1 The national regional modelling projects of England and Wales
Mark Whiteman
1*
,Keith Seymour
2
Mark Grout
3
, Paul Hulme
4
, Jan van Wonderen
5
and Clare
Wilson
6
Over the last ten years there has been extensive development of regional groundwater models across England and Wales for water resources purposes lead by the Environment Agency. Eight regionally managed programmes are underpinned by a framework, which has allowed a coordinated national approach. The main uses of the models are for Catchment Abstraction
Management Strategies, abstraction licensing, water availability forecasts and Habitats Directive
Review of Consents. Models have also assisted in monitoring network design, groundwater quality investigations and groundwater protection zones. A five-yearly review of the programmes recognised the importance of benefit realisation as well as technical good practice.
*lead author mailto:mark.whiteman@environment-agency.gov.uk
4
5
6
1
2
3
Environment Agency, Leeds
Environment Agency, Warrington
Environment Agency, Peterborough
Environment Agency, Solihull
Mott MacDonald, Cambridge
Entec UK, Leamington Spa
M Whiteman
726945212
Page 1 4/15/2020

2 Extending the use of regional groundwater flow models to simulate contaminant transport
Jane Dottridge
1*
Although modelling of groundwater contamination requires a finer grid and greater vertical resolution than those used for regional groundwater flow models, the uncertainty in the flow pattern usually has less influence on the results than the transport parameters. Thus a steady state flow model is adequate for many contamination problems. Import of the geometry, hydraulic properties, average recharge and flow distributions from a calibrated regional model provides an accepted understanding of the aquifer’s behaviour and saves time. Two examples of local contaminant transport models, based on the groundwater flows of a larger regional model, are used to illustrate this approach.
*lead author mailto:Jane.Dottridge@mottmac.com
1 Mott MacDonald, Cambridge
3 Using a tiered approach for management of water resources in an aquifer susceptible to saline intrusion and upconing
S.R. Arthur
1*
, S.R. Buss
1
, A.B. Taylor
2
, S.J. Gebbett
3
, K.J. Seymour
3
& F.C. Brassington
4
Permo-Triassic sandstone aquifers of North West England are susceptible to the effects of sea water intrusion and upconing of deep brines. This paper presents the results of a tiered approach for assessing the risk that a proposed abstraction might pose with respect to these effects.
Initially a spreadsheet-based approach that can be used as a screening tool is described. Then the results of a sensitivity analysis of saline intrusion using in FEFLOW are described: key factors that control the risk that abstraction will cause saline intrusion inform a management strategy for the aquifer. The paper concludes with a case study of modelling an abstraction that lies within a risk area for both saline intrusion and upconing, to optimise borehole construction and pumping regime to minimise risk of salinity issues.
*lead author mailto:simonarthur@esinternational.com
1
2
3
4
ESI Ltd
Groundwater Modelling Solutions
Environment Agency, Warrington
Newcastle University
4 Using models to help protect and improve groundwater quality
Nick Rukin
1*
& Peter Ravenscroft
1
The WFD requires that aquifers reach good chemical as well as quantitative status by 2015 (or have a justifiable alternative objective in terms of timescale or status). The protection of groundwater quality as a resource for public supply is also an economically significant issue.
Considerable effort has gone into groundwater resources models over the last 10 years. This paper provides examples of where the conceptualisation and numerical outputs from such projects have been used to inform groundwater vulnerability, source protection zones, and the impacts of diffuse pollution (nitrate) on drinking water quality. Suggestions are made as to how model datasets could provide further benefits in these areas.
*lead author mailto:rukin@entecuk.co.uk
1 Entec UK, Shrewsbury
M Whiteman
726945212
Page 2 4/15/2020

