Impact of urban Form on outdoor thermal comfort in the Tropical city of chennai

Abstract

The population in urban areas in most cities around the world, newlineis constantly increasing. In India, this rapid growth has compelled local newlinegovernments to revise planning regulations on a regular basis, with the newlinegoal of providing urban living more affordable. As a result, the built newlinedensity was increased without considering the impact of such changes newlineon human thermal comfort. The term quotUrban Heat Islandquot refers to the newlinedifference in atmospheric conditions between urban regions and its newlinefringe areas, which is mostly due to modifications in the urban built newlineform. Outdoor microclimate is one of the significant factors that newlinedetermines the quality and usage of outdoor spaces. Therefore, the main newlineaim of this research is to evaluate the severity of heat island in Chennai newlinealso assess the relationship of the urban built form and development newlineregulations as well as its impact on outdoor thermal comfort. newlineThe research has three objectives: first, to determine the newlinevariance in urban heat island intensity over time using the traverse newlineapproach. Second, examine the performance of an urban newlineneighbourhood s outdoor thermal comfort by determining the newlinerelationship between urban built form and microclimate parameters. newlineThird, to understand the relationship between development regulations newlineand urban morphology, as well as their impact on microclimate newlineparameters and outdoor thermal comfort. newlineA traverse survey was conducted in the Chennai Metropolitan newlineArea to determine the intensity of heat island. The study confirms the newlinepresence of UHI in Chennai, with a winter temperature of 4.5°C and a newlineix newlinesummer temperature of 2.5°C. Eight stationary locations in a mixed-use newlineneighbourhood with different urban built morphology were selected for newlinethe study to explore the spatial distribution of climate parameters using newlineENVI-met simulations. The study reveals a daytime air temperature newlinedifference of 5.7oC between the eight locations at the micro-scale level. newlineThe study found a maximum PET difference of 14.22°C. and a newlinemaximum mean radiant temperature difference of 27.7°