remote sensing Article Potential and Limitations of Open Satellite Data for Flood Mapping Davide Notti 1 , Daniele Giordan 1,* , Fabiana Caló 2 , Antonio Pepe 2 , Francesco Zucca 3 and Jorge Pedro Galve 4 1 National Research Council of Italy, Research Institute for Geo-Hydrological Protection (CNR-IRPI), Strada delle Cacce 73, 10135 Torino, Italy;
[email protected] 2 National Research Council (CNR) of Italy, Institute for the Electromagnetic Sensing of the Environment (IREA), via Diocleziano 328, 80124 Napoli, Italy;
[email protected] (F.C.);
[email protected] (A.P.) 3 Department of Earth and Environmental Science, University of Pavia, Via Ferrata 1, 27100 Pavia, Italy;
[email protected] 4 Departamento de Geodinámica, Universidad de Granada, 18071 Granada, Spain;
[email protected] * Correspondence:
[email protected] Received: 31 July 2018; Accepted: 17 October 2018; Published: 23 October 2018 Abstract: Satellite remote sensing is a powerful tool to map flooded areas. In recent years, the availability of free satellite data significantly increased in terms of type and frequency, allowing the production of flood maps at low cost around the world. In this work, we propose a semi-automatic method for flood mapping, based only on free satellite images and open-source software. The proposed methods are suitable to be applied by the community involved in flood hazard management, not necessarily experts in remote sensing processing. As case studies, we selected three flood events that recently occurred in Spain and Italy. Multispectral satellite data acquired by MODIS, Proba-V, Landsat, and Sentinel-2 and synthetic aperture radar (SAR) data collected by Sentinel-1 were used to detect flooded areas using different methodologies (e.g., Modified Normalized Difference Water Index, SAR backscattering variation, and supervised classification).