Progress Report October 2008
Source: environment.data.gov.uk (2018-06-19)

Flood Risk for Extreme Events (FREE): Radiosonde, Wind Profiles Data and Model Output from the Exploitation of new data sources, data assimilation and ensemble techniques for storm and flood forecasting project. The Exploitation of new data sources, data assimilation and ensemble techniques for storm and flood forecasting Project is a NERC Flood Risk for Extreme Events (FREE) Research Programme project (Round 1 - NE/E002137/1 - Duration January 2007 - April 2010) led by Prof AJ Illingworth, University of Reading. This project investigates possible methods of producing ensemble weather forecasts at high-resolution. These ensembles will be used with raingauge and river flow to improve methods of flood forecasting. The dataset includes radiosonde and wind profiles in England and Wales derived using Doppler radar returns from insects. The radial velocity measurements from insects were converted into VAD profiles by fitting a sinusoid to radial velocities at constant range. All measured profiles have been interpolated to the instrument location. 
Model output files from experiments assimilating radial winds from insects are also available.

Floods in the UK are often caused by extreme rainfall events. At present, weather forecasts can give an indication of a threat of severe storms which might cause flash floods, but are unable to say precisely when and where the downpours will occur, due to the complex range of processes and space-time scales involved. The first stage is to predict the air motions leading to convergence and ascent at a certain location where the precipitation will be initiated, then the development of the precipitation needs to be forecast, and hydrological models used to produce accurate, quantitative, probabilistic flood predictions. Data assimilation is a sophisticated mathematical technique that combines observations with model predictions to give an analysis of the current state of the atmosphere. This analysis may be used to initialise a weather forecast. Although precipitation is well observed by weather radar, attempts to assimilate radar data have had little success; by the time the rain develops the forecast model state is too far from the truth and the air motions are inconsistent with the position of the first radar precipitation echo.

We propose to overcome this problem by assimilating new types of data from weather radars. These provide information on the evolving humidity fields and air motions in the lower atmosphere so that the model can accurately track the developing storm before precipitation appears. The model used will be a new Met Office model that can be run with a resolution (i.e., grid-spacing) of order 1-4km. This enables storm-cloud motions to be explicitly calculated, rather than treated as a sub-grid-scale effect. Furthermore, current operational forecast models are only updated with observations every few hours; in the new approach the model will be updated much more frequently. This should yield weather forecasts with improved locations (in space-time) for rainfall events.

Initialisation errors are not the only cause of inaccuracies in storm-scale weather forecasts. Models are often run only for a small region of the world, and the data on the boundaries of this area provided from a larger-scale model. These data are known as lateral boundary conditions. Errors in these lateral boundary conditions and modelling errors also contribute to the errors in the forecast. Even if these errors were reduced, the nonlinear nature of the storm dynamics ensures that there is a limit, beyond which the value of deterministic forecasts becomes questionable. After that point it becomes important to determine the uncertainties in the forecast precipitation, so an ensemble approach is required. (An ensemble is a collection of perturbed forecasts that may be considered as a statistical sample of the forecast probability distribution.)

The appropriate construction of a storm-scale ensemble is an open question. We propose a structured approach where perturbations will be designed on the basis of physical insight into convective forcing mechanisms. The resulting probabilistic rainfall forecasts can be interfaced to hydrological models used for flood forecasting. For the first time, this project will allow different scales of application of these methods to be supported: ranging from localised flash flooding of small catchments, through to indicative first-alert forecasting with UK-coverage and forecasting of river discharges to the sea. The project will also assess the impacts of improvements in numerical weather prediction on flood forecast performance.

In this project we anticipate fruitful interactions between the different disciplines of observations and measurement, meteorology and hydrology. Radar assimilation software development and ensemble forecasts will take place using Met Office models, so improvements can be implemented operationally very easily. The use of operational radars makes this project well placed to take advantage of data from any extreme events occurring during the period of the study.

Flood Risk from Extreme Events (FREE) 
 
Progress Report October 2008 
 
Chris. G. Collier, FREE Science Coordinator 
Centre for Environmental Systems Research, University of Salford 
 
 
A. 
Progress against Research Themes 
 
Theme 1: 
Improved 
modelling and 
forecasts through 
new data 
assimilation 
methods 
Theme 2: New 
approaches to 
modelling 
uncertainty in an 
integrated 
modelling 
environment 
Theme 3: The 
statistics of 
extremes and their 
use 
Theme 4: The 
Impacts of a 
changing climate 
on the occurrence 
of flooding 
Illingworth – 
NWP and new 
remote sensing 
observations 
Zou – linking 
meteorological, 
hydrological and 
coastal models 
using ensemble 
methods 
Svensson – joint 
probability analysis 
of fluvial and 
estuarine floods 
Osborn – changing 
occurrence of 
rainfall 
Dance – 
initialisation of 
coastal sediment 
models 
Beven – 
constraining 
uncertainty in 
hydrologic 
modelling 
McSharry – 
quantifying flood 
risk using density 
forecasts based on 
a new digital 
archive and 
weather ensemble 
predictions 
Cloke – changes in 
hydrological and 
hydraulic flows 
TBC – reducing 
the risk of pluvial 
flooding 
Wheater – 
groundwater 
modelling of rare 
events 
Toumi – a hybrid 
model for 
predicting the 
probability of very 
extreme rainfall 
Reynard – changes 
in fluvial flooding 
and inundation 
 
O’Connell – 
impact of land use 
on behaviour of 
floods 
 
Williams – 
changes in 
characteristics of 
coastal floods 
 
 
 
 
1

 
Theme 1: Improved modelling and forecasts through new data 
assimilation methods 
 
Considerable progress has been made in developing numerical weather prediction and 
new remote sensing observations (Illingworth). Five months of quasi-operational 
refractivity data has now been collected at Cobbacombe. In early April the 
Intermediate Frequency filters were optimised for refractivity work at Cobbacombe 
providing a significantly improved range pattern of the radar pulse. Comparisons with 
synoptic stations close to Cobbacombe over several months show that the refractivity 
inferred from the radar tracks well.  The accuracy of the radar data continues to be 
assessed so that errors can be derived. Data is clearly degraded when the radar 
transmit frequency exhibits very large excursions.  Following the success of the trials 
at Cobbacombe, the code will be rolled-out to several other radars in the UK 
operational network in the coming months.  
 
On deriving insect winds, the comparison between the Thurnham and Chenies radar 
has been completed, pending modifications to improve the Thurnham radar's 
sensitivity. The insect season has begun and data are now being examined from all 
operational Doppler radars. This will give a better idea of data availability and 
coverage for insect wind measurements. The operational threshold for Doppler returns 
has been lowered, so during this summer changes to insect return utilisation for VADs 
in the Met Office's NWP are being monitored. Test assimilations of insect VADs have 
been conducted with the Met Office observation processing and assimilation systems. 
Experiments to assimilate VADs from all radars into a full quasi-operational 
assimilation-forecast cycle are under development. This will test the effect of the 
additional wind data on the forecast. 
[Relevance: Observing the two new parameters is crucial to the success of the 
project.]  
 
