Quantifying urban heat island using multiple data sources for planning a sustainable city in an arid climatic zone

The effects of urbanization on cities have been well documented around the world. The term "urban heat island" (UHI) refers to one of several consequences of urbanization. The intensity of UHI is quantified in Muscat and its neighbouring sub-cities during 2019-2020. These sub-cities have seen a rapid increase in inhabitants over the last decade ranging between 15.1 and 107.4%. Land surface and air temperature were measured to quantify UHI under different land use types. The study found that all the selected sub-cities have shown variations in UHI influenced by land surface temperature, which ranged from 0.24 to 6.74 degrees C. In general, the measured land surface temperature indicated maximum UHI values in both winters (UHI = 6.74 degrees C) and summer (UHI = 5.07 degrees C) seasons. While measured air temperature shows the formation of UHI in the winter season in all sub-cities with a maximum value of 4.65 degrees C. In contrast, in summer it occurs only in two sub-cities with values of 0.65 degrees C and 4.17 degrees C at the night. Analyzing meteorological and remotely sensed data emphasizes findings from field measurements with the formation of UHI in all sub-cities in winter with values ranging between 0.43 and 5.37 degrees C, meanwhile, its absence in most sub-cities during the summer. There are significant differences (P < 0.05) among the land use types with the lowest mean value in greenery space (21.70 +/- 0.59 degrees C). The mean land surface temperature with respect to land cover type follow the pattern of road > pavement > bare soil > vegetation except for the daytime in summer, clearly demonstrates the influence of vegetation in reducing UHI effect. This was also verified by the evidence that the air temperature above the vegetation cover were reduced by 1.3 to 2.1 degrees C and 2.6 to 3.1 degrees C during day and nighttime respectively. Additionally, there was a moderate correlation between land surface and air temperature in the winter (R-2 = 0.58) compared to the summer (R-2 = 0.29). Quantification of UHI is important for city planners to ensure sustainable urbanization and take into account land use and land cover changes in the future to build resilient cities.