The Global Flood Detection System

A methodology for satellite based flood detection developed at Dartmouth Flood Observatory (DFO) wasmodified at the Joint Research Centre (JRC) of the European Commission and implemented on an automaticoperational basis. The technique is using AMSR-E passive microwave remote sensing data of the descendingorbit, H polarization, 36 GHz band which is sensitive to water surface changes. The sensor revisits every placeon Earth once per day and can therefore provide a daily temporal resolution. Sensor data is available 24 hoursafter acquisition. Thresholding the signal of water surface change allows the detection of riverine inundationevents. The comparison of in field gauging and satellite measurements show a significant correlation in the increase ofriver discharge on-site and changes at the observed signal of the sensor. Thus following the technique thedetection of flood events in ungauged and inaccessible remote river channels is feasible from space. A procedure chain was developed at the JRC to automatically acquire and process the remotely sensed data inreal time on an operational basis. After the validation of the satellite based Global Flood Detection System(GFDS) the remotely observed flood events are to be integrated into the Global Disaster Alert and CoordinationSystem(www.gdacs.org/floods) including the estimation of its humanitarian impact. GDACS is running at theJRC providing near real-time alerts about natural disasters around the world and tools to facilitate responsecoordination, including news and maps.