Environmental Engineering Reference
In-Depth Information
MODELLING THE DRIVERS
National SE
Scenarios
Coupled Climatic and Socio-
economic Scenarios (IPCC)
Downscaling
Flood Risk
Management Strategy
Urban/ Rural/
Coastal Futures
Climate and Socio-economic
Variables at City and Basin Scales
MODELLING THE PRESSURES
Population Growth
Demographic
Changes
Urban/Rural/Coastal
Land Use Scenarios
Models of
Urban/Rural/Coastal
Futures
MODELLING THE STATES
Sources
Rainfall
Runoff
Sea level
Flood Risk
Economic, risk
to life, social,
natural
environment etc
Pathways
River networks
Urban surfaces
Flood defences
Floodplains
Receptors
People
Houses
Industries
Infrastructure
MODELLING THE IMPACTS
Economic
Damage: Local
Economic: Regional
Social
Assessment
Environmental
Habitats
Biodiversity
EVALUATING THE RESPONSES
Policy Options
Portfolios of
Response Options
Infrastructure
Land Use Planning
Emissions
Reduction
Governance and
Stakeholder
Empowerment
Institutional Frameworks
Public Participation
Regulation
Integrated Assessment of Policy Options
(Risk, Uncertainty, Sustainability)
Catchment Flood Management Plans
Coastal Management Plans
Fig. 12.1
Drivers, Pressures, States, Impacts, Responses-Flood Risk Management (DPSIR-FRM) decision support
framework. FromWheater et al. (2007). Reproduced with the permission of the Department of Environment, Food and
Rural Affairs (Defra).
at the scale necessary to support flood risk man-
agement decisions. Table 12.1 provides a summa-
ry of the methods and the range of appropriate
application for each method.
Most practical problems of floodplain inunda-
tion, where horizontal length scales typically
exceed flood depths by several orders of magni-
tude, are best described in 2D. Two-dimensional
approaches are almost exclusively based on the
two-dimensional shallow water equations. These
(also referred to as 2D St-Venant equations, by
extension of the use of this terminology; see
Hervouet 2007) can be derived by integrating the
Reynolds Averaged Navier-Stokes equations over
the flow depth. In this integration process a
hydrostatic pressure distribution is assumed (see