5 A successful model? The 30 year operational life of the Lincolnshire Chalk model.
Phil Hayes
1*
, Rik Ingram
1
& Mark Grout
2
A groundwater flow model of the Lincolnshire Chalk has been used as a water resource management tool since 1978, informing abstraction decisions to limit saline intrusion from the
Humber Estuary. This paper describes the history of the model from its initial development, through the expansion of the model domain and its updating and operational use by the then
Anglian Water Authority and its successors: The National Rivers Authority, Environment
Agency and Anglian Water Services. The reasons for the longevity of the model and its success in management of water resources and saline intrusion control are considered together with lessons learnt that may apply more widely.
*lead author mailto:hayep@entecuk.co.uk
1
2
Entec UK, Shrewsbury
Environment Agency, Peterborough
6 Modelling the hydrogeology and managed groundwater system of the Chalk across
Southern and South West Regions
Tim Power
1*
, Rob Soley
2
, Rory Mortimore
3
, Giles Bryan
4
, Jane Dottridge
5
& Paul Shaw
6
Over the past 10 years, Southern and South-West Regions of the Environment Agency, in conjunction with local Water Companies, have commissioned eight fully distributed numerical groundwater models of the Chalk and Upper Greensand aquifers. This paper synthesises the conceptual understanding and numerical modelling of this groundwater system from Kent across to Dorset with particular reference to the importance of geological structure, lithostratigraphy and variable permeability with depth (VKD) in the development of preferential groundwater flow pathways within the Chalk. The paper also emphasises the importance of storage within the
Upper Greensand, stream augmentation schemes and water cress and fish farm operations in maintaining low flows in Chalk rivers.
*lead author mailto:powet@entecuk.co.uk
1
2
3
4
5
6
Entec UK, London
Entec UK, Cornwall
Independent
Environment Agency, Exeter
Mott MacDonald, Cambridge
Environment Agency, Worthing
7 Groundwater resource modelling for public supply management in London: A review of recent developments
Michael Jones
1*
, Jamie Riches
1
, Simon Starling
1
, Sally Hughes
1
, Andrew Hughes
2
, Christopher
Jackson
2
, Majdi Mansour
3
, Jan van Wonderen
4
& Vasileios Tyriakidis
4
To assist management of groundwater abstractions from the London Chalk for public water supply and aid planning of future resource development, Thames Water develops, maintains and uses regional groundwater models. These models provide a framework for understanding the
Chalk groundwater system and so enable assessment of sustainability and risks to groundwater source viability. Using the London Basin and Swanscombe groundwater models, this paper will present examples including development of new abstractions to meet environmental drivers in the Darent valley, abstraction planning to manage rising groundwater levels and minimize environmental risk, and use of artificial recharge for groundwater resource management.
*lead author mailto:Michael.Jones@thameswater.co.uk
1
2
3
4
Thames Water
BGS Keyworth
BGS Wallingford
Mott MacDonald, Cambridge
M Whiteman
726945212
Page 3 4/15/2020

8 Development and Application of the Kennet Valley Groundwater Model
Lesley McWilliam
1*
, Emma Everard
1
, Birgitte von Christierson
2
, Nigel Hoad
3
& Michael Jones
4
Work on the Kennet Valley Groundwater Model (KVGM) was initiated by the Environment
Agency in 2001 to create a tool for decision-making as part of the Thames Region Modelling
Strategy. Although a previous bespoke model of the area existed, there were a number of versions and extremely limited documentation. A new model has been developed by Atkins using MODFLOW-VKD and this has been used extensively by both the Environment Agency and Thames Water. This paper will present a summary of the KVGM development and focus on some of the main applications, demonstrating where the model has contributed to the decision making.
*lead author mailto:lesley.mcwilliam@atkinsglobal.com
1
2
3
4
Atkins
HR Wallingford
Environment Agency, Reading
Thames Water
9 Modelling without boundaries - comparing, joining and disaggregating neighbouring groundwater models.
Alastair Black
1*
, Will Witterick
1
, Tim Lewis
1
& Mark Grout
2
Neighbouring models often have large area overlaps to avoid boundary issues but may also develop inconsistent representations of similar aquifers and processes. This paper presents the aggregation of four adjacent models spanning East Anglia into one ‘boundary-less’model. The process included a review of conceptual and numerical discontinuities at the model boundaries and resulted in a more consistent and robust modelling approach over the whole area. The large model is slow to run but is used to delineate simulated groundwater divides and their transient migration, and to investigate wetland impacts close to these. It can be easily disaggregated to the original component model scale along simulated groundwater divides, or to smaller areas for rapid local simulations incorporating boundary conditions from the parent model.
*lead author mailto:blaca@entecuk.co.uk
1
2
Entec UK, Cornwall
Environment Agency, Peterborough
10 Advances in modelling groundwater behaviour in Chalk catchments
Adrian Butler
1*
, Andrew Hughes
2
, Chris Jackson
2
, Andrew Ireson
1
, Thalia Vounaki
2
, Simon
Parker
1
, Howard Wheater
1
& Denis Peach
2
Groundwater in Chalk catchments is a major resource that also helps support internationally important habitats and ecosystems. Recent impacts from groundwater flooding as well as vulnerability to drought have raised questions over the ability of traditional approaches to model these aquifers. Current work on recharge processes and groundwater emergence has highlighted the importance of including the unsaturated zone, karst features, sedimentary deposits and valley bottom processes in any modelling system. Another key requirement is the three-dimensional structure of the system including explicit representation of surface topography. Methods for incorporating these features and their use in modelling Chalk catchments are described.
*lead author mailto:a.butler@imperial.ac.uk
1
2
Imperial College London
British Geological Survey, Keyworth
M Whiteman
726945212
Page 4 4/15/2020

