Hydrological Risk Map for the Danube Delta—A Case Study of Floods Within the Fluvial Delta

The Danube Delta is the only morphohydrographical unit of its type declared for biosphere reservation. The reduced altitudes and the increase in the frequency of hydrological risk phenomena in recent years have suggested that this area is under constant stress. To generate the hydrological risk map of floods within the fluvial delta, cartographic materials created by predecessors and LiDAR techniques were used. In recent years, extreme water levels were recorded: a minimum in 2003 and a maximum in 2006. The use of extreme data allowed the generation of the flood risk map based on hydrogrades. The levels recorded at hydrograde “0” and at hydrograde “10” were assessed. The most exposed areas are found in the apex of the fluvial delta, where the highest levels are recorded. The least exposed areas are found within the delta, where the water has a larger surface area because it is directed through the secondary channels and through other channels. The enclosures with dams, e.g., the polders (Pardina and Sireasa), are protected from floods. The dams can be affected only if they break because of poor maintenance.