Change Detection in Land Surface Temperature After Construction of Pokhara International Airport using Remote Sensing

Abstract

This study quantifies the thermal environmental impact of Pokhara International Airport in Nepal by analyzing land surface temperature (LST) trends before and after its construction. Using the Google Earth Engine (GEE) platform, TerraClimate (1987-2025) and MODIS datasets are processed to perform a spatiotemporal analysis across two distinct periods from pre-construction (i.e., 1987-2017) and post-construction (i.e., 2018-2025) of Pokhara International Airport. The derived LST trends is validated through zonal analysis of urban heat island (UHI) intensity using urban (500 m, 1 km) and rural (2-4 km) buffers and correlated with a time-series analysis of the Normalized Difference Vegetation Index (NDVI). The results indicate a pronounced acceleration in warming following the airport’s construction, with the LST trend rising from 0.44◦C/decade in the pre-construction period to 2.53◦C/decade afterwards. Statistical validation via the Mann–Kendall test and Sen’s slope estimator confirmed a significant increasing trend (p < 0.001). This warming is coupled with a strengthening of the UHI effect, where the mean urban–rural LST difference increased from 0.5◦C to 1.34◦C, and a sustained decline in NDVI, signifying vegetation loss. The findings demonstrate that major infrastructure projects can rapidly alter local microclimates, exacerbating surface warming and UHI effects.