Expansion of Urban Impervious Surfaces in Lahore (1993-2022) Based on GEE and Remote Sensing Data

Impervious surfaces are an essential component of our environment and are mainly triggered by human developments. Rapid urbanization and population expansion have increased Lahore's urban impervious surface area. This research is based on estimating the urban imper-vious surface area (UISA) growth from 1993 to 2022. Therefore, we aimed to generate an accurate urban impervious surfaces area map based on Landsat time series data on Google Earth Engine (GEE). We have used a novel global impervious surface area index (GISAI) for impervious surface area (UISA) extraction. The GISAI accomplished significant results, with an average overall accuracy of 90.93% and an average kappa coefficient of 0.78. We also compared the results of GISAI with Global Human Settlement Layer-Built and harmonized nighttime light (NTL) ISA data products. The accuracy assessment and cross-validation of UISA results were performed using ground truth data on ArcGIS and GEE. Our research findings revealed that the spatial extent of UISA increased by 198.69 km2 from 1993 to 2022 in Lahore. Additionally, the UISA has increased at an average growth rate of 39.74 km2. The GISAI index was highly accurate at extract-ing UISA and can be used for other cities to map impervious surface area growth. This research can help urban planners and policymak-ers to delineate urban development boundaries. Also, there should be controlled urban expansion policies for sustainable metropolis and should use less impermeable materials for future city developments.