Estimates of change in surface meteorology and urban heat island over northwest India: Impact of urbanization

Abstract Change in land-use and land-cover (LULC) at local, regional, and global scales is one of the fundamental causes of global climate change. The present study aims to quantify the impact of LULC changes that occurred in a decade on surface meteorology and the urban heat island intensity over northwest India using the Weather Research and Forecasting (WRF) model. The analysis focuses on eight major metropolitan cities of northwest India, which witnessed the highest expansion of urban areas. Satellite-based LULC over northwest India suggests a significant increase in built-up/urban settlement areas over all the growing cities in the decade. Simulations of two months (January and May) for the year 2016 using LULC corresponding to 2016 and 2006 are used to estimate the impact of change in LULC over the urban locations during winter and summer months. Results showed a significant increase in near-surface temperature (3-5 °C) and decreased humidity (up to 10%) over the newly formed urban areas with more substantial variations during winter. Besides, there is an increase in the areas of higher temperature zones due to urban expansion. Night-time averaged UHI intensity is in the range of 2.4–5 °C during winter and 0.6–2 °C during 2016 over the cities considered.