Environmental Engineering Reference
In-Depth Information
11
Data Utilization in Flood
Inundation Modelling
DAVID C. MASON, GUY J-P. SCHUMANN
AND PAUL D. BATES
Introduction
of two- and higher-dimensional inundation mod-
els, which require 2D data for their parameteriza-
tion and validation. The situation hasmoved from
a scenario in which there were often too few data
for sensible modelling to proceed, to one in which
(with some important exceptions) it can be diffi-
cult tomake full use of all the available data in the
modelling process.
This chapter reviews the use of data in present-
day flood inundation modelling. It takes the
approach of first eliciting the data requirements
of inundationmodellers, and then considering the
extent to which these requirements can be met by
existing data sources. The discussion of the data
sources begins by examining the use of data for
model parameterization. This includes a compar-
ison of the main methods for generating Digital
Terrain Models (DTMs) of the floodplain and
channel for use as model bathymetry, including
airborne scanning laser altimetry (Light Detection
and Ranging: LIDAR) and airborne Interferometric
Synthetic Aperture Radar (InSAR). Filtering algo-
rithms for LIDAR data are reviewed, as are the use
of remotely sensed data for distributed floodplain
friction measurement and the problems of inte-
grating LIDAR data into an inundation model. A
detailed discussion follows on the use of remotely
sensed flood extent and water stage measurement
for model calibration, validation and assimilation.
Flood extent mapping from a variety of sensors is
considered, and the advantages of active micro-
wave systems highlighted. Remote sensing of
water stage, both directly by satellite altimeters
and InSAR and indirectly by intersecting flood
Flood inundation models are a major tool for
mitigating the effects of flooding. They provide
predictions of flood extent and depth that are used
in the development of spatially accurate hazard
maps. These allow the assessment of risk to life
and property in the floodplain, and the prioritiza-
tion of either the maintenance of existing flood
defences or the construction of new ones.
There have been significant advances in flood
inundation modelling over the past decade. Prog-
ress has been made in the understanding of the
processes controlling runoff and flood wave prop-
agation, in simulation techniques, in low-cost
high-power computing, in uncertainty handling,
and in the provision of new data sources.
One of the main drivers for this advancement
has been the veritable explosion of data that have
become available to parameterize and validate the
models. The acquisition of the vast majority of
these new data has been made possible by devel-
opments in the field of remote sensing (Smith
et al. 2006; Schumann et al. 2009). Remote sens-
ing, from both satellites and aircraft, allows the
rapid collection of spatially distributed data over
large areas, and reduces the need for costly ground
survey. The two-dimensional synoptic nature
of remotely sensed data has allowed the growth
