Urban Heat Island Phenomenon Research Articles

La isla de calor urbano superficial y su manifestación en la estructura urbana de la Ciudad de México

From the processing of high- and low-resolution satellite images (Landsat and Modis), the development of bivariate correlations between daytime and nighttime land surface temperatures, and 27 metrics associated with urban structure and location, this work has analyzed the intensity of the phenomenon of Urban Heat Island manifested in Mexico City in one of the warmest months of the year 2018 to identify the most vulnerable areas to this phenomenon and their urban structure characteristics. Thus, the highest temperatures are found at a shorter distance from the inner city, as the most consolidated area. The population aged 65 or over, which is the most vulnerable to health problems associated with high temperatures and body thermoregulation, is located in areas of the city where the highest night temperatures are concentrated. Likewise, to a lesser extent, there is a direct correlation between high temperatures and areas with higher housing density, a greater surface area of paved streets, and a greater concentration of economic units per hectare. On the contrary, the zones with the lowest temperatures identified within the City were located in areas with the greatest heights above sea level, on steeper slopes, and with a greater surface of open areas. Likewise, the population aged 0 to 14 years, also identified within the range of vulnerability to high temperatures, is located mainly in areas with moderate and/or low temperatures. On the other hand, to identify the diurnal and nocturnal thermal variations, both in artificial and natural cover soil and their land use, thermal profiles were generated with measurements at every 1000 meters. This has allowed it to observe more pronounced thermal oscillations during the day, with the highest temperatures in the cultivation areas, residential land, and mixed-use. On the contrary, night temperatures stabilize and manifest the phenomenon of the Urban Heat Island in which it is shown that the highest temperatures are concentrated in the densest area of the city (Alcaldía Cuauhtémoc and Alcaldía Benito Juárez), which have stored a greater amount of heat due to the characteristics of the materials and composition of the urban environment, and the areas with a natural cover go down due to the ease of dissipating heat.

The significance of shade provision in reducing street-level summer heat stress in a hot Mediterranean climate

The rise in air temperature in urban areas has been attracting the attention of urban climate researchers for years now, focusing on the intensity of the so-called Urban Heat Island (UHI) phenomenon. Recently, though, it has been rightly questioned whether the concept of UHI intensity is helpful in assessing mitigation of urban heat stress, especially since the concept does not reflect the spatial and temporal microscale climatic differences between adjacent intra-urban locations and the much lower magnitude of the UHI effect during daytime. Moreover, while UHI research is focused on near-surface air temperature levels, the existing evidence makes it clear that air temperature does not fully describe the intensity of street-level daytime heat stress during the hot season.This study attempted to evaluate the correlation between exposure to shortwave radiation and significant increases in heat stress under summer conditions through extensive monitoring. Using a mobile measurement setup we monitored summer daytime outdoor conditions in 148 unique locations in Tel Aviv-Yafo, a coastal city with a hot-summer Mediterranean climate. Analysis of the resulting dataset showed the decisive effect of solar exposure on significantly increased heat stress according to three common thermal comfort indices. A much weaker correlation was observed between comfort levels and air temperature, relative humidity, and wind speed levels. These findings support the conclusion that under summer daytime conditions in similarly hot climates the provision of shade has a far stronger positive effect on reducing heat stress than, for example, feasible reductions in air temperatures or increases in wind speed.

Analysis of Vegetation Density and Surface Temperature in Buahbatu District, Bandung using Landsat 8 Oli/Tirs Satellite Images

Urban Heat Island is a phenomenon of increasing temperature that occurs in the city area compared to the surrounding area. Urban Heat Island is caused by reduced vegetation due to changes in rural land use to urban areas. This study was conducted to analysis the relation between vegetation density (NDVI) and surface temperature (LST) in Buahbatu District as an effort to control the impact of the Urban Heat Island phenomenon. This research was conducted by processing data from Landsat 8 OLI/TIRS satellite images in 2019-2020, namely from May to October 2019 and May to October 2020. Data collection was carried out through Google Earth Engine to retrieve geospatial data visualization (satellite imagery) and USGS to download Landsat 8 satellite imagery on Bands 4 and 5, then the data is processed using Arcmap, and Pearson correlation test is performed on SPSS. The results obtained are a correlation between vegetation density and surface temperature. In Buahbatu District, the correlation between vegetation density and surface temperature shows a value of (-.403*) in 2019 and (-.386*) in 2020. Both show a negative correlation, which means that if an area has high vegetation density, the surface temperature will decrease, and vice versa. In addition, Buahbatu District gets a good UHI with an NDVI above 0.25, and an LST below 30 but not less than 25.

