Abstract
Concerns are growing against the increasing strength of typhoons, the increasing severity of damage caused by floods and storm surges, attributed to the effect of global warming. As natural disaster hazard intensifies drastically, the capacity to prevent disaster is weakening due to degrading infrastructure and an aging population. In order to reduce the damage caused by such disasters, a flood control dam without a slide gate in a spillway, known as ‘dry dam’, has been reviewed, planned and built in some sites in Japan.
A simple analytical model for flood control by a dry dam is proposed in order to encourage the construction of such a dry dam. An implicit integral equation based on the continuity equation to solve the flood control is a basis of the simple analytical model. The equation is easily solved by a spreadsheet program, e.g. Excel, so that the analytical model would be widely used by hydraulic engineers or students.
The analytical results using the simple model was compared with some laboratory experimental results or other analytical results by the method of finite differences. As a result, it is made clear that the accuracy of the model is considerably good, especially on the maximum water level of a dam reservoir. Therefore, the peak discharge in a flood would be precisely detected by using the simple analytical model.
