• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 63
  • 26
  • 14
  • 9
  • 6
  • 6
  • 4
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 159
  • 159
  • 159
  • 46
  • 31
  • 25
  • 24
  • 24
  • 21
  • 21
  • 21
  • 21
  • 20
  • 20
  • 16
  • 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.
121

Estimativa da temperatura de superfície na região metropolitana de Goiânia por meio de imagens Landsat e previsão de temperaturas para períodos posteriores / Estimated surface temperature in the region in metropolitan Goiânia Landsat images media and temperatures forecast for subsequent periods

Siqueira, Rubens Villar 03 December 2015 (has links)
Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-04-01T19:43:27Z No. of bitstreams: 2 Dissertação - Rubens Villar Siqueira - 2015.pdf: 4882241 bytes, checksum: 3f8cb0b344dec7efd60e3c7564ed2c56 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-04-04T11:52:29Z (GMT) No. of bitstreams: 2 Dissertação - Rubens Villar Siqueira - 2015.pdf: 4882241 bytes, checksum: 3f8cb0b344dec7efd60e3c7564ed2c56 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-04-04T11:52:29Z (GMT). No. of bitstreams: 2 Dissertação - Rubens Villar Siqueira - 2015.pdf: 4882241 bytes, checksum: 3f8cb0b344dec7efd60e3c7564ed2c56 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-12-03 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Climate analysis, whether at global, regional or local level, it has been the subject of research in various fields of earth sciences. Among the climatic parameters, temperature and precipitation have gained importance in recent decades because of significant changes in their magnitudes. Thus, this work performs a detailed analysis of the temperature for the Greater Goiânia, using satellite images to generate surface temperature for the study area, at first, through an analysis between the years 1997 and 2008 and after in about twenty years, periodically every four years, for the years 1997, 2001, 2005, 2009 and 2014. The elaborate maps, besides showing the spatial variation of urban heat islands, show that there was significant changes to the minimum temperature, maximum and average. Between the period 1997 and 2008, the minimum decrease about 1.4°C and maximum jump of 31.2°C to 36.0°C. Test results for the five periods between 1997 and 2014, show that the year 2014 is presented as the hottest in the years studied. Through the resulting maps of this analysis, it can see that the range of temperatures, the difference between the maximum and minimum, grow with the years. An estimated temperature of satellite validation model was performed by direct comparison between the surface temperature and the data of GOIÂNIA weather station belonging to INMET, with differences of 0.7°C to 1.9°C between the temperatures demonstrating the applicability of satellite images to estimate temperatures in areas that do not have a dense meteorological network. The last analysis performed is forecast monthly temperatures for the period between the years 2040-2047, using the method of Holt-Winters. The model used for predicting allowed the computation of the seasonality of the minimum monthly temperatures, average and maximum for the historical period between the years 1970 to 2015. The predicted temperatures renew the expectation of increased minimum temperatures, average and maximum presented by the analysis of Historic data. As shown, in addition to the monthly increases in temperature, the occurrence of these will be situated in the highest classes of about 1.0° C warmer. We can see that, too, after 2000, all temperatures rise significantly, where their amplitudes between the minimum and maximum are located at a higher level than in previous years. / A análise do clima, seja em escala global, regional ou local, tem sido objeto de pesquisa em diversas áreas das ciências da terra. Dentre os parâmetros climáticos, a temperatura e a precipitação ganharam importância nas últimas décadas devido as alterações significativas em suas magnitudes. Desta forma, este trabalho executa uma análise particularizada da temperatura para a Região Metropolitana de Goiânia, utilizando imagens de satélites a fim de gerar a temperatura de superfície para a área de estudo, em um primeiro momento, por meio de uma análise entre os anos de 1997 e 2008 e após em cerca de vinte anos, periodicamente a cada quatro anos, para os anos de 1997, 2001, 2005, 2009 e 2014. Os mapas elaborados, além de mostrarem a variação espacial das ilhas de calor urbano, demonstram que houve variações significativas para as temperaturas mínimas, máximas e médias. Entre o período de 1997 e 2008, as mínimas decrescem aproximadamente em 1,4°C e as máximas saltam de 31,2°C para 36,0°C. Os resultados da análise para os cinco períodos entre 1997 e 2014, demonstram que o ano de 2014 se apresentou como o mais quente entre os anos estudados. Por meio dos mapas resultantes desta análise, é possível notar que a amplitude das temperaturas, diferença entre as máximas e mínimas, crescem com o decorrer dos anos. Um modelo de validação das temperaturas estimadas por satélite foi executado por meio da comparação direta entre a temperatura de superfície e os dados da estação meteorológica GOIÂNIA, pertencente ao INMET, apresentando diferenças de 0,7°C a 1,9°C entre as temperaturas, demonstrando a aplicabilidade de imagens de satélite para estimativa de temperaturas em áreas que não dispõem de uma rede meteorológica adensada. A última análise executada trata da previsão de temperaturas mensais para o período entre os anos de 2040 a 2047, utilizando o método de Holt-Winters. O modelo adotado para a previsão permitiu a computação da sazonalidade das temperaturas mensais mínimas, médias e máximas para o período histórico entre os anos de 1970 a 2015. As temperaturas previstas reafirmam a expectativa do aumento das temperaturas mínimas, médias e máximas apresentadas pela análise dos dados históricos. Conforme demonstrado, além dos aumentos nas temperaturas mensais, a ocorrência destas se situará em regiões mais altas, com cerca de 1,0°C mais quentes. Podemos notar que, também, após o ano 2000, todas as temperaturas se elevam de forma significativa, onde suas amplitudes entre as mínimas e máximas se situam em um patamar mais elevado que nos anos anteriores.
122

