Quantifying diurnal and seasonal variation of surface urban heat island intensity and its associated determinants across different climatic zones over Indian cities

2021 ◽  
pp. 1-27
Author(s):  
Pir Mohammad ◽  
Ajanta Goswami
2020 ◽  
Author(s):  
Pir Mohammad ◽  
Ajanta Goswami

<p>Surface urban heat island (SUHI) is a major anthropogenic alteration of the urban environment, and its geospatial pattern remains poorly understand over a larger area. SUHI has been investigated in many regions of the world, but the complete understanding of its dynamics over a large area, across different climatic regime is missing, especially in India. In this study, Moderate Resolution Imaging Spectroradiometer (MODIS), land surface temperature (LST) data from 2003 to 2018 is used to investigate the diurnal, seasonal, and interannual variations in the SUHI intensity, difference in urban and rural LST, across 150 major Indian cities situated over different climatic zones. The result shows the presence of surface urban heat/cool island depending upon climatic zones and seasons. The general sequence of mean SUHI intensity observed over different climatic zones is winter nighttime>summer nighttime>winter daytime>summer daytime. During the daytime, the cities situated in tropical monsoon (Am) (coastal cities), hot steppe (BSh), and hot desert (BWh) climatic zone shows a cool urban island, especially in summer. The nighttime SUHI intensity showed less obvious seasonal variations and always showed positive heat intensity. The cities situated in the humid subtropical (Cwa) zone, which is mainly Indo-Gangetic plain and a major hub of the Indian population, shows strong daytime as well as nighttime SUHI intensity. Mann-Kendall and Sen’s slope estimator test are used to detect the long-term trend of SUHI intensity in different climatic zones. The results show the presence of a decreasing trend in most of the cities during the daytime as compared to nighttime in both the summer/winter season.</p>


2018 ◽  
Vol 56 (4) ◽  
pp. 576-604 ◽  
Author(s):  
Qihao Weng ◽  
Mohammad Karimi Firozjaei ◽  
Amir Sedighi ◽  
Majid Kiavarz ◽  
Seyed Kazem Alavipanah

2019 ◽  
Vol 46 (4) ◽  
pp. 2204-2212 ◽  
Author(s):  
Rui Yao ◽  
Lunche Wang ◽  
Xin Huang ◽  
Wei Gong ◽  
Xiangao Xia

Author(s):  
Tao Chen ◽  
Anchang Sun ◽  
Ruiqing Niu

Man-made materials now cover a dominant proportion of urban areas, and such conditions not only change the absorption of solar radiation, but also the allocation of the solar radiation and cause the surface urban heat island effect, which is considered a serious problem associated with the deterioration of urban environments. Although numerous studies have been performed on surface urban heat islands, only a few have focused on the effect of land cover changes on surface urban heat islands over a long time period. Using six Landsat image scenes of the Metropolitan Development Area of Wuhan, our experiment (1) applied a mapping method for normalized land surface temperatures with three land cover fractions, which were impervious surfaces, non-chlorophyllous vegetation and soil and vegetation fractions, and (2) performed a fitting analysis of fierce change areas in the surface urban heat island intensity based on a time trajectory. Thematic thermal maps were drawn to analyze the distribution of and variations in the surface urban heat island in the study area. A Multiple Endmember Spectral Mixture Analysis was used to extract the land cover fraction information. Then, six ternary triangle contour graphics were drawn based on the land surface temperature and land cover fraction information. A time trajectory was created to summarize the changing characteristics of the surface urban heat island intensity. A fitting analysis was conducted for areas showing fierce changes in the urban heat intensity. Our results revealed that impervious surfaces had the largest impacts on surface urban heat island intensity, followed by the non-chlorophyllous vegetation and soil fraction. Moreover, the results indicated that the vegetation fraction can alleviate the occurrence of surface urban heat islands. These results reveal the impact of the land cover fractions on surface urban heat islands. Urban expansion generates impervious artificial objects that replace pervious natural objects, which causes an increase in land surface temperature and results in a surface urban heat island.


2018 ◽  
Vol 624 ◽  
pp. 262-272 ◽  
Author(s):  
Huidong Li ◽  
Yuyu Zhou ◽  
Xiaoma Li ◽  
Lin Meng ◽  
Xun Wang ◽  
...  

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