Abstract
It is very important to grasp the hydraulic characteristics of flood flows for the river improvement works and management. This study aims to clarify the propagation mechanism of flood flow in rivers with vegetations. We constructed the model of unsteady quasi-2D flow available for flood flows. By using this method incorporating observed water surface profiles, discharge hydrograph, water storage and propagation speed of flood flow are accurately estimated in compound channels with vegetation. We also derived a theoretical expression for propagation speed of floods and showed that the theory provided a good agreement with observed propagation speed of floods in the Tone river.
