MAFF/Environment Agency Advisory Committee on Flood and
Coastal Defence Research and Development
Recommendations for research related to weather radar
Introduction
The recommendations made by the Committee, chaired by Professor Edmund Penning-Rowsell,
for research related to weather radar were made under the heading of Flood forecasting and
warning.
Flood forecasting and warning: indicative research topics
The Committee identified a number of common themes which served to focus the research
needs. These themes in some cases involved “cross cutting” technologies and work practices
such as remote sensing, data assimilation and international participation. They all involved
interlinked sub-projects. The themes with an interface with weather radar were outlined as
follows:
1.
Assessing the sensitivity of flood forecasts to forcing factors
The preparation of flood warnings involves putting together modules to acquire data in both
real-time, and off-line to describe catchment and channel characteristics, to initialise models
and to describe the dynamics of the rainfall-runoff conversion and river routing. The success
of the models depends upon their sensitivity to a number of forcing factors which include
errors in data inputs and deficiencies in the parameterisations of physical processes. Of
particular importance is the use of weather radar data. The Agency has, and continues to
invest heavily in this technology, yet the error characteristics of the data mitigate against its
use in real-time as input to models. Improvements in data quality and guidance on error
characteristics are urgently needed.
In spite of many years’ research, quantitative rainfall forecasting for a few hours ahead
remains problematic. The Agency has supported research in this area, based upon the use of
radar data, with encouraging results, but further research is needed to complement
Meteorological Office activities and ensure that the needs of real-time flood forecasts are met.
Sub-topics were defined as follows:
(i)
(ii)
real-time improved accuracy of weather radar data
development of real-time quality indices for weather radar data
Both (i) and (ii) are important elements of real-time data acquisition
(iii) rainfall forecasting
(iv) model structures for extreme fluvial events
2.
New datasets
GIS has enabled comprehensive datasets of terrain, soils, vegetation, land use etc. to be
readily accessible for use by distributed hydrological models. River channels and estuaries are
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constantly changing particularly during storm events. There is a need to develop generic
procedures for providing flood forecasts for ungauged catchments based upon the use of GIS
information and remotely sensed data. New datasets also require procedures for their
assimilation with real-time forecast models which should be developed continually. In the
future this might include appropriate representations of channel and shoreline geomorphology.
Sub-topics include:
(i)
(ii)
forecasting for ungauged “flashy” catchments
data assimilation
3.
Decision support
Good flood forecasts are not enough. The utility of different lead times requires investigation.
Presentation and dissemination of these forecasts in ways which aid decision taking, e.g. when
and where to issue forecasts and marshall defences; to whom forecasts should be issued; how
reliable forecasts should be; the responsiveness of people; and real-time targeting of flood
warning systems are central issues. The effectiveness of warnings needs to be assessed
continually.
Specific sub-topics include,
(i)
(ii)
(iii)
(iv)
(v)
utility of different lead times; assessing what are “effective” flood forecasts
how reliable forecasts need to be
response of communities to flood warnings
tactical management and emergency procedures at times of flooding
social targeting of flood warning systems in real-time
4.
Assessing the performance of flood warning systems
Model inter-comparisons, and real-time operational assessments over long periods, and
emergency response involving public awareness analyses through consultation, must underpin
effectiveness studies. However, the information so gathered must feedback to improve
operational procedures and models. This requires the development of methods (both off-line
and real-time) for assessing the performance of flood warning systems
Links to other themes and budgets
The links between the Flood Forecasting and Warning Theme and other Themes in the
Committee’s report are as indicated in the table below. The table also indicates other bodies
that might fund related research, which include NERC, the Met. Office and Local Authorities,
as well as MAFF and the Environment Agency.
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Decision support
Indicative cost, £k
Other potential funders and collaborators
Community interface
Biodiversity, conservation and sustainability issues
Institutional change
Preventative options: land use and related issues
Integration with environmental needs



Met. Office
100

NERC
100



Data assimilation



Utility of different lead times


















Tactical management - emergency procedures
Social targeting of flood warning systems

Developing methods of assessment

100

Forecasting for ungauged "flashy" catchments
Response of communities
Met. Office



How reliable forecasts need to be
Assessing the performance of flood
warning systems
Engineering
Risk and uncertainty
Indicative research topics
Model structures - fluvial
New datasets
Flood forecasting and warning

Performance evaluation
Rainfall forecasting
Economic and community impacts


Climate change
Fluvial, estuarine and coastal processes

Real-time data acquisition: quality indices for radar data
Sub-themes
Assessing the sensitivity of flood
forecasts to forcing factors
Broad scale models
Data and information
Real-time data acquisition: improved accuracy of weather
radar
THEMES



100
100



250
Local Auth.

TOTAL
100
850
Flood Forecasting and Warning: Links to other themes and budgets
Timescales and phasing
The Committee suggested that the four priority research topics could all be undertaken in
parallel. Since the data referred to in the first two areas already existed, nothing was to be
gained from delaying this work. Work on modelling shoreline and channel geomorphology
was likely to be some time in the future, perhaps beyond the timescale over which this
research is operable, and was therefore not included as a topic.
No one single research group is essential to more than one area. However, since the first two
areas could be regarded as providing important information for the decision support and
performance assessment work, the Committee considered it might be appropriate to phase the
first two areas about one year before the start of the third and fourth areas.
In reality, the timing of the research is also influenced by the availability of funding. It is
unlikely that the Agency will be committing significant funding to this area of research before
the 2001/2 financial year. MAFF may be funding research in this area next year (2000/1).
MAFF and the Agency have agreed to develop their programmes of R&D for flood defence in
collaboration. The Agency will lead the development of the definition of projects within the
programme for flood forecasting and warning through their new Centre for Flood forecasting
and Warning, agreeing the content with MAFF. This will inevitably delay the start of major
collaborative initiatives.
Dissemination
The Committee identified dissemination as a subject that needed much improvement. This is
being addressed in the proposals for implementing the report of the Advisory Committee.
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