesel, so consumer and producer surplus in the transport fuel market will decrease. In the third essay, the Regression - Seasonal Autoregressive Integrated Moving Average (REGSARIMA) model is employed to predict the impact of air temperature on daily peak load demand in Houston. Compared with ARIMA and Seasonal Model, a REGARIMA model provides the more accurate prediction for daily peak load demand for the short term. The estimated results reveal air temperature in the Houston areas causes an increase in electricity consumption for cooling but to save that for heating. Since the daily peak electricity consumption is significantly affected by hot air temperature, this study makes a conclusion that it is necessary to establish policies to reduce urban heat island phenomena in Houston.

A ten year analysis was conducted on the ten county Nashville metro area to determine which atmospheric thermodynamic parameters are important for thunderstorm development in North-Central Tennessee. Spatiotemporal patterns of thunderstorm activity around the city were also studied. Two case studies depicting initiation (July 10, 2009) and bifurcation (June 13, 2010) of thunderstorms were additionally discussed. The purpose of the analysis was to determine whether heat from the urban heat island (UHI) or moisture from the Gulf of Mexico was a larger factor in thunderstorm formation. A similar methodology completed by Dixon and Mote (2003) for Atlanta, Georgia was used for Nashville, Tennessee. Two land based weather stations collecting dry-bulb temperatures, twice daily radiosonde measurements, and local NEXRAD weather radar were used to determine where, when, and how thunderstorms developed around Nashville. One-sample t-test hypothesis testing of 24-hour land-surface temperature differences ahead of each event along with average daily radiosondes dry-bulb and dewpoint temperatures at five standard pressure levels were examined to determine if statistically significant mean differences (α = 0.05) were found between average study days. Atmospheric stability indices and other moisture parameters such as precipitable water (PWAT), mixing ratio, theta-e, and lapse rates were examined for average differences between average study days. Ultimately, 22 events were found (18 initiations and 4 bifurcating) over the 10-year period with the non-drought years 2005 and 2010 exhibiting the most events. The warm season month of August showed the largest distribution of events with 8 events during diurnal hours (between 2 p.m.-4 p.m. CDT). The analysis also found 12 storm centers (32%) formed within 1km of interstate highways with 77% (23) of initiation locations falling within 3 km of limited access highways. Statistical results showed that moisture, rather than heat from the UHI, were a larger component to thunderstorm formation over the city of Nashville. / Department of Geography

The urban heat island (UHI) is a phenomenon of noticeably higher temperatures in the cities as compared to their respective surrounding areas. This thesis aims at characterizing the influence of city expansion to the urban heat island phenomenon. The study is carried out in a city of Caceres in the Spanish province of the same name. A model input data is obtained with Landsat multispectral images. The analysis of satellite images shows that functional vegetation cover and water surfaces help in mitigating urban heat island effect. However, the Caceres city expansion does not influence the urban heat island intensity. A possible explanation for it is as the city expanded the ratio of vegetation to dry land remains constant in time.

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.