Modelling the backscattering coefficient of salt-affected soils using AIEM model

摘要

Soil salinity principally affects soil properties, environment and productivity of agricultural areas for developing countries. Currently, no inversion algorithms exist for directly determining soil salinity from microwave remote sensing data, but we hope to draw on the soil moisture retrieval algorithms to obtain soil salinity amount. So the effect of moisture and salinity on dielectric constant and the backscattering coefficient (VV and HH polarization mode) are simulated using the advanced integral equation model (AIEM) combined with the modified Dobson dielectric mixing model. The results indicate that real part of dielectric constant decreases with soil salinity content, however, the imaginary part increases with it especially for the high moisture regions. Both soil moisture and salinity affect the VV and HH polarization backscattering coefficient, with moisture the backscattering coefficient increases evidently, but with soil salinity backscattering coefficient increase at the small moisture region and it remains unchanged for the HH polarization or expresses the weakly downward tendency for W polarization respectively at the high moisture region. Moreover, the simulation results also suggest that VVor HH polarization can be used to retrieve soil salinity for the soil with low moisture (<0.3 cm~3·m~(-3)).