Coastal Evolution of the Upper Adriatic Sea due to Sea Level Rise and Natural and Anthropic Land Subsidence

Abstract

The Upper Adriatic basin has experienced in recent times continuous changes due to the precarious setting of the coastal environment and the low ground elevation above m.s.l. of many coastal areas. Major events which may influence the future stability of the beach profile include the natural and anthropic land subsidence, the sea level rise caused by the climate global change, storm surge and wave set-up, and the reduced littoral sediment transport. In the CENAS project all these events are addressed and simulated with the aid of ad hoc numerical models, and the modeling results are used to predict the Upper Adriatic Sea coastal morphodynamics in the next century. The models are integrated and implemented into a GIS together with a large database of all the essential information and records needed for the analysis. These data concern geometry, geology, hydraulics and meteorology of the basin, and the related input parameters. The area investigated by the project is 350 km long and comprises three local sites south of the Po river delta (Ravenna, Cesenatico and Rimini) where a detailed coastal study has been performed. The results indicate that a general regression of the beach is to be expected in the next decades, mainly in the area south of the Po river delta, due to mean sea level rise and land subsidence, and that a large portion of the present coastal lowland is potentially flooded in 2100 during severe meteo-marine events. The basin as well as the local risk maps of inundation have been built using the GIS and some indication is given as to the locations where major coastal defence actions are to be undertaken in the years to come.