Study of urban warming in Chandigarh union territory, India: geospatial approach

Abstract

Increasing population density leads to higher building density and significant alterations in urban land use and land cover (LULC). Particularly, the expansion of built-up areas substantially influences land surface temperature (LST), contributing to the formation of urban heat islands (UHI). This study aims to determine the relationship between UHI formations and the presence of urban grey infrastructure versus green spaces over a 22-year period. The research involves developing maps of NDVI, NDBI, LULC, LST, UHI, and UTFVI using Landsat 4–5 TM and 8–9 OLI/TIRS satellite images for the years 2000 and 2022. Data processing was conducted using ArcGIS Desktop and ERDAS Imagine, with results assessed in MATLAB and Excel. The findings reveal significant changes in NDVI, NDBI, and LST in the study area over time, highlighting the UHI effect characterized by a temperature increase of approximately 5–6 °C. Conversely, the UTFVI study indicated an improvement in ecological conditions in some areas by 2022 due to increased NDVI. This study underscores the importance of comprehensive land-use strategies to promote a sustainable and climate-resilient future for Chandigarh by mitigating the UHI effect through the enhancement of green vegetation in regions with rising LST. Furthermore, the LULC mapping accuracy is tested with an outstanding precision of 95%.