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. Landsat8 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.