SASI - Soil Adjusted Salinity Index

Soil salinity and ground surface morphology can directly or indirectly impact the stability of environments. Soil salinization is a major pedological problem related to several natural factors, and the topography appears to be important in understanding the spatial distribution of soil salinity. In Yahiaoui et al.  relationship between topographic parameters and soil salinity was analyzed. Also, a good relationship between the spectral bands and measured soil EC was found, allowing authors to define a new salinity index called soil adjusted salinity index (SASI). SASI showed a significant correlation with elevation and measured soil EC values. This index can be used alone or in comparison with other indices to estimate and spatialize salinity from remotely sensed imagery.

Formula:

Sentinel-2 Bands Formula: 

Other Salinity Indices formulas (for comparison): 

References

• Yahiaoui et al. (2015) Soil salinity prediction in the Lower Cheliff plain (Algeria) based on remote sensing and topographic feature analysis. Journal of Arid Land, 7, 794-805.