Improving models of river flood inundation using remote sensing

摘要

Flooding remains a substantial natural hazard despite recent advances in the understanding of the scientific mechanisms causing it and increased expenditure on flood defences. There is a need to improve river flood inundation extent maps by developing better flood models. Two dimensional hydraulic models are currently at the forefront of research into river flood inundation prediction. The two dimensional nature of these models requires spatially distributed 2-D data for their parameterisation and validation. Remote sensors carried on satellites and aircraft are now proving to be a rich source of such data. We have been using satellite and airborne Synthetic Aperture Radar (SAR) and airborne scanning laser altimetry (LiDAR) data to improve flood models. The flood inundation extents observed in satellite and airborne SAR imagery have been used to validate the modelled flood extents. LiDAR data have been used to improve model parameterisation, providing the model with a dense and accurate DTM of the floodplain, and parameterising friction in the model by providing information for assessing vegetation resistance to flood flow. Methods developed for rural flood extent prediction are now being extended to the urban environment.