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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

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

Camila Tavares Homann 13 November 2014 (has links)
A Região Metropolitana de São Paulo (RMSP) conta com mais de 20 milhões de habitantes em 7958 km², o que a caracteriza como uma megacidade. Este fato ocasiona o efeito de ilha de calor que pode resultar em interações complexas com circulações de mesoescala, tais como a brisa marítima, podendo influenciar nos padrões de circulação local e afetar diretamente o tempo e o clima da região. Dessa forma, através da modelagem numérica com o modelo de mesoescala WRF este trabalho se propôs a analisar e avaliar os possíveis efeitos da expansão da mancha urbana - passada e futura - na modificação destes padrões em duas estações do ano de 2007: inverno (18/08) e verão (07/03). Para isto introduziu-se diferentes manchas urbanas no modelo, supondo nenhuma urbanização, urbanização observada em 1952 e em 2007, bem como uma suposta urbanização prevista para o ano de 2030. O acoplamento de um modelo de dossel urbano junto ao WRF também foi avaliado, e os resultados mostraram que para o inverno a inclusão do mesmo se mostrou dispensável, enquanto para o verão as simulações em que o módulo esteve ativo se mostraram mais coerentes à realidade. Para as duas estações observou-se a influência da expansão da mancha urbana nos eventos de brisa marítima, sendo que quanto maior a área urbanizada maior o tempo de deslocamento da frente de brisa continente adentro, podendo a diferença chegar a 2 horas. Diferenças na temperatura também puderam ser vistas, principalmente à noite no período de inverno, de forma que algumas regiões chegaram a apresentar 6 °C a mais em 2007. Observou- se uma frente de umidade acompanhando a frente de brisa marítima e quanto maior a urbanização, menor a quantidade de umidade associada, chegando a uma redução de 22% durante o inverno e de 33% durante o verão. No inverno não foram observadas grandes diferenças na precipitação, enquanto que no verão foram encontradas diferenças significativas em praticamente todo o domínio de simulação, chegando a 50 mm em determinadas regiões (a mais ou a menos). Tais diferenças na precipitação não se mostraram lineares com a expansão da mancha urbana. Cortes verticais não evidenciaram circulações bem definidas associadas à ilha de calor, nem para o inverno nem para o verão, no entanto, claramente pôde-se observar a influência que a expansão urbana tem sobre os episódios de brisa marítima, em quaisquer das variáveis meteorológicas analisadas. / The Metropolitan Area of São Paulo (MASP) has over 20 million inhabitants over a 7958 km² area, which characterizes a megacity. This fact causes the heat island effect that can result in complex interactions with mesoscale circulations such as the sea breeze and can influence the local circulation and directly affect the weather and climate of the region. Therefore, through numerical modeling of the atmosphere using the WRF mesoscale model this work analyses and evaluates the possible effects of urban expansion - past and future on the modification of these patterns in two days representatives of the winter and summer (18/08 and 07/03, respectively). For that purpose we introduced different types of urban areas in the model, assuming no urbanization, using the urbanization observed in 1952 and 2007 as well as a hypothetical urbanization numerically predicted for the year of 2030. The coupling of an urban canopy model (UCM) along with WRF was also evaluated and the results showed that the inclusion of UCM proved to be unnecessary during wintertime. However, in the summer, the simulations where the module was activated were more consistent with reality. For the two seasons we observed the influence of urban expansion in the events of sea breeze, and the higher the urbanized area more increased was the travel time of the sea breeze front inland, being the time difference as high as 2 hours. Differences in temperature were also observed, especially at night in the winter, so that some regions were as high as 6 °C hotter in 2007. A moisture front accompanying the sea breeze front and the higher the urbanization the lower the amount of moisture associated, reaching a reduction of 22% during winter and 33% during the summer. During the winter no major differences were observed in precipitation, while in the summer significant differences were found almost over all simulation domain, reaching 50 mm in certain regions (positive or negative). Such differences in precipitation were not linear with the expansion of urban area. Vertical sections did not show well-defined circulations associated with urban heat island, neither for the winter nor for summer, however, we can clearly observe the influence that urban area extension has on episodes of sea breeze in any of the weather variables.
92

