A conceptual framework for a nonstructural approach to reduce flood impact in urban catchments.

Owing to historical processes that can be traced back over two millennia, flooding in urban
catchments is managed using the wider UK flood risk management (FRM) cost-benefit
approach focussing on structural defences. While in principle, structural defences are
effective for managing flooding in urban catchments, difficulties in appraising the
consequences of this type of flooding in terms of derived economic benefit, means providing
structural protection for urban catchments is often economically inappropriate. Since the
benefits of structurally protecting urban catchments rarely outweigh the costs, incidences of
flooding in urban catchments are inevitable. The conceptual basis for a non-structural
approach to reduce flood risk is developed in this PhD thesis. The findings indicate that over
the long-term, a non-structural approach can reduce flood risk, be less expensive than the
structural counterpart and serve as an additional dimension to the current FRM system.
Tangible and intangible Flood Impact (the core components of flood risk) is reduced through
a process of influencing behaviour through stakeholder group-specific Capacity Building
using appropriate and effective engagement of stakeholders and novel use of existing
technology systems such as GIS. Tangible Flood Impact such as flood damage can be reduced
by providing tactical stakeholders (TSHs) with quality catchment data that over time will
enable creation of greater accuracy drainage models. Intangible Flood Impact such as trauma
can be reduced by providing inexpensive but comprehensive and appropriate support to
receptor stakeholders (RSHs) and dwellers.
The framework has been derived from involvement in three case studies: ERA NET CRUE
case study, Glasgow, Scotland, Non-Structural Responses (NSR), Defra case study FD 2603
(part ofINTERREG ivb1
), Managing Adaptive REsponses to changing flood risk in the North
Sea Region (MARE), and; Defra case study, West Garforth, England, Integrated Urban
Drainage pilot (IUD). The basis for the framework was identified in the Glasgow NSR case
study and was derived from engagements with professionals and dwellers in Glasgow. This
basis was developed into a conceptual framework during the remaining two case studies
which involved engagement with professionals and dwellers in England. The framework is
now available for application.