Present day and future scenarios of coastal erosion and flooding processes along the Italian Adriatic coast: the case of Molise region

Coastal erosion and flooding are the main hazards affecting coastal areas, especially low-lying ones, which are particularly prone to damage by storm surges. Due to climate change and socio-economic development, the potential impacts of coastal hazards are globally increasing, and erosion and flooding processes will persist in the future especially when considering the future sea level rise projections. In this paper, we have applied an index-based methodology for the evaluation of the present-day susceptibility to erosion and flooding processes along an Italian Adriatic coastal stretch, the Molise coast. The susceptibility indexes that characterize the coastal system in terms of beach and dune system morphologies, shoreline evolution, wave climate effect, river features and coastal topography, have allowed for dividing the study coast into stretches according to their degree of erosion and flooding susceptibility. To identify the hotspot areas, i.e., the areas characterized by the highest potential coastal risk, susceptibility and socio-economic exposure indexes have been combined. The latter have been evaluated for coastal sectors of 1 km according to the CRAF 1 phase of the RISC-KIT index-method, based on indicators referring to land use categories, economic activities and social vulnerability. Taking in consideration the IPCC sea level projections, future hazard scenarios based on estimated global sea level rise by 2065 and 2100 have been evaluated by means of specific erosion and flooding models executed for the hotspot areas. These scenarios have shown that sea level rise will cause strong erosion of beach and dune systems along the study coast, exposing the economic activities and ecological assets to potential serious damage. The study highlights that correct predictions of future coastal hazard scenarios are essential for the assessment of the long term coastal risk and the definition of related prevention and mitigation measures.