Urban Heat Island Phenomenon Research Articles

Micro-scale UHI risk assessment on the heat-health nexus within cities by looking at socio-economic factors and built environment characteristics: The Turin case study (Italy)

Today the most substantial threats facing cities relate to the impacts of climate change. Extreme temperature such as heat waves and the occurrence of Urban Heat Island (UHI) phenomena, present the main challenges for urban planning and design. Climate deterioration exacerbates the already existing weaknesses in social systems, which have been created by changes such as population increases and urban sprawl. Despite numerous attempts by researchers to assess the risks associated with the heat-health nexus in urban areas, no common metrics have yet been defined yet. The objective of this study, therefore, is to provide an empirical example of a flexible and replicable methodology to estimate the micro-scale UHI risks within an urban context which takes into account all the relevant elements regarding the heat-health nexus. For this purpose, the city of Turin has been used as a case study. The methodological approach adopted is based on risk assessment guidelines suggested and approved by the most recent scientific literature. The risk framework presented here used a quantitative estimate per each census tract within the city based on the interaction of three main factors: hazard, exposure, and vulnerability. Corresponding georeferenced maps for each indicator have been provided to increase the local knowledge on the spatial distribution of vulnerability drivers. The proposed methodology and the related findings represent an initial stage of the urban risk investigation within the case study. This will include participatory processes with local policymakers and health-stakeholders with a view to guiding the local planning agenda of climate change adaptation and resilience strategies in the City of Turin.

Diurnal Outdoor Thermal Comfort Mapping through Envi-Met Simulations, Remotely Sensed and In Situ Measurements

Physiological equivalent temperature (PET) is one of most used indices for outdoor human well-being evaluation; its determination is particularly helpful for adaptation strategies in built-up areas affected by the urban heat island (UHI) phenomenon. In this work, we presented a methodology to compute spatially and temporally resolved PET values during a heatwave at the city level, based on a combination of satellite products, in situ measurements and Envi-met model runs upscaled from specific test areas to the broader city. The method exploits the ECOSTRESS sensor to detect surface thermal patterns at different diurnal times by developing an hourly based index called hUHTI (hourly urban heatwave thermal index) that serves as a proxy. A case study on Prato (Italy) municipality during the 2021 summer heatwave events is presented. Based on the available satellite products, a set of six hourly diurnal PET maps at 10 m spatial resolution were derived and daytime outdoor thermal patterns and trends were investigated according to land cover. hUHTI index resulted a more suitable tool as PET proxy compared to the sole ECOSTRESS land surface temperature (LST) product, especially for morning and evening times. Hourly PET maps were summarized by the use of an average exceedance map providing public administrations and stakeholders a synthetic tool for urban regeneration purposes at city scale.

Investigation Properties of Pervious and Water-Retaining Recycled Concrete to Mitigate Urban Heat Island Phenomena

The urban heat island (UHI) effect poses significant challenges to urban environmental quality and public health. Over the decades, research efforts have been made to develop various UHI mitigation strategies, including pavement materials, such as, water-retentive pavement, reflective pavement, and pervious concrete. This paper focuses on the improvement of the hygric and water retention properties of pervious concrete to mitigate UHI phenomena. The hydric and hygroscopic tests were carried out under dry and wet conditions on four different pervious concretes, where natural aggregates were replaced with recycled aggregates at different mass percentages. The results show a significant improvement in these properties by increasing the amount of recycled aggregates incorporated in the mixtures. The mixes made from recycled aggregates alone showed an absorption that reached 75 L more than the control in one cubic meter under wet condition. With an upwelling capacity of up to 30 kg of retained water in a square meter under dry condition, these improvements in water performance represent this permeable concrete as a water retention pavement solution for UHI mitigation. Regarding the mechanical properties, a decrease of 50% in compressive strength was noted only when 100% of the recycled aggregate was incorporated, remaining at 20 MPa for other mixtures.