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

Felipe Vemado 11 May 2012 (has links)
Eventos de brisa marítima (BM) são comuns na Região Metropolitana de São Paulo (RMSP). No verão, em particular, estão associados com tempestades, chuvas, rajadas de vento, granizo e descargas atmosféricas intensas na RMSP. Utilizou-se o método de OLIVEIRA e SILVA DIAS (1982) para identificar os eventos de BM. Todos os eventos de BM entre 2005 e 2008 foram analisados por meio de medições de superfície, altitude, radares meteorológicos, satélite e modelagem numérica da atmosfera. Em geral, a penetração da frente de BM na RMSP ocorre entre o meio e o fim da tarde com aumento da temperatura do ponto de orvalho. Ainda, o ambiente urbano mais aquecido tende a intensificar as tempestades que podem produzir enchentes, alagamentos, queda de árvores, entre outros impactos socioeconômicos muito significativos. A partição anual pluviométrica devido a BM foi estimado com o radar meteorológico de São Paulo. Os resultados indicam um núcleo de máxima precipitação acumulada com pico de 600 mm sobre a RMSP, muito maior que no entorno dessa. A modelagem com o ARPS permitiu simular condições médias espaciais em baixos, médios e altos níveis de diversas variáveis dos eventos analisados. As simulações de controle e específicas com ARPS sugerem um impacto significativo da cobertura do solo na distribuição espacial da precipitação. As análises foram complementadas com medições do radar meteorológico MXPOL e demonstram a importância desse tipo de sensoriamento remoto na detecção e previsão a curtíssimo prazo da penetração de BM, com alta resolução espaço-temporal. / Sea breeze events (SB) are common in Metropolitan area at São Paulo (MASP). Particularly, in the summer, SB triggers over MASP deep convection, heavy rainfall, wind gusts, hail and lightning. OLIVEIRA and SILVA DIAS (1982) method was used to identify the SB events. SB events between 2005 and 2008 were analysed by means of surface and upper air measurements, weather radar, satellite and numerical modelling. In general, the SB front penetrates in MASP between midafternoon and evening increasing dew point. Moreover, the warmer urban environment tends to intensify storms that produce flooding, falling trees, among other large socioeconomic impacts. The annual rainfall partition due to SB was estimated using the São Paulo weather radar. The results indicate a core of maximum rainfall accumulation of 600 mm over MASP, much larger than that in the vicinity. The modelling with ARPS allowed simulate conditions spatial average in low, medium and upper levels of several variables of the analysed events. Moreover, the ARPS system was used to simulate SB with control and specific runs. Results suggest significant impact of surface cover on rainfall distribution. MXPOL weather radar measurements of SB were important in detecting and nowcasting SB inflow at very high spatial and temporal resolution.
93

Observational and modelling approaches to study urban climate : application on Pakistan / Méthodes d'observation et de modélisation pour étudier le climat urbain : application sur le Pakistan

