Emergency mapping of mud extent in the context of October 29th 2024 flash floods in Valencia

Natural events become disasters when they affect human populations, demanding a rapid, coordinated response supported by accurate geospatial information. Satellite remote sensing (RS) is essential for providing timely and scalable data, especially during flood events where early warning systems, rapid mapping, and post-event analysis are critical. This study focuses on the flash floods that struck València on October 29, 2024. The Image Processing Laboratory and the Department of Geography at the University of València collaborated to collect and analyse data from both citizen science and remote sensing sources. Copernicus Emergency Management Service (CEMS) maps were validated and refined using ground-level reports. A novel mud mapping approach was developed using Sentinel-2 imagery to assess post-flood impacts, offering a wide-scale, synoptic view of the affected areas. The study demonstrates the value of integrating remote sensing and citizen data for effective disaster response and flood impact assessment.