A thermal infrared remote sensing approach for estimating soil porosity

Porosity is a significant property of soil, yet an elusive parameter to retrieve from remote sensing data. Here, an empirical relationship between soil water contents and infrared emissivity is employed for porosity mapping. The assumption is that by deriving the soil water content at saturation point, soil porosity could be indirectly measured. Through time series analysis of daytime ASTER thermal data acquired during the wet seasons, a porosity map was generated over a test site in the Qom area (Iran) and qualitatively verified using field observations. The approach was shown to yield reasonable results over exposed soil and lithologic outcrops. This approach can potentially provide an effective tool for topsoil porosity mapping at local to regional scales.