Active Remote Sensing for Saline Soils Mapping in Arid and Semi-Arid Environments

Abstract. Mapping of human induced or natural occurring saline soils using satellite remote sensing has been an active area of research in the past few decades. In particular in agricultural lands as saline soils negatively impact crop yield and plant growth. Within arid and semi-arid regions saline soils have adverse effects on urban structures, land surface subsidence, soil erosion and soil degradation. While most previous studies of mapping saline soils have focused on broad-band passive remote sensing data, there has been minimal exploration into the utilization of active radar remote sensing data, particularly Synthetic Aperture Radar (SAR). This research aims to bridge this gap by employing C-band Sentinel-1 data enhanced by the polarimetric analysis, to identify and map saline soils within arid and semi- arid environments. Preliminary results highlight the challenges of using active remote sensing in mapping saline soils. Relying on the correlations between electric conductivity measurements and with scattering entropy resulted in accuracies of only 17% and 15% using polarimetric anisotropy. Other soil parameters such as soil electric properties, and perhaps soil moisture would improve the detection of saline soils using SAR data. However, the incorporation of polarimetric SAR (PolSAR) techniques offers a new avenue for improving soil salinity mapping by leveraging the unique scattering mechanisms and dielectric properties of saline soils.