Salinity mapping using geopedologic and soil line approach

Salinization is the process of accumulation of soluble salts in the soils which may be caused by groundwater rise due to improper land use practices in dry lands. It is well known that salt concentration in soil has negative impact on crop growth which results in reduced crop yield. Thus it is necessary to timely detect the process for monitoring and combating purposes.

In order to map soil salinity in an efficient way a step-wise approach is proposed using remote sensing and topographic data. The area is first subjected to geomorphic analysis for which a stereo-model is generated using satellite data and digital elevation model derived from interpolating contours lines. The second step is application of band rotation technique to transform near-infrared and red spectral bands to derive soil line. Soil line minimizes vegetation influence while maximizing spectral response from bare soil. Soil line values were used to map soil salinity levels. For the purpose of validation soil line values were correlated with topsoil conductivity measurements. Geopedologic modeling gave overall view of the depth wherein salinization is active. This approach is simple and can be considered very efficient in mapping soil salinity.