Recognition of Rocky, Sandy and Calcareous Soils from the Surface in the South of the Volga Upland (Volgograd Oblast) from Satellite Images

The purpose of the work is to recognize rocky, sandy and calcareous soils from the surface using a multi-zone satellite image in the south of the Volga Upland in the Volgograd oblast. The object of the study was the Volga-Don irrigation system, within the experimental station “Oroshayemaya”. The recognition was carried out by the spectral brightness of the space image of the bare soil surface in 4 bands. The most ranked values among them were marked in B1 band. Three catenae were studied, along which field information about soils was obtained. It was found that the greatest brightness (B1) is created by stones, rubble and sand scattered on the surface (970–1100 units). This is followed by: surface-effervescent soils with strongly rubbled rocks at a depth of about half a meter and sandy loam soils (710–830 units), with effervescence from the soil surface on mottled loams and sands of about half a meter (up to 700 units), and surface-calcareous soils, where mottled loams and sands occur deep (more than 70 cm), or with the absence of calcareous material in the surface horizons, with a brightness of 560–670 units. The use of this approach will enable more detailed recognition of soils on the basis of satellite imagery materials and separate surface-rocky and sandy soils from surface-calcareous soils, which are displayed in images with a similar spotty heterogeneity, but differ in spectral brightness.