Indirect Method of Identifying Fluoride (F) Affected Soil

The study indirectly identified fluoride (F) stressed areas using existing multispectral indices. The regions where stress-affected plants were identified from the plant senescence reflectance index (PSRI). The areas affected by salinity were identified from the modified salinity index (MSI). The spatial correlation was carried out between PSRI and SI to determine the influential factor for crop stress. The places with a negative correlation were found to have low salinity and high plant stress. According to the field investigation, the places with a negative correlation prevail with high F content in the soil. The results of remote sensing simulations have shown a high correlation (
$\mathrm{R}^{2}=0.9$
) and an overall accuracy of 90% with respect to ground F measurement. The analysis quantified around 880 sq.km area as F affected area.