1 Spatial Modelling of the Terrestrial Environment - Georeferencial

5
Flood Inundation Modelling Using
LiDAR and SAR Data
Paul D. Bates, M.S. Horritt, D. Cobby and D. Mason
5.1 Introduction
Flood inundation is a major hazard in the UK and worldwide. Its prediction and prevention
require considerable investment, even aside from the socio-economic consequences of severe
flooding episodes. Better flood extent prediction is relevant to a significant percentage
of the global population, as well as raising fundamental scientific issues and challenges relating
to remote sensing, distributed environmental modelling, risk analysis and uncertainty.
In recent years, remote sensing of floodplain environments has increasingly become an
operational tool that may begin to resolve some fundamental problems in flood conveyance
estimation. In a number of areas, in particular topography and validation data, we are moving
rapidly from a data-poor to a data-rich and spatially complex modelling environment
with attendant possibilities for model testing and development. The availability of rich and
relatively accurate spatial data sources in digital format may lead to significant changes in
scientific and engineering practice in flood conveyance estimation over the next 5–10 years
and it is the purpose of this chapter to identify potential areas in which integration of
hydraulic models and remotely sensed spatial data may be of benefit.
Traditional methods of hydraulic investigation for real river reaches have focussed largely
on model validation against bulk flow measurements such as stage and discharge measured
at only a single point in the system, typically the reach outflow (e.g. Bates et al.,
1998a). The main calibration parameter for these applications is boundary friction, and it
is relatively easy to match the available validation data with a spatially lumped parameter
set that has been calibrated to maximize some objective measure of fit between the observed
and predicted outflow hydrographs. Whilst hydraulic resistance does have a sound
Spatial Modelling of the Terrestrial Environment. Edited by R. Kelly, N. Drake, S. Barr.
C○ 2004 John Wiley & Sons, Ltd. ISBN: 0-470-84348-9.