Seasonal Soil Salinity Detection Using Salinity Indices from Landsat 8 Satellite Images in El-Sharqiyah Governorate, Egypt

Abstract

Soil salinity is a major issue that causes land degradation, especially in arid regions which affects negatively on soil properties and reduces agricultural productivity. Remote sensing is an essential tool for detecting and monitoring salinity changes upon time. In this research an assessment was carried out to determine the best representative salinity index based on filed measurements of soil salinity in El-Sharqiyah governorate in the northeast of Egypt. The index was validated in accord with other field soil salinity data in term of total dissolved salts (TDS) measured through 3-years intervals in 2015, 2018 and 2021. Landsat-8 satellite images were used to calculate NDSI (Normalized Difference Salinity Index). Seven indices were used to determine soil salinity, where the best correlated index was based on 2015 field work and used to produce salinity map of the study area. The best correlated index on 2015 was validated upon data of 2018 and 2021. Finally, this approach led to the sensitivity of remote sensing to soil salinity and the ability of its indices for soil salinity predication.