Sajjad, Sajjad Hussain 16 April 2013 (has links)
L'objectif majeur de ce travail est d'étudier le climat urbain, principalement en mettant l'accent sur les tendances de la température. Il s’agit principalement de l’augmentation des températures grâce à des techniques d'observation et de modélisation. A cet effet, des données températures de 1950 à 2004 ont étudiées sur plusieurs stations de mesure au Pakistan. Les données de températures annuelles et saisonnières moyennes quotidiennes minimales (Tmin) et maximales (Tmax) de 37 observatoires météorologiques du Pakistan (17 urbain, 7 petite ville et 13 rurale) pour la période 1950-2004 ont d'abord été homogénéisées, puis analysées. Les résultats montrent qu’après les années 1980, Tmin et Tmax tendent à augmenter plus vite que la période d'avant 1980 sur les zones urbaines. Au cours de la période 1980-2004, l'augmentation annuelle de Tmin sur les stations urbaines est observée plus élevée que sur les stations des petites villes et les stations rurales. Pour comprendre l’effet de la taille de la ville, le changement du l’utilisation des sols et la hauteur du bâtiment sur l'évolution des températures minimales et maximales des zones urbaines a été étudié en utilisant le model FVM (Finite Volume Model) et des simulations ont faites pour trois jours à partir de 00:00 (GMT) le 19e jour de chaque mois et se terminant à 00:00 (GMT) le 22e jour de chaque mois. Pour chaque mois, 48 combinaisons possibles de scénarios de simulation sont exécutés (4*4*3) et au total, 576 simulations (48*12) sont exécutés pendant un an. Les résultats centre montrent que Tmin et Tmax augmente lorsque fraction urbaine u, taille de la ville r et hauteur du bâtiment h augmente. Mais on remarque que Tmax augmente plus que le Tmin quand u augmente, Tmin augmente plus que Tmax lorsque r augmente et Tmin augmente plus que Tmax lorsque h augmente. Parmi tous les facteurs urbains (fraction urbaine u, taille de la ville r et hauteur du bâtiment h), la taille de la ville est le facteur majeur qui contribue principalement à augmenter la température minimale plus que température maximale dans les zones urbaines. / The objective of this work is to study the urban climate, mainly by focusing on urban temperature trends. The specific focus is to understand the reasons of increase in minimum temperature through observational and modelling techniques. For this purpose, the temperatures data from 1950 to 2004 measured on several meteorological stations of Pakistan is studied and analyzed. Daily averaged annual and seasonal minimum (Tmin) and maximum (Tmax) temperature data of 37 meteorological observatories of Pakistan (17 urban, 7 town and 13 rural) from 1950 to 2004 is first homogenized and then analyzed. The results show that after 1980s Tmin and Tmax increase faster than the period before 1980s at urban areas. During 1980–2004, the increase in Tmin at major urban stations is observed higher than the smaller towns and rural stations. To understand, the effect of the size of the city, changing land use and the building height on the evolution of minimum and maximum temperatures in urban areas has been studied by using the FVM (Finite Volume Model) model and the simulations are run for three days starting at 00:00 (GMT) on 19th day of each month and ending at 00:00 (GMT) on 22nd day of each month. For each month, 48 possible combinations of simulation scenarios are run (4*4*3) and in total, 576 simulations (48*12) are run for a year. The main results show that Tmin and Tmax increase when urban fraction u, city size r and building height h increase. But it is noticed that Tmax increases more than the Tmin when u increases, Tmin increases more than the Tmax when r increases and Tmin increases more than the Tmax when h increases. Among all urban factors (urban fraction u, city size r and building’s height h), city size is the major factor that mainly contributes to increase the minimum temperature more than the maximum temperature in urban areas.
94

A Landscape of Thermal Inequity: Social Vulnerability to Urban Heat in U.S. Cities

Mitchell, Bruce Coffyn 04 July 2017 (has links)
A combination of the urban heat island effect and a rising temperature baseline resulting from global climate change inequitably impacts socially vulnerable populations residing in urban areas. This dissertation examines distributional inequity of exposure to urban heat by socially disadvantaged groups and minorities in the context of climate justice. Using Cutter’s hazards-of-place model, variables indicative of social vulnerability and biophysical vulnerability are statistically tested for their associations. Biophysical vulnerability is conceptualized utilizing a urban heat risk index calculated from summer 2010 LANDSAT imagery to measure land surface temperature , structural density through the normalized difference built-up index, and vegetation abundance through the normalized difference vegetation index. A cross-section of twenty geographically distributed metropolitan statistical areas (MSAs) in the U.S. are examined using census derived variables at the tract level. The results of bivariate correlation analysis, ordinary least squares regression, and spatial autoregression analysis indicate consistent and significant associations between greater social disadvantage and higher urban heat levels. Multilevel modeling is used to examine the relationship of MSA-level segregation with tract-level minority status and social disadvantage to higher levels of urban heat. Segregation has a significant but varied relationship with the variables, indicating that there are inconsistent associations with urban heat due to differing urban ecologies. Urban heat and social vulnerability present a varying landscape of thermal inequity in different urban areas, associated in many cases with residential segregation.
95