Further analysis of the previously-performed 4km ensemble simulations for CSIP 
[Convective Storm Initiation Project funded by NERC] IOP18 is being carried out and 
is now near completion. The analysis aims to determine the direct effects of the 
perturbation on the model state, and based on this to build an understanding of the 
variations in cloud distribution and RMSE of precipitation. Preliminary results 
indicate that the sensitivity to the perturbation changes during the day, and is 
dependent on perturbation intensity with a modulating effect due to the typical scale 
length. Conclusions from this work will drive the choice of the perturbation strategy 
for the 1.5 km experiments. The Boscastle flood was chosen for several parts of this 
study as common event to test both the hydrological effects of the current version of 
the ensemble, and the data exchange with the Joint Centre for Mesoscale Meteorology 
(JCMM).  
 [Relevance: Knowledge of physical processes that lead to predictabilty and error 
growth is key for a meaningful design of the meteorological ensemble.]   
 
Further results have been obtained using the distributed G2G hydrological model 
configured over an area of southwest England as part of the Boscastle case study. The 
model performance is being assessed in both simulation and forecast mode 
(assimilation of flow data) for a range of lead times.  
 
2

 
[Relevance:  Progress on a convective storm case study using high resolution NWP 
rainfall forecasts in a distributed flood forecasting model and in ensemble mode.]. 
 
The project led by Dance has received tidal constituent data from Roger Proctor at 
POL. These will provide the tidal boundary conditions for the Morecambe Bay and 
Dee estuary hydrodynamic models. Discussions are underway with Kevin Horsburgh 
at POL (replaced Roger Proctor who has taken a new position in Hobart) to obtain 
surge input data for the hydrodynamic models. Surge input is necessary for assigning 
heights to the waterline data.  
 
Various numerical schemes for solving the sediment conservation equation have been 
received, and it has been decided to use the Euler-WENO method of Long et al. (Long 
W, Kirby JT, Shao Z, 2008. A numerical scheme for morphological bed level 
calculations. Coastal Engineering 55, p167.). This has been implemented in the old 
Morecambe Bay model, for comparison against the old Lax-Wendroff scheme, which 
suffers from dispersion. The Euler-WENO scheme has some teething problems. The 
data assimilation/parameter estimation scheme has been further developed to estimate 
the parameters associated with the sediment flux in a simple nonlinear model. The 
results of this scheme are currently being analysed. 
 
There has been significant involvement with other bodies including the Environment 
Agency, HR Wallingford and Lancaster City Council. Nigel Cross of Lancaster City 
Council arranged for Tania Scott and Polly Smith to visit Morecambe Bay and 
familiarise themselves with the site. This involved a quad-bike tour of the flats 
organised by NWNW Sea Fisheries Association). Nigel Cross visited ESSC to discuss 
the project and exchange data. He is interested in mapping changes in low-water 
channels in Morecambe Bay for flood management purposes, and to aid navigation 
across the flats. Nigel supplied the project with complete LiDAR coverage of 
Morecambe Bay flown at low-water in November 2005. This will be extremely useful 
for data assimilation and model validation. He also provided data from GPS surveys 
of the tidal flats. In return access to SAR images was provided. 
 
 
Theme 2: New approaches to modelling uncertainty in an integrated 
modelling environment 
 
The project aimed at linking meteorological, hydrological and coastal models using 
ensemble methods (Zou) has set up the MM5 mesoscale model in two regions to simulate 
extreme events included in the ERA40 re-analysis data set such as the 1987 and 1990 
storms. The MM5 has been setup using the four dimensional data assimilation option 
(fdda) in order to assimilate the re-analysis data when running the model for several days. 
The MM5 allows assimilating wind, temperature and mixing ratio. For every field to be 
assimilated, a nudging coefficient has to be defined allowing the model state to move 
towards the analysis. The nudging coefficient is very important because it may force the 
model state too much towards the re-analysis, decreasing the ability of the model to 
resolve mass-momentum imbalances. Different nudging factors have been tested and the 
results will be compared using hundred of wind and atmospheric pressure observations 
from ground surface stations within the UK. A study is also currently underway to 
develop a methodology to generate ensemble simulations using the re-analysis data.  
  
 
3

 
The work on tide, surge & wave model has focused on the sensitivity tests of both 
POLCOMS and WAN models to gain further understanding of hydrodynamics produced 
by the model. Two sites have been used for these tests: the Irish Sea and English Channel, 
in order to get the model ready for specific sites to be identified in the project.  
 
(a) Irish Sea  
 
The quantitative assessment of wind and wave boundary forcing effects on wave climates 
has been carried out by running WAM model alone in the North Atlantic Sea (NAS) and 
in the Irish Sea (IRS). The model was first run in NAS domain, with 64 different wind 
forcing cases: combinations of 8 different wind directions (0º, 45º, 90º, 135º, 180º, 225 º, 
270 º, 315 º, anti-clockwise to East) with 8 different wind speed (5m/s, 10m/s, 15m/s, 
20m/s, 25m/s, 30m/s, 35m/s, 40m/s). The model was then run in IRS domain with three 
scenarios: (a) wind forcing only; (b) wave forcing only; and (c) both wind and wave 
forcing for all the wind speeds. The same wind conditions were used in these two 
domains and the wave forcing conditions for the IRS domain were obtained from the 
larger NAS domain by nesting techniques. Fig 1 shows the comparisons of the significant 
wave height and mean wave direction (vectors) between different forcing scenarios for 
cases with U=40m/s and Dir=90 º. It can be seen clearly that wave height responses to the 
wind forcing well, but is limited by the wind fetch (Fig 1a). As shown in Fig 1b, the wave 
forcing which represents the swell waves from far field affects significantly the wave 
field in the domain, but propagates to the limited area near the forcing boundaries, 
without the details of the waves affected by the local winds, in comparison with Fig 1c. 
The sensitivity of wind velocity and direction on different locations has been analysed 
and several look-up tables of the significant wave height at selected points have been 
created, although not shown here.  
 
 
 
 
(a) wind forcing only  
(b) wave forcing only  
(c) both wind and wave 
forcings  
Figure 1: Computed significant wave height (contours) and mean wave direction 
(vectors)  
 
 
(b) English Channel  
 
The POLCOMS and WAM models have also been successfully set up in the English 
Channel, with appropriate implementations of parameter settings for local bathymetry, 
tidal and wave boundary conditions required. The preliminary results on tidal currents and 
 
4

 
waves are shown in Fig 2. Further validations of models with the field measurement data 
is currently being carried out.  
 
 
 
Computed surface elevation ( m) and 
tidal currents (m/s)  
 
Computed significant wave height (m)  
Figure 2: Computed tides and waves at 00:00:00 09/11/2008  
 
 
Constraining uncertainty in hydrological modelling (Beven) has involved has 
involved assembling comprehensive data sets for model application and development 
for the specified test site from a variety of sources. In particular, topographic 
information (such as river cross sections, LiDAR and IfSAR data) were acquired and 
processed (see Fig. 3). Also, historic river flow and level data have been gained from 
the Environment Agency (EA) for the River Dee, River Alun and other major 
tributaries. Finally, two satellite images of the December 2006 flood event were 
acquired from the European Space Agency (ESA) and processed in order to derive 
flood extent maps (see Fig. 3). 
 
