ROLE OF URBAN GREEN INFRASTRUCTURE (UGI) IN REDUCTION OF URBAN HEAT ISLAND (UHI) EFFECT IN CITIES

Abstract

The urbanization of major cities gets further accelerated in the near future and due to this the environmental parameters like atmosphere, biosphere, hydrosphere, and lithosphere also gets drastically affected which in turn affect the Global Climate Change (GCC). It refers to the long-term shift in temperature and weather pattern. It is a prime major of concern in the present scenario and many countries in the world are adopting the sustainable ways to deal with it. From many studies, it has been found that the carbon-di-oxide concentration drives global climate change and is indirectly responsible for risks related to other climate indicators such as rise in temperature, change in rainfall pattern, to list a few. The rise in temperature in the cities due to urbanization causes the heat island effect. In this, the cities tend to experience higher temperatures than its proximate neighboring rural or non-urban area. As we know, the capital city of India i.e., New Delhi is known for its inordinate heat conditions during summer months during which the highest day time temperature on an average rise to 46 degrees Celsius and the night-time temperature falls to 37 degrees Celsius as per the IMD (Indian Meteorological Department) data maintaining a temperature difference of 15 degrees Celsius with the nearby rural areas causing the effect of urban heat island in the city. For this study, three-dimensional urban microclimate simulations were carried out to reduce the effect of UHI. The study area chosen is the Academic Block of Delhi Technological University. The parameters used were the percentage of green cover surrounding the site, atmospheric temperature, speed of wind, orientation of the building and other factors such as impervious surface and anthropogenic conditions. From the study, it was found that by the increment of vegetation in the vicinity by means of green roofs and more roadside cover the value of maximum temperature decreased by 0.19 degrees Celsius and the value for minimum temperature decreased by 0.47 degrees Celsius.