Procedura per l'analisi del territorio a rischio da inondazione tsunami: prima valutazione di impatto sugli edifici

In the past, tsunami waves of considerable dimension hit Japan, Alaska, Hawaii, South America and South-East Asia. Also the Mediterraneo Sea is a geologically active area with characteristics suitable for tsunami occurring, particularly in correspondence of Italian and Greek coasts. In Italy in the last nine hundred years 71 tsunami happened, between them remember the event in 1908 that caused 70000 dead men and the destruction of more than 90% of the buildings in Messina. In the present work we have predisposed a GIS procedure with which the vertical run-up of the wave attacking the coastline and its propagation inside the coast is calculated in function of the onshore wave height and of the terrain morphology. Moreover, the maximum impact that the tsunami wave might exercise on the buildings in the inundated area is evaluated. The procedure was applied to a reach of the Ligurian coast, obtaining realistic results although many simplifications were introduced. The inundation and impact maps so realized may be useful either for town-planning of the coastal reaches at tsunami risk and for the emergency plan, indicating potentially inundated areas and crucial structures in it (like harbours, depuration systems, hospitals, schools, roads, railways, etc.) that could be damaged