Flood risk analysis for the Bac Hung Hai polder, Vietnam : a preliminary assessment of the system approach, taking effects of flooding on the entire system into account

Deals with the application of the 'crude Monte Carlo' method to asses dike failure and flood damage with due account of system behaviour. The suitability of this probabilistic approach to determine the sequence of improvements of dike segments surrounding the polder to reduce the risk of flooding in a most cost effective manner has been investigated. The method has been applied to the Bac Hung Hai polder in the Red River delta in Vietnam. the 'crude Monte Carlo' involves a large number of deterministic simulations of flood events, where for each individual simulation the random parameters and boundary conditions are sampled from their respective probability distribution functions. The result of each Monte Carlo simulation is flood damage, eliminating problems of double counting of damages when dike failure and flood damage are treated separately. Effects of dike breaches on the hydraulic conditions elswehere (system behaviour) have been incorporated.