The Role of Urban Cemeteries in Ecosystem Services and Habitat Protection

Cemeteries, like urban public parks, are an important part of the urban ecosystem, providing semi-natural habitats for many plant and animal species as well as a wide range of ecosystem services: they improve air quality, reduce the urban heat island phenomenon and provide aesthetic and recreational value. This paper explores the role of the cemeteries in the green infrastructure network beyond their sacred and memorial role and their importance as a habitat for urban flora and fauna. In our study, we compared two large public cemeteries of Budapest (Nemzeti Sírkert/National Graveyard and Új Köztemető/New Public Cemetery) with the Zentralfriedhof Wien (Central Cemetery of Vienna), the latter of which has been forward-looking in terms of green infrastructure development and habitat creation in the past years. Our goal was to determine which maintenance technologies and green space development methods are most beneficial in terms of sustainable habitat creation and the use of appropriate plant species in public cemeteries.

THE NBS PROJECT FOR THE ADAPTATION OF THE KYIV OSOKORKY DISTRICT TO CLIMATE CHANGES

Global climate changes have significant impact on cities around the world, although the exact threats can vary significantly depending on the geographic region. Kyiv is a capital city with large population and vast area, which faces different challenges imposed by changing climate. The analysis of climate models demonstrates vulnerability of Kyiv urban infrastructure to heat waves, urban heat island, increasing precipitations and negative weather phenomena. The research was conducted for the Osokorky district of Kyiv to determine its problem points and evaluate the resilience of infrastructure. The results of analysis show that in spite of novelty of the district it lacks sustainability components, has poorly developed green and blue infrastructure, as well as inefficient road network. All these factors combined with dense construction create favorable conditions for the thermal pressure at local population and other biotic components of the district. The suggested approach to the adaptation of Osokorky district to climate changes is through the implementation of nature-based solutions with the aim to expand green infrastructure and increase the volume of ecosystem services provided by urban plants. The green roofs design was developed for 15 sites around the district, based on their location and favorable technical conditions. The economic costs of the project were estimated and the payback period based on the value of ecosystem services provided was defined. In order to strengthen the resilience of the district a complex of additional organizational measures is necessary to support the progress towards safe urban environment.

Using a blue landscape to mitigate heat stress during a heatwave event: a simulation study in a hot-humid urban environment

AbstractThe urban heat island (UHI) phenomenon and climate change have become the major concerns for city sustainability in the wake of global warming and rapid growth in urbanization. This has resulted in increased intensity of heat stress and worsened outdoor thermal environmental conditions in urban microclimates. Water bodies are among the most effective means to alleviate the UHI and improve the thermal environment of urban microclimates. The thermal comfort conditions are observed at the pedestrian's level in a horizontal direction and at different vertical levels by assessing the reduction in three variables: ambient air temperature, surface temperatures, and alteration of flow velocity. The water body model used in this simulation is first validated using the sub-configuration method by replicating a previous experimental study. Two different scenarios (one with a realistic setting and the other with a representative water body) were studied and the results show that, for isolated streets, the water bodies can effectively improve thermal comfort conditions by reducing ambient air temperature (i.e. a reduction of 0.9 °C) and surface temperature by 3.5 °C, thereby reducing energy consumption. Moreover, a significant increase in wind velocity was also observed reaching its maximum value at peak times of thermal stress.

The Urban Heat Island Analysis for the City of Zagreb in the Period 2013–2022 Utilizing Landsat 8 Satellite Imagery

Urban Heat Island (UHI) is a phenomenon specific to urban areas where higher air temperatures manifest in the city area in relation to its surrounding rural landscape. Currently, UHI is one of the most dangerous environmental conditions for cities as well as their residents. It is expected that the intensity of UHI will increase with climate change. This work presents an analysis of the UHI phenomenon for the City of Zagreb, Croatia in the summertime period 2013–2022. In order to explore UHI, Land Surface Temperature (LST) was calculated using Landsat 8 (OLI TIRS sensor) satellite imagery. After the delineation of UHI, calculated temperatures were put in relation to NDVI (Normalised Difference Vegetation Index) and NDBI (Normalised Difference Built-Up Index) indices for the study area. Results show the similarity of mean temperatures over the observed period. However, the influence of external variables on UHI’s spatial expression was observed. Forest-covered areas and other green parts of the city’s infrastructure express the lowest temperatures, while built-up sites are the hottest points in cities. Results confirm the importance of urban green infrastructure for resilient cities and present the results of a long-term UHI observation in a Southeast European city.

