Evaluation of coastal vulnerability to flooding: comparison of two different methodologies adopted by the Emilia-Romagna Region (Italy)

L. Perini, L. Calabrese, G. Salerno, P. Ciavola, C. Armaroli
2015 NHESSD  
This paper aims at presenting and comparing two methodologies adopted by the Emilia-Romagna Region, northern Italy, to evaluate coastal vulnerability and to produce hazard and risk maps for coastal floods, in the framework of the EU Floods Directive. The first approach was adopted before the Directive had been issued. Three scenarios of damage were designed (1, 10, 100-year return periods), produced by the concurrent happening of a storm, high surge levels and high water spring tidal levels.
more » ... ng tidal levels. Wave heights were used to calculate run-up values along 187 equally spaced profiles and these were added to the tidal and atmospheric water level contributions. The result is a list of ten vulnerability typologies. To satisfy the requests of the Directive, the Geological, Seismic and Soil Service (SGSS) recently implement a different methodology that considers three scenarios (10, 100 and > 100-year return periods) in terms of set-up (not including run-up) plus the contribution of surge levels as well as the High Water Springs. The flooded area extension is determined by a series of computations that are part of a model built into ArcGIS<sup>®</sup>. The model uses as input a high resolution Lidar DEM that is then processed using the Cost-Distance tool of ArcGIS<sup>®</sup>. Inundation maps are then overlapped to land use maps to produce risk maps. The qualitative validation and the comparison between the two methods are also presented, showing a positive agreement.
doi:10.5194/nhessd-3-4315-2015 fatcat:gbnx3ig6nfdz5i5lxxrhq73pn4