This study examines the relationship between land use and temperature change in Dallas County, TX. The purpose of this research is to analyze the relationship between temperature and land use and to identify the primary factors contributing to the formation of urban heat islands based on different categories of land use. Specifically, this research analyzes the elements that contribute to the urban heat island effect in Dallas County using temperature data provided by remote sensing imagery and parcel-based land use data using Geographic Information System (GIS) technique and a correlation analysis method, which was employed to analyze the relationship between temperature and land use. The results of this study showed that every land use category has different temperature averages and those patterns were observed similarly in both 2000 and 2005. Parking, airport, commercial, industrial, and residential areas have relatively high temperatures. In contrast, water, undeveloped area and parks showed relatively low temperatures. Another major finding was ratio of land use composition affected the temperature of census tracts. Correlation analyses of land use and temperature in 2000 and 2005 indicate that various types of land use categories have significant relationships with temperature. Among them commercial, industrial, residential, parking, and infrastructure, are positively associated with temperature, while undeveloped, parks, water, and dedicated areas are negatively associated with temperature. Areas with a high ratio of commercial use showed the highest and undeveloped areas showed the lowest relationship. Furthermore, through the analysis of the relationship between land use and temperature change for five years (2000-2005), this study finds that temperature change depends on the ratio of each land use category change. The results of this study can help local planning and policy decisions which are related to urban land use planning concerning temperature change such as zoning, environmental regulations and open space preservation.

The urban heat island effect is considered one of the main causes of global warming and is contributing to increasing temperatures in the urban United States. This phenomenon enhances the intensity of summer heat waves and the risk to public health due to increased exposure to extreme thermal conditions. Characteristics of spatial development patterns can significantly affect urban temperature because they are related to the arrangement of development and land surface materials, which are crucial elements needed to determine land surface temperature. While previous studies revealed that the effect of the urban heat island varies depending on different land use types and surface characteristics, few have considered the overall development patterns of urban form. I address this under-studied aspect of heat hazards by analyzing the relationship between spatial development pattern and urban heat island effect across a sample of 353 metropolitan regions of the U.S. Specifically, I employ a series of landscape metrics to measure urban development patterns using a national land cover dataset from the U.S. Geological Survey. Linear regression models are used to statistically isolate the effect of different spatial development patterns on increasing the urban heat island effect while controlling for multiple contextual variables including built-environment, environmental, and demographic characteristics. The result of this study showed that the daytime mean surface urban heat island effect (4.04˚F) is higher than that of nighttime (2.41˚F). Ecological context (i.e. Ecoregions) has proved to be a statistically significant modulator that helps to explain the spatial distribution of the urban heat island effect. Regarding the main research question of this study, the results indicate that specific categories of urban development pattern including density, continuity, and clustering are statistically associated with increasing the urban heat island effect. This initial evidence suggests that the overall development patterns are an important issue to consider when mitigating the adverse impacts related to the urban heat island effect. In addition, when contextual heat contributors are held constant, the intensity of the urban heat island effect can differ depending on the configuration of development in urban areas. This study can be used as a starting point for a comprehensive approach to both spatial land development and hazard-resistant planning by providing alternative ways of measuring and modeling spatial development patterns.