Are New Residential Areas Cooler than Older Ones?

This study was conducted to investigate if passive cooling technologies have been implemented in commercially supplied new residential areas in Bangkok and to observe if there were significant differences in the land surface temperature (LST) compared to old residential areas. Values of LST were compared among 62 residential areas that differed in completion year. The mean LST for the most recent residential areas completed in 2013 or later was significantly less than that for the other older categories, suggesting that passive cooling effects were significantly better functioning in the new residential areas. A roof treatment on old buildings in a public housing project was still quantitatively effective after 8 years. This suggested the possibility of a deteriorated cooling function in the older categories among the residential areas. The possibility of deterioration was quantitatively investigated. The results stressed the importance of the periodic maintenance of passive cooling functions. As an extension of precise basic studies, this is the first study to quantify the passive cooling effects on commercially supplied residential areas. In terms of spatial extent, this residential area–scale study bridges precise analyses of single buildings/materials and regional observations, mainly relying on satellite data. The study results can aid in the mitigation and prevention of the urban heat island phenomenon. Doi: 10.28991/ESJ-2022-06-06-08 Full Text: PDF

Climate Justice in the City: Mapping Heat-Related Risk for Climate Change Mitigation of the Urban and Peri-Urban Area of Padua (Italy)

The mitigation of urban heat islands (UHIs) is crucial for promoting the sustainable development of urban areas. Geographic information systems (GISs) together with satellite-derived data are powerful tools for investigating the spatiotemporal distribution of UHIs. Depending on the availability of data and the geographic scale of the analysis, different methodologies can be adopted. Here, we show a complete open source GIS-based methodology based on satellite-driven data for investigating and mapping the impact of the UHI on the heat-related elderly risk (HERI) in the Functional Urban Area of Padua. Thermal anomalies in the territory were mapped by modelling satellite data from Sentinel-3. After a socio-demographic analysis, the HERI was mapped according to five levels of risk. The highest vulnerability levels were localised within the urban area and in three municipalities near Padua, which represent about 20% of the entire territory investigated. In these municipalities, a percentage of elderly people over 20%, a thermal anomaly over 2.4 °C, and a HERI over 0.65 were found. Based on these outputs, it is possible to define nature-based solutions for reducing the UHI phenomenon and promote a sustainable development of cities. Stakeholders can use the results of these investigations to define climate and environmental policies.

Modelling the impact of Urban Heat Island mitigation strategies on Urban Air Quality

Increasing urban sprawl has caused many severe problems like surge in pollution, rapid climatical variations, and the intensification of temperature in the urban areas, termed Urban Heat Islands (UHI). Population density has caused theconversion of most land areas into cities, and cities have expanded vastly. UHI phenomenon has caused temperature rise in the cities. Most of the metropolitan regions of India are experiencing consequences of UHI and the severity of pollution formation, which is a crucial research area. Since the rising temperature has a direct linkage with urban air pollution; the mitigation measures for UHI are also linked with urban air pollution mitigation; efficacy of mitigation measures of UHI phenomenon in correlation with urban air quality is being studied extensively, which emphasizesthescientific approach and planning concerns of implementation agency to consider the same into urban design and planning aspects. Ahmedabad is one of the growing metropolitan regions of India. The city has grown economically and physically by expanding its boundaries in a radial pattern. This study has attempted temporal assessment of remote sensing data to derive the UHI and the city's growth, and its changing land uses. Assessment has been performed from2008 to 2018 from Landsat data for temperature profile at surface level and type of usage of land of the study area. The spatial profile of Particulate Matter (PM2.5 and PM10) has been generated based on data from the state pollution control board. Four variables, LST, PM2.5, PM10, and LULC, are taken to establish the relationship between all variables present in different layers withthehelp of regression statistical analysis. A strong positive correlation between PM2.5, PM10, and LST has been discovered, which was eventually used to assess the impact of mitigation strategies of UHI, specifically urban greening and a white roof to particulate matter concentrations.

