The generation of flood damage time sequences.

Research Report

There is a need in water resources planning to develop a procedure for determining the time pattern in which flood damages occur as a function of the rise and fall of the flood hydrograph. The widely used approach for estimation of flood damages does not take into account the fact that the frequency of the annual flood peak may not be the same as the frequency of the total annual flood damages. As examples, several small storms during the year may do more damage than a single larger storm, or flood damages may be reduced by a reduction in flood duration rather than the flood peaks. A digital computer subroutine DAMAGE can be used to estimate the direct and indirect damages to property in the four basic categories of crop, field, urban, and public facilities as functions of the depth and duration of flooding, seasons, and the time laps between flood events. DAMAGE may be called with recorded or simulated annual hydrographs and used to analyze the time pattern of damages in the flood plain for optimizing the policies for operating resevoir flood control storage or for estimating the average annual damages for use in formulation of alternative flood control schemes