A “flood” means water temporarily covering land that is usually not covered in water. This includes floods caused by rivers, mountain and Mediterranean water streams that are normally dry, intensive melting of ice/glaciers as well as flooding of coastal areas by the sea. A flood originates mainly from heavy or prolonged rainfall and can have significant effects on the water load of rivers, streams and canals.
A stream can swell up and overflow, i.e., break the banks, flooding the surrounding areas. Not all of the streams, however, appear and behave in the same way. Torrents, for example, become rivers only when it rains a lot. With decreasing rainfall, the water level can decrease and leave the riverbed dry.
Floods are a potential cause of incidents and population exoduses, inflicting damage on the environment and seriously disrupting economic development. In general, floods have more serious effects in urban centres. Although floods are triggered by natural phenomena that cannot be prevented, their negative consequences can be reduced.
“Flood risk” means the combination of the possibility of flooding and the potential negative consequences for human health, the environment, cultural heritage and economic activity connected with flooding.