The influence of seasonal land-use-land-cover transformation on thermal characteristics within the city of Pietermaritzburg

Urbanisation has been identified as a major threat to the environment as it increases demand for urban spaces and transforms natural landscapes to impervious surfaces, leading to the Urban Heat Island (UHI) phenomenon. Natural landscapes such as vegetation and water bodies act as thermal sinks that absorb heat while impervious surfaces such as buildings and concrete pavements act as thermal sources that retain and emit heat. The thermal emission results in several negative effects such as temperature inversion, compromised human health, pollution, species loss, high energy consumption and climate change at a local, regional and global scales. Whereas studies on UHI are abound, there is paucity in literature on the influence of seasonal urban Land Use Land Cover (LULC) transformation on urban thermal characteristics. Specifically, the proportional seasonal variability and contribution of individual LULCs to urban heat is often poorly understood. Using the freely available Landsat 8 optical and thermal bands, this study examined the seasonal characteristics of the UHI phenomenon in relation to LULCs in the Pietermaritzburg city, South Africa. Results in this study revealed that UHIs exist in both winter and summer, but with more intensity in summer. The study also established that LULCs varied with seasons. Bare surfaces and dense vegetation had the most thermal influence during winter while dense vegetation and low density buildings had the most thermal influence during summer. These findings provide a better understanding of thermal distribution based on LULC seasonality changes, valuable for sustainable urban planning and climate change mitigation.

Spatio-temporal variance and urban heat island in Akure, Nigeria: A time-spaced analysis Using GIS Techniqu

The threat of the increasing global temperature is now of global concern than ever before. This prompted the authors to gain insights on the Urban Heat Island (UHI) phenomenon in a medium-sized city of Akure, Nigeria. A random sampling of three hundred and twenty-five (325) structured questionnaires was administered and analyzed with the aid of the Statistical Package for Social Sciences (SPSS). Landsat satellite imagery for the years 2000; 2007; 2013 and 2018 were acquired and used for the computation of land use-land cover (LULC) and the Land Surface Temperature (LST) of the study area using ArcGIS 10.5. Between the years 2000 and 2018, built-up area increased by 8.78% at the expense of the non-built up land use. The residents were aware of UHI and climate change but characterized by superficiality. The study recommends a community awareness program on the menace of climate change and the integration of climate education into the curriculum of schools and other institutions of higher learning.

Urban Heat Island Mitigation Strategy based on Local Climate Zone Classification using Landsat 8 satellite imagery

Appropriate strategies on urban climate mitigation should be formulated by considering the physical morphology of the urban landscape. This study aimed to investigate, analyze, and promote possible strategies to mitigate Jakarta’s urban heat island (UHI) phenomena. Jakarta’s local climate zone (LCZ) was classified into 17 classes using Landsat 8 data and the random forest method. Land surface temperature (LST) characteristic in each LCZ class was analyzed from 2018, 2019 and 2020. The result revealed that most of the local climate zone in Jakarta is dominated by LCZ 6 (open low-rise) and LCZ 3 (compact low-rise), which is the typical residential area in Jakarta. However, the mean LST in 2018, 2019 and 2020 showed that LCZ 3 (compact low-rise) and LCZ 7 (lightweight low-rise) are the areas that were most likely causing high surface temperature with the highest UHI intensity. During the COVID-19 pandemic in 2020, LST in Jakarta decreased drastically in some parts of the area, especially in public facility such as airport. However, the LST value in low-rise areas (LCZ 3 and LCZ 7) remains higher than the other LCZ classes. Materials of the building and land cover play a significant role in raising the land surface temperature. Therefore, mitigation strategies for urban heat islands in Jakarta should be focused on such particular areas mentioned.

