On October of last year's catastrophic landslide events of Messina, Ionian, they emphasized the fragility of coastal settlements in Sicily. On 10 November 2009 and September 9, 2010 Casamicciola Atrani, in Campania, nature has dealt a blow to two well-known havens "of luxury holiday. Few days ago (October 4) have been hit and badly damaged again densely urbanized areas of the Ligurian coast. Forty victims, caused by a total of catastrophic events mentioned. The question arises: Why? We're not sure? We are not protected by These flash floods? The rainfall events that caused the disaster from the south to the north of Italy are typical for the short duration and the large amount of water poured on the soil surface investing in areas of limited size, ranging from tens to hundreds of square kilometers.
The storms, as illustrated by the radar images, we are continuously fed by the energy and the convergence of sea fronts and currents along the coasts. These storm-healing cells that are activated quickly during periods of transition of the seasons and mainly affect coastal areas characterized by morphological barriers that rise steeply from sea level to over 1000 meters, are typically made as the Mediterranean coast. As for the flash-floods, it is of the deadly storm mesoscale systems (MCS Mesoscale Convective System) in the last 60 years, in Italy, have caused about 500 deaths and immense damage to housing stock and infrastructure. Their danger has always been known, and Italy is a country for very vulnerable to this kind of phenomena: for this reason, the civil protection system should be organized to protect the lives of citizens, but unfortunately it is not. From the point of view of the forecast, there are still technologies that allow us to predict exactly where these phenomena (Which are very localized in a small area of \u200b\u200bthe territory) strike. After all
meteorologists regularly launch warnings and alerts relating to the wider area within which it is possible that such violent episodes occur. Catastrophic events have dramatically highlighted remember that the areas concerned were affected suddenly caught unprepared citizens and institutions. it is clear that you must fill this gap, which mostly affects the security of citizens. After the disaster of Messina developing guidelines to provide the territory of a proper system of civil protection in order to limit the damage caused by heavy rains. First you need to identificare le aree potenzialmente soggette ai fenomeni estremi. Poi bisogna pensare ai moderni radar meteo che consentono di individuare le perturbazioni sopraggiungenti che possono alimentare alluvioni-lampo, insieme ad altre adeguate strumentazioni che consentono di monitorare le variazioni di pressione atmosferica, di vento e intensità della pioggia che solitamente caratterizzano i più violenti temporali.
Anche l’osservazione diretta di occhi “educati” a riconoscere i fenomeni atmosferici contribuisce all’individuazione del fenomeno. La sicurezza che un’area sia investita dalle intense e pericolose piogge viene fornita dall’osservazione della curva pluviometrica in tempo reale. Dal momento che l’area invested by the phenomenon may be of limited magnitude, you need a dense mesh of meteorological stations. The simultaneous recording of meteorological parameters in adjacent sites provides an indication of the area you are interested from the start of the event. After a few minutes you have the almost certainty that the event can escalate to become "flood" and potentially catastrophic as that of the previous rounds of Genoa.
Research performed in recent years in many areas devastated by flash floods, the rain beginning to show that the triggering of landslides, floods and landslides various steps from 15 to 120 minutes, a period of time critical to safeguard human lives. It should be clear that rainfall so much violent Messina (300mm in less than three hours) and Genoa (400mm in no time) cause repercussions in the area, around the world, wherever they occur. On these occasions the nature manifests its power, we get the space needed to dispose of the exceptional flows in accordance with the laws governing natural phenomena which also includes exceptional occurrences. it is clear that the man should have taken account of the spaces that are periodically "claimed" by natural phenomena. Unfortunately, the man-made laws have always been the presumption that nature should be subject to the power man. The urban areas were often to the contact with the torrential river beds and, very often the latter have been covered (such Atrani, Casamicciola and Messina) and turned into roads.
addition to that building, unfortunately we have to deal with a widespread "illegal environment", also made in respect of planning instruments, related to the urbanization of areas that would have to comply with the laws of nature and to be left available to exceptional events . In coastal areas such as Messina, the peninsula coast, the Calabrian coast, the Ligurian coast of Italy and many other areas subject to landslides and flooding cycles, million people live: they are densely urbanized even at the mouth of rivers at the foot of steep hills and hydrogeological unstable. You can not find the financial resources to put them in structural safety. If you want to avoid new victims should focus on modern weather forecasting and prevention, just encouraging the spread of new radar and weather stations and early warning systems: it is the only way to beat the time the fury of nature, of course without being able to pretend to stop it but at least managed to rescue the population.
* Professor of Geology and Director of the Department of Planning and Science Planning, University of Naples Federico II
** Director www.meteoweb.it - Online Journal of Meteorology
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http://www.terranews.it/news/2010/10/frane-e-dissesti-ecco-perche-siamo-rischio
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