Impact of green roof on micro climate to reduce Urban Heat Island

Heat island forms when the temperature difference between urban area and rural area temperature is significant. It can occur any time year-round during the day and night (Oke, 2003). The temperature differences are often largest during calm, clear evenings because rural areas cool off faster at night than cities. Surface materials used in urban areas retain much of the heat stored in roads, buildings and other structures (Weng, 2004). This study investigates the UHI phenomenon and outdoor thermal environment at micro scale level in Mumbai metropolitan area in India by using ENVI-met software. It also studies measures to mitigate the effect of heat island impact by various percentages of greening the study areas to come up with recommendations on the extent of such mitigation measures that need to be undertaken. Vertical walls and also dense urban vertical cover or forests are recommended to reduce the effect of Urban Heat Island Effect (Gunawardena et al., 2017).