 
 
Figure 3: Test site: River Dee between Farndon and Iron Bridge and River Alyn between Pont-y-
Capel and the confluence (black line); Environment Agency gauging stations (black circles); 
flood extent derived by using the ESA satellite image (ERS-2 SAR, grey area) [left panel]; DTM 
at 2 m resolution derived by using LiDAR and IfSAR data (grey scale) [right panel]. 
 
 
A variety of 1D and 2D hydrodynamic models were built for the test site (e.g. Fig. 4):  
• 1D model (HEC-RAS);  
• Low resolution 2D model (50m, LISFLOOD-FP, Fig. 2);  
• High resolution 2D model (20m, LISFLOOD-FP).  
 
5

 
 
 
Figure 4: Low resolution 2D model (20m, LISFLOOD-FP): Results in terms of maximum water 
depth (blue scale) for the November 2000 flood event. 
 
Working is ongoing in developing adaptive real time Transfer Function forecasting 
techniques applicable for the River Dee. Work has focused upon capturing the 
interaction of the tidal and river dynamics. Of particularly interest have been the tidal 
bore and any control placed on the drainage of the flood plain (after flooding). The 
nature of the transfer functions constructed for a prediction of a single location is 
inherently multiple input, single output (MISO). The ARMAX transfer function 
formulation formulation for MISO systems appears unable to reproduce the system 
dynamics so alternative transfer function formulations are being explored. These 
include the use of state dependant denominators and the use of a separate transfer 
function for each input the results of which are then summed (see Jakeman et al., 
1980, IEEE Transactions on systems, man and cybernetics, Vol 10 Pgs 593-602.) 
An adaptable framework for incorporating heteroscedacicity into the error structure 
for the forecasting model has been formalised and incorporated within the simulation 
environment constructed for testing purposed.  
 
Software and hardware infrastructure has been configured and deployed at the 
gateway site in the new River Dee deployment. This infrastructure, in combination 
with the previously reported software framework will allow the deployment of 
transfer function models developed by Lancaster’s Environmental Science department 
to be hosted locally on the flood plain and integrated with the sensing hardware. 
 
Deployment of the gateway node is complete and further deployment locations 
(Figure 5) have been refined based upon the results of the initial results from WP1, 
on-site range testing and surveying of specific locations for sensor deployment. 
Discussions are ongoing with local landowners and fishing clubs to ensure suitable 
access. 
 
 
6

 
 
Figure 5: A detailed map of the proposed study area around the confluence of the River Dee and 
River Alun (Alyn). Red stars mark the proposed deployment locations of the GridStix hardware 
in river reaches, while blue stars denote deployment on the flood plain. The gold star marks the 
location of the EA Trevelyan pumping station which houses the gateway to GridStix network. 
 
 
The previously reported Dust/Java wrapper has been extended significantly, allowing 
for fine-grained remote control of critical mote functionality such as scheduling 
sensor readings and modifying network structure. A new C-based Dust network driver 
has also been created allowing the Dust motes to be used as a network interface card 
by host systems with insufficient resources to support Java. Additionally, a graphical 
system has been developed for logging and retrieving sensor data over the GSM link 
to the flood site. 
 
The campus-based test deployment of Dust sensor nodes has been successfully 
completed and factors such as battery life and range have been tested with extremely 
positive outcomes (e.g. high reliability and battery life of multiple years).  Ongoing 
work in this area now focuses upon testing of the same hardware at the River Dee 
deployment site. 
 
Work has continued on improving the understanding of the groundwater system to be 
able to better predict groundwater flooding (Wheater). Specifically, an understanding 
of the 2000/1 groundwater flooding event continues to be developed, including the 
collation of data which describes this event. The MaBSWeC model has been 
enhanced to simulate the 2000/1 event on a daily time step. Work has also been 
 
7

 
carried out to ensure that the ZOOMQ3D model can be run on the National Grid 
Service (www.ngs.ac.uk). Time series techniques have been developed and applied to 
simulate groundwater levels. 
The 1D model has been applied to all field sites. Performed well except in 2006, 
where large gaps in rainfall data are thought to be the problem. Further insights will 
be made with 2D model. This has been applied to the hillslope around East Ilsley. 
Currently the simulated water table response is too attenuated, which is thought to be 
associated with the specific storage.  
A meeting was held after the last quarterly report submission, in which a work plan 
was drawn up regarding how to proceed with modelling of the river Lambourn around 
the village of Boxford. Specific objectives were to determine the distance away from 
Boxford beyond which changes in aquifer parameters would not affect Boxford 
hydrology and to determine how adjusted aquifer parameters at Boxford would affect 
the time-variant boundary conditions supplied by the larger regional model, were that 
model to be run with those adjusted parameters. Additionally, it was agreed that the 
effect of layering would be examined. This work is ongoing. 
 
A technical meeting of the staff from the project led by O’Connell was held at 
Lancaster (May 28/29th). The meeting included a field visit to the Hodder catchment, 
during which several sites undergoing land use/management changes were identified 
for small scale monitoring (by Newcastle University) to support the Imperial College 
metamodelling (WP1). Newcastle are in the process of obtaining permissions for the 
installation of weirs at the sites, which are required for the provision of accurate flow 
measurements. A technical meeting was also held at Gregynog (July 10th/11th). This 
included a field trip to the Pontbren catchment (Upper Severn), which has been the 
focus for the initial development of the IC metamodelling. 
 
Soil properties data (including HOST) have been purchased from NSRI (Cranfield) 
for each of the three study catchments (Severn, Eden, Hodder). These data are being 
used to setup the small-scale physics-based models that underpin the metamodelling 
approach, and to support regionalisation. 
 
A preliminary comparison of regionalisation approaches has been carried out for 
Pontbren. A new approach to regionalisation has been developed, using the Base Flow 
Index (from the HOST classification) as an uncertainty restriction for modelling 
current conditions. Land use effects for the Pontbren field-based model have been 
evaluated using a local precipitation scenario and an extreme event recorded near 
Carlisle. 
 
A physics-based model of drained / undrained peat response has been developed and 
used for sensitivity studies. The development has utilised data from the Upper Eden 
(Gais Gill). Agreement has been reached with Joe Holden (University of Leeds) to 
access experimental data sets from peat plots/hillslopes to support model development 
and parameterisation. This will supplement the data being collected in the Hodder. 
 
Software has been developed to generate river networks from high resolution DEMs ). 
This will be used to couple the hydraulic models and the runoff generation 
metamodels for the test catchments. A field survey of channel cross sectional 
 
8

 
geometry has been performed in the Hodder. Using these data, scaling relationships 
have been developed (bankfull depths / widths / area relationships with upstream area) 
to fine-tune a DEM generated network of the Hodder. A grid representation of the 
Pontbren catchment has been prepared (100m x 100m scale). The grid representation 
and corresponding parameter sets have been provided for Information Tracking 
implementation. The Upper Severn (to Shrewsbury) boundaries have been obtained 
from Hannah Cloke (King’s College London FREE project). 
 
