scholarly journals Trend Analysis of Urban Heat Island Intensity According to Urban Area Change in Asian Mega Cities

2019 ◽  
Vol 12 (1) ◽  
pp. 112 ◽  
Author(s):  
Kyungil Lee ◽  
Yoonji Kim ◽  
Hyun Chan Sung ◽  
Jieun Ryu ◽  
Seong Woo Jeon
Keyword(s):  
Urban Heat Island ◽  
Urban Area ◽  
Anthropogenic Heat ◽  
Heat Island ◽  
Individual Factor ◽  
Long Term Trends ◽  
Urban Heat ◽  
Increasing Trends ◽  
Mega Cities

Urban heat island (UHI) is a phenomenon that occurs in cities worldwide. Therefore, there is an increasing need for studies on the changes in UHI intensity and long-term trends based on macroscopic characteristics related to urbanization. In this study, changes in seasonal UHI intensity based on urban area were analyzed for eight Asian mega cities from 1992–2012. The results indicate that the change in pattern of UHI intensity varies for different cities and seasons. UHI intensity increased as the urban area size increased. Furthermore, the dependency of UHI intensity on the economic situation was also demonstrated. With respect to the seasons, significantly increasing trends appeared during the summer. Moreover, depending on urban characteristics such as geography and climate, increasing trends appeared during other seasons. Population was also found to affect UHI intensity by generating anthropogenic heat; however, its effect as an individual factor appeared to be insignificant. This is a macroscale study that analyzes the effect of urban area size on UHI intensity. Future studies on urbanization factors and levels influencing the UHI intensity using higher resolution materials are required

Long-Term Evolution of Anthropogenic Heat Fluxes into a Subsurface Urban Heat Island

2013 ◽  
Vol 47 (17) ◽  
pp. 9747-9755 ◽  
Author(s):  
Kathrin Menberg ◽  
Philipp Blum ◽  
Axel Schaffitel ◽  
Peter Bayer
Keyword(s):  
Urban Heat Island ◽  
Long Term Evolution ◽  
Heat Fluxes ◽  
Anthropogenic Heat ◽  
Heat Island ◽  
Term Evolution ◽  
Urban Heat

scholarly journals Urban heat island of the Moscow megacity: the long-term trends and new approaches for monitoring and research based on crowdsourcing data

2020 ◽  
Vol 606 ◽  
pp. 012063
Author(s):  
M I Varentsov ◽  
P I Konstantinov ◽  
N V Shartova ◽  
T E Samsonov ◽  
P E Kargashin ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Heat Island ◽  
New Approaches ◽  
Long Term Trends ◽  
Urban Heat

scholarly journals Assessing urban heat island impact on long-term trends of air temperatures in Ljubljana

Dela ◽  
2015 ◽  
pp. 41-59
Author(s):  
Darko Ogrin ◽  
Marko Krevs
Keyword(s):  
Urban Heat Island ◽  
Air Temperature ◽  
City Centre ◽  
Heat Island ◽  
Temperature Trends ◽  
Air Temperatures ◽  
Long Term Trends ◽  
Urban Heat ◽  
The Hill

The paper presents an assessment of urban heat island (UHI) impact on air temperature trends inLjubljana. The assessments are based on the comparison between the long-term air temperature trends inLjubljanaandZagreb. Meteorological station Zagreb-Grič operated on the hill in the city centre since its establishment in 1862, while theLjubljanastation changed its location several times. The analysed UHI effect on the measurements of air temperature inLjubljanagradually increased, especially after 1950.

scholarly journals Quantitative Analysis of Factors Contributing to Urban Heat Island Intensity

2012 ◽  
Vol 51 (5) ◽  
pp. 842-854 ◽  
Author(s):  
Young-Hee Ryu ◽  
Jong-Jin Baik
Keyword(s):  
Urban Heat Island ◽  
Single Layer ◽  
Anthropogenic Heat ◽  
Heat Island ◽  
Impervious Surfaces ◽  
Additional Heat ◽  
Urban Geometry ◽  
Causative Factors ◽  
Urban Heat ◽  
Vertical Walls