L'ilot de chaleur urbaine à Beyrouth / On the Urban Heat Island in Beirut

Kaloustian, Noushig 17 November 2015 (has links)
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
96

Det finns inget dåligt väder, bara dåliga bostäder : Kartläggning av bebyggelse med risk för höga temperaturer i Kalmar läns största tätorter / There’s no bad weather, only lousy residences : Mapping of buildingswith risk of high temperatures in Kalmar County's largest cities

Johansson, Victor January 2021 (has links)
Global warming risks overthrowing the Earth's climate system, which would mean thatmany communities need to be reshaped and adapted to a new climate. The PublicHealth Agency of Sweden has run a project during the years 2017-2019 that aims toincrease society's ability to identify, prevent and manage harmful heat in existingbuildings. The project focuses on covering the occurrence and developing measures toprevent heat stress in both urban outdoor- and indoor environments. The agency has commissioned a GIS method which, based on the buildings' groundcover, aims to identify areas that are at risk of developing harmful temperatures. Themethod is based on first calculating the total land area of the cities in order to be able tocalculate the proportion of the area covered by high vegetation, hardened surfaces,building bodies and low vegetation. Based on this calculation, areas with a highproportion of paved surfaces and building bodies as well as a low proportion of highvegetation have been identified as areas with a higher risk of developing harmfultemperatures. In this essay, the method has been used to identify risk areas in KalmarCounty's largest cities; Kalmar, Västervik and Oskarshamn. High temperatures can be dangerous for all people, but elderly people are highlighted asa particularly vulnerable group as they have a reduced ability to regulate bodytemperature. Therefore the survey of the thesis has been supplemented with data onwhere people over the age of 65 live in relation to the risk areas in order to make furtherpriorities in where the measures are needed the most. The conclusion is that the need for cooling measures in the mapped cities is greatest inthe urban centers, as the high density of urban areas there provides good conditions fordeveloping high temperatures while a large part of the old population live in thesecentral areas. Several industrial areas have been identified as risk areas in all mappedcities, but there the need for cooling measures is less as they are usually located on theoutskirts of the cities and lack residents over 65 years. The exception is the OldIndustrial Area in Kalmar, whose central location and the circular design of Kalmarindicate that high temperatures develop here at night, which can drive the urban heatisland in the city.
97

Étude de la dispersion nocturne de polluants atmosphériques issus d’une décharge d’ordures ménagères. : Mise en évidence d’un îlot de chaleur urbain / Study of the nocturnal dispersion of air pollutants from an open lan : evidence of an urban heat island