Significant advances have been made in the development of a new algorithm for 
Information Tracking.. An adjoint model has been created for the non inertia 
approximation to the Saint Venant equations, with special attention given to the 
accurate representation of flows at junctions and backwater effects. The algorithmic 
differentiation of the adjoint model provides a Jacobian, the elements of which relate 
the sensitivity of an impact (e.g. the catchment peak flows) to a change in a model 
parameter at a particular location. Using this approach it is possible to simultaneously 
calculate the impact sensitivities with respect to all possible perturbations in channel 
flow, resulting from a change in a model parameter, in a single simulation (i.e. the 
sensitivity is known for a change at any given landscape unit). This allows the 
creation of 2D vulnerability maps, showing where local scale changes will have the 
greatest impact on downstream flooding. 
 
Current activities are focusing on the further development of the adjoint model to 
study the propagation of impacts during extreme events, initially focusing on the 
Hodder. To create physically realistic coupling, attention is being paid to the 
interaction between channel processes and the hydrological processes on adjacent 
land surface (i.e. flood inundation processes). 
 
A space-time rainfall model has been developed for the Upper Eden (upstream of 
Temple Sowerby). In the first instance, the model has been calibrated using daily data. 
Hourly data have now been assembled to improve the calibration. Finally a literature 
review on peat hydrology has been completed. This includes information regarding 
the hydrological impacts of upland peat gripping and grip blocking. 
 
 
Theme 3: The statistics of extremes and their use 
 
Three more trial locations have been selected in Great Britain, and data have been 
retrieved for use by both CEH Wallingford (Svensson) and Lancaster.  The trial 
locations now total five sites, with varying soils/geology and climatic characteristics. 
The CEH work focuses on an event-based joint probability approach, although 
continuous data series are used to appropriately define the event variables. The 
characteristics of rainfall events of different durations are being investigated, and 
some tentative series of monthly rainfall maxima have been derived. Monthly river 
flow maxima have also been retrieved and plotted together with the associated 
rainfalls. Convex hull plots have been derived for some of the data, to illustrate the 
seasonal variation in the dependence between the variables, and in the marginal 
distributions of the variables.  
 
 
9

 
Lancaster have concentrated on developing covariate and random effects models for the 
rate of occurrence of flow events. Covariates used so far include baseflow and a moving 
average of (lagged) rainfall. The use of random effects was motivated by the observation 
that the number of events per year is over-dispersed for many UK catchments (even after 
accounting for covariates). Random effects are useful when there are missing covariates. 
Investigations of a more theoretical nature have also been made into the effect on the 
distribution of the annual maxima when different probability distributions are used for the 
number of events per year and, when included, the random effects. So far efforts have 
been concentrated on a single site, with considerable time being spent on identifying flow 
events and their properties. Some time has also been spent on getting acquainted with 
relevant hydrological literature.  
 
The project led by McSharry has reached a milestone in reporting on a procedure for 
producing site-specific probability density rainfall forecasts which are needed to price 
insurance premiums, contracts, and other financial products based on precipitation.  
 
The digitisation and GIS part of the project including British Rainfall (BR) data 
entry and map scanning;  BR data entry checking and extreme event classification has 
been  complete. A data preparation analysis including ECMWF data conversion and 
other data arching (Met Office MIDAS, NCEP GENS forecasts) has also been 
completed. In addition GLM ensemble calibration and quantile regression have been 
completed as has the model development. 
 
The spatio-temporal correlations in UK daily rainfall amounts over the Thames Valley 
have been investigated, and a statistical, Markov chain generalised linear models 
(Markov GLM) of rainfall have been constructed. Point and density forecasts of total 
rainfall amounts have been produced, and compared with each other and with 
forecasts of probability of occurrence rain from other proposed density models, 
including persistence, statistical climatology, Markov chain, unconditional gamma 
and exponential mixture models, and density forecasts from GLM regression 
post-processed NCEP numerical ensembles, at up to 45 day forecast horizons.  
 
The Markov GLMs and GLM processed ensembles produced skilful one-day ahead 
and short term point forecasts. Diagnostic checks show all models are well-calibrated, 
but GLMs perform best under the continuous-ranked probability score. For lead times 
of greater than one day, no models were better than the GLM processed ensembles at 
forecasting occurrence probability. Of all models, the ensembles are best able to 
account for the serial correlations in rainfall amounts. In conclusion, we recommend 
GLMs for future site-specific density forecasting. Investigations explain this 
conclusion in terms of the interaction between the autocorrelation properties of the 
data and the structure of the models tested.  
 
Work on the development of a hybrid model for predicting the probability of very 
extreme rainfall (Toumi) continues. A numerical modelling case study of a very 
extreme rainfall event is underway. In order to fully understand the response of the 
model to changes in atmospheric moisture availability a simpler set of idealised 
experiments are underway. To date, most of the work has concentrated on these 
idealised experiments. 
 
 
10

 
A suite of experiments using the WRF (Weather Research and Forecasting) model has 
been completed. This suite of experiments comprises both 2-D and 3-D simulations of 
an idealized squall line for a range of temperatures with relative humidity held 
constant. In this way, the precipitable water (i.e. the atmospheric moisture vailability) 
can be changed while the system remains in dynamic balance. A detailed analysis of 
the model response to the changes in moisture availability is currently being 
undertaken. 
 
The WRF model (version 3) is a fully compressible, non-hydrostatic regional 
atmospheric model that is under constant development through the collaborative 
efforts of various research and operational institutions worldwide. One of the main 
advantages it has over other similar models is that it has been developed to enable 
simulations of a number of atmospheric situations within an idealised framework. 
This allows the user to fully isolate the effects of changes to any of the forcing 
mechanisms in the initial conditions or model physics. 
 
For the experiments the model is run with a horizontal resolution of 1km on a domain 
that is 800km in the x-direction and 160km in the y-direction (for 3-D simulations). 
80 vertical levels are used with a grid spacing of 250m with the model top at a height 
of 20km. Open lateral boundary conditions are used in at the x boundaries and 
periodic boundary conditions are applied at the y boundaries. For cloud microphysics 
parameterisation, a Kessler type scheme is used. This is a simple warm cloud scheme 
that includes water vapour, cloud water and rain. The effects of Coriolis force, surface 
physics and atmospheric radiative transfer are not included. 
 
The model is initiated with vertical profiles of temperature and water vapour that are 
based on a typical condition for strong midlatitude convection. The vertical profile of 
wind includes strong shear in the lowest 2.5 km of the atmosphere. Squall lines are 
initiated by a line oriented thermal perturbation with a x-radius of 5km and vertical 
radius of 1.5 km placed at the domain centre 1.5km above the ground. For the 3-D 
experiments small random temperature perturbations are added to the thermal in order 
to accelerate the squall line towards a 3-dimensional structure. 
 