ASSESSMENT OF SPATIAL AND TEMPORAL DISTRIBUTION OF URBAN HEAT ISLANDS (UHI) IN SEMI-ARID CLIMATE

An urban heat island phenomenon has increased in the last decades due to rapid urbanization, resulting in a significant impact on local climate. In this study, remote sensing data was used to analyze Spatiotemporal patterns of Urban Heat Island Intensity (UHII) over a 20 years period in a semi-arid climate area. The relationship between the Land Surface Temperature (LST), vegetation and Land Cover Types (LCTs) were examined. The relation between the UHII and its driving factors (different LCTs and meteorological conditions) was analyzed. Analysis of 8-day daytime and nighttime LST data acquired from MODerate-resolution Imaging Spectroradiometer (MODIS) shows that Amman has a significant UHII in both daytime and night time. The results show a negative correlation between the LST and vegetation indicators and between the UHII and the wind speed average, indicating a positive correlation between the UHII and temperature. Vegetation has been proven to significantly reduce LST, mainly in the daytime, due to its cooling effect that results from the transpiration process and shadow effect.

Estimation of anthropogenic heat from buildings based on various data sources in Singapore

Heat released from the energy consumption in buildings (QB) is an important component of anthropogenic heat, which is a major contribution to the urban heat island (UHI) phenomenon. However, it is still a challenge to integrate all the available data to improve the estimation of QB due to inconsistences among multiple data sources. This paper presents a solution to estimate the anthropogenic heat from buildings in Singapore by classifying the buildings into the electricity consumption sectors based on a random forest classification model using multiple data sources. The classification model achieves a cross-validation accuracy score of 95% by using building use type, land use type of land parcel where the building stands, location and area as predictors. Based on the classification result, the annual average QB from the commercial buildings (CS), Housing and Development Board (HDB) apartments, private apartments and condominiums (AC), and landed properties (LP) were estimated to be 12.1, 4.4, 3.2 and 1.1 W m−2 on a 200 m-by-200 m grid, respectively. QB was approximately 9% of the net all-wave radiation in Singapore in 2015. Our approach can serve as a useful tool for integrating datasets from different sources with inconsistent categorizations, and our results can benefit urban planning as well as urban climate modeling at both microscale and mesoscale.

Local Climate Zones to Identify Surface Urban Heat Islands: A Systematic Review

The Land Surface Temperature (LST) obtained by remote sensing data is an essential indicator for analyzing the Surface Urban Heat Island (SUHI). A factor contributing to its occurrence is the reflections of the different materials in urban and rural areas, which significantly affect the energy balance near the surface. Therefore, recent studies have increasingly used the Local Climate Zones (LCZs) classification system to discriminate those urban areas. Therefore, our study aims to perform a systematic review using the PRISMA method of LCZ classification applied to understand the LST and the SUHI phenomenon. At first, 10,403 related articles were found in the scientific literature which, after passing through filtering stages, resulted in 51 that were further analyzed. Our results showed that these articles were very recent, beginning in 2016, and present an increasing trend. Even though all articles reviewed somehow try to understand the Urban Heat Island phenomenon, in more than half of them, the SUHI calculation method was not mentioned. China was the country with the most studies. Images from Landsat and TERRA/AQUA sensors appeared in 82% of the studies. The method that appears the most to LCZ definitions is from the World Urban Database. Finally, we conclude that LCZ mapping methodologies were accurate enough for SUHI studies considering the current climatic changes. Therefore, this systematic review can help new studies on SUHI identification through LCZ in different world areas using remote sensing data to estimate the LST.