Plocoste, Thomas 29 April 2013 (has links)
En 2003 des mesures au spectromètre IR à Transformée de Fourier (FTIR) ont permis d'identifier et de mesurer les COV émis par la décharge à ciel ouvert de la Gabarre, principale de l'île Guadeloupe, située entre une zone urbaine et une mangrove. Ces COV ont été retrouvés (2004) la nuit dans les cités, justifiant les plaintes des riverains. Dans le cadre de cette thèse, des mesures au spectromètre de masse portatif MS 200 ont validé ces résultats du FTIR. De nouvelles mesures au MS 200 ont été menées dans toute la zone de la décharge. Les cités concernées étant à l'opposé du flux synoptique d'Alizés-Est, les facteurs météorologiques permettant la dispersion et le transport des COV de la décharge vers la zone urbaine ont été recherchés. La diminution nocturne de l'intensité des Alizés au dessus de l'ile peut laisser place à des phénomènes locaux tels les brises. L'idée d'une brise terre-mer a été éliminée. Un maillage autou~ de la décharge (cités et mangrove) avec 8 thermomètres a révélé un îlot de chaleur urbain nocturnegénérant une brise thermique d'environ Ims- I (mesurée et calculée). Avec les radiosondages Météo France et un SODAR installé dans la décharge, une très forte stabilité dans les basses couches atmosphériques de la couche limite nocturne avec une inversion de surface d'environ 120mvv apparait. Ces facteurs expliquent la pollution des cités par les COV de la décharge, Un modèlevGaussien en tenant compte a été validé par les mesures de COV.vCette étude peut être étendue à d'autres décharges à ciel ouvert et à d'autres types de traitement de polluants de décharge. / In 2003, the VOC emissions coming from "La Gabarre", the main open landfill in Guadeloupe, located in-between an urban area and a mangrove, were identified and quantified with a portable FTIR spectrometer. In 2004, COVs found at nighttime in the urban area nearby confirmed why residents complain about. As part of this thesis, portable mass spectrometer MS 200 measurements validated these FTIR figures. New systematic SM measurements have been carried on around the landfill. Since the polluted urban area stands on the opposite way of the East Trade winds synoptic flux, aIl the weather factors likely to scatter and transport the dump COVs were scrutinized. At night, the strength of the Trade winds decreases over Guadeloupe, which may give way to local phenomena such as breezes. The occurrence of land/sea breeze was eliminated. A close surveying surrounding the landfill with 8 thermometers both in the projects and in the mangrove revealed an urban heat island causing thermal breezes of about lms-l (measured and calculated). Using soundings from Meteo France, and a SODAR inside the dump, we found a great stability of the night boundary layer with a surface inversion near 120m. Pollution of the nearby urban area with landfill COVs is elucidatcd by the above factors. A transport Gaussian model is in agreement with COV measurements. This study can be extended to different open landfills and different types of polluting matters processes in dumps
98

City limits: Heat tolerance is influenced by body size and hydration state in an urban ant community

Johnson, Dustin Jerald 01 January 2019 (has links)
Cities are rapidly expanding, and global warming is intensified in urban environments due to the urban heat island effect. Therefore, urban animals may be particularly susceptible to warming associated with ongoing climate change. Thus, I used a comparative and manipulative approach to test three related hypotheses about the determinants of heat tolerance or critical thermal maximum (CTmax) in urban ants—specifically, that (1) body size, (2) hydration status, and (3) preferred micro-environments influence CTmax. I further tested a fourth hypothesis that native species are particularly physiologically vulnerable in urban environments. I manipulated water access and determined CTmax for 11 species common to cities in California's Central Valley that exhibit nearly 300-fold variation in body mass. Inter- (but not intra-) specific variation in body size influenced CTmax where larger species had higher CTmax. The sensitivity of ants’ CTmax to water availability exhibited species-specific thresholds where short-term water limitation (8 h) reduced CTmax in some species while longer-term water limitation (32 h) was required to reduce CTmax in other species. However, CTmax was not influenced by the preferred foraging temperatures of ants. Further, I did not find support for my fourth hypothesis because native species did not exhibit reduced thermal safety margins, or exhibit CTmax values that were more sensitive to water limitation relative to non-native species. In sum, understanding the links between heat tolerance and water availability will become critically important in an increasingly warm, dry, and urbanized world that may be selecting for smaller (not larger) body size.
99

Spatio-temporal Analysis of Urban Heat Island and Heat Wave Evolution using Time-series Remote Sensing Images: Method and Applications

Yang, Bo 11 June 2019 (has links)
No description available.
100

Resilience Through Form : A case study of Metro Boston, Exploring the Relationship of Urban Form & Extreme Heat / Resiliens Genom Form: : Fallstudie av metro Boston, utforskning av förhållandet mellan stadsform och extrem värme