Review of the optimization techniques for cool pavements solutions to mitigate Urban Heat Islands

Impermeable pavements in high-density cities are one of the main causes of the aggravation of the Urban Heat Islands (UHI) phenomenon. The transformation of impermeable pavements into cool pavements constitutes a promising and innovative technique for the mitigation of UHIs. This review paper treats the technique of cool pavements or evaporative pavements, firstly on the basis of the energy balance that occurs on the surface of such pavements, in the aim of identifying the different approaches that can be adopted to enhance the technique employed. Then, this work will place particular emphasis on the various factors and properties that help to optimize this technique, as well as on the effect that incorporating certain materials has on the properties mentioned, in order to expand perceptions in the design of cool pavements. The paper ends with the main criteria for durability of cooling pavements and the corresponding maintenance techniques.

URBAN HEAT ISLAND DI KOTA TANGERANG SELATAN

The industrial revolution opened up opportunities in changing people’s lives from an agrarian economic activity to an industry-based economy so that many people mass produced the phenomenon of migration. In 2018, 55% of the world’s population live in urban areas and by 20150 this will increase to 70 percent (United Nations, 2019). Migration disturbs the heat energy balance in urban areas as compared to suburban or surrounding areas, resulting in a temperature difference phenomenon known as urban heat island (Sharma et al. 2019). South Tangerang is one of the districts adjacent to the city of DKI Jakarta which is known as the world’s big city so it has vulnerability as a migration destination. So it is necessary to conduct a study that can provide an overview of the future phenomena of the emergence of potential urban heat island (UHI) that can be used as mitigation of the impacts of climate changes. As a results, from 2004 and 2020 there was an increase 0,3 0 C UHI Index. The UHI phenomenon that occurs in South Tangerang City is also a result of existing developments in DKI Jakarta for areas that are directly connected to DKI Jakarta, such as Pondok Karya, Pondok Betung, and Cirendeu will experience urban growth.

30-Year Spatial-Temporal Analysis of Air Surface Temperature as Climate Change Mitigation

Natural and anthropogenic factors, such as volcanic eruptions and land use, are indirect causes of changes in the micro-scale climate. Over the past 30 years, climate change has been detected with increased air surface temperature (AST) above 30.00C, a phenomenon of Urban Heat Island. Therefore, this study aimed to create a spatial model to see changes in AST in Bandar Lampung City from1990 to 2020. The spatial and temporal analysis uses Landsat data to produce land surface temperature (LST) and AST models. The results showed a temperature rise in the LST area, which tends to be the northern part of Bandar Lampung City, by 25.0oC and above for 30 years. Compare LST and AST from two stations between 30 years is 5.00C. In 1990, the LST concentrated on the spatial distribution of the AST model with a temperature above 30.00C, while in 2020, it diffused to the northern part of Bandar Lampung City. The results concluded that the air temperature in the city has warmed up to 0.46OC (+10C), which is in line with the findings of IPPC and various world cities. It is also in occurrence with the UHI phenomenon since 2014 that climate change is part of mitigation.

Urban heat island reduces annual building energy consumption and temperature related mortality in severe cold region of China

The urban heat island (UHI) phenomenon has gained increasing attention as it not only affects the energy consumption of buildings but also threatens the health of urban dwellers. In this study, we calculated the UHI intensity in major China cities across different climates based on the measured weather data of year 2019. The influences of UHI intensity on the building energy consumption and temperature-related mortalities were then quantified. Results show that the impact of UHI on urban dwellers is not always negative in terms of building energy consumption and temperature-related mortality. In most severe-cold-region cities in China, UHI reduces the annual building energy consumption caused by the cooling and heating load, because the amount of heating load reduced in winter is larger than the cooling load increased in summer. The annual temperature-related mortality is also reduced by UHI in certain cities. These reductions indicate that UHI has favourable effects in certain regions. Our findings indicate that detailed evaluation should be performed on a case-by-case basis to quantify the UHI effects on urban dwellers.