Solar reflection and effect of roof surfaces material characteristics in heat island mitigation: toward green building and urban sustainability in Ha’il, Saudi Arabia

Abstract Several materials have the ability to absorb, accumulate and transmit solar radiation to their surrounding environment. The thermal island effect and micro-climate of urban areas are subject to notable influence from the composition of materials within the city’s crust. The present investigation was carried out with the aim of assessing the impact of roofing and pavement materials’ properties on solar reflection and their potential to mitigate urban heat islands (UHIs). A study of an experimental nature was carried out on a total of 20 conventional materials that are commonly used in the construction of roofs, sidewalks, streets and rooftops in Ha’il, Saudi Arabia. The objective of the research was to investigate the impact of different urban surface materials on the rise of ambient air temperature in their vicinity. The present investigation aimed to assess the thermal performance of the specimens, with the purpose of ascertaining the impact of the thermophysical and radiative characteristics of the substances. The findings of the experiments indicate that the Solar Reflectance and temperature of the surrounding environment are primarily influenced by the color and substance of surface materials. Conversely, the texture’s condition has a comparatively minor effect. Both effective factors play an equally significant role in the overall mechanism of increasing the ambient air temperature. The results suggest that a significant proportion of the samples exhibit a maximum surface temperature exceeding 59.4°C, while concurrently displaying a Solar Reflectance Index and albedo <49%. Meanwhile, the implementation of green roofs composed of various types of vegetation, including grass, can effectively alleviate the UHI phenomenon.

Urbanization Trends Analysis Using Hybrid Modeling of Fuzzy Analytical Hierarchical Process-Cellular Automata-Markov Chain and Investigating Its Impact on Land Surface Temperature over Gharbia City, Egypt

Quick population increase and the desire for urbanization are the main drivers for accelerating urban expansion on agricultural lands in Egypt. This issue is obvious in governorates with no desert backyards. This study aims to (1) explore the trend of Land Use Land Cover Change (LULCC) through the period of 1991–2018; (2) upgrade the reliability of predicting LULCC by integrating the Cellular Automata (CA)-Markov chain and fuzzy analytical hierarchy process (FAHP); and (3) perform analysis of urbanization risk on LST trends over the Gharbia governorate for the decision makers to implement effective strategies for sustainable land use. Multi-temporal Landsat images were used to monitor LULCC dynamics from 1991 to 2018 and then simulate LULCC in 2033 and 2048. Two comparable models were adopted for the simulation of spatiotemporal dynamics of land use in the study area: CA-Markov chain and FAHP-CA-Markov chain hybrid models. The second model upgrades the potential of the CA-Markov chain for prediction by its integration with FAHP, which can determine the locations of high potential to be urbanized. The outcomes stated a significant LULCC in Gharbia during the study period—specifically, urban sprawl on agricultural land, and this trend is predicted to carry on. The agricultural sector represented 91.2% in 1991 and reduced to 83.7% in 2018. The built-up area is almost doubled by 2048 with respect to 2018. The regression analysis revealed the LST increase due to urbanization, causing an urban heat island phenomenon. Criteria-based analysis reveals the district’s vulnerability to rapid urbanization, which is efficient for data-gap zones. The simulation results make sense since the FAHP-CA-Markov simulated the LULCC in a thoughtful way, considering the driving forces of LULCC, while the CA-Markov chain results were relatively random. Therefore, the FAHP-CA-Markov chain is the pioneer to be relied upon for future projection. The findings of this work provide a better understanding of LULCC trends over the years supporting decision makers toward sustainable land use. Thus, further urbanization should be planned to avert the loss of agricultural land and uninterrupted increasing temperatures.

