Assessment of land-use land-cover dynamics and urban heat island effect of Dehradun city, North India: a remote sensing approach

Urbanisation is a crucial issue for urban planners and researchers worldwide, especially in South Asia, where rapid urbanisation has led to several negative impacts on the environment, economy, and people. Land-use change is one of the associated problems of urbanisation that can lead to an increased land surface temperature (LST) and surface urban heat island (SUHI) effect. This study aimed to investigate the impact of urbanisation on the local climate in Dehradun city, India, by analysing the relationship between land-use and land-cover (LULC) change, LST, and the UHI effect. Geospatial analyses were carried out using Landsat multispectral data from 1996 to 2019. LULC classification using a machine learning-based supervised classification technique, support vector machine and LST were derived using a mono-window algorithm, and the surface UHI (SUHI) effect was quantified using the urban thermal field variance index (UTFVI). The study found that the built-up cover increased by 28%, resulting in seasonal LST increases of 7 & DEG;C and 2 & DEG;C for the summer and winter seasons, respectively. The findings show that the regions with no SUHI effect reduced significantly from 42.59% in 1996 to 21.55% in 2019, while the strongest SUHI regions increased from 0% in 1996 to 10.7% in 2019. This study contributes to delivering scientific information on the impact of urbanisation and land-use change on the urban thermal environment of the city, which may be useful for policymakers in developing appropriate strategies to reduce the impact of urbanisation on the environment and to improve the quality of life for citizens.