Flood Inundation Modelling to Support Flood Risk Management - Flood Risk Science and Management - page 230

Table 12.1 Classification of flood inundation models (adapted from Pender 2006)

Typical
computation
times

Example
models Method Description Application Outputs

1D Solution of the

one-dimensional
St-Venant equations

Design-scale modelling, which can be of the
order of tens to hundreds of kilometres,
depending on catchment size

Minutes Water depth, cross-section averaged velocity,

and discharge at each cross-section

Mike 11
HEC-RAS

Inundation extent if oodplains are part of

1D model, or through horizontal
projection of water level

ISIS
InfoWorks RS

1D þ 1D plus a storage cell

approach to the
simulation of

Design-scale modelling, which can be of the
order of tens to hundreds of kilometres,
depending on catchment size; also has the
potential for broad-scale application if used
with sparse cross-section data

Minutes As for 1D models, plus water levels and

inundation extent in

Mike 11
HEC-RAS
ISIS
InfoWorks RS

oodplain storage

cells

oodplain ow

2D- 2D minus the law of

conservation of
momentum for the
oodplain ow

Broad-scale modelling and applications where
inertial effects are not important

Hours Inundation extent LISFLOOD-FP

Water depths JFLOW

2D Solution of the two-

dimensional shallow
water equations

Design-scale modelling of the order of tens of
kilometres. May have the potential for use in
broad-scale modelling if applied with very
coarse grids

Hours or days Inundation extent TUFLOW

Water depths Mike 21

Depth-averaged velocities TELEMAC

SOBEK
InfoWorks-2D

2Dþ 2D plus a solution for

vertical velocities
using continuity only

Predominantly coastal modelling applications
where 3D velocity pro les are important.
Has also been applied to reach-scale river
modelling problems in research projects

Days Inundation extent TELEMAC 3D

Water depths
3D velocities

3D Solution of the three-

dimensional
Reynolds averaged
Navier - Stokes
equations

Local predictions of three-dimensional velocity
elds in main channels and oodplains

Days Inundation extent CFX

Water depths
3D velocities