Flood risk assessment in Australia : application of a holistic approach

Flooding is one of the worst natural disasters that cause notable loss of lives and economic damage in Australia similar to many other countries around the world. In Australia, during the 2010-12 periods alone, flood damage costs were estimated at over $20 billion and over 25 human deaths. The flood risk assessment is an essential part of development and operation processes which are subject to flood risk, such as design of hydraulic structures, development control and flood insurance studies. This chapter reviews the commonly adopted flood risk assessment methods adopted in Australia. This, in particular, presents the evolution of a holistic approach of flood estimation known as Joint Probability Approach (JPA)/Monte Carlo Simulation Technique (MCST) in Australia. This method considers the probabilistic nature of flood producing variables and their correlation in flood modelling using a runoff routing model. A case study is presented to illustrate the regionalisation and application of the JPA/MCST to an Australian catchment. It is found that the JPA/MCST can be applied successfully in practice with regional input data. This method can easily be adapted to other countries.