Landslide occurrences during the high-intensity rainfall event of march-april 2013 in the emilia-romagna region (North apennines, italy

Abstract

Extensive landslide occurrences affected the Emilia-Romagna Region (north Apennines, Italy) during March-April 2013 due to a high-intensity precipitations and contemporaneous snow melting.During this period, incessant and intense precipitations characterized by a maximum height equal to 350 mm in the piedmont sector and 700 mm in the inner zones (up to fourfold the amount of predictable rainfalls) occurred. This event produced a relevant economic loss due to damagesto several private properties and public infrastructures; in fact, local authorities advisedabout 1,500 damages. The landslide typologies occurred are generally earth slides and earth flows, even if some rock falls was also documented. Usually, landslides appeared as reactivation of preexisting movements and mainly involved the terrain belonging to the Ligurian Flysch Units, characterized by a stratigraphic succession of sandstones, marls and clays. Landslides advised by local authorities have been verified and successively included in the “Historical database of landslide events” of the Emilia-Romagna Region that presently records about 9,000 events, starting from 1,800 to present days. Major landslides was checked in the field and their geometry systematically updated in the already existing GIS-based “Landslide inventory map” ofthe Emilia-Romagna Region. The updated landslide data are relevant for immediate planning purposesand remediation strategies at both local and regional scale. They are also significant for subsequent susceptibility modeling and related hazard assessment.