A SPECTRAL INDEX-BASED APPROACH FOR MAPPING SALT-AFFECTED SOILS USING SENTINEL-2 IMAGERY: A CASE STUDY OF FAISALABAD, PUNJAB, PAKISTAN

Abstract Salinity is a major issue in arid and semi-arid regions, affecting agricultural production and crop yield, leading to food scarcity in developing countries. However, the availability of data on salt-affected soils is hindered by resources and advanced technology. Pakistan's arid and semi-arid climate zone requires accurate management strategies due to the lack of salt-affected soil data. Advancements in GIS and remote sensing technology enable accurate monitoring of soil salinity. Thus, from June 2017 to June 2023, this study was designed to map and comprehend changes in salt-affected soils in tehsil Samundari and Faisalabad, Punjab, Pakistan. Sentinel-2 photos with a 10m resolution were used in this investigation. Land use land cover (LULC) maps for 2017, 2019, 2021, and 2023 were created by processing satellite pictures, calculating indices, and using supervised classification. The study's findings demonstrated that SAS's coverage area grew. There was a decrease in the amount of barren land, although it was more pronounced in Tehsil Faisalabad. However, because the land was no longer suited for agriculture and the contractors exploited it for commercial reasons, the build-up and grassland areas were expanded, increasing the build-up land. However, a rise in build-up land and salt-affected soils caused farmland to initially decline, although an improving trend in agriculture was noted in 2023. The study's findings, however, indicated that by determining the recent extent or expansion of these problematic soils, the application of GIS and RS technology can be very helpful in the successful execution of various management and reclamation strategies. Without this information, the situation would be extremely difficult and concerning for future generations.