Llasat, Maria-Carmen (Department of Astronomy and Meteorology, University of Barcelona, Spain)
One of the main objectives of the AMHY/FRIEND project of the UNESCO is the regionalization of different hydrological processes. Particularly, this paper mades reference to the first results obtained after a global analysis of those events called "extreme rainfall events" in the Mediterranean Area. First of all, the concept of "extreme rainfall" has been clarified. In order to do this objective, statistical, physical and dynamical features of those events, joined to the damages and floods produced, have been analysed. Beside this, the production of an "extreme rainfall" can be related with the accumulated precipitation, rainfall rate, return period, geomorphology and orography of the affected zone, soil saturation, distribution of villages and industrial activity, drainage networks and so on. Therefore, different kinds of extreme rainfall events have been considered.
In second place, the information which has been available for carrying on this analysis has been obtained from the data base developed into the AMHY/FRIEND project or from some bibliographical sources. A first recopilation of those rainfall events with accumulated precipitation equal or above to certain threshold has been made. In all those cases in which daily or monthly series have been available, the statistical properties have been considered.
With all this information, different criteria to identify an "extreme rainfall event" have been defined. The most afefcted zones and the worst months have been shown for the countries included in the AMHY/FRIEND project. Beside this, a comparision between the main meteorological features of those events has been made.