Abstract
In a river with a lack of flood plane so called wando, water level rises up locally during flood. It is important to predict this change in water level for preventing the flood disaster. By using the two-dimensional shallow-water-flow model, it isable to estimate the plane distribution of water level and flow pattern in a river with a wandand it is shown that the calculation results on the longitudinal distribution of water level agree with the model experimental those. It becomes clear that the change in water level occurs mainly due to the local change in cross sectional area and its value relates to the velocity and the length, width, depth of lack. The convenient evaluating method of the change in water-level due to a lack of flood plane is proposed.
