Impact of Green Cover on Urban Heat Island: A Comparative Assessment of Two Major Cities of North-West India

The cities all around the world have observed rapid urbanization which caused the changes in landscape at the expense of productive land. Urban change, which is a result of the urbanization process, has emerged out as a global issue, and it is a major contributor to climate change. One of the measures to mitigate the climate change is increasing green cover in the urban areas. A study was carried out to investigate the effects of green cover on the surface urban heat island in two Indian cities of north-west India using satellite remote sensing: the smart city Ludhiana in Indian Punjab and the city beautiful Chandigarh. Landsat Operational Land Imager (OLI) sensor data (Landsat 8) of May 2021 was used to identify the green cover and built up, and retrieval of land surface temperature (LST) in both the cities. The LST was higher in Ludhiana city than Chandigarh. The LST in Chandigarh was higher in outskirts of the city with less vegetated and unplanned areas than planned core areas of city. In Ludhiana, LST was higher in the south-east direction of the city. The normalized difference vegetation index (NDVI) values were higher in Chandigarh city than Ludhiana city, but NDBI values were higher in Ludhiana city than Chandigarh city. The relationships among LST, NDBI, and NDVI showed a positive correlation with NDBI and negative correlation with NDVI. The urban heat island (UHI) was higher in Ludhiana city than Chandigarh city due to variations in green cover. These results are useful for framing policies by government on the building material and reflective paints along with awareness of people by constructing green roofs to counteract the effect of UHI on human health and sustainable development.