Frequency Analysis of Flood Damage

Determination of flood damage frequencies constitutes a fundamental component of any comprehensive flood-risk methodology. A time series of flood damage may contain zero values. Therefore, the probability distribution of damage should be derived taking into consideration these zero values. This distribution was derived using the total probability theorem (in conjunction with gamma, log-normal and Weibull distributions), order statistics, kinematic diffusion (KD) model, and the Box-Cox transformation. Flood damage frequencies determined using these methods were compared with those determined empirically for Alabama, Louisiana, Mississippi, and Texas in the United States. For the four southern states studied, it is found that of all three different analysis methods, the method based on the total probability theorem gave the best results for the flood damage analysis containing zero-damage, and the KD model method is not suitable for the flood damage analysis.