Application of microwave remotely sensed surface soil moisture for estimation of sub-surface soil hydraulic properties

Multi-temporal microwave remote sensing techniques have been employed to obtain information on surface soil moisture dynamics during June 10-18, 1992 in the Little Washita watershed, Oklahoma. Analysis of remotely sensed data in conjunction with soils map revealed that changes in brightness temperature and soil moisture hold a direct relationship with soil texture. Areas identified by loam/silt loam are characterized by higher changes of total soil moisture and those of sand/sandy loam soils by remarkably lower amounts of change. Detailed study yielded valuable information on soil physical properties (soil texture) and saturated hydraulic conductivity (K_sat). The Root Zone Water Quality Model has been employed to simulate soil water redistribution during the dry down period, and therefore to estimate profile soil properties. Results provided good relationships between surface soil moisture dynamics and profile K_sat values. It follows that temporal variability of surface soil moisture can be used as indicators of both surface and sub-surface soil properties. These findings have potential application of microwave remote sensing of soil moisture to obtain quick estimates of spatial distributions of soil properties for parameterization of mesoscale hydrologic and general circulation models