For constant relative humidity, theory suggests that the amount of atmospheric 
precipitable water is constrained by the water vapour content of saturation, which is 
governed by the Clausius-Clapeyron relation. The Clausius-Clapeyron relation 
predicts that there will be a 7% increase in precipitable water per degree of warming. 
Fig. 1 shows the peak 1-hour rainfall accumulation from the simulated idealised squall 
line for a range of initial surface temperatures. It is clear that up to a temperature of 
about 25C the response of peak hourly precipitation to increased temperature (and 
therefore moisture as relative humidity is held constant) scales with the Clausius-
Clapeyron relation. However, at higher temperatures this scaling diminishes. For the 
8-hour accumulation period, the peak accumulation actually decreases with increasing 
temperature. 
 
 
11

 
 
Figure 6: Peak precipitation accumulation on a logarithmic scale as a function of 
temperature.  
 
 
The solid line in Figure 6 shows the peak 1-hour precipitation, the dashed line shows 
the peak 8-hour accumulation and the dotted lines show the Clausius-Clapeyron 
relation (7% increase per degree C). The decrease in peak 8-hour accumulation and 
diminishing increase for the 1-hour accumulation with increasing temperature is due 
to an increase in the speed at which the squall line moves. Fig. 7 shows Hovmöller 
diagrams for squall lines with initial surface temperatures of 22C, 25C and 28C. From 
Fig. 7 it is clear that as the temperature is increased, the heaviest rainfall moves more 
rapidly to the east. At this stage, the team believe that this is due to increased latent 
heat release as a result of a warmer moister atmosphere. This energy is converted to 
momentum that increases the strength of the rear-to-front flow in the squall line thus 
accelerating the system. A full momentum analysis is being undertaken in order to test 
this hypothesis. The results suggest that, at least for the case of an idealised squall 
line, increased moisture availability does not necessarily result in an increase in point 
rainfall accumulations, particularly for warmer temperatures and longer accumulation 
periods. This means that rainfall extremes, which are typically associated with 
convective rainfall, may not be governed by moisture availability alone. Further 
idealised experiments are planned that will help to clarify the role of other influences 
on extreme rainfall for squall lines such as vertical wind shear and topography. 
 
 
 
 
 
 
 
 
 
12

 
(a) 
 
 
(b) 
 
 
(c) 
 
 
Figure 7: Hovmöller plots of 5-minute rainfall accumulations for different initial surface 
temperatures for 2-D squall line simulations: (a) 22C, (b) 25C, (c) 28C. The y-direction is 
time from 0 to 8 hours with a resolution of 5 minutes, and the x-direction is distance 
along the domain with a resolution of 1km. 
 
 
Initially the plan was to use the Met Office Unified Model (UM) to study the July 
2007 extreme rainfall event. However, for consistency with the idealised experiments, 
it was decided to use the WRF model. In addition, it was felt that the WRF model 
provides a much more user-friendly solution to performing the sorts of experiments of 
interest. 
 
A control run to simulate the July 2007 event has been carried out using the WRF 
model with initial and boundary conditions provided by analyses from the Global 
Forecasting System. The model is run in nested configuration with the highest 
resolution nest having a grid length of 3km. At this grid length it is expected that the 
model will be able to explicitly resolve convective processes, so no cumulus 
parametrisation is employed. An initial examination of the model output suggests that 
WRF does a reasonable job in simulating the rainfall extremes observed in this event, 
although there are some small errors in the timing and location of the extreme rainfall. 
For this project interest is focused on the effects of increasing atmospheric moisture 
availability on the extreme amounts of rainfall rather than timing and location of these 
 
13

 
extremes, so it was felt that such errors would not affect the interpretation of the 
results. Modifications have been made to the WRF code to allow the temperature in 
the initial and boundary conditions to be increased whilst keeping the relative 
humidity fixed in a consistent manner. Simulations are ongoing. 
 
 
Theme 4: The impacts of a changing climate on the occurrence of flooding 
 
Work continued to study the relation between air flow indices and precipitation 
extremes in the UK (Osborn). VGAM (Vector Generalised Additive Models) 
statistical models have been developed that describe the relationships between airflow 
indices and the probability distribution of monthly precipitation maxima across the 
UK.  The spatial and seasonal variations in the statistical model parameters have been 
visualized, and physical explanations for these variations, including elevation and 
exposure to prevailing winds, have been sought.  These statistical models have been 
used to identify time-variations in UK precipitation extremes that can be explained by 
time-variations in the air flow characteristics over the UK, and also the residual 
variations that cannot be explained in this way by our models. 
 
New work has been begun during this period to extend the analysis of the 
relationships between air flow and UK precipitation extremes to simulations with the 
HadRM3H regional climate model. 
 
Knowledge about the covariates is important to identify physical drivers of extreme 
precipitation. These links are now being used to evaluate the performance of regional 
climate models. Knowledge about their future behaviour will also help to better 
predict changes in extreme precipitation. 
 
Work continues (Cloke) on developing uncertainty assessments of flood inundation 
Impacts using spatial climate change scenarios to drive an ensemble of distributed 
models for extreme conditions. The aim is to improve estimates of flood inundation 
hazard by propagating uncertainties from Regional Climate Model precipitation 
projections into an ensemble of flood inundation predictions for large river catchment 
scales, based on the Upper Severn catchment, UK (in particular the reach Buildwas to 
Montford which includes the town of Shrewsbury). The initial simulation set is now 
almost complete with regards to generating the various input precipitation fields, 
routing these through part of the model cascade (LisfloodRR and FP) and analysing 
the sensitivities of the modelling components. All RCM data is now downloaded and 
processed along with new observed gridded meteorological data from the Met Office. 
 
Overall the intention is  to use a cascade of distributed climate, rainfall-runoff and 
flood inundation models to: (i) Quantify the top-end uncertainties by assessing 
extreme precipitation fields produced using two contrasting approaches. (ii) Assess 
the impact of these top-end uncertainties on flood inundation predictions. (iii) 
Quantify all inter- and intra- model uncertainties of the cascade framework for various 
climate, land use and soil moisture scenarios. (iv) Assess the impacts of using 
different existing rainfall-runoff and flood inundation models with a relatively low 
number of simulations using novel techniques. (v) Deliver a methodology for general 
use that is highly scaleable. 
 
14

 
 
The major progress over the last 6 months in the 
project FRACAS: A next generation national 
Flood Risk Assessment under climate ChAnge 
Scenarios (Reynard) has been in applying the 
large basin NSRP model to simulate spatial 
rainfall for the Eden catchment (Cumbria) at the 
hourly level.   All available hourly and daily 
rainfall data above Temple Sowerby (near 
Carlisle, 616 km2 area) have been analysed and 
used in fitting the model (see Figure 8).  
•
•Figure 8: The locations of the daily and hourly 
raingauge records for the Eden catchment above 
Temple Sowerby. 
 
The model performs well for a range of daily and 
hourly properties, including cross-correlations 
(Figure 9) and extremes at high and low elevation 
sites (Figure 10).    
 
 
 
 
 
 
 
Figure 9:  Daily cross-correlation against raingauge separation estimated for all observed sites 
for (Obs) for January and July compared with the corresponding estimate from a 10 member 
ensemble of 20y simulations sampled at all raingauges.  
 