A relação entre ilha de calor urbana, o uso e cobertura do solo e o balanço de energia no município de São Paulo: avaliação do campo térmico nos parques públicos de lazer / The relationship between the urban heat island, use and land cover and energy balance in São Paulo: evaluation of thermal field of public leisure parks

Hugo Rogério de Barros 03 June 2016 (has links)
A Ilha de Calor Urbana no município e Região Metropolitana de São Paulo foi estudada por uma série de autores da Geografia e Meteorologia através da aplicação de metodologias de estudos empíricos na avaliação do fenômeno. A vigente pesquisa apresenta uma nova metodologia na avaliação do campo térmico urbano e o conjunto de variáveis climáticas e antrópicas que o condicionam. Para tal foi realizado o seguinte teste de hipótese: a dinâmica territorial da Ilha de Calor Urbana corresponde às interações entre as condições sinóticas, uso e cobertura do solo e balanço de energia. Além desta, dentre os diversos objetivos específicos, o estudo contou com a avaliação do campo térmico dos parques públicos de lazer. Para tal foram utilizados os métodos descritivo, seguido do comparativo e análise integrada descritiva, aliados a uma simbiose entre aplicações de técnicas de sensoriamento remoto e geoprocessamento. Um total de nove imagens do satélite Landsat-5 sensor TM no período de 2007 a 2011 foram utilizadas na geração de imagens termais, posteriormente estas foram vetorizadas e sobrepostas a padrões oficiais de uso do solo, também foram adotados índice de vegetação, fotografias áreas, cartas e boletins sinóticos e dados de campo referentes à temperatura do ar, umidade relativa, precipitação, direção e velocidade do vento, evaporação e radiação solar global. O modelo SEBAL (Surface Energy Balance Algorithms for Land) foi aplicado a três imagens do mapeador temático Landsat-5 de diferentes datas, através do mesmo foram gerados mapas de albedo da superfície, saldo de radiação à superfície, fluxo de calor sensível e latente. Os resultados demostraram a veracidade da hipótese, a conformação e dinâmica territorial da Ilha de Calor Urbana corresponderam a diferentes condições de tempos sinóticos, os quais determinaram o transporte de umidade do oceano para atmosfera continental e por seguinte transformaram o balanço de energia local. Foram verificados três diferentes padrões territoriais, em todos eles os padrões de uso do solo ligados a comércio e serviços, armazéns e indústrias que apresentaram índice de biomassa vegetal igual zero, obtiveram a melhor correlação espacial com o fenômeno. O cenário chamou atenção para a preservação e expansão do arboreto urbano, parques e unidades de conservação, visto que estes demonstraram ser a fonte para redução da temperatura da superfície urbana. / The Urban heat island in the city and metropolitan region of São Paulo has been studied by several authors in the areas of geography and Meteorology through the application of methodologies of empirical studies on the evaluation of the phenomenon. Our research presents a new methodology in the evaluation of the urban thermal field and the set of climatic and anthropogenic variables that influence it. To this end, the following hypothesis testing was conducted: the territorial dynamics of the urban heat island corresponds to the interactions between synoptic conditions, use and coverage of the soil and energy balance. Additionally, among several other specific objectives, the study was also preoccupied with the evaluation of the thermal field of public parks. For such purpose we applied the descriptive method, followed by the comparative method and descriptive integrated analysis, combined with a symbiosis between applications of remote sensing and GIS techniques. A total of nine satellite images Landsat-5 TM sensor in the period from 2007 to 2011 were used on thermal imaging, these were later vectorized and superimposed on official standards of land use. Other than that, vegetation index, air photographs, letters and synoptic bulletins and field data related to air temperature, relative humidity, precipitation, wind direction and speed, global solar radiation and evaporation were also adopted. The model SEBAL (Surface Energy Balance Algorithms for Land) was applied to three thematic mapper images Landsat-5 from different dates; through these images were generated albedo maps from the surface, the surface radiation balance, sensible and latent heat flux. The results proved the hypothesis true, the conformation and territorial dynamics of the urban heat island corresponded to different conditions of synoptic climates, which determined the humidity transportation from the ocean into continental atmosphere and, consequently, transformed the balance of local energy. Three different territorial patterns were investigated; in all of them the land use patterns linked to trade and services, warehouses and industries that showed the index of plant biomass equal zero obtained the best spatial correlation with the phenomenon. The scenario drew attention to the preservation and expansion of the urban arboretum, parks and protected areas since these proved to be the source for the development of thermal environmental urban quality.
123

