1. Introduction
From the perspective of hydrology, a distinction is made between a flood and an inundation. The former is defined as a “condition in a body of aboveground water in which the surface level or flow rate reaches or exceeds a certain value (threshold value)” [23. 15 f.]. The three key values for a flood are peak discharge, duration, and the water quantity flowing [13. 294–296]. A flood can break the banks of a riv…