Impact of Urbanization on Temperature Regime in Indian Subcontinent—A Case Study of Patna City

Land use change ranks as the second most significant human-made factor affecting climate, following greenhouse gas emissions. Patna is rapidly expanding cities in Bihar state. Urbanization caused substantial alterations in land use patterns in Patna, driven by its rapid urban growth and increasing population. Urbanization and population growth caused a rapid increase in built structures to cater the demand, which caused reduction in vegetation, water body, and wasteland cover, due to which land cover changed. Land cover change detection plays a vital role in identifying its impact on diurnal temperature range (DTR). To study the impact, land use/ land cover change map for the city is produced from Landsat images for the study area Patna during 1995 to 2023. The supervised classification method is used to identify substantial changes in vegetation cover during 1995 and 2023 as a result of changes in land use and land cover. Landsat image supervised classification shows a growth of 47.80 percent in built-up areas in the last 28 years in the city of Patna. The classified image also shows a consistent decline of 31.74 percent in vegetation cover over the period of 28 years. Urbanization-driven changes in land use and land cover have led to a significant decrease of 20.24 percent in the near-surface DTR, average decrease of 12.54 percent in maximum temperature and an increase of 75.68 percent in minimum temperature of the city. The study offers scientific insights into how urbanization and human activities are impacting the eco-environment of the city.