Assessing the Impact of Wind Conditions on Urban Heat Islands in Large Australian Cities
Mustansiriyah University, Iraq
Swinburne University of Technology, Melbourne, Australia
Adam Mickiewicz University, Poland
Centre for Urban Research, RMIT University, Melbourne, Australia
Ilham Al-Obaidi   

Mustansiriyah University, Iraq
Data publikacji: 02-12-2021
J. Ecol. Eng. 2021; 22(11):1–15
Urban regions are well known to be warmer than the outlying surrounding regions: this phenomenon is termed an urban Heat Island (UHI). Depending upon its severity, an UHI can influence human health, the condition of urban vegetation, as well as air and water quality leading to a general decline in the living conditions of the affected urban environments and residents. Some studies have shown that prevailing weather conditions, like wind patterns, can influence UHI magnitudes. These studies suggest that wind speeds may be inversely related to UHI magnitude. However, long-term and high frequency weather and temperature measurements are exceedingly rare, so the exact nature of the relationship between wind speeds and directions as well as UHI magnitudes remain unknown. In order to address this problem, this study investigates howUHImagnitudes in five Australian cities affect wind speed and wind direction. The results of this study revealed that urban–non-urban temperature differences are most pronounced under calm weather conditions. The UHI intensity weakened as wind velocity increased: strong significant negative correlations were found between the mean UHI intensity and mean wind speed magnitudes. The results show that the greatest UHI intensities are recorded when wind is weak (less than 2 ms-1), while the lowest magnitudes are found when wind speeds exceed 6 ms-1. Further, the results show that the critical wind speed value, above which the strength of the UHI is considerably minimized, is around 4-5 ms-1. In addition, the study shows that wind direction in each city is a critical driver factor that determines the intensity of the UHI effect. When winds originate from dry environments, they favour high UHI intensities at all wind speeds, while the winds from the ocean side of coastal cities tend to cool urban regions, reducing UHI intensities or even promoting the urban cool island formation.