Lewis, Gavin January 2019 (has links)
The severity of extreme heat events paired with the urban heat island effect cannot be overstated, as the impacts are substantial and widespread, affecting peak energy demands, transport systems, air and water quality, and most notably causing heat-related illnesses and death. These consequences make evident the importance of reducing heat in urban areas and ensuring that urban populations are safe during extreme heat events. In order to both reduce the urban heat island effect and prepare cities for a hotter future, it is critical to building our understanding of the cities at risk and the relationship between heat and the urban environment. This thesis applies urban morphology theory and remote sensing techniques to explore how urban typologies in Metro Boston perform during an extreme heat event. Included within the thesis is a literature review exploring urban heat methodologies and urban morphology, a desktop review examining a set of cities’ climate action reports, and a remote sensing-based analysis to determine the feasibility of uniting land surface temperature and public weather station data. The desktop review of cities determined that while each city has begun to implement numerous socially driven initiatives and large-scale green infrastructure plans, there is little work incorporating urban form within these strategies. Additionally, while the land surface temperature and weather station maps from the remote sensing analysis were deemed insufficient, several valuable questions and findings arose through the process. The case study analysis of Metro Boston identified three predominant urban forms in the study area and 12 sites were studied in relation to their heat performance in the morning, afternoon, and evening. The heat maps applied were developed through Heat Watch Report, a collaboration between the National Oceanic and Atmospheric Administration, the municipalities of Boston, Brookline, and Cambridge, and CAPA Strategies. The analysis revealed there is a universal change in temperature among all forms throughout the day, with peak temperatures occurring in the late afternoon period. The study also concluded that while temperature between forms was not significant, variation between sites of the same form was observed, with internal vegetation composition (NDVI) and neighboring landcover and urban form becoming key factors in increasing or reducing experienced heat. / Svårighetsgraden av extrema värmehändelser i kombination med stadens värmeöeffekt kan inte överskattas eftersom dessa effekter är betydande och utbredda, vilket påverkar energibehov, transportsystem, luft- och vattenkvalitet och framför allt orsakar värmerelaterade sjukdomar och dödsfall. Dessa konsekvenser visar tydligt vikten av att minska värmen i stadsområden samt se till att stadsbefolkningarna är säkra under extrema värmehändelser. För att både minska stadens värmeöeffekt och förbereda städer för en varmare framtid är det avgörande att fördjupa vår förståelse för städer i riskzon och förhållandet mellan värme och stadsmiljö.  Denna avhandling tillämpar urban morfologiteori och fjärranalys tekniker för att utforska hur urbana typologier i Metro Boston presterar under en extrem värmehändelse. I avhandlingen ingår en litteraturöversikt som utforskar stadsvärmemetoder och stadsmorfologi, en undersökning av en uppsättning av städers klimatinsatsrapporter och en fjärravkänningsbaserad analys för att undersöka genomförbarheten att förena markytstemperaturen och offentliga väderstationsdata. Undersökningen av stadsklimatrapporterna visade att även om varje stad har börjat genomföra många socialt drivna initiativ och storskaliga gröna infrastrukturplaner, finns det i dagsläget lite arbete kring integrerande av stadsform i dessa strategier. Även om markytstemperaturen och väderstationskartan från fjärranalysanalysen ansågs otillräckliga uppstod flera värdefulla frågor och fynd genom processen.  Fallstudieanalysen av Metro Boston identifierade tre dominerande urbana former i studieområdet och 12 platser studerades i förhållande till deras värmeprestanda på morgonen, eftermiddagen och kvällen. De värmekartor som tillämpades utvecklades genom Heat Watch Report, ett samarbete mellan National Oceanic and Atmospheric Administration, kommunerna Boston, Brookline och Cambridge och CAPA Strategies. Analysen avslöjade en universell temperaturförändring bland alla former under dagen, med topptemperaturer som inträffar under sen eftermiddagsperiod. Studien visar också att medan temperaturskillnaderna mellan formerna inte var signifikanta, observerades variation mellan platser med samma form, med intern vegetationssammansättning och angränsande marktäkning och urban form som nyckelfaktorer för en ökad eller minskad upplevd värme.

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