•
•
Figure 10.  Gumbel plots comparing simulated daily and hourly annual extreme rainfall 
amounts. Estimates of the observed extremes are plotted as curves. Simulated extremes are 
plotted as confidence intervals displaying the 10th and 90th percentiles of the simulated extreme 
distribution.  
−2
−1
0
1
2
3
4
0
10
20
30
40
Reduced variate
Annual maximum hourly rainfall (mm)
Hourly  Extremes
2
5
10
20
50
Return period (years)
 
 
 
 
AISG   
SHAP   
Simulated AISG   
Simulated SHAP   
−2
−1
0
1
2
3
4
0
20
40
60
80
100
Reduced variate
Annual maximum daily rainfall (mm)
Daily Extremes
2
5
10
20
50
Return period (years)
 
 
 
TPLS   
Simulated TPLS   
KIRK2   
Simulated KIRK2   
 
0
10
20
30
40
0.0
0.2
0.4
0.6
0.8
1.0
Separation (km)
Correlation
January
Obs 
Sim
0
10
20
30
40
0.0
0.2
0.4
0.6
0.8
1.0
Separation (km)
Correlation
July
Obs 
Sim
 
15

 
 
This parameterisation has been obtained using detailed statistics from the observed 
rain gauge network, which is a time-consuming process and is not practical for 
repetition in other, larger basins. This model will therefore be used as a benchmark for 
comparison with more parsimonious fitting methods suitable for application in 
regional and national settings.  
 
This approach will use 5km statistics derived from the UKMO 5km data sets used in 
the UKCIP08 weather generator, allowing the same methodology for perturbation for 
climate change to be applied.  An extension of the UKCIP08 methodology to spatial 
application has now been outlined and work will commence soon on implementation.  
 
Work has also progressed on the frequency curve mapping (Ledingham).  The overall 
aim is to develop a technique to estimate flood frequency curves (ffc) from rainfall 
frequency curves (rfc), accounting for antecedent rainfall.  A number of advances 
have been made in the last 6 months: 
 
Data Discretisation. Since daily rainfall data are more widely available than hourly, 
analysis was carried out to allow the estimation of the fraction of the effective flood 
generating rainfall contained within the same or previous 24 hr period (09.00-09.00) 
as the flood peak.  Discretisation factors in the region of 1.14 were found, this agrees 
broadly with the work undertaken by Dwyer and Reed (1995).   
 
Rainfall and Flow Seasonality.  The seasonality of annual maximum and POT5 
rainfall and flow data have been investigated for around 500 UK catchments. Polar 
plots such as those shown in figure 11 provide an initial assessment of how well the 
rainfall and flow regimes correspond, therefore indicating those catchments where the 
Flood Curve Mapping (FCM) methodology is more likely to work.  
 
 
Development of the Link between Rainfall and Flood Frequency.  Work has 
centred on assessing the correlation of the r-largest events in the rainfall and flood 
peak series (where r=1 corresponds to an annual maximum analysis). Work has now 
moved on to investigation of dependence of matching on physical catchment 
descriptors such as area and PROPWET.  Key findings so far include: 
• 
With annual maximum data, patterns of matching are similar to the 
distribution of mean annual rainfall in the UK with better matches in the West and 
Northern Areas (Figure 12). 
• 
Maximum matching values are around 60% for the annual maximum analysis, 
with most around the 40% mark. 
• 
The POT analysis provided broadly similar results and with the top three 
rainfall events provided improved matching with around 90-95% maximum matching 
values. 
 
 
 
16

 
 
 
Figure 11:  Flow and Rainfall Polar plots of annual 
maximum events on the Meig, showing the time of 
year of these events as the Julian Day.  Plots are 
standardised by qmed and rmed respectively. 
 
Figure 12:  Map of the UK showing the percentage of 
annual maximum flow events that can reasonably be 
attributed to the annual maximum rainfall events.  
Light colours show low matching and darker colours 
show higher matching (max. c. 60%).  Background is a 
DEM. 
 
 
For the work to develop national rainfall datasets to derive the Grid-to-Grid (G2G) 
model Having sourced the RCM rainfall data sets have been sourced, and alternative 
sources are now being collated. These include the space-time rainfall for the study 
catchments from Newcastle University and the rainfall data from the Upper Severn 
catchment from the “Uncertainty Assessments of Flood Inundation Impacts: Using 
spatial climate change scenarios to drive ensembles of distributed models for 
extremes” FREE project led by Kings College, London. 
 
The G2G Model has been configured for a range of UK catchments including the 
Thames region. The model, which has recently been reconfigured to use soil datasets, 
has been run at the national scale using the Hadley Centre RCM data from the 
HadRM3 (“acqqa” and “acqqb”) runs. Figure 13 shows the estimated percentage 
change in modelled 20-year return period flow across the UK. G2G modelled river 
flows for the Eden catchment near Carlisle are being used by HR-Wallingford to drive 
the new methodologies being developed within RASP HLMplus. 
 
 
 
17

 
 
 
 
Figure 13: Estimated percentage change in modelled 20-year return period flow across the UK 
 
 
Three options have been devised for incorporating continuous flow data, provided by 
the CEH G2G model, into the RASP HLMplus framework, where each approach 
offers differing advantages and disadvantages in terms of ease of implementation and 
benefits gained over the existing approach.  The preferred option is outlined in Figure. 
14 and offers the following enhancements over the existing RASP HLMplus model: 
• 
The assumption of load dependence between different river reaches is 
relaxed through the use of continuous flow data to represent flood events.  
• 
Consideration of continuity between the river and the floodplain is 
improved, allowing losses upstream to be better accounted for when 
estimating downstream flood risks. 
• 
More advanced breach volume calculations, involving varying breach size 
with time, are enabled through the use of HR Breach within InfoWorks 
RS. 
 
However, this option also necessitates significant modification of the existing flood 
risk analysis model, requiring the development of new software code to allow 
additional analyses to be undertaken and to enable linking/communication between 
new and existing model components, which hitherto have not been coupled.  It is still 
unclear at this stage whether such modifications will be feasible; thus, it may be 
necessary to resort to alternative options for incorporating continuous flows into the 
flood risk analysis framework.  These options would either involve a simplified 
defence system analysis (using expected values) or simplified floodplain volume 
calculations 
 
Nevertheless, each of the three devised options requires the sampling/screening of 
flood events from the continuous flow series to allow efficient computation of flood 
risk.  Work has progressed on the development of a flood event selection tool 
comprising a pre-processing method for extracting summary hydrograph information, 
 
18

 
a flow database for storing continuous flows and summary characteristics, and a 
flexible query/selection method based on peaks-over-threshold.  This tool is being 
developed with the use of a test dataset provided by CEH consisting of 2 months of 
continuous flow data for the Carlisle area. 
 
 
 
 
Figure 14: Preferred option. 
 
