Abstract:
The paper proposes a mathematical model for studying the erosion of the coastal slope of the Pemzenskaya channel (Amur River) in the area of the overflow dam after the formation and expansion of the proran. The proran in the overflow dam was formed due to the erosion of the right bank during the floods of 2019-2022. It is known that the time to establish the hydrodynamic parameters of the flow is much shorter than the time to change its flow rate, therefore, the flow in the dam area is described within the quasi-stationary approximation. The algebraic model of Leo K.Van Rijn is used to model the turbulent viscosity of the flow. Changes in the bottom and shore markings of the riverbed are calculated using an analytical model of sediment movement developed in the works of Petrov and Potapov (2019). In order to prevent siltation of the proran during lateral movement of bottom material from the dry shore, a runoff term is introduced into the equation of bottom deformations. This term regulates the proran depth, which asymptotically tends to its regime depth. An algorithm based on the finite element method has been numerically developed to solve the problem. The results of calculations of coastal deformations were compared with experimental data, which showed their good qualitative and quantitative agreement. The experimental data was obtained from the Amur open source information system.
Keywords:channel processes, bottom deformations, channel cross section, information system, open source, overflow dam opening, Pemzenskaya channel, Amur River