Monitoring of Erosion Processes on the Bank Slopes of the Oka River in Summer-Autumn Period

Abstract

The purpose is to determine the rate and volumes of erosion of soil strata on the banks of the Oka River by means of aerial photography and to identify prerequisites for local mobilisation of bank sediments. Materials and methods. We undertook an aerial survey of the steep banks of the Oka River during the low-water phase of the water regime. This was accompanied by soil sampling to determine particle size distribution and weight moisture content. We complied digital elevation models (DEMs), which made it possible to record manifestations of erosion. Inter relations between the intensity of relief-forming and soil properties and their spatial position on slopes were also identified. Results and discussion. It was found that the rates of erosion process are distributed relatively evenly along the slopes, the discrepancies between the erosion of soils of diff erent mechanical composition are statistically unreliable. Correlations between erosion rate and sediment properties and their hypsometric position showed weak relationships. Relief-forming was caused by diff erent in mechanism of occurrence, but similar in intensity processes. It is assumed that the fall fl ood produced a noticeable erosion of the lower parts of the slopes when their full moisture content was reached. In dry summer 2022, the leading geodynamic role was played by crumbling, morphologically expressed in the form of plumes on the fi nal DEMs. Conclusion. Application of geodetic methods of erosion control on the Oka River channel ledges allowed us to register and quantitatively analyze even small erosion eff ects. Optimal periodization of cutbank condition monitoring requires supplementing aerial photo-scanning conducted in the off -season of the hydrological year with additional surveys at the boundary of its seasons.