Impact of storms along the coastline of Emilia-Romagna: the morphological signature on the Ravenna coastline (Italy)

Abstract

P. CIAVOLA, C. ARMAROLI, J. CHIGGIATO, A. VALENTINI, M. DESERTI, L. PERINI and P. LUCIANI, 2007. Impact of storms along the coastline of Emilia-Romagna: the morphological signature on the Ravenna coastline (Italy). Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), pg – pg. Gold Coast, Australia, ISBN) The coastal zone of the Emilia-Romagna region is exposed to risk from coastal flooding during storms. The vulnerability of this coastline is a topic of interest for future coastal planning as this area provides large revenue for coastal communities and the whole region. An assessment of the historical record of storm events for the period 2000-2004 was carried out using a wave generation model, fed by archived atmospheric circulation data. High-resolution air-borne laser detection technology (LIDAR) and video-monitoring (ARGUS) have permitted to undertake a feasibility study for the assessment of coastal erosion and flooding patterns along one of the bestpreserved dune systems of the area. The source of the work was the comparison between two LIDAR flights at an interval of one year (July 2003-September 2004) with the second flight carried out after a major storm occurred in September 2004, with a return period of 25-years. Following this exceptional event the whole coastal system resulted to be in a state of weakness. The study presented in this paper suggests that for the coast of the Emilia-Romagna region the critical factor that controls dune destruction and inland flooding is the joint occurrence of storm waves and surges. Beach slope is the main morphological control on wave run-up and the impact evaluation for the exceptional event has proved that a wide beach can be considered a symptom of safety. A small beach replenishment was undertaken on the test site but this resulted to be ineffective because of the small volume.