Yerlan Alimzhanovich Shynbergenov

The dynamics of sedimentation in the bottoms of small catchments in the forest–steppe zone of the Central Russian Upland was assessed using the soil–morphological, radiocesium and magnetic tracer methods, which made it possible to calculate the rate of soil loss 1) since 1986, 2) since 1954, 3) since the launch and active operation of the railway, 4) since the mass plowing the entire catchment area. Two groups of small dry valleys have been identified: the catchment area of the first group includes tributaries of larger dry valleys, where the average rate of loss during the agricultural period is 2,1–2,4 t∙ha-1 per year and exceeds modern ones (since 1986) by 0,6–0,7 t∙ha-1 per year. The catchments of the second group include the sources of larger valleys, where the average rate of loss during the agri- cultural period is 0,6–0,9 t∙ha-1 per year and less than modern ones (since 1986) by 0.3–0.8 t∙ha-1 per year. The max- imum rates within all catchments were observed in the period 1954–1986, which is associated with soil compaction by heavy agricultural machinery, as well as the contribution of snowmelt runoff, which was regular for this period.