5.3 UHI Classification and Human Thermal Comfort in MMA

Figure 18. Changes in areas of UHIs, heat sink, vegetation and built-up from 2000 to 2017.

Figure 19. UHI classification within MMA during August 2000.

5.3 UHI Classification and Human Thermal Comfort in MMA

There are several health risks associated with high temperatures and exposure of human body to hot and humid environment reduces its ability to cool itself eventually resulting in heat related illness. The UHI effect supplements these risks within cities. The UHI classification based on Urban Thermal Field Variance Index (UTFVI) has been carried out to know where high intensity UHIs exist within the MMA. The heat index classification based on National Oceanic & Atmospheric Administration (NOAA) heat index chart have also been carried to look into the urban quality of life in terms of thermal comfort within MMA. The strongest category UHI areas during summer in 2000 were in the south-west side of MMA and the built-up area had UHIs ranging from moderate to stronger categories.

The heat zones within MMA during summer of 2000 were found to be following the pattern of UHI categories as hot zone were consisting of moderate to strongest UHI category areas. The very warm and normal zones were found to be consisting of weak and normal UHI categories respectively.

During summer of 2010, UHI stronger and strongest categories cover almost 60% of the total MMA whereas moderate and strong UHI categories cover 15% of the area.

Temperature Degrees Celsius

Figure 20. Urban quality of life in terms of thermal comfort based on NOAA heat index classification during August 2000.

Figure 21. UHI classification within MMA, August 2010.

The heat zones during the summer of 2010 almost followed the UHI categories pattern as hot zone was found to be in the strongest UHI areas whereas very warm zone covered moderate to strong UHI category areas within MMA.

During the summer of 2017, UHI strong and strongest categories were found to be covering vacant land and high-density built-up area. Moderate and strong UHI categories were in the low-density built-up areas

Temperature Degrees Celsius

Figure 22. Urban quality of life in terms of thermal comfort based on NOAA heat index classification, August 2010.

Figure 23. UHI classification within MMA, August 2017.