Flood boundary delineation from Synthetic Aperture Radar imagery using a statistical active contour model

Flood extent maps derived from remotely sensed data can provide distributed validation data for hydraulic models of fluvial flow, and can be used for flood relief management and to develop spatially accurate hazard maps. A st atistical active contour model is used to delineate a flood from the first European Remote Sensing satellite Synthetic Aperture Radar (ERS-1 SAR) imag ery as a region of homogeneous speckle statistics. The segmentation uses bo th local tone and texture measures and is capable of accurate feature bound ary representation. The results are assessed by comparison with simultaneou s aerial photography, the SAR segmentation scheme classifying 75% by area o f the shoreline region correctly. Seventy per cent of the shoreline coincid es with the ground data to within 20m. The main error is due to unflooded v egetation giving similar radar returns to open water.