A Three-Dimensional Investigation of Spatial Relationship between Building Composition and Surface Urban Heat Island

Urban heat island (UHI) phenomena are on the increase and are responsible for excessive energy use, environmental harm, and detrimental effects on human health in many parts of the world. Case studies of individual cities imply that wise planning and policymaking might lessen the consequences of UHI by altering aspects of urban settings such as land use/cover (LULC). Determining the influence of LULC planning on UHIs has proven difficult due to the diversity of elements that can alter urban surroundings. This study evaluated building functions and the three-dimensional distribution of structures on land surface temperatures (LSTs) in Tsukuba, a science city in Japan, to estimate the influence of landscape composition on UHIs. We used multiple regression analysis to examine the relationship between LST and LULC, building height, building function, and other variables (e.g., distance to/from roads). Our results showed that management and control of the distribution of buildings, population density, and energy consumption could significantly reduce LSTs, realize sustainable development, and ensure a healthy environment in a planned city. Furthermore, a better theoretical understanding of what makes cities sustainable can enhance the ecological awareness of urbanites and help cities evolve in a sustainable way.

Utilization of Terra-MODIS Satellites for Phenomenon Analysis Urban Heat Island in Kalimantan Island

Urban development on the island of Kalimantan in various aspects can in principle increase productivity through the expansion of built-up land. This can have an impact on increasing temperatures in urban areas and lower temperatures around them. This phenomenon is known as urban heat island (UHI). For this reason, it is essential to analyze the phenomenon. The UHI analysis in this study utilizes remote sensing technology using the Terra-MODIS satellite. Terra-MODIS satellite imagery is used to determine land surface temperature (LST) and normalized difference vegetation index (NDVI). The urban areas that are the object of analysis are Pontianak City and Balikpapan. The data used is imagery data from 2001 to 2020. In the province, ESG and NDVI are inversely proportional, but in this study, a condition was produced where the situation was directly proportional. This condition shows that in the analysis of the UHI phenomenon, other factors are needed besides these two parameters, such as humidity and precipitation.

A monthly performance comparison of green infrastructures enhancing urban outdoor thermal comfort

Among the problems caused by the increase of the urban heat island phenomenon, the worsening of the outdoor thermal comfort at pedestrian level was addressed to improve urban resilience. Starting from the analysis of a real urban area in Venice, Italy, the study was extended to different urban forms classified by the Local Climate Zones (LCZs) method. The Physiological Equivalent Temperature (PET) calculated with the ENVI-met code was used to evaluate outdoor thermal comfort. Different mitigation strategies were compared for the whole summer period. For this purpose, a monthly assessment was performed using the monthly mean day approach rather than the usual single days analysis. A new index (%DPET) was proposed, indicating the percentage reduction in the discomfort rate in PET of the original scenario achieved by mitigation measures. The results show that the largest PETs, corresponding to very hot human thermal sensation, for the original scenario occur in the case of lowrise buildings. In this case, green and cool roofs provide their best performances and the seasonal %DPETs reach 9.1% and 7.5%, respectively. Green wall technology is the most effective in all urban forms studied with %DPET values ranging from 28% to 115%, sometimes reaching the neutral comfort level.

Spatial and temporal variation of heat islands in the main urban area of Zhengzhou under the two-way influence of urbanization and urban forestry.

