Some Specifics in Using Optical Properties of Soil Surface for Moisture Detection.

The research was aimed at the analysis of relationship between the soil surface spectral reflectance and the moisture content in soil samples as the basis for moisture detection based on remote sensing data. By the example of nine samples from the arable horizons of podzolized chernozem, gray forest and soddy-podzolic soils analyzed in laboratory, the relationship was assessed between the spectral reflectance of soil surface in the visible spectral band detected with the HandHeld-2 spectroradiometer and the moisture content in samples. It was found that changes in the soil moisture content induce synchronous changes in the integral reflection in the visible spectral band only in a rather narrow interval of moisture, being specific for different soils. Variation in soil moisture content beyond these intervals does not change the spectral reflectance of soil surface. The results obtained prove that most of the satellite survey data in the optical range register the dry state of open soil surface, though the arable horizon proper may be rather moist. These regularities should be taken into account when developing satellite techniques for prompt monitoring of soil moisture by the remote sensing data obtained within the optical range of electromagnetic waves. [ABSTRACT FROM AUTHOR]