Thermal characterization of Ajmer City: Insights into urban heat dynamics

Abstract

Human development, urbanization, and ongoing environmental issues have led to environmental disturbances and climate changes in Ajmer, a crucial rest station for migrating birds. Congested and poorly planned urban areas, reduced vegetation cover, and increasing emissions from industries and automobiles all contribute to climate challenges. The rise in land surface temperature (LST) has led to the formation of urban heat islands (UHI). The goal of this research is to investigate UHI in Ajmer City, India. Using remotely sensed LANDSAT data and Geographic Information System (GIS), we analyzed LST and Normalized Difference Vegetation Index (NDVI) for the summer months (March to June) in Ajmer from 2015 to 2022, including the period when nationwide curfews were implemented due to Covid-19. The extraordinary measures taken to restrict human activities during the pandemic resulted in remarkable temporary declines in aerosols and atmospheric pollutants (NO2, CO, SO2, and PM) mainly due to restrictions on fossil fuel burning and transportation emissions. The analysis reveals that Urban LST was 312.07 K in 2019 and decreased to 308.228 K in 2020 due to the strict Covid-19 lockdowns. With the gradual easing of restrictions and resumption of human activities, LST slightly increased to 308.27 K in 2021 and further to 311.71 K in 2022. Researchers can now explore the effects of reduced surface vehicle heat and air pollution on LST and UHI intensity in Western Indian cities, providing valuable insights for urban planning and climate mitigation strategies.