Flood extent mapping, River Severn 2007 using Envisat ©ESA
Floods occur throughout the world and often their extents are very difficult to predict even using highly detailed elevation models. The ability to rapidly capture data for large areas is of critical importance to obtain an accurate representation of land affected. Satellites, particularly those with Synthetic Aperture Radar sensors are ideally suited to this task.
The multiple SAR sensors operating on the COSMO-SkyMed constellation provide an ideal means to monitor flood events on a daily basis.
Fugro NPA have developed semi automatic methods to extract flood extents from radar and high resolution elevation data. Flood extents can then be overlain with other GIS datasets of an area in support of relief effort or for analysing flood records. Different polarisations of radar imagery can also provide unique insights into flooding extent.
Monthly Flood monitoring in Iowa following significant flooding in 2008
(left to right) before and after flood event.