Investigating Surface Urban Heat Island (SUHI) Effect for a Hill City

Abstract

Urban Heat Island (UHI) along with Climate Change has created a new challenge for Urban Planners in terms of environmental sustainability. In composite climate its effect will be, ‘decrease in outdoor activity’ by urban dwellers and ‘surge in energy demand’ for thermal comfort. Urban Heat Island effect is a phenomenon when the ambient temperature of the urban areas is higher than their counterpart peri urban and rural areas. Ranchi, the capital city of Jharkhand once boasts to be the summer capital of Bihar is feeling the reels of hotness as reported by the older generation of the city. This research paper examines the Urban Heat Island effect in the district of Ranchi, Jharkhand, India using the accepted methodology of Land Surface Temperature (LST) using satellite images and application of Geographical Information System (GIS). Through findings it has been observed that the city of Ranchi is under the influence of Urban Heat Island. It has also been observed that the greener areas of Ranchi and presence of water bodies negates the effect of Urban Heat Island in some wards of Ranchi Municipal Corporation. Almost same Land Surface Temperature of Ranchi urban areas hovers to more of its Western and Southern part of the district. Through findings it has been observed that the urban areas of Ranchi (Ranchi Municipal Corporation) experience an average Urban Heat Island Intensity (UHHI) of around 1.6 degree Celsius as compared to its rural counterpart at around 10:12 AM for the year 2023. Earlier studies shows that, the core area of Ranchi used to be cooler in summer months and warmer in cooler months to its peri-urban counterparts. But recent studies show a different picture. Blue-green infrastructure of Ranchi, and rocky terrain in peri urban areas, which used to make the city core a cool-spot is showing negative results for the year 2023 and early 2024.