Zhodnocení přínosu zahrnutí urbanizace do předpovědního modelu počasí / On the assessment of urbanization application in weather forecasting model

Nováková, Tereza January 2018 (has links)
Built-up areas represent an artifiial impait to natural environment with large spatial variability and speiifi meihaniit radiationt thermal and ihemiial properties. Despite of inireasing horizontal resolution of numeriial weather prediition modelst the impait of loial built-up area on mesosynoptiv weather phenomena is still not well resolved. Therefore it is neiessary to use some of urban environment modelst whiih were designed to parameterize speiifi urban prosiessest not expliiitly resolved inside the grid box. In the thesis main urban iharaiteristiis are explained (impait on the struiture of boundary layert radiation and heat balanie of urban environment or urban heat island)t basii priniiples of urbanization appliiation in the numeriial weather model are desiribedt as well as different urban parameterizations available in numeriial model WRFe (Weather Reseaih and Feoreiasting). Number of validation experiments were performed for summer and winter episode in non-hydrostatii mode at 3t3 km resolutiont where different urban parametrizationst antropogenii heat adjustment and impait of mosaii land-use were tested. April 2018 Prague weather foreiast was verifiated in ionsideration of urban heat island.
124

Impact of Carbon Sinks on Urban Heat Island Effects : Assessment Using Satellite Data in Water Scarce Region of the Thesis

Macauley, Nadine January 2020 (has links)
Urbanization modifies the thermal characteristics of the land and makes way for a succession of transformations in the urban environmental system. This phenomenon, known as Urban Heat Island (UHI), is characterized by elevated temperatures in urban areas that negatively impact on the quality of life and environment in urban areas including, increased emissions of Green House Gases (GHGs) and rising energy consumption. These impacts add to global climate change and thus, mitigating UHI is essential to mitigating global climate change. One GHG, Carbon Dioxide (CO2), accounts for about half of the Earth’s anthropogenic GHG emissions. Terrestrial ecosystems can act as Carbon sinks (C sinks), i.e. natural vegetation reservoirs that absorb more C than they release. Thus, C sinks play an essential and critical function in lowering CO2. Furthermore, providing appropriate C sinks at both the building and urban scales can decrease UHI and contribute to reduction in energy consumption. This study used Landsat 8 imagery of the site, Al Bayt Stadium in Qatar, to investigate the effects of surface UHI by computing the Land Surface Temperature (LST) difference of the site---pre- and post-construction, as well as examine the correlation between natural vegetation abundance and temperature in ten locations within the site’s vicinity. Results show that minimum, maximum and mean LST of the case study area (2014 vs. 2020) decreased 2.80 oC, 5.5 oC and 2.3 oC, respectively, as well as a decreasing trend in the LST as a function of increasing C Sinks. These results demonstrate the importance of introducing C sinks to lower LST and mitigate UHI. Mitigating UHI also has a direct effect on Energy Consumption Balance (ECB). This equilibrium is achieved not only through the introduction of C sinks, but balancing C sinks with high albedo materials and natural ventilation.  Thus, this study also investigated the site’s various design aspects (e.g. cooling technology, structure and surface albedo materials, landscaping) and found that Al Bayt Stadium’s design successfully incorporates strategies to reduce energy consumption at both the urban (macro) and building (micro) scales.
125

