Classification of sediments on the exposed banks of the Oka River using granulometric composition; Опыт классификации отложений на эрозионных берегах реки Оки по их гранулометрическому составу

An overview of the lithological diversity of soils at the bottom of the Oka River valley, particularly its Ryazan section, was performed. In a semi-stationary study of the geomorphic processes, a total of 231 soil samples were collected from the channel slopes with distinct erosion patterns. The geological data were supplemented by topographic mapping with unmanned aerial vehicles (UAVs), during which the boundaries of sedimentary facies on the exposed banks of the semi-stationary areas were identified and delineated in the GIS products. Granulometric analysis by the hydraulic and sieving methods, along with the analysis of the distribution of coarse clastic material within the geological strata, was carried out to determine the mechanical composition of soils on the Oka River banks. Based on the ratio of sand, silt, and clay measured through clustering and machine learning, the fine clastic soils were classified into four to five homogeneous groups. Four granulotypes of floodplain sections, each with a distinct occurrence of glacial and alluvial facies, can serve as a valuable geological and geomorphological element for applied modeling in regional estimates of horizontal channel deformation rates. © 2025 Elsevier B.V., All rights reserved.