Within the Coastal Flooding by Extreme Events (CoFEE) project (Williams) the 
University of Plymouth team have produced a review of state-of-the-art for the 
CoFEE study site (Sefton Coast) has been completed and will, be made available to 
all CoFEE Partners at the next Project meeting to be held in Plymouth on 20-21 
October 2008. This includes: Introduction; Description of the Study Sites; General 
overview; Description of the UK study site: Dee estuary and Liverpool Bay; risk 
definition (for each site); existing hazards at each study site; existing management 
plans; shoreline management plans (SMPs); catchment flood management plans 
(CFMPs); Proposed methods to be used to assess each risk at the study area (on a 
probabilistic base approach); strategic approaches (e.g. vulnerability indexes, set-back 
lines – used for special planning on a decadal basis); operational approaches (e.g. real 
time models – used for civil protection plans); potential improvements; civil 
protection schemes; summary of datasets availability; final considerations; and works 
cited. In addition they have been: (a) analysing remote sensing data to assess rates of 
shoreline recession; (b) progressing coastal flooding modelling using ANUGA; (c) 
compiling and processing the Sefton GIS; and (d) analysing net shoreline movement 
using the USGS Digitial Shoreline Analysis System (DSAS) with ESRI ArcGIS to 
 
19

 
give statistics for 100 years and for the Dune Toe GPS surveys from 2001-2008. 
These will be cross-referenced to historical storms. 
 
Data management (BODC): In collaboration with BADC, the period May to 
September has been spent identifying the main data types used by CoFEE project 
partners. With these data types identified, the feasibility of using different data 
management methods has been assessed. It is now becoming clear that the best 
approach to data management for CoFEE involves selective banking, concentrating on 
definitive model runs along with the boundary condition inputs, aerial photographs 
and verification data such as erosion monitoring data. Work to assemble a suitable 
data suite is currently underway.  
 
POL has been working on improving the coupling between the wave model WAM 
and POLCOMS aimed primarily at the related surface stresses and looking at the 
effect that this modified stress has on the storm surge, hence its implication for 
flooding. This work has been submitted to Continental Shelf Research and presented 
in PECS 2008 and UK Marine Sciences. An abstract and paper have been submitted 
to Littoral’08. It should be noted that work during the last 6 months has been 
hampered at POL due to catastrophic failure of its disk system, which left us without 
reliable computers for 2 months. Nevertheless, a 10 hind cast of  waves and currents 
have been carried out for the North Atlantic and work preparing simulations for the 
Irish see are almost in place. Setting the fine resolution Livepool Bay is almost ready, 
tidal barotropic runs have been successful in reproducing tidal elevation and currents 
(work presented at PECS, paper in preparation) and work is been carried out to 
properly couple wind and waves with the wetting and drying algorithms. 
 
EHU have continued with the bi-monthly sedimentary monitoring along the north 
Sefton Coast. A small number of short [50cm] cores have been taken from across the 
Marshside marshes and north Southport beach, some of which have had preliminary 
work [particle size, magnetics and some chemistry]. EHU have met [with GL] with 
the RSPB warden from Hesketh Out Marsh and assessed the site with the aim of co-
ordinating the placement of a series of sediment traps across the Marsh. Note: 
Hesketh Out Marsh was selected for returning to the sea by DEFRA and Natural 
England as part of their flood protection strategy for the Ribble Estuary. It is 
considered that the breaching of the [1980s] embankment may ultimately have 
significant effects upon the sediment deposition and accretion further south i.e. across 
our monitoring sites. This may be detected in the monitoring over the next couple of 
years. 
 
UoL activity has undertaken: a review of published literature and reports on the 
evolution of the interface between the Mersey Estuary and the Irish Sea: the South 
Sefton Shore; a review of published literature and reports on the sediments of the Irish 
Sea and their interaction with the Sefton coast; and a collation of particle size data on 
the bed sediments of the Irish Sea, and laser granulometry of the sediment samples 
collected during Irish Sea Observatory cruises. These reports and data will be passed 
to Project Partners soon. 
 
 
 
 
20

 
B. 
Papers 
 
1. Contribution to paper on groundwater flooding for the Floodrisk 2008 conference 
(www.floodrisk2008.net) [Wheater project]. A paper at this conference was also 
presented on the FREE Project by the Science Coordinator. 
2. A paper on the Carlisle Flood Case Study using high resolution NWP rainfalls for 
flood warning has been accepted for publication in Met. Apps.. This work was  
presented as a poster paper at EGU2008 in April along with a second oral paper 
on model initialisation and data assimilation for the distributed G2G hydrological 
model. [Illingworth project – CEH Wallingford]. 
3. 
Planet Earth magazine invited JJW to write a feature article. This was 
submitted on 8 May 2008 and will appear in the next edition. 
4. A draft report on data assimilation for parameter estimation with a linear 
advection model has been written. Once a few details have been polished it will be 
published on the web as a Reading Mathematics Dept Report. 
5. Monthly Weather Review paper (see below) has been accepted for publication. 
6. Weather paper (see below) currently in revision. 
7. Second paper for Hydrology and Earth Systems Sciences (see below) describing 
the automated classification technique has been accepted for publication. 
8. Exploration for the use of HTML files for displaying data is in progress. 
 
Peer-Reviewed Papers and Conference Presentations 
 
9. “Site-Specific Density Forecasting of UK Daily Rainfall: Generalised Linear 
Models versus Ensembles”, M. A. Little, P. E. McSharry, J. W. Taylor, Monthly 
Weather Review (in press) 
 
10. “Extreme Rainfalls in the British Isles 1866-1968”, H. J. E. Rodda, M. A. Little, 
R. G. Wood, N. MacDougal, P. E. McSharry, Weather (in revision) 
 
11. “Parsimonious Modeling of UK Daily Rainfall for Density Forecasting”, in 
Geophysical Research Abstracts, EGU General Assembly, Vienna 2008, Volume 
10. 
 
12. The UEA team received the reviews of their paper about the annual cycle of 
extreme UK precipitation (submitted to the International Journal of Climatology). 
It has been revised and returned to the Journal Editor. 
 
13. A poster (“Estimating climate change impacts on river flows across the UK: how 
uncertainties in model structure can affect predictions”) was presented at a 
workshop on Hydrological Monsters and Outliers, Cemagref and ENGREF-
AgroParistech, Paris, 18-20 June 2008. A draft paper has been written describing 
and comparing the application of two alternative configurations, the “Slope-G2G” 
and the “Soil-G2G”, at the national scale, as well as presenting change in peak 
 
21

 
flows under a future climate scenarios and a method for assessing those areas of 
the country where the signal of change in peak flows is more “robust”.  
 
14. A paper has been drafted by the Beven team for the forthcoming special issue of 
Meteorological Applications. 
 
 
C. 
Web sites 
 
1. Development of a website and wiki (http://www.groundwaterflooding.org) for 
the Wheater project. 
2. Sefton's Dynamic Coast Landform, Ecology and Management Conference was 
held 
in 
Southport 
on 
1st 
September 
2008, 
(http://www.seftoncoast.org.uk/research_conf2008.html). The conference was 
attended by the majority of CoFEE Partners. 
 
D. 
Deliverables 
 
There follows a first attempt to assess the level to which the Programme Deliverables 
specified at the beginning of the Project have been achieved. 
 