Analysis of patterns of urban sprawl and surface urban heat island in solan town of himachal pradesh using remote sensing and gis

Rapid unplanned urbanization consequently influencing the land surface temperature globally that lead to Urban Heat Island (UHI) phenomenon that has negative impact on the quality of life of population exist within that area. Impervious surfaces effect the functioning of ecosystem that’s why urban monitoring is important. Present study was focused on detection of presence of the UHI phenomenon in the Solan town of Himachal Pradesh (H.P.) from year 1990, 2000, 2010 and 2020. Multitemporal analysis is performed to analyze trend of temperature using Landsat 5, 7 and 8 thermal infrared sensors processed within Geographical Information System (GIS). Google Earth engine also used as a platform for the detection of urban sprawl with the help of classified map extracted from it. R software used for the detection of fragmentation and other landscape indices on the classified map. Region of interests (ROIs) was created in the urban and surrounding rural area to analyze the difference in temperature and landscape metrics in both of ROIs. Study highlighted the presence of Surface Urban Heat Island (SUHI) phenomenon in the medium size town of Solan in all the decades with the maximum LST difference of 1.92°C in year 1990, 0.68°C in year 2000, 1.02°C in year 2010 and 2.12°C in year 2020 between the two ROIs. Temperature values in year 2020 has declined due to reforestation in the area and the consequence of global pandemic lead to change in temperature due to lower pollutant concentration. LST variation indicate a rise of 4.61°C in the minimum and 9.19°C in the maximum temperature from 1990 to 2010. Urban sprawl has been reported, the urban expansion was maximum from year 1990 to 2000 in the Centre of city with the percentage of 31.27 km2 while total rate of change in urban surfaces is 131.48km2 which includes rural area along with road has been converted in impervious surface with the passage of years. Overall accuracy of the classified maps was 88%. The classified maps indicate correlation of landscape indices with the urban expansion of town where heterogeneity significantly increased with time whereas patch number and density is increasing with the urban growth and declining with reforestation in the urban and rural ROIs it fluctuate accordingly. This study reported the need of effective and sustainable urban planning method in the developing cities of Himalayas. Policy makers should introduce green spaces and plantation in urban area to mitigate the UHI phenomenon in future.

Mountain valley cold air flow interactions with urban morphology: A case study of the urban area of Changwon, South Korea

The formation of urban heat islands (UHIs) is accelerated due to reckless development in urban areas; hence, continuous improvement is required in urban planning. In particular, in urban areas with basin topography, air circulation is not smooth and hot air is stagnant, resulting in a vicious cycle of aggravating the UHI phenomenon. To improve air circulation in an urban area with a basin topography, a study was conducted to prepare a wind corridor strategy considering urban spatial types and cold air flow in Changwon, South Korea. The cold air was discharged from mountain valleys on the outskirts of the city and moved from the valleys through connected rivers. In certain areas with high building density, the mountain valleys were not connected to rivers, resulting in the stagnation of cold air. Therefore, to create urban wind corridors, it is necessary to build low- and mid-rise residential areas along rivers to facilitate the drainage and movement of cold air based on urban spatial types. This study identified the main drainage, movement, and stagnant areas of cold air for the creation of urban wind corridors, which is expected to serve as a reference for urban planning strategies for wind corridor implementation in urban areas with basin topography and mitigate the impacts of UHIs.

Spatio-temporal analysis of urban heat island (UHI) and its effect on urban ecology: The case of Mekelle city, Northern Ethiopia

