FOCA: a new quality-controlled database of floods and catchment descriptors in Italy

Abstract. We here present FOCA (Italian FlOod and Catchment Atlas), the first systematic collection of data of Italian river catchments for which discharge historical time series are available. Hydrometric information, including annual maximum peak discharge and average daily annual maximum discharge, is complemented by several geomorphological, climatological, extreme rainfall, land cover and soil-related catchment attributes. All hydrologic information derives from the most recently released datasets of discharge and rainfall measurements. This paper provides a description of all the raw data and the algorithms used to build the basin attributes dataset, to enhance reproducibility and transferability of the analysis. We also describe the approaches adopted to solve problems encountered during the Digital Elevation Model elaboration in areas characterized by complex morphology. Details about the data quality-control procedure developed to detect and correct errors is also reported. One of the main novelties of FOCA with respect to other national-scale datasets is the inclusion of a rich set of geomorphological attributes and of extreme rainfall features spatially averaged over the watershed. With this first nationwide data collection (available at https://doi.org/10.5281/zenodo.8060737), a wide range of environmental applications, with particular reference to flood studies, can be undertaken on the Italian territory.