2. Natural hazard inventories

In some cases, the risks are known: all we need to do is assess their importance and define the zones concerned. This is the case for avalanche, flood, earthquake, volcanic and other risks.

In other cases, local history provides no information on potential risks. They are unknown, or their probability is so low that they are ignored. This is the case for unforeseeable ground collapses, natural pollution uncovered by sophisticated measuring equipment, storms, exceptional rainfall accompanied by mudslides, and so on.

The main risks due to natural or geological events are :

• flooding and river overflows ;

• EARTHQUAKE;

• torrential rains, mudslides ;

• falling rocks and stones;

• ...