Flood

After the retreat of the glaciers, human settlement of the Alpine region at first took place in higher, safer areas. The valleys of larger river landscapes were not suitable for the land use methods of that time. As economic development progressed, human beings also began to settle in less secure valley areas. The reasons were the proximity to water as a means of production and transport, and better preconditions for technical infrastructure. At this time, human beings began to actively protect themselves against water.

How does flooding occur?

Events that trigger floods can be:

• Heavy (convective) precipitation of short duration, usually accompanied by thunderstorms
• Prolonged heavy precipitation (advective precipitation)
• Blockages in rivers and streams caused by ice fragments, debris flow or rockfall.

How can we protect ourselves?

Concrete measures are necessary to protect against flooding:

• Controlled floods and the preservation of existing flood plains improve water retention. Natural (water meadows) as well as artificial (retention basins) flood plains can of course be used in this preventive flood protection.
• Technical measures (e.g. dykes, walls, water body regulation measures) prevent flooding in built-up areas (settlements) and channel the water harmlessly through.
• The most effective protection against flood damage is, however, the relocation of valuable assets away from the endangered areas and farsighted spatial planning. In addition, hazard maps are being produced in many European countries, to be used in spatial planning following risk assessment.

Precautionary measures

For cases in which large-scale protection is technically or economically impossible, damage can be reduced through precautionary measures. These include:
 

• Local protection measures (flood-proof buildings)
• Preparedness through insurance coverage and government support
• Plans of action for a state of crisis (behavioural preparedness)