Exploratory Eddy Covariance Measurements of Surface Heat and CO2 Fluxes in the Roughness Sublayer of an Urban Environment

Burnett, Benjamin F. 01 January 2010 (has links)
In this study eddy covariance was used to measure sensible heat, latent heat, and carbon dioxide fluxes for the months of August, September, and October of 2009 within the roughness sublayer (RSL) of the urban center of Portland, OR. Vehicle traffic and solar radiation were also measured for the month of October. Flux measurements were compared with measurements from other urban areas as a test of reasonableness. CO₂ fluxes were nearly always positive and were strongly correlated with the weekday diurnal traffic cycle. CO₂ fluxes averaged 6.6 μmol/m^²s, which is less than other published measurements in urban areas. Sensible and latent heat fluxes followed the expected diurnal profile associated with solar radiation. Average sensible heat flux decreased as the season changed from summer to fall, moving from an average of 39 W/m^² in August to 12 W/m^² in October. A corresponding increase in latent heat flux was observed during this period, changing from an average of 10 W/m^² in August to 17 W/m^² in October. Heat flux behavior and amplitude was consistent with other urban measurements, though amplitude varies considerably from city to city. Stationarity was shown to positively influence measured CO₂ fluxes, but to have little effect on measured heat fluxes. Preliminary comparisons of October sensible heat and CO₂ fluxes to an inventory-based estimate of vehicle emissions indicate that eddy covariance measurements underestimate the true fluxes by 50%.
126

Addressing Urban Sustainability Challenges in a Changing Environment: Insights into Park Usage, Heat Mitigation and Green Space Sensing