The bio-geophysical effects of land cover classes are considered to be an important factor in land surface temperature variations between urban and suburban areas. This means that major cities are significantly warmer than surrounding suburban or rural areas, which is known as the Urban Heat Island (UHI) effect. The aim of this study was to assess and analyze the spatiotemporal variation, correlation and impact of UHIs on Mekelle city (1990–2020) using remote sensing techniques. The study's primary objective was accomplished using the a number of techniques, including the extraction of LULC classes, estimation of the seasonal LSTs, assessment of UHI and UTFVI, and showing the relationship between LULC and LST as well as the interactions between UHI, UTFVI, and urban LULC classes. By analyzing TIRs/OLI thermal band data after calibrating uncertainty in the images and validating it using the concept of theoretical relationships and least squares fitting method, estimates of local LST, UHI (both in Mekelle and periphery rural areas), and UTFVI were obtained. The result of standard multiple regression models showed that impervious urban land surface, built-up areas, and dry bare soil highly contribute and influence variation at LST intensity caused for the formation of UHI in the study area. The result showed that the maximum UHI value in Mekelle city was 2.73 °C during the dry season in 1990. It decreased slightly to 2.53 °C in 2000 and then increased regularly to 2.83 °C and 2.98 °C in 2010 and 2020, respectively. To determine the city's UHI status in comparison to eight selected peripheral suburban areas, a trend analysis has been done. The UHI intensity of Mekelle city was higher relatively to that of most of the periphery suburban districts, particularly in 2020 (both dry and rainy seasons); this could be due to the city's explosive growth. It's worth noting that the research area affected by the urban heat island effect has grown over time, and as a result, the study area also has severe microclimate conditions that primarily damage the quality of urban life and create the worst conditions for thermal discomfort. The results of this study provide major conceptual understandings of how improper distribution and use of urban land affects the urban environment and fuels the creation of the UHI and thermal discomfort phenomena. Hence policy makers and urban planners should consider the effects of LST and UHI and integrate UHI comprehensive mitigation strategies with urban development patterns, and current and projected local climate changes in order to create sustainable urban environments, cities, and communities. In conclusion, compared to the conventional method, satellite remote sensing provides a faster and more efficient method for researching LST and UHI.

Innovative light-coloured porous asphalt for low-impact pavements: A laboratory investigation

In recent years, research is pushing toward more sustainable solutions in the road sector such as cool pavement and eco-friendly paving components. Cool pavements are advanced pavement technologies characterized by lower surface temperature thanks to the use of light-coloured binders and an open-graded structure. In this framework, the present study intends to provide a laboratory characterization of two different open-graded wearing courses produced with Construction and Demolition waste (CDW) aggregates and virgin aggregates and with a transparent resin-based binder. The final aim of the research is to provide scientific evidence on the possible application of the adopted resin-based transparent binder with light-coloured aggregates for open-graded wearing courses in order to minimize the Urban Heat Island phenomenon. The results show that the addition of 50% of CDW aggregates to the porous asphalt enhances the abrasion resistance and the mechanical performance of the mixture.

Impact of Sustainable Buildings in Arid Environment on the Indoor and Outdoor Air Quality: Workshop Report

Abstract Qatar Environment and Energy Research Institute (QEERI) hosted a workshop entitled “Impact of Sustainable Buildings in Arid Environment on the Indoor and Outdoor Air Quality,” held in Doha, Qatar, on May 17–19, 2022, co-funded by the Qatar National Research Fund (QNRF), and co-organized by City College of New York (CCNY). The workshop provided a premier interdisciplinary platform for local researchers and enablers to engage and exchange knowledge and experiences with international leading practitioners and subject matter experts in the fields of sustainable buildings, indoor and outdoor air quality, and the urban heat island phenomena. A diverse number of regional partners and stakeholders were represented. The workshop benefitted from a pool of invited international subject experts from various universities and entities. The outcome-driven workshop included breakout sessions where participants actively engaged in brainstorming discussions guided by facilitators. The discussions focused on driving impact in Qatar and beyond by examining the current research landscape and identifying collaborative opportunities. The short-term and long-term outcomes of potential initiatives and project proposals are outlined in this summary. An example of a short-term outcome is the proposed collaborative project to investigate the impact of almost doubling the state of Qatar’s population (over 1.5 million fans are expected to visit the country during the World Cup causing a shock to the system) on vital elements in the city, such as mobility, telecommunication services, and the local environment. In addition, multiple potential research proposals with international collaborations were proposed. A special issue on the subject in the Journal of Engineering for Sustainable Buildings and Cities was recommended as an immediate actionable outcome.