Objective 1 
• 
Joint research to be undertaken by an identifiable integration of science 
communities. 
Several of the projects are bringing together different communities. For example in 
the project led by Illingworth Hydrologists at CEH Wallingford are working with 
meteorologists from the JCMM at Reading. In the project led by Dance satellite 
remote sensing scientists are working with coastal oceanographic modellers, and in 
the project led by Zou hydrometeorologists are working with ocean wave modellers. 
The UEA joint British Council/DAAD (German Academic Exchange Service)  
project was completed and a final report sent to the British Council (this project 
supported scientific exchanges between UEA and the University of Potsdam, with 
much knowledge shared and joint analysis done on the topic of climate/weather 
extremes). 
 
The project led by O’Connell has collaborated King’s College London FREE project 
for the modelling of the Upper Severn (Hannah Cloke’s group: “Uncertainty 
Assessments of Flood Inundation Impacts”). This project has also agreed with  
Joe Holden (University of Leeds) for the provision of access to field data collected 
from upland peat sites. Collaboration with the FRACAS FREE project and the 
Newcastle-led project has also been arranged for the generation of rainfall fields 
under present and future climates.  
 
The modelling work in the FRACAS Project will involve use of Met Office and 
UKCIP08 datasets. 
 
22

 
 
 
• 
Language integration across discipline boundaries leading to the training of a 
new generation of scientists having an integrated way of approaching 
environmental scientific research. 
Research students such as Polly Smith (Reading; Dance project), Josie Geris 
(Newcastle; O’Connell project|), Jamie Ledingham (Newcastle;Reynard project) and 
Kim Bartholomew (Reading, Illingworth project) are all working in projects involving 
cross-discipline activities.  
 
• 
Synergy between different models specifically demonstrated by a prototype 
complete integrated system or through its component parts. 
Particularly good examples of synergy between models are discussed in sections 1, 2 
and 4 above.  
 
Objective 2 
 
• 
Specifying techniques for data assimilation through coupled models between 
meteorological, hydrological, hydraulic, coastal and climate models. 
Work in the projects led by Illingworth, Dance, Wheater, Cloke, Williams, Zou and 
Reynard illustrate excellent progress towards this deliverable. 
 
• 
Transfer of data handling, quality control and assimilation techniques 
between disciplines. 
There is evidence that this is happening within projects, but not between projects, 
although the Data Management Plan is providing a framework for data archiving..  
 
• 
Demonstrated complimentarity with, but not duplication of, the FRMRC 
programme. 
Several of the FREE researchers are working on FRMRC projects for example Beven, 
Wheater, Reeve and O’Connell. At present overlaps do not seem to be occurring, but 
further analysis will be undertaken. 
 
Objective 3 
 
• 
Quantification of forecast uncertainty across disciplines and within data and 
models. 
There is much activity in specifying and dealing with uncertainty, see for example the 
projects let by Toumi, McSharry and Svensson. Much more work in this area is 
planned. 
 
23

 
• 
Specifying and managing the propagation of uncertainty across discipline and 
model boundaries. 
This is particularly well illustrated in the projects led by Beven, Cloke and 
Illingworth. 
 
• 
Estimating and utilising uncertainty in the physical processes represented in 
models. 
To some extent the derivation of refractivity and insect winds in the project led by 
Illingworth provide information which will reduce uncertainty in high resolution 
meteorological models. In addition the project led by Beven work is well advanced in 
the project led by Toumi using the WRF model. 
 
• 
Analysis of factors impacting changes in frequency and intensity of storms and 
extreme flood events. 
The projects led by Osborn and Reynard are investigating the impact of climate 
change upon extreme rainfall, and the projects led by Svensson and Toumi are 
examining frequency analysis and conditions leading to extreme storms.. 
 
• 
Preparing a scientific approach to the development of risk assessment tools. 
New approaches are being developed in the projects led by Beven, McSharry, 
Svensson, Reynard and Toumi. 
 
• 
New approaches for forecasting extreme events in rapid response catchments. 
The CEH work in the Illingworth led project is particularly relevant to this 
deliverable. 
 
• 
New approaches for forecasting extreme pluvial events in urban and built up 
areas. 
Not being addressed yet. 
 
• 
Analysis of the relative contributions to flooding from natural variability and 
human forcing of climate change. 
The projects led by Williams, Reynard, O’Connell and Cloke are particularly relevant. 
 
Objective 4 
 
• 
Achieve a better understanding of the sensitivity of fluvial, surge and total 
water levels to uncertainties in model inputs. 
 
24

 
Projects led by Zou, Williams, Dance, O’Connell, Wheater and Beven are all relevant 
to this deliverable.  
 
• 
Development of procedures for constraining and presenting risk and 
uncertainty to end users, and the impact of this uncertainty on the 
environment. 
The Beven led project aims to deliver appropriate procedures as do the projects led by 
Cloke, Zou, Williams and McSharry. 
 
• 
Consider the relationship of meteorological indices in global models to the 
likelihood of catchment flooding and coastal surges. 
To be analysed. 
 
Objective 5 
 
• 
Identifying the implications of uncertainty across disciplines for policy 
development e.g. within the framework of the EU Water Framework Directive. 
To be analysed. 
 
• 
Identifying consequent changes in engineering design risk in both fluvial and 
coastal zones arising from the impact of sediment transport and 
geomorphologic change caused by extreme events. 
To be analysed. 
 
• 
Development of a national network of world class scientists and professionals 
in this multi-disciplinary field. 
Certainly the FREE Projects promise major outputs which will illustrate the 
excellence of UK research in the multi-disciplinary field represented by FREE.   
 
Objective 6 
 
• 
To develop for this programme a methodology for gathering new data and 
collating existing data for extreme events shortly after they occur. 
The basis of a methodology has already been established through FLoAT. 
 
• 
Archiving within the Research Council Data Centres using the e-science Data 
Grid, data sets derived from research studies and extreme events occurring 
during FREE. 
 
25

 
The FREE Data Management Plan has been established. 
 
Objective 7 
 
• 
Quarterly updates describing activity and new opportunities presented by 
research outputs. 
Updates are being produced as required by most projects, although some projects have 
to be pushed! 
 
• 
Identification of specific routes to user involvement and early adoption of 
science by operational agencies. 
The Met Office and the Environment Agency are both closely involed in some of the 
projects. The Met Office has already adopted the procedures for deriving refractivity 
and insect winds developed in the project led by Illingworth. 
 
• 
Demonstrations of outputs at appropriate events or workplaces. 
The radar products from the Illingworth project have been demonstrated at the 
Cobbacombe Met Office operational radar site. It is expected that other 
demonstrations from other projects will take place. 
 
• 
Transfer of research outcomes to policy makers. 
To be analysed. 
 
Objective 8 
 
• 
Research degrees awarded from FREE supported research. 
To be analysed at the end of the programme. 
 
• 
Involvement of a mix of cross-disciplinary students in FREE and related 
international activities. 
To be analysed.  A number of students are participating in national and international 
conferences. 
 
26