Zhao, Haokai January 2023 (has links)
Cities are home to more than half of the world’s population, and this figure is set to continue to rise amidst ongoing global urbanization trends. Against this backdrop, urban development is increasingly confronted with multifaceted challenges. These range from public health emergencies, exemplified by the COVID-19 global pandemic, to the environmental hazards driven by climate change, including extreme heat waves and more frequent severe storms. Confronted with these substantial risks, the urgency of devising and implementing strategies for sustainable and resilient urban development has become paramount. Given this context, the work presented in this thesis aims to advance understanding of some critical urban sustainability challenges, and to develop models, tools, and sensing systems that can support progress towards a more sustainable and resilient urban future. The first part of the thesis focuses on the role and usage of urban parks during a global public health emergency. Urban parks became critical for maintaining the well-being of urban residents during the COVID-19 global pandemic. To examine the impact of COVID-19 on urban park usage, New York City (NYC) was selected as a case study, and SafeGraph mobility data, which was collected from a large sample of mobile phone users, was used to assess the change in park visits and travel distance to a park based on park type, the income level of the visitor’s census block group (visitor CBG) and that of the park census block group (park CBG). All analyses were adjusted for the impact of temperature on park visitation, and the research work was focused primarily on park visits made by NYC residents. Overall, for the eight most popular park types in NYC, namely – Community Park, Flagship Park, Jointly Operated Playground, Nature Area, Neighborhood Park, Playground, Recreation Field/Courts and Triangle/Plaza – visits dropped by 49.2% from 2019 to 2020. The peak reduction in visits occurred in April 2020. Visits to all park types, excluding Nature Areas, decreased from March to December 2020 as compared to 2019. Parks located in higher-income CBGs tended to have lower reductions in visits, with this pattern being primarily driven by visits to large parks, including Flagship Parks, Community Parks and Nature Areas. All types of parks saw significant decreases in distance traveled to visit the park, with the exception of the Jointly Operated Playground, Playground, and Nature Area park types. Visitors originating from lower-income CBGs traveled shorter distances to parks and had less reduction in travel distances compared to those from higher-income CBGs. Furthermore, both before and during the pandemic, people tended to travel a greater distance to parks located in high-income CBGs compared to those in low-income CBGs. Finally, multiple types of parks proved crucial destinations for NYC residents during the pandemic. These included Nature Areas to which the visits remained stable, along with Recreation Field/Courts which had relatively small decreases in visits especially for lower-income communities. Results from this particular research study can support future park planning by shedding light on the different users of certain park types before and during a global crisis, where access to green spaces can help alleviate the human well-being consequences associated with mitigating the crisis, including the type of “lockdown” or limited mobility policies implemented in 2020 during the COVID-19 global pandemic. The second part of the thesis investigates the role of urban greening and other land surface features in influencing the urban heat island effect in NYC. The urban heat island (UHI) effect describes the phenomenon whereby cities are generally warmer than surrounding rural areas. UHI effects can exacerbate extreme heat events, leading to an increase in heat-related illness and mortality. Here, the runoff coefficient was used as a numerical surrogate for urban greening, with lower runoff coefficients being associated with higher fractions of urban greening. Using a high-resolution landcover GIS dataset developed for New York City (NYC), which classified the city into more than 13 million land patches, the runoff coefficient of land use across the entire city was mapped down to a resolution of 30m×30m, along with five other variables including surface albedo, distance to water bodies, land surface elevation, building density and building height. Daytime land surface temperature (LST) in summer was used as a surrogate for the UHI effect in NYC, and the work investigated the relationship between the runoff coefficient and LST. The work also examined the relationship between LST and the variables of surface albedo, distance to a water body, land surface elevation, building density and building height. Results indicate that runoff coefficient can explain a large portion of variability related to urban LST, with lower runoff coefficients (more greenery) being associated with lower LST. Use of the five other variables improves the predictability of LST, although the influence each variable has on LST varies with urban setting and context. The research work presented in this part of the thesis also shows the disproportionately higher exposure to urban heat in lower-income communities in NYC. The findings can be used to develop strategies to mitigate UHI effects in NYC and other cities around the world. In the third part of the thesis, a wireless environmental sensing system is developed for monitoring urban green spaces, with demonstrated application for stormwater management. The monitoring of urban green spaces, including monitoring of soil conditions and soil health, is crucial for sustainable urban development and ecological resilience. Leveraging advances in wireless environmental sensing, a LoRaWAN-based system capable of measuring air temperature/humidity, soil temperature and moisture, and soil moisture dynamics is designed and deployed across seven diverse urban green spaces for a full year at Columbia University’s Morningside Campus in New York City. The data collected by this sensing network reveals notable variations in soil moisture across the seven monitored sites, which are influenced by a combination of vegetation type, soil conditions, and physical settings. Monitored lawns consistently showed higher soil moisture levels due to their slower draining soil type, underlying concrete structures, and lower canopy rainfall interception and transpiration loss, whereas one monitored tree pit site with a more rapidly draining soil type showed significantly lower soil moisture throughout the study period, despite having comparable physical settings with another monitored site. Seasonal trends indicated lower summer moisture in some monitored areas due to increased evaporation and transpiration under high temperatures, while others areas maintained higher soil moisture as a result of frequent irrigations. Models were developed to quantify soil moisture response to rainfall events. It was found that the increase in soil moisture at each monitored site was highly dependent on the rainfall depth and the initial soil moisture. Overall, the results show that a range of diverse green spaces can help retain and drain storms up to certain sizes of 30-50mm. However, proactively designed soil drainage systems are needed to handle extreme storm events above 50mm. The study highlights the effectiveness of LoRaWAN technology in urban environmental monitoring and provides valuable insights into how different urban green spaces can contribute to stormwater management. The findings presented in this portion of the thesis demonstrate the instrumental role that monitoring, data analysis and modeling can play in helping city planners and environmental managers optimize urban green spaces for ecological benefits and enhance urban resilience, including in the face of stressors such as climate change. Overall, with its data-driven, evidence-based insights, this work contributes to the understanding of the multifaceted urban sustainability challenges in a changing environment, including public health emergencies such as the COVID-19 global pandemic, and climate change induced environmental hazards such as extreme heat events and more frequent severe storms. Alongside deepening understanding, the developed quantitative models and sensing technologies presented in this thesis offer practical solutions to support urban development towards a more sustainable and resilient future.
127

Identification of spatiotemporal nutrient patterns and associated ecohydrological trends in the tampa bay coastal region