11 The use of groundwater levels and models for the management of a moderatediffusivity aquifer
Martin Shepley
1*
& Rob Soley
2
The adequacy of predictions from a numerical time-variant distributed regional groundwater model has been compared with those based on observed groundwater levels for the purpose of managing surface water low flows across an unconfined, moderate diffusivity aquifer – the West
Midlands-Worfe Permo-Triassic Sandstone in the United Kingdom. The impacts of groundwater abstraction have been analysed by comparing a recent actual baseline predictive simulation with simulations where groundwater abstractions are switched off, including a ‘naturalised’ simulation. By reference to the historic simulation, the predictive model results are compared against observed groundwater levels.
It is demonstrated that groundwater levels have an ambiguous relationship with surface water flow impacts for a moderate-diffusivity aquifer. This relationship is dependent on the aquifer hydraulic characteristics as well as on the interaction between groundwater levels and the surface drainage network which may change seasonally in response to natural recharge variations as well as due to groundwater abstraction. River flows are also directly influenced by surface discharges and abstractions. All these influences can be built into a groundwater model to improve confidence in the surface water flow implications of groundwater abstraction management interventions.
Abstraction impacts on groundwater levels are large for the West Midlands-Worfe aquifer, but difficult to detect from observed groundwater level records. This is a consequence of the moderate diffusivity, but also because much of the groundwater abstraction development preceded systematic groundwater level monitoring by more than half a century.
The groundwater model can be used to identify which observation boreholes have negligible abstraction impacts – this may be valuable for identifying groundwater level records that are useful for climate change analysis. However, using observed groundwater levels as management trigger to modify groundwater abstraction rates is not appropriate for a moderate-diffusivity aquifer such as the West Midlands-Worfe Permo-Triassic Sandstone. Longer-term strategies are required to reduce overall rates of groundwater abstraction and use the storage more creatively.
1
2
A groundwater model is the better tool for exploring these options.
*lead author mailto:martin.shepley@environment-agency.gov.uk
Environment Agency, Solihull
Entec UK, Cornwall
12 Effects of faulting on regional groundwater flow dynamics in the Lower Mersey
Basin and North Merseyside Permo-Triassic aquifer, UK
C.D. Bemment
1*
, L.R. Brown
1
& S.J. Gebbett
2
Groundwater flow in the Permo-Triassic sandstone aquifer of the Lower Mersey Basin and North
Merseyside areas has previously been shown to be compartmentalised into discrete faultbounded aquifer blocks. A regional groundwater flow model was constructed to investigate groundwater resources of the aquifer, and to improve understanding of the effects of faulting on regional groundwater flow within and between aquifer blocks. This paper presents the results of the modelling and offers a comprehensive new understanding of the location, influence and significance of the faulting. Summary evidence is provided to support these divisions and the patterns of flow within and between these blocks is defined.
*lead author mailto:chrystinabemment@esinternational.com
1
2
ESI Ltd
Environment Agency, Warrington
M Whiteman
726945212
Page 5 4/15/2020

13 Simulation of an unlined water transfer tunnel in the Lichfield Permo-Triassic
Sandstone aquifer, UK
P.J.J. Daily
1*
, S.R. Buss
1
, J.J. Riley
1
& M.G. Shepley
2
The Leamonsley Brook, a low flow stream on the Lichfield Permo-Triassic sandstone aquifer, is under-drained by a 5 km water transfer tunnel. Quantitative assessment of the interaction of the
Hanch Tunnel with the groundwater system, and its impact on the Leamonsley Brook, was undertaken within a regional groundwater model. A version of the USGS MODBRNCH code was used which had been previously adapted to enable simulation of sub-water table adits. This paper reports on the modelling, with an emphasis on the effects of the tunnel on the local groundwater and surface water systems. Considerations when implementing the adapted
MODBRNCH code are presented.
*lead author mailto:pauldaily@esinternational.com
1
2
ESI Ltd
Environment Agency, Warrington
M Whiteman
726945212
Page 6 4/15/2020

14 