Impact of ganga canal on thermal comfort in the city of Roorkee, India.

The rise in urban air temperature has forced the researchers to look for nature-based solutions to resolve the problem sustainably. Urban waterbody plays a multidimensional role in the well-being of the city by catering to its economical, ecological, and socio-cultural needs. It can offer a potential solution for urban heat attenuation, but its effect on outdoor thermal comfort is contentious in humid subtropical climate. This study investigates the thermal impact of waterbody on its surroundings in humid subtropical climate by adopting a human centric approach. Waterbody impact on ambient air temperature, PET, and UTCI are evaluated and compared for a better understanding of its thermal impact on nearby surroundings. This study employs a CFD-based simulation model Envi-met for microclimate analysis. The results show that a dynamic waterbody lowers the ambient air temperature during daytime in summer of its nearby surroundings in humid subtropical climate. Maximum cooling is observed in open mid-rise LCZ where the cooling impact range is 140 m with the amplitude of 2.59 °C and compact low-rise LCZ exhibits minimum cooling of the identified LCZs with the cooling impact ending 24 m from waterbody edge with amplitude being 0.131 °C in the study area. Air temperature, UTCI, and PET do reflect the same trend when moving away from the waterbody in large low-rise LCZ, but it decreases drastically in open mid-rise LCZ and is non-existent in compact low-rise. This result provides an insight on the impact of waterbody on thermal comfort in its surroundings in humid subtropical climate, thus assisting urban planners and designers in making context-specific holistic decision.