Wimberly, Brent 01 May 2012 (has links)
Improvements for environmental monitoring and assessment were achieved to advance our understanding of sea-land interactions and nutrient cycling in a coastal bay.; The comprehensive assessment techniques for monitoring of water quality of a coastal bay can be diversified via an extensive investigation of the spatiotemporal nutrient patterns and the associated eco-hydrological trends in a coastal urban region. With this work, it is intended to thoroughly investigate the spatiotemporal nutrient patterns and associated eco-hydrological trends via a two part inquiry of the watershed and its adjacent coastal bay. The findings show that the onset of drought lags the crest of the evapotranspiration and precipitation curve during each year of drought. During the transition year, ET and precipitation appears to start to shift back into the analogous temporal pattern as the 2005 wet year. NDVI shows a flat receding tail for the September crest in 2005 due to the hurricane impact signifying that the hurricane event in October dampening the severity of the winter dry season in which alludes to relative system memory. The k-means model with 8 clusters is the optimal choice, in which cluster 2 at Lower Tampa Bay had the minimum values of total nitrogen (TN) concentrations, chlorophyll a (Chl-a) concentrations, and ocean color values in every season as well as the minimum concentration of total phosphorus (TP) in three consecutive seasons in 2008. Cluster 5, located in Middle Tampa Bay, displayed elevated TN concentrations, ocean color values, and Chl-a concentrations, suggesting that high colored dissolved organic matter values are linked with some nutrient sources. The data presented by the gravity modeling analysis indicate that the Alafia River Basin is the major contributor of nutrients in terms of both TP and TN values in all seasons. Such ecohydrological evaluation can be applied for supporting the LULC management of climatic vulnerable regions as well as further enrich the comprehensive assessment techniques for estimating and examining the multi-temporal impacts and dynamic influence of urban land use and land cover.
128

Reproductive Timing of Passerines in Urbanizing Landscapes

Shustack, Daniel P. 10 September 2008 (has links)
No description available.
129

Causal relationship between Air Quality (AQ) and the Urban Heat Island (UHI)

Ereminaite, Marija, Jayasinghe, Yasas January 2024 (has links)
This study critically examines the (UHI) effect in urban and suburban neighbourhoods of Quito, Ecuador, over a 19-year period, focusing on the interplay between atmospheric pollution and urban/ suburban temperature. Utilizing Empirical Dynamic Modeling(EDM) and Convergent Cross-Mapping (CCM), this study dives into the nonlinear dynamics of environmental factors, a method that traditional linear models fail to address effectively.The results unveil a consistent and strong positive correlation across various neighbourhoods, with temperature fluctuations indicating a typical UHI effect. This is most noticeable in urbanized areas where the temperature is significantly higher due to dense infrastructure and reduced greenery, a pattern that diminishes as one moves towards the outskirts. Specifically, pollutants like PM2.5 exhibit a non-uniform positive correlation, suggesting their collective increase or decrease across different regions, whereas CO shows a very slight and inconsistent inverse relationship across locations. The causal analysis further substantiates a significant interaction between PM2.5 concentrations and temperature, with the data revealing a reciprocal predictive capacity between these variables. The CCM analysis, through its graphical representation of predictive skills, confirms the causal effect of PM2.5 on urban temperature, marking an essential contribution to understanding the UHI effect and its implications for urban environmental dynamics. This study provides a comprehensive overview of the UHI phenomenon, highlighting the intricate relationship between urbanization, atmospheric pollution, and climate. The findings emphasize the necessity for urban planning and policy to consider these complex interactions to mitigate the effects of climate change on urban environments.
130

Främja resiliens i den svenska stadsplaneringen mot urbana värmeöar : En fallstudie av Gävle, Sundsvall och Uppsala stad

