Daily Monitoring of the May 2023 Emilia-Romagna Flood Using Cosmo-SkyMed Data

A big flood affected the Emilia-Romagna region (northern Italy) starting from 16 May 2023. During this event, more than 20 rivers burst their banks and about 15 people were killed. A persistent satellite-based mapping was requested by the Italian Department of Civil Protection (DCP) to monitor the time evolution of the Emilia Romagna flood. For this purpose, the X-band SAR data provided by the COSMO-SkyMed constellations (first and second generation) were exploited. This paper proposes a new procedure to map floods using SAR data acquired with different viewing geometries in order to fully exploit the on-demand capability of satellites like COSMO-SkyMed. The procedure includes the tasking of the satellites, the collection of a set of pre-flood images, the selection for each flood image of the most suitable pre-flood ones, and the generation of the flood maps using an automatic algorithm based on change detection. These activities were performed during the May 2023 Emilia-Romagna flood and allowed us to daily provide DCP with flood maps useful to support decision making and assess the damages.