Application of mat traps to determine the present speed of accumulation of alluvium at the Ryazan area in the middle reaches of the Oka river

Investigation of the processes of channel sedimentation in riverbeds of lowland rivers has important fundamental and practical importance. In the economic development of river valleys a lot of attention is paid to the dynamics of the major relief-forming processes within the floodplain. A typical example showing the pattern of forming landforms and type of floodplain processes is deposition and redeposition of riverine sediment. In the future sedimentation of alluvium in areas of riverine floodplain makes the growth rate of natural levees, islands and shoals. For the average flow of the Oka river the pace of modern dynamics of accumulation of alluvium in the riverine areas is clarified. For the first time in this area the method of mat traps is applied. Rubber and coconut fiber were selected as the main materials for the traps. Specific features of the application methods and the difficulties encountered in its application were defined. The authors obtained the data about thickness of the layer of sediment accumulation of river flood of 2015, the results of particle size analysis of alluvial material with traps. The main patterns of distribution of fractions of alluvium and the pace of accumulation of various forms of riverine floodplain accumulation were identified. Tested methodology has proven its effectiveness and was found promising for use in the future in this region.