Rapid urbanization and associated impacts on land surface temperature changes over Bhubaneswar Urban District, India.

Urban settlements are the socio-economic drivers of human community. However, rapid urban expansion during recent times has a profound effect on regional as well as global rise in temperatures. Remote sensing is a powerful tool to monitor and quantify the expansion of urban built-up area and assess its effects on regional heating. Landsat-derived Land Use Land Cover (LULC) maps have shown a very rapid urbanization in Bhubaneswar, a tier-2 city and the capital of Odisha in the eastern part of India, almost doubling over the last 15 years. Our study on the effects of urbanization reveals that during the period of 2003-2017, the built-up area in the urban district of Bhubaneswar has increased by about 77% at the cost of natural vegetative cover and agricultural/fallow land. This affects the behavior of several climate variables over the urban centers with a clear distinction in these variables observed between the urban and surrounding rural settlements. Land surface temperature (LST) derived from the thermal bands of Landsat satellites at a spatial resolution of 30 m is used for the analysis over the area of interest. The Bhubaneswar airport (urban reference) has shown an increase in mean summer LST by 8% over the study period of 15 years, and 9.84% in LST in the last 5 years from 2013 to 2017 alone. From the present study, it is inferred that it is essential to adopt a sustainable approach for any urban growth to restrain its effect on urban temperature rise.