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.

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.

No description available.

[pt] Os padrões atuais de desenvolvimento urbano produzem uma série de impactos, que acarretam em consequências para o clima das cidades. A falta de um planejamento atento à questão ambiental, vem ocasionando problemas na qualidade de vida humana, tal como o desenvolvimento do fenômeno das Ilhas de calor urbanas (ICU). Diante desta problemática, este estudo analisa a evolução do fenômeno no estacionamento do BarraShopping (Barra da Tijuca, Rio de Janeiro), com o enfoque na mitigação das Ilhas de calor em estacionamentos a nível de escala microclimática, objetivando o desenvolvimento de soluções que visam melhorar o desempenho ambiental do meio urbanizado. A metodologia da pesquisa foi desenvolvida com base no referencial teórico, na análise de temperaturas de superfície, com utilização de imagens de satélite para delimitação do local de estudo e visitas ao local a fim de registrar as temperaturas durante as horas mais quentes do dia. Após a análise das medições, conclui-se que fatores como a alta densidade construída, a falta de vegetação e grande quantidade de materiais de superfície com alta absorção de radiação solar acarretam mudanças nos elementos climáticos aumentando a temperatura. Diante desses dados, foi possível traçar estratégias para a mitigação do fenômeno, como a combinação da mudança de pavimentos e inserção de arborização, respondendo melhor à redução de temperatura de superfície. / [en] The urban heat islands (ICU) are the most evident example of climate changes inadvertently caused by man, having been observed in practically all cities in the world. This thermal pattern suggests the existence of a warmer urban center, since the materials used in urban and suburban areas absorb and retain more heat than the sun than natural materials in less urbanized rural areas. The Brazilian practical experience in mitigating the effects of heat islands has been constantly evolving, with substantial research in the academic area, pointing to the importance of the issue in the Brazilian urban panorama. Most of this scientific production turns to theoretical models, in most cases, punctual. As a result of urban expansion, the importance of urban climate studies is debated and, in this context, they are fundamental for the understanding of ICU in the regional climate, through scales of analysis, integrating the environmental quality of the citizen. When thinking, on a scale closer to daily life, studies on urban microclimates come into play. When correlating to the field of architecture and urbanism, we can understand the urban microclimate as a change in the climate of an area on a small urban scale, being formed according to the influence of the natural environment and the built environment (Duarte, 2015). Evaluating this scenario, this dissertation seeks to evaluate the microclimatic conditions around Barrashopping, more specifically its parking, and propose mitigating measures for the phenomenon of heat islands in its surroundings. In the public space, pedestrians are subject to variations in environmental comfort and discomfort, being constantly influenced by the surrounding urban landscape and the surrounding buildings that are naturally heated and cooled, releasing energy in the surrounding urban environment, in the form of heat.

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.

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.

Current global agricultural practices are recognized as unsustainable. The increase in overall human population as well as the global trend of rural to urban migration, partially as a result of historically and continual unsustainable agricultural practices, exacerbates the vicious cycle of poverty and hunger in developing countries. Furthermore, cities and regions in developed countries practice unsustainable food production, distribution and consumption patterns, and as a result, exceed their global ecological footprint (Rees 2009). Consequently, the world is facing a global food (FAO 2009) and water crisis (UN Sick Water 2010). Cities and Regions must learn to feed themselves to address local food insecurity as well as protect from the climate effects of increased urbanization, including the Urban Heat Island effect (UHIe) by optimizing and fully integrating the local ecosystem services of food, water and forest within a tightly woven compact urban form through the implementation of strategic urban and regional food system planning. Cities can mitigate climate change and reduce the UHIe, by implementing sustainable intensive urban agriculture approaches through policy and zoning interventions that include concepts such as intensively productive urban agriculture that includes green roofs, vertical farming and greenways as continuously productive and edible urban landscapes, referred to in this paper as continuously productive urban agriculture and forestation (CPUAF) in the private and public realm. A highly participative, adaptive systems approach is explored as the key to sustainability within an economic world order that included corporate social responsibility and social enterprise as the foundation for the integration of multiple synergies. An increasing body of evidence often links urban forestation with urban greenery initiatives, as a carbon sink to reduce UHI effects, to reduce GHG emissions and as a tool for urban beautification and place making (ISDR: 2009,109). Urban agriculture, through the production of local food is increasingly recognized as a means to reduce fossil fuel emissions by reducing transportation and production outputs, to provide a secure local food source, enhance biodiversity and educate the public regarding food source while fostering a sense of community, environmental awareness and stewardship. This thesis explores the links between intensive urban agriculture and forestation, and the relationship between climate change, and the UHI’s as an adaptation and mitigation process in global cities, implemented as a interconnected, integrated, holistic urban management approach that has a further benefit of providing food security and a sustainable and local urban food source. / Dissertation (MTRP)--University of Pretoria, 2012. / Town and Regional Planning / unrestricted

