Urban areas and procedures for responding to extreme rainfall events: phenomenon analysis and protection strategies

Abstract

The most vulnerable components of the territory are represented by urban areas, located in geo-environmental contexts whose balances become unstable because of natural physical changes (eg .: changing climate conditions) and/or changes induced by human interventions (construction of infrastructures, represented by someone, in the pejorative way, with the term “overbuilding”).
The city, as anintegrated system of infrastructures, may be exposed not only to the critical geo-environmental hazard of the site where they are located (eg. coastal erosion, slope instability, subsidence, flooding, etc.) but also to those generated by boundary areas, sometimes even at a considerable distance.
The recent meteorological history shows a growing incidence of hydrological and hydrogeological events (such as, for example, storms in Genoa in 2011 and 2014, the ones in Sardinia, Calabria, Sicily, Benevento, etc., all occurred in the last five years), demonstrating an increasingprobability of involvement of towns.
The research of strategies of prevention and protection is a difficult task to deal with, but politics, as a consequence of recurring loss of life and the huge costs that burden on society, has to consider it as a priority.In this scenery, the activity of planning, considered as the activity of organization of a urban settlement afterwards a rigorous and accurate analysis of all relevant aspects, both human and natural, plays a major role to obtain acceptable risk level.