The importance of including compound events in the implementation of the Floods Directive

The phenomenon known as compound flooding, caused by the coincident occurrence of multiple flood drivers such as high precipitation events, storm surges or high runoff rates, has caused some of the most destructive flooding in Europe.

To date, however, the compounding nature of multiple drivers has not been given sufficient consideration in current flood hazard and risk scenarios developed, for example, in the context of the Floods Directive. This may lead to a biased assessment of flood risk, both for current and future climate conditions. IMPREX puts forward a host of reasons as to why it is important to incorporate compound events into flood hazard and risk assessments, providing related methods and tools:

• Incorporation of compound events can enhance the reliability of flood statistics and consequently flood hazard maps
• Probability of compound events may change in the future climate - Compound events may call for different flood measures, making it imperative to factor them into the flood risk management plans drawn up.