Indiana University-Purdue University Indianapolis (IUPUI) / Heat is one of the most important factors in our atmosphere for precipitation (thunderstorm) formation. Thermal energy from local urban land-cover is also a common source of heat in the lower atmosphere. This phenomenon is known as the urban heat island effect (UHI) and is identified as a substantial cause to a changing climate in surface weather modification. The proceeding study investigates this connection between the UHI and surface weather using remote sensing platforms A ten-year analysis of the Indianapolis UHI and thunderstorms were studied from the summer months of May, June, July, August and September (MJJAS) from 2002 until 2011. LANDSAT space borne satellite technology and land-surface based weather radar technology was used in this analysis for thunderstorm investigation. Precipitation areas identified from land-based NEXRAD WSR-88D technology were used to identify convection from non-synoptic forcing and non-normal surface diurnal heating scenarios. Only convection appearing from the UHI were studied and analyzed. Results showed twenty-one events over eighteen days with the year 2005 and 2011 having the largest frequency of events. The month of August had the largest concentration with seven events during the late afternoon hours. UHI results showed July had the largest heat island magnitude with April and September having the lowest magnitude in UHI temperatures. Three events of the twenty-one storm paths did not had a significant mean temperature difference in the heat island below the storm reflectivity. The nineteen storm paths that were significant had a warmer area underneath storm path development by an average 6.2°C than surrounding areas. UHI initiation points showed twelve of the twenty-one events having statistically significant differences between 2 km initiation areas and the rest of the study areas. Land-cover results showed low intensity developed areas had the most land-cover type (48%) in the 2km initiation buffer regions.

Dans le contexte du changement climatique, la chaleur est, depuis le début des années 2000, une préoccupation grandissante, d’abord en tant qu’enjeu sanitaire puis comme problématique affectant la qualité de vie des citoyens. Au Québec, le concept d’îlot de chaleur urbain, issu de la climatologie urbaine, a graduellement émergé dans le discours des autorités et de certains acteurs de l’aménagement. Or, on constate l’existence d’un certain décalage entre les connaissances scientifiques et l’interprétation qu’en font les urbanistes. Dans le cadre de ce mémoire, on a tenté d’identifier les facteurs explicatifs de ce décalage en s’intéressant au processus d’acquisition des connaissances des urbanistes québécois. Par le biais d’entretiens réalisés auprès des principaux acteurs ayant contribué à l’émergence de l’ICU au Québec, on a été en mesure d’identifier les éléments ayant entraîné certaines distorsions des connaissances. L’absence d’interdisciplinarité entre la climatologie urbaine et l’urbanisme tout au long du processus d’acquisition des connaissances ainsi qu’une interprétation tronquée de la carte des températures de surface expliquent principalement la nature du décalage observé. / In the context of current debates on climate change, heat has become a growing concern since the early 2000s, as it impacts people’s health and quality of life. As an element of urban climatology, the concept of urban heat islands emerged as a standard reference used by a number of Quebec scholars and practitioners in environmental management. However, there appears to be certain discrepancies between our current scientific knowledge and its interpretation by urban planners. The objective of this thesis is to better understand the factors that explain this discrepancy, through a study of knowledge acquisition among Quebec urban planners. Using a series of interviews with key actors in the emerging field of UHI’s in Quebec, it has been possible to identify the elements that caused distortions in knowledge transfer. Generally, the lack of interdisciplinarity in the areas of urban climatology and planning throughout the knowledge acquisition process, as well as a partial understanding of the surface temperature maps, help explain the nature of these discrepancies.

都市地區因人口增長、大量人工建成環境與能源使用等緣故，將產生都市熱島效應。都市熱島效應產生都市高溫化，進而衍生各種都市環境問題，如都市微氣候改變、能源消耗與供給壓力增加、空氣汙染物不易擴散等(Landsberg, 1981)。臺灣位於亞熱帶氣候地區，人口多集中於都市地區，尤其是臺北市。先前相關研究指出臺北市具有都市熱島效應。本研究從有高蓄熱特性的道路與建築量體所構成之「都市街道」為尺度範圍，將進行固定監測站之量測，實際取得都市微氣候之數據（溫度與熱舒適性指標），配合都市街道熱環境因子之調查，一併探討都市街道熱環境因子產生都市高溫化的關係，有別於其他研究探討都市整體的熱島效應，或是單一影響因素導致的都市高溫化，如街廓、材料、植栽、人工排熱等對微氣候的影響。此外，本研究輔以計算流體力學（Computational Fluid Dynamics，簡稱CFD），將量測的數據做為模擬之基本條件，進而模擬都市街道的風場與溫度場，搭配實測數據與模擬值作分析，並且加入都市街道熱環境因子與兩者作探討。研究成果指出植栽綠化與遮蔭將有效改善都市高溫化現象。