Post-event Flood Documentation and Communication Using a Hydrological Map Information System

In order to support authorities in performing their mandates to protect the population from floods and minimize damages, additional documentation methods are needed. Before and during a flood event, the use of appropriate real time hydrological maps for improved early warning and monitoring activities is undisputed. After an event, however, the gained knowledge and expertise (i.e. the “lessons learned”) must be retained and fostered. This should preferably take place in a formalized way and the storage in a spatiotemporal database is one promising way to achieve this goal. However, such data-base driven map information systems used as repositories for hydrological knowledge have so far gained little attention. The added values of these kinds of systems are: a more profound understanding of flood processes; a better basis for decision-making; and improved means of post-event documentation and communication to peers and to the public. The usefulness of interactive map information systems for flood documentation and communication purposes is shown, using an implementation of the main following concepts: the integration of quantitative, qualitative, and multimedia data; combination of these data types for cartographic visualization; retrieval of historical maps in an easy, time-saving way; user-defined customization of map content to explore the interplay of flood-causing hydrological factors, during every flood phase; toggling of map symbols to represent data on different temporal aggregation levels; and the animation of both maps and connected map elements (e.g. time series graphs).