The Global Flood Monitoring (GFM) product is a new component of the EU’s Copernicus Emergency Management Service (CEMS) that provides continuous monitoring of floods worldwide, by processing and analysing in near real-time (NRT) all incoming Synthetic Aperture Radar (SAR) imagery acquired by the EU’s Copernicus Sentinel-1 satellites, in Interferometric Wide Swath (IW) mode and as Ground Range Detected (GRD) products (Salamon et al., 2021; European Commission, 2020; Matgen et al., 2020; Wagner et al., 2020). The GFM product is designed to deliver, in NRT, critical information on ongoing floods events to users worldwide, including national authorities, emergency units, research centres, decision-makers and other stakeholders.
The GFM product is specifically designed to address three major user requirements, namely:
Furthermore, the GFM product will provide a long-term archive of global flood monitoring data, making it an ideal source of information for planning specific mitigation and preparedness measures regarding future flood events, such as designing flood protection systems or calibrating hydrological models. Finally, combining data from the GFM product with data from other Copernicus services (e.g. the Copernicus Climate Change Service or C3S) can deliver useful information for addressing the challenges in the area of climate change response management.
At a technical level, the GFM product is designed as an automated, global, satellite-based flood monitoring system that enables a continuous, systematic monitoring of all major global flood events in near real-time, complementing the existing CEMS components for flood early warning and on-demand mapping. At the core of the GFM product are three independent, state-of-the-art algorithms - which were developed by three leading research teams (LIST, DLR and TU Wien) who are members of the GFM consortium - for the systematic, automated delineation of flooded areas and water-bodies based on all-weather, day-and-night SAR images provided by the Copernicus Sentinel-1 satellites. The three GFM flood mapping algorithms are implemented in an “ensemble” approach (see Section 4 below), to ensure an optimal accuracy of the derived flood and water extent maps, and to build a high degree of redundancy into the production service.
The operational implementation the GFM product includes the following key elements:
The GFM product has been developed and implemented by an international partnership - the “Global Flood Monitoring Alliance”, consisting of the following organizations:
The GFM partnership represents Europe’s leading group of scientific experts in the field of satellite-based flood monitoring systems, with a wide-ranging and unique experience in global flood mapping services, and with extensive links with the main information services of Copernicus (the EU’s Earth observation programme), including the Copernicus Land Monitoring Service (CLMS) and the Copernicus Emergency Management Service (CEMS). Starting from the earliest days of satellite-based flood mapping and monitoring methods, the individual members of the Global Flood Monitoring Alliance have built up unprecedented, complementary capabilities for flood mapping, monitoring and related disaster risk services, and have accumulated a long history of implementing high-quality, successful applications and projects, and developing the related systems for global data processing and access.
Further details on the members that make up the Global Flood Monitoring (GFM) consortium are provided in the Annex at the end of this document.