Urban heat islands are major factors hindering the quality of present-day urban habitats. The ongoing acceleration of the worldwide urbanization process is leading to an exacerbation of the urban heat island effect; however, urban forestry can mitigate it. For a sustainable urban development, it is particularly important to evaluate the dual effect of both factors on the urban heat island phenomenon. In this study, we focused on Zhengzhou City (China), at the center of the Central Plains Forest City Cluster. The spatial and temporal evolutions of the local urban heat island and vegetation coverage were measured from Landsat 5 and Landsat 8 remote sensing images taken between 2006–2020 and the effects of urban construction and urban forestry on the urban heat island effect were evaluated. The results showed that, in the past 15 years, the high-temperature zone in the urban area of Zhengzhou City has gradually spread from its center to surrounding areas. Within the same period, the whole urban heat island has deteriorated and gradually improved: its area increased by 138.72 km2 between 2006–2014 and decreased by 135.66 km2 between 2014–2020. Notably, the development of vegetation coverage occurred consistently with the improvement of the heat island. A quantitative analysis of the relationship between urban construction, the urban forest, and the urban heat island has shown that factors like population density (representing urban construction), urban planning, and vegetation cover (representing the urban forest) all have an impact on the urban heat island. Based on the dynamic changes of the urban heat island in the urban area of Zhengzhou City between 2006–2020, we conclude that urban forest construction strategies are beginning to bear fruit. Overall, the findings of this study provide a theoretical basis for future urban construction and urban forest construction plans; moreover, they can support landscape pattern optimization and urban heat island mitigation.

Analysis of Land Surface Temperature Dynamics in Islamabad by Using MODIS Remote Sensing Data

The rapid pace of unattended urbanization has caused the urban heat island phenomenon, due to which the United Nations SDGs agenda 2030 calls for immediate actions for “sustainable cities and communities”. In this context, the case of the emerging metropolitan city Islamabad has been studied based on its developmental discourse vis-à-vis associated environmental problems. A time-series trend for the land surface temperature was generated by investigating the change in minimum and maximum variability against a dataset of 1960–2012 which was obtained from the Pakistan Meteorological Department, along with MODIS LST images from January 2000 to December 2015. The statistical comparison of an eight-day composite of the maximum (Tmax) and minimum (Tmin) temperature reveals an increasing trend with R2 values of 0.2507 (Tmin) and 0.1868 (Tmax). The box plots for both the Tmin and Tmax depict changes in seasonal patterns for Islamabad, with summers becoming longer and winters becoming harsher. Moreover, the application of the Mann–Kendall test affirmed the slope of the R2 linear trend map and showed the temperature regression in the Margalla Hills National Park and in such urban zones which had an expanded vegetative cover. These findings will act as a guide for urban planners and future researchers to maintain a standardized urban heat island and promote the concept of sustainable cities in the future course of action.

Anthropogenic Vehicular Heat and Its Influence on Urban Planning

Anthropogenic heat (QF) is one of the parameters that contributes to the urban heat island (UHI) phenomenon. Usually, this variable is studied holistically, among other anthropogenic flux such as industrial, vehicular, buildings, and human metabolism, due to the complexity of data collection through field measurements. The aim of this paper was to weigh vehicular anthropogenic heat and its impact on the thermal profile of an urban canyon. A total of 108 simulations were carried out, using the ANSYS Fluent® software, incorporating variables such as the number of vehicles, wind speed, urban canyon orientation, and urban canyon aspect ratio. The results were compared with a database of 61 American cities in 2015 and showed that orientation is the main factor of alteration in vehicular heat flow, increasing it in a range of 2 °C to 6.5 °C, followed by the wind speed (1.2 to 2.2 m/s), which allows for decreases of 1 to 3.8 °C. The exploration of these variables and their weighing in the definition of urban street canyon temperature profiles at the canopy level of urban structures provides valuable information on the hygrothermal comfort of its inhabitants; its appropriate quantification can be an example of many urban energy balances altering processes.

The Impact of the Green Spaces On the Land Surface Temperature in Urban Areas - Analysis of the Land Surface Temperature in the City of Oradea using Landsat 8 Satellite Images

People living in urban areas face temperature discomfort due to the urban heat island phenomenon that is in correlation with the land surface temperature (LST) generated by the buildings for living and other construction. In this paper, we aim to use remote sensing data to retrieve the LST values to demonstrate the visual correlation that exists between these values and green spaces. To retrieve the LST values and to obtain the raster dataset necessary to identify the correlation between the green spaces and these values, we applied the method of single window algorithm using data from Landsat 8, acquired on 27th May 2021, in ArcGIS software for the City of Oradea area. The obtained results confirmed the strong correlation between green spaces and low values of land surface temperature.