**3. Methods**

48 Studies on Environmental and Applied Geomorphology

Fig. 2. Geological scheme of the Abruzzo Region (modified from Vezzani and Ghisetti, 1998; ISPRA, 2011); the red dots indicate the location of landslides (modified from Progetto IFFI, D'Alessandro et al., 2007). The black boxes indicate the approximate distribution of heavy rainfall events and related geomorphological effects: a dash-dot line for the 2003 event; a

faulted homocline ridges, tectonic basins and homocline reliefs) (Cipollari et al., 1997; Lavecchia et al., 2004; Parotto and Praturlon., 2004; Patacca and Scandone, 2007; Cosentino et al., 2010). In the chain as a whole, the morphogenetic processes began during the last phases of thrust belt emplacement in the Early Pliocene. However, the most important morphogenetic impulses are due to the regional uplift processes and the development of extensional tectonics. After the Apennine area emerged, the activity of morphosculptural processes in the continental environment began in a variable relationship with morphostructural processes. This process, together with the morphostructural action of the extensional tectonics, has controlled the geomorphological evolution of the ridge, basin and valley of the chain and in the piedmont relief of the major fluvial valleys systems and the coastal plain. These processes also induced the mantling of slopes and valleys with a cover

continuous line for the 2007 event; a dashed line for the 2011 event.

This work is based on the analysis of the meteorological aspects and geomorphological effects of heavy rainfall occurring during the three events affecting the piedmont and coastal area of the Abruzzi region: 1) on 23-25 January 2003 (in the whole region), 2) on 6-7 October 2007 (in a small part of the hilly and coastal Teramo area), and 3) on 1-2 March 2011 (in the hilly and coastal Teramo and Pescara area). The analysis was performed by means of the statistical processing of precipitation data and by means of field surveys, aerial photo analysis and inventories and technical reports.

The meteorological aspects were studied processing a >40 pluviometric station database provided by Servizio Idrografico e Mareografico (Direzione Protezione Civile e Ambiente, Regione Abruzzo), including daily and monthly historical data (30-70 years) and 5-15 min pluviometric registrations for at least six days around the main events. The data processing enabled the analysis and comparison of hourly rainfall intensity, event cumulative rainfall, daily rainfall, monthly rainfall and previous monthly rainfall.

The geomorphological effects of these heavy rainfall events were analysed through field surveys, aerial photo analysis, and inventories and technical reports, and they enabled the mapping of landslides, soil erosion and flooding. The percentage and areal distribution of these effects was also analysed for the different events and so also concerned the affected lithologies, providing a contribution for the definition of the controlling factors' role.
