Optimizing Urban Morphology to Mitigate Urban Heat Islands: A Case of Hyderabad

Abstract

Urbanization, changing urban geometries and surfaces, forms hotspots called urban heat islands (UHI). Several studies have been conducted to understand its cause, intensity, and impact on urban microclimate. The current study attempts to assess the impact of the urban morphology of multiple residential urban blocks in Hyderabad on urban heat island intensity. The study explores the possibility of UHI mitigation by modifying morphology constructed on policy measures like zoning regulations. Six urban residential blocks under the city's peri-urban belt are studied for their morphology and microclimate. Field study, 2D building database, and satellite imagery are used to develop urban built geometry of the blocks. The microclimate, i.e., air temperature and wind speed, is determined using a numerical model, ENVI-met. The simulated microclimate data is used to compute UHI intensity based on reference climate data of an urban block at the time of the investigation. The urban morphology is then modified to reduce UHI intensity. The modified urban geometry with a significant reduction in UHI intensity is used to suggest planning/design recommendations through zoning regulations. Further, the paper reinforces the significance of the correlation between UHI and urban morphology, which can be regulated through zoning.