Environmental Engineering Reference
In-Depth Information
impacts within the DPSIR-BSMmodelling frame-
work in Figure 2.3:
.
Detection of land use management impacts in
catchment flood response data [followed up in
Project FD2120 (Beven et al. 2008)].
.
Multiscale experiments across a range of catch-
ment scales that would cover a range of land use
management interventions and provide high-
quality data for model validation; these are needed
to answerQuestion 2 above: howdoes a local-scale
effect propagate downstream, and how do many
different local-scale effects combine to affect the
flood hydrograph at larger catchment scales?
.
New distributed modelling approaches that
would allow impacts to be tracked from local to
catchment scales.
.
Field trials of mitigationmeasures (responses) to
determine their performance.
.
Tools to support decision-making such as SPR
modelling and vulnerability mapping.
There are four ongoing field experiments
(SCaMP, CHASM, Pontbren and Belford), which
are supplying high-quality data, while newmodel-
ling developments are taking place within both
the Natural Environment Research Council
'Flood Risk from Extreme Events' (NERC-FREE)
and FRMRCprogrammes that will ultimately feed
through into the next generation of catchment-
scale flood risk management planning (e.g. in
Modelling and Decision Support Framework,
MDSF). All of these are summarized below.
respect to specific topographic, soil, cropping and
climatic conditions.Moreover, suchmeasures can
also control nutrient pollution and sediment
transport, thus generating multiple benefits for
the water environment.
Local-scale mitigation measures (e.g. at the
farmscale) can be viewed as 'prevention at source',
but, since their effect will essentially be to delay or
attenuate the delivery of runoff (e.g. by changing
the partitioning of surface and subsurface runoff
through increased infiltration), the overall effect
on the catchment flood hydrographwill depend on
how these changes affect the hydrological func-
tioning of the catchment as a whole, given that
they will interact with other ongoing changes (e.g.
to river and floodplain management).
Strategic Research Framework
In a recent review of future research requirements
for flood risk management (Wheater et al. 2007),
broad-scale modelling requirements to support
decision-making in planning whole catchment
and whole shoreline flood risk management were
identified. The various elements of the proposed
broad-scale modelling (BSM) programme were
then mapped into a DPSIR framework (Fig. 2.3).
Figure 2.3 illustrates that a comprehensive, inte-
grated modelling approach must encompass not
just the central impact modelling and prediction
that is typically formulated to support a Source-
Pathway-Receptor approach to the management
of flood risk, but also consideration of the drivers
and pressures that may give rise to future land
use management changes. Moreover, mitigation
interventions must be assessed using a broad,
integrated assessment approach that considers
economic, social and environmental aspects of
sustainability as outlined in 'Making Space for
Water'.
Figure 2.4 is a schematic of the various
elements of an integrated research programme
assembled to address the following priorities iden-
tified by O'Connell et al. (2005); these relate to
understanding, modelling and predicting states,
impacts and land use management
Multiscale Experimentation in Support
of Modelling and Prediction
The CHASM multiscale experimentation
programme
The importance of understanding scale effects,
particularly the factors controlling the variability
in response both within and between catchments,
was recognized in 1998 when a consortium of
universities and research institutes was formed
to develop the Catchment Hydrology and Sustain-
able Management (CHASM) programme of inte-
gratedmultiscale experimentation, modelling and
prediction. In CHASM, the instrumentation of
response
