Geospatial assessment of land surface temperature in Nagpur, India: an impact of urbanization

Temperature is one of the factors which affects the meteorological phenomenon prevailing in an urban area and ultimately leads to climate change and global warming. Measurement of surface temperature with conventional temperature sensors is tedious, has single point value and expensive. Satellite data of 2005, 2008, 2010 and 2016 are used to assess the land use land cover (LULC) and to measure the land surface temperature (LST) during the hottest month of May in Nagpur city, India. Based on the image analysis, it is observed that there is an increase in the average temperature from 40.0 to 44.6 ºC. This may be due to an increase in built-up area from 55.5 to 69.8% during 2005 to 2016, respectively. It has also been revealed that the outskirts of the city are hotter than the central portion of the city as there is more barren land on the outskirts. Results were compared to ambient temperature sensor that showed good agreement between temperature retrieved from satellite and temperature sensor. The study suggests that urban areas should be developed intermixed with vegetation and plantation and provisions of green belt along the city roads, highways and ring roads. Based on LST and LULC analysis, a green belt of 30 m along both sides of the road would lower the road temperature by 9.3 ºC from existing temperature of 44.7 ºC. This would help in lowering down the average temperature of the city.