As consequence of recent large-area flooding the public interest increased. But, if flood events do not occur for a long period of time, the risk of flooding as well as the damage caused by flood events are forgotten. Residents are often not prepared sufficiently in case of further flood events.
To avoid or reduce the impact of floods is a task of Integrated Flood management (IFM). IFM comprises flood probability assessment and flood impact assessment as well as all forms of structural and non-structural mitigation measures and the decision making process.
Risk assessment is an essential part of flood impact assessment. To get a better idea of the possible amount of damages in case of a flood event diverse strategies of risk assessment have been developed.
The results of risk assessment can become visualised on a map, showing the levels of expected losses which can be anticipated in specific areas, during a particular time period and as a result of a particular flood event. These maps are called risk maps. Risk maps are an important medium of communication in sustainable flood management. They may help to transfer the risk information to the residents as they depict flood risk in a colourful and easy understandable way.