Reuithe, Karin, von Friesendorff, Filip January 2024 (has links)
Klimatförändringarnas påverkan på stadsmiljöer blir alltmer påtagligt med ökande frekvenser av extrema väderfenomen, vilket kräver resilienta städer med förmågan att anpassas till framtida störningar. Urbaniseringen förtätar städerna och leder till mer hårdgjord mark och minskad vegetation som kan resultera i fenomenet urbana värmeöar. Fenomenet koncentrerar och förlänger värmen i städer, vilket hotarmänniskors hälsa, särskilt under extrema värmeböljor. Värmeöar är väldokumenterade globalt men är en förbisedd fråga i Sverige. Examensarbetets syfte var därför att öka förståelsen kring värmeöar för svenska kommuner och myndigheter med exempel från städerna Gävle, Sundsvall och Uppsala. Målen var att föreslå resilienta planeringsåtgärder som både kan förbättra det pågående arbetet mot värmeöar samt nya inslag från internationell forskning.Studiens metoder var litteraturstudie, dokumentstudie av översiktsplaner (ÖP) samtintervjuer. En spatial multikriterieanalys (MKA) användes för att skapa farokartor av var värmeöar kan uppstå. Kriterier valdes genom litteratur, viktades med analytisk hierarkiprocess samt genomgick en känslighetsanalys. Farokartorna valideradessedan med Myndigheten för samhällsskydd och beredskaps (MSB) värmekartering. Resultaten visade att värmeöar behandlades på en övergripande nivå i ÖP. Varierade kunskaper om fenomenet framkom av respondenter från både kommuner och myndigheter. Flera utmaningar, möjligheter och planeringsåtgärder identifierades iarbetet mot värmeöar. Resiliens framhölls som ett nyckelkoncept i stadsplaneringen för att beakta olika klimatrisker där värmeöar är ett exempel. Litteraturstudien gav förslag på resilienta planeringsåtgärder i arbetet mot värmeöar som kan användas i svensk stadsplanering, vilka sedan sammanställdes. För att skapa resilienta städer krävs både reduceringsåtgärder (minska den byggda miljöns påverkan på stadsvärme)samt hanteringsåtgärder (förebyggande arbeten för att minska människors värmeexponering).  Farokartorna visade att värmeöar framför allt kan uppstå i bostads-, handels- och industriområden. MKA som metod för kartläggning av värmeöar överensstämdedelvis med marktemperaturer från MSB:s värmekartering. Slutsatsen av studien var att värmeöar behöver uppmärksammas mer i den svenska stadsplaneringen. Utmaningarna inkluderade att inkorporera värmefrågor i befintlig bebyggelse, medan möjligheterna fanns i fler planeringsunderlag och detaljerade kartläggningar. Främjandet av resiliens, särskilt genom reducerings- och hanteringsåtgärder,behöver utvecklas i Sverige för att stärka planeringsarbetet mot värmeöar i både nutida och framtida stadsplanering. / The impact of climate change on urban environments is becoming increasinglyapparent with higher frequencies of extreme weather phenomena, which requires resilient cities with the ability to adapt to future disturbances. Urbanization densifies cities and leads to more hard surfaces and reduced vegetation which can result in urban heat islands (UHI). This phenomenon concentrates and prolongs heat in citieswhich threatens human health, especially during extreme heat waves. UHI are well documented globally but are an overlooked issue in Sweden.  The aim of the study was therefore to increase the understanding of UHI for Swedish municipalities and authorities with examples from the cities of Gävle, Sundsvall and Uppsala. The goals were to propose resilient planning measures that can both improve the ongoing work against UHI as well as new elements from international research. The study's methods were a literature study, a document study of comprehensive plans (översiktsplan) and interviews. A spatial multicriteriaanalysis (MCA) was used to create hazard maps of where UHI can occur. Criteria were selected through literature, weighted using analytic hierarchy process and underwent a sensitivity analysis. The hazard maps were validated with the Swedish Civil Contingencies Agency’s (MSB) heat mapping. The results showed that UHI were treated at an overall level in comprehensiveplans. Varied knowledge about the phenomenon emerged from respondents from both municipalities and authorities. Several challenges, opportunities and planning measures were identified in the work against UHI. Resilience was highlighted as a key concept in urban planning to consider various climate risks where UHI are an example. The literature study provided suggestions for resilient planning measures in the work against UHI that can be used in Swedish urban planning, which were then compiled. To create resilient cities, both reduction measures (reducing the built environment's impact on urban heat) and management measures (preventive work to reduce people's heat exposure) are required.  The hazard maps showed that UHI mainly occur in residential, commercial and industrial areas. MCA as a method for UHI mapping partially matches ground temperatures from MSB's heat mapping. The conclusion of the study was that UHIneed more attention in Swedish urban planning. Challenges included incorporating heating issues into existing buildings, while the opportunities were in more planning documents and detailed mapping. The promotion of resilience, especially through reduction and management measures, needs to be developed in Sweden to strengthen the planning against UHI in both present-day and future urban planning.

Page generated in 0.0738 seconds