Ανάλυση ισχυρών βροχοπτώσεων στον Ελληνικό χώρο κατά τύπο καιρού

Studying rain considering the prevailing weather type, is a statistic approach through which we study some specific characteristics of the phenomenon. This approach operates additional to rainfall modeling and constitutes an additional methodology for determinate it’s basic characteristics. Grouping same conditions of weather and sorting rain according to the weather type that caused it, was made in the past for specific places and climates. In this thesis we use Maheras weather types in order to study the intense rainfalls that observed in Greece from 1970 to 1990. The rain data management and processing was done using a Geographic Information System (G.I.S.) and intense episodes are presented on maps using bar charts for sequential daily rainfalls. Through this thesis, came up the ability for direct supervision of process and geographic allocation of rain, which achieved using the GIS. From studying the intense rainfalls it looks that there is a correspondence between the weather types and their expected (from definition) characteristics. For example, cyclonic types cause strong rains, but few episodes affect the bigger part of the country. There were also some quantitative data that came up concerning the frequencies with which the weather types appear in summer and winter months and their geographical allocation (stations or areas in Greece that the specific types affect).