Urban Heat Island’s Vulnerability Assessment by Integrating Urban Planning Policies: A Case Study of Montpellier Méditerranée Metropolitan Area, France

The energy balance differences between urban and rural areas give rise to a representative phenomenon of urban climate change called the urban heat island (UHI). The UHI phenomenon, which is exacerbated by global warming effects and urban expansion, exposes urban areas and populations to thermal stress and overheating. Therefore, measuring the intensity of UHI vulnerability is needed to mitigate its effects on health, comfort, energy consumption and infrastructure. Additionally, urban decision makers are looking for methodologies to identify the most vulnerable areas in urban planning. This research aims to investigate areas prone to urban overheating in Montpellier Mediterranean metropolitan area as a representative case study of the French urban planning context. The objective is to develop a methodology for assessing UHI vulnerability based on the interaction of exposure and sensitivity to urban planning policies. Accordingly, a set of fifteen indicators is developed to visualize urban planning policies, exposure and sensitivity to urban overheating. A statistical-based method is applied to determine the individual weights based on the indicators’ variance, which is calculated using principal component analysis (PCA). The spatial and urban planning distribution of vulnerability is then analyzed. The results indicate that the areas with the highest urban planning challenges are most vulnerable to UHI. In fact, the results reveal that these areas have urban planning characteristics likely to aggravate urban overheating. Therefore, this research proposes a methodology for integrating mitigation solutions into urban planning: increase in permeable and green areas; improvement of urban ventilation and heat exchange and decrease in anthropogenic heat generation. It demonstrates that combining urban planning policies with exposure and sensitivity is a new perspective for vulnerability studies. The findings of this study can be utilized by decision makers to better visualize areas susceptible to UHI and plan appropriate mitigation strategies.

Method of identifying urban heat islands by remote sensing based on big data

In recent decades, the speed of construction, expansion, and development of smart cities by humans has been increasing faster, thanks to new technologies. However, alongside the fantastic development of new technologies also comes negative impacts such as climate change. One of the characteristics of climate change is the changing thermal comfort of humans living in the city. Heat stress is a feature of the urban heat island phenomenon. Congestion of airflows within the urban area causes localized hot areas, causing a temperature difference of 2-3 degrees between the areas inside the city and the suburbs. This study presents a method for determining surface temperature and the location of heat islands based on Google's cloud computing platform. The platform uses a combination of satellite imagery, Earth observation data, and machine learning algorithms to allow users to identify and measure changes in land use, ecosystems, and climate patterns at a global scale. Google Earth Engine enables researchers and organizations to process enormous amounts of data with short turnaround times. The method described in the article allows the analysis and retrieval of data in the large dataset of the Landsat 8 satellite. By determining the location of heat islands, the government, policymakers, and planners can develop plans to cope with the urban heat island phenomenon and improve the quality of life for residents.

Exploring the potential of alley gardens in Seoul based on a study of Daegu

Seoul has experienced rapid economic growth and industrialization, and it has become the central city of South Korea. These densely populated urban spaces have undergone the urban heat island (UHI) phenomenon, wherein the temperature is higher than that of the surrounding areas. Green spaces constitute the primary response to this problem, yet Seoul has not yet taken measures to create small-scale green spaces, such as alley gardens. Therefore, this study analyses the case of alley gardens in Daegu and argues for the necessity of their introduction. Alley gardens in Daegu have proven effective in reducing heat and have influenced the residential satisfaction of residents in densely populated, old housing. After confirming that the concept of alley gardens can serve as a micro-urban planning tool to establish small-scale green spaces and alleviate the UHI effect in Seoul, we explored the target areas where alley gardens can be applied within Seoul. Through heat-related environmental indicators and social factor indicators, this study found that Mullae-dong is experiencing the UHI effect, and that the introduction of alley gardens would have a positive impact due to the concentration of small-scale, old residences. This paper establishes the rationale for applying alley gardens to Seoul, while also deriving the importance and implications for the dissemination and revitalization of micro-level urban environment policies.