Mathematical Modeling of Transformation of Flood Waves in Stream Channels with Floodplains

A. F. Voevodin, V. S. Nikiforovskaya, and V. V. Ostapenko

Two mathematical models based on the Saint-Venant equations are considered for calculating unsteady flows in stream channels with floodplains. In model 1, the influence of floodplain on the release or flood wave travelling is taken into account through the total morphological and hydraulic characteristics of stream channel and floodplain. In model 2, based on singling out a fluvial flow, the floodplain plays a role of an accumulation capacity. To study the field of a practical applicability of the proposed models, comparative calculations have been carried out with a two-dimensional (plan) model. The analysis of results demonstrated a sufficient efficiency of models 1 and 2 with allowance for floodplains in meandering stream channels. Due to a less laborious preparation of initial data, model 2 is more preferable.