L'Ilot de Chaleur Urbain (ICU) est l'un des phénomènes du changement climatique les plus documentés. Il est le résultat de températures plus élevées dans le centre des villes que dans leurs banlieues ou les zones rurales alentour et peut avoir des conséquences néfastes sur les habitants des villes, notamment au niveau de la qualité de l'air, la consommation d'énergie, la santé publique et même le taux de mortalité. À Beyrouth, capitale du Liban, la littérature scientifique existante dénote un déficit de recherche sur ce sujet. L’objectif de cette thèse est donc d'étudier l'intensité de l'ICU à Beyrouth, d'identifier les mesures les plus appropriées susceptibles d'en alléger les effets d'un point de vue technique, d'en évaluer les conséquences sur les politiques d'urbanisme et de faire des propositions pour la planification urbaine et la conception des bâtiments à Beyrouth. Dans cette thèse, l'ICU à Beyrouth a été étudié à l'aide du modèle Town Energy Balance (TEB), outil de modélisation servant à calculer les échanges d'énergie et d'eau entre les villes et l'atmosphère, développé par Météo France (Masson, 2000). TEB est inclus dans le système de modélisation des surfaces continentales SURFEX. SURFEX est une contraction de « Surface Externalisée » et c'est un code qui modélise les processus d'échange d'énergie entre l'atmosphère et les surfaces urbaines. Des simulations ont été effectuées à Beyrouth durant une journée, en hiver, le 1er janvier de 00:00 UTC (soit 02:00 heure locale) à 23:00 UTC et une journée, en été, le 1er juillet de 00:00 UTC à 23:00 UTC à des intervalles d'une heure. En été, des écarts significatifs allant jusqu'à 6°C ont été enregistrés pour les températures de canyon. Typiquement, les températures les plus élevées ont été enregistrées dans les zones à forte densité de construction où la part de surfaces travaillées par l'homme est la plus grande et où on a mesuré les albédos les plus bas (généralement 0.2). En hiver, les écarts de température ont été moins significatifs avec un différentiel de 1°C entre les zones à forte densité de construction et les espaces naturels. On en a déduit que les zones avec une grande proportion de végétations ont un rôle réfrigérant à Beyrouth. De plus, nous avons mesuré un écart significatif dans la consommation d'énergie pour la climatisation en été dans différentes parties de Beyrouth ; les simulations ont déterminé la demande requise d'énergie à 50 W/m2 dans les quartiers caractérisés par une grande proportion de jardins et jusqu'à 800 W/m2 dans les quartiers à forte densité de construction. En hiver également, les simulations ont montré des écarts importants au niveau de la demande d'énergie pour le chauffage dans différents quartiers de Beyrouth variant de 20 à 300 W/m2. Six scénarios ont été modélisés sur TEB et ils ont indiqué que l'augmentation de la surface des végétations et l'augmentation de l'albédo des toits produisaient les effets de refroidissement les plus notables. Cette thèse a mis en évidence des opportunités pour améliorer les lois de l'Urbanisme et le Code de la Construction au Liban pour une meilleure prise en compte des aspects microclimatiques urbains et recommande la mise en place de stratégies pour le développement d'espaces verts urbains et pour l'optimisation du refroidissement par les toits. Cette thèse a donc contribué à une meilleure compréhension de l'environnement urbain de la ville de Beyrouth et des paramètres urbains pouvant avoir le plus grand impact sur la réduction des effets de l'ICU. Ce faisant, cette étude a préparé le terrain pour des travaux plus poussés en vue de réduire les effets de l'ICU à Beyrouth dans le but de créer un environnement confortable et sain pour ses habitants et pour les générations futures / The urban heat island (UHI) is one of the more commonly documented phenomena of climate change. It is related to higher urban temperatures in the city centers as compared to the surrounding rural or suburban areas and can lead to unpleasant effects on urban dwellers not least of all on air quality, energy consumption levels, human health, and even mortality rates. In Beirut, the capital city of Lebanon, the literature clearly points to a lack of research on this topic. In addition, there is no evidence that there is a systematic transfer of urban climatic knowledge between concerned stakeholders like urban planning and environmental authorities which is cause for concern given the ever-increasing worldwide attention being given to climate change adaptation and mitigation measures and sustainable city developments. The objective of this research is to therefore investigate the intensity of UHI in Beirut, to identify most suitable measures to alleviate the effects of UHI from a technical perspective, to assess the implications on urban planning processes and to accordingly find opportunities for planning and design practices in Beirut. Beirut is a coastal city that sits on a peninsula that extends westward into the Mediterranean Sea. It covers a surface area of about 20 square kilometers, has a population of approximately 500,000 inhabitants, with a very high population density of about 21,000 inhabitants / km2.The UHI in Beirut was investigated using the Town Energy Balance (TEB) urban surface exchange modeling scheme developed by Météo France (Masson, 2000). TEB is included in the SURFEX land-surface modeling system. SURFEX means “surface externalisée” and it is a code that represents the energy exchange processes that occur between the atmosphere and the urban surfaces. Simulations were accordingly run across Beirut using TEB for 1 day during the winter season on 1 January, from 00:00 UTC (equivalent to 2:00AM local standard time) to 23:00 UTC, and 1 day during the summer season on 1 July from 00:00 UTC to 23:00 UTC with one hour time steps or one hour output results. During the summer significant variations of up to 6oC were found for canyon temperatures whereas areas characterized by dense urban fabrics had higher temperatures typically due to the larger fraction of man-made as opposed to natural surfaces and due to the lower albedo values (generally 0.2). During the winter, temperature variations were not as significant, differing by up to 1oC between aforementioned areas across Beirut. Therefore areas with high garden fractions were found to play an important cooling effect in the simulations for Beirut. In addition, a significant variation in cooling energy usage was found during the summer across Beirut where simulations showed energy demands as low as 50 W/m2 in areas characterized by higher garden fractions whereas simulations were much higher, up to 800 W/m2, in areas with dense urban fabrics. In the summer heating energy demands were also significant ranging from as low as 20-300 W/m2 across Beirut. Six scenarios were also run on TEB which showed that increasing the albedo of roofs and the fraction of gardens had the most noteworthy cooling effects. This research found that there are opportunities for improvement of the Urban Planning Law and the Building Code of Lebanon for better consideration of the urban microclimatic issues and recommended emphasis on urban greening strategies and cool roofing strategies. this thesis contributed to a better understanding of the urban environment of the city of Beirut and the respective urban parameters that have the most significant impact on reducing some of the impacts of the urban heat island phenomenon. In doing so, this research has paved the way for further work on reducing the UHI effect in Beirut, with the ultimate aim of creating a comfortable and safe environment for its residents, and future generations

Background: Numerous epidemiological studies have demonstrated a possible correlation between high temperature and mortality in different settings. Most of these studies have focused on urban settings in industrialized countries, concluding that urban populations are more vulnerable to heat effects than rural populations. This has mainly been attributed to the urban heat island (UHI) effect, a phenomenon which explains the elevated temperatures in urban areas. Others have contradicted this finding and concluded that rural residents are more vulnerable. For this study, we test the hypothesis that rural populations and sub-populations are also vulnerable to heat mortality. Method: A comprehensive literature search was conducted using PubMed, Web of Science and Google Scholar to identify peer-reviewed studies investigating heat mortality in rural settings. Using keywords and a set of rigorous inclusion and exclusion criteria, ten studies were selected. Meta-analysis was then performed using the Comprehensive MetaAnalysis V3.exe software. Results and discussion: The pooled relative risk (RR) was 1.191 (95% confidence interval: 1.130-1.251). Although rural populations may not be exposed to as high temperatures as urban populations, they remain vulnerable to heat effects. Conclusion: There is evidence of heat vulnerability in rural populations and subpopulations. Heat vulnerability is not only determined by heat exposure, but also by sensitivity and adaptive capacity. Rural populations and sub-populations may be vulnerable to heat mortality due to low adaptive capacity. Further studies are needed to assess risk factors that predispose rural populations and sub-populations to heat mortality in order to develop effective public health interventions.