AbstractThis study identifies causative factors of the urban heat island (UHI) and quantifies their relative contributions to the daytime and nighttime UHI intensities using a mesoscale atmospheric model that includes a single-layer urban canopy model. A midlatitude city and summertime conditions are considered. Three main causative factors are identified: anthropogenic heat, impervious surfaces, and three-dimensional (3D) urban geometry. Furthermore, the 3D urban geometry factor is subdivided into three subfactors: additional heat stored in vertical walls, radiation trapping, and wind speed reduction. To separate the contributions of the factors and interactions between the factors, a factor separation analysis is performed. In the daytime, the impervious surfaces contribute most to the UHI intensity. The anthropogenic heat contributes positively to the UHI intensity, whereas the 3D urban geometry contributes negatively. In the nighttime, the anthropogenic heat itself contributes most to the UHI intensity, although it interacts strongly with other factors. The factor that contributes the second most is the impervious-surfaces factor. The 3D urban geometry contributes positively to the nighttime UHI intensity. Among the 3D urban geometry subfactors, the additional heat stored in vertical walls contributes most to both the daytime and nighttime UHI intensities. Extensive sensitivity experiments to anthropogenic heat intensity and urban surface parameters show that the relative importance and ranking order of the contributions are similar to those in the control experiment.

LCZ scheme for assessing Urban Heat Island intensity in a complex urban area (Beirut, Lebanon)

Urban Climate ◽  
2021 ◽  
Vol 37 ◽  
pp. 100846
Author(s):  
Nada Badaro-Saliba ◽  
Jocelyne Adjizian-Gerard ◽  
Rita Zaarour ◽  
Georges Najjar
Keyword(s):  
Urban Heat Island ◽  
Urban Area ◽  
Urban Heat Island Intensity ◽  
Heat Island ◽  
Urban Heat

scholarly journals A High-Resolution Monitoring Approach of Canopy Urban Heat Island using Random Forest Model and Multi-platform Observations

2021 ◽  
Author(s):  
Shihan Chen ◽  
Yuanjian Yang ◽  
Fei Deng ◽  
Yanhao Zhang ◽  
Duanyang Liu ◽  
...  
Keyword(s):  
High Resolution ◽  
Random Forest ◽  
Urban Heat Island ◽  
Air Temperature ◽  
Anthropogenic Heat ◽  
Heat Island ◽  
Model Framework ◽  
Rapid Urbanization ◽  
Urban Heat ◽  
The City

Abstract. Due to rapid urbanization and intense human activities, the urban heat island (UHI) effect has become a more concerning climatic and environmental issue. A high spatial resolution canopy UHI monitoring method would help better understand the urban thermal environment. Taking the city of Nanjing in China as an example, we propose a method for evaluating canopy UHI intensity (CUHII) at high resolution by using remote sensing data and machine learning with a Random Forest (RF) model. Firstly, the observed environmental parameters [e.g., surface albedo, land use/land cover, impervious surface, and anthropogenic heat flux (AHF)] around densely distributed meteorological stations were extracted from satellite images. These parameters were used as independent variables to construct an RF model for predicting air temperature. The correlation coefficient between the predicted and observed air temperature in the test set was 0.73, and the average root-mean-square error was 0.72 °C. Then, the spatial distribution of CUHII was evaluated at 30-m resolution based on the output of the RF model. We found that wind speed was negatively correlated with CUHII, and wind direction was strongly correlated with the CUHII offset direction. The CUHII reduced with the distance to the city center, due to the de-creasing proportion of built-up areas and reduced AHF in the same direction. The RF model framework developed for real-time monitoring and assessment of high-resolution CUHII provides scientific support for studying the changes and causes of CUHII, as well as the spatial pattern of urban thermal environments.

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