Cologically stressed zones. In yet another study, Bokaie et al. [27] employed Landsat Thematic Mapper (TM) data to map the SUHIs of Tehran in 2010 and investigate its partnership with all the Land Use/Land Cover (LULC) map and Normalized Difference Vegetation Index (NDVI) image. They reported full compliance between typical LST values and LULC classes as well as a moderate adverse correlation between LST and NDVI values, which was also in accordance with other studies [28]. Likewise, quite a few other scholars incorporated multi-temporal remote sensing data to map the spatio-temporal variability of SUHI patterns [291]. For example, de Faria Peres et al. [32] explored the trend of SUHI evolution over 30 years and compared the outcomes with LULC maps. The results suggested that the main cause for the two C rise of SUHI intensity in Rio de Janeiro was linked with urban expansion because of the important development of LST in urban regions. GYY4137 manufacturer Additionally, Nadizadeh Shorabeh et al. [33] employed five Landsat pictures involving 1985 and 2017 to study the SUHI variations in Tehran. Later, they applied the Cellular Automata-Markov (CA-M) and Artificial Neural Networks (ANN) model to predict the LULC of 2033 to model the future surface SUHI intensity. Tehran is definitely the largest and most populated metropolitan in Iran, and as the central hub (i.e., political, economic, DNQX disodium salt Cancer social) with the country, it has skilled massive population growth and extensive urbanization [34]. Quite a few studies had been carried out to study and monitor SUHI and LST variations all through the city [351]. Even so, the SUHIs have been nonetheless extracted by a single image in these studies, to ensure that they could not be regarded as as a thorough description of annual or seasonal SUHI. This is due to the fact Using timeseries remote sensing photos produces a far more detailed and persuasive understanding of the complexity of SUHI in comparison with analyzing this phenomenon with limited images [42,43]. Additionally, the thermal environmental condition of Tehran has not been analyzed in earlier research. Towards the ideal of our know-how, no comprehensive study was devoted to investigating 3 decades of SUHI and UTFVI patterns in Tehran via time-series data. In addition, Tehran is suffering from severe air pollution [44], and hence, itRemote Sens. 2021, 13,3 ofis essential to appraise the partnership among air pollutants and SUHI intensities, which has not been carried out in Tehran. In reality, the contradictory reports with the partnership involving air pollutants and SUHI intensities in distinctive locations necessitate performing these analyses for Tehran [458]. These investigations would present profound info about the environmental situation of Tehran, leading to powerful decision-making for any sustainable city. Contemplating the foregoing, this paper aims to extend preceding studies and give relevant details from new aspects by investigating the spatio-temporal variability of SUHI and thermal comfort and appraising the relationship of SUHI intensities and air pollutant concentrations in Tehran. Especially, the present study follows three objectives: (1) Investigating the SUHI changes over the past 3 decades and examining its intraannual variations, giving the SUHI magnitudes and footprints; (two) exploring the spatial alterations of the environmental condition of Tehran more than the final three decades employing the UTFVI; and (three) identifying the connection involving SUHI intensities and distinctive air pollutants concentration for Teh.
