Predicting floodplain inundation: raster-based modelling versus the finite-element approach

MS Horritt*, PD Bates

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

262 Citations (Scopus)

Abstract

We compare two approaches to modelling floodplain inundation: a raster-based approach, which uses a relatively simple process representation, with channel flows being resolved separately from the floodplain using either a kinematic or diffusive wave approximation, and a finite-element hydraulic model aiming to solve the full two-dimensional shallow-water equations. A flood event on a short (c. 4 km) reach of the upper River Thames in the UK is simulated, the models being validated against inundation extent as determined from satellite synthetic aperture radar (SAR) imagery. The unconstrained friction parameters are found through a calibration procedure, where a measure of fit between predicted and observed shorelines is maximized. The raster and finite-element models offer similar levels of performance, both classifying approximately 84% of the model domain correctly, compared with 65% for a simple planar prediction of water surface elevation. Further discrimination between models is not possible given the errors in the validation data. The simple raster-based model is shown to have considerable advantages in terms of producing a straightforward calibration process, and being robust with respect to channel specification. Copyright (C) 2001 John Wiley & Sons, Ltd.

Original languageEnglish
Pages (from-to)825-842
Number of pages18
JournalHydrological Processes
Volume15
Issue number5
Publication statusPublished - 15 Apr 2001

Keywords

  • TOPOGRAPHY
  • CHANNEL FLOWS
  • calibration
  • finite elements
  • CHOICE
  • LASER ALTIMETER MEASUREMENTS
  • flood modelling
  • remote sensing

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