Evaluation of Geomorphic Descriptors Thresholds for Flood Prone Areas Detection on Ephemeral Streams in the Metropolitan Area of Bari (Italy)

Using geomorphic descriptors is a fast and reliable approach for mapping flood-prone areas exploiting Digital Elevation Models and their tools. However, calibration and validation procedures require a flooded map obtained by 1D/2D hydraulic simulation, which usually needs lots of information (available, for example, from remote sensing techniques) and important computational efforts. This approach is usually performed by calibration on a single event, using linear binary classifiers method and Receiver Operating Characteristics curves, in order to define an optimal threshold corresponding to a selected flooded map. On the other hand, the availability of flood-risk maps, provided by public or private institutions, is an important source of data for applying this procedure on a wide and hydrologically homogeneous area, in order to analyze some similitudes. In this study some interesting case studies located in Puglia region (Southern Italy) are investigated, using flooded maps for return periods of 30, 200 and 500 years provided by Basin Authority of Puglia; the aim of the proposed work is to compare the known flooded map areas with those obtained using several geomorphologic index on four case studies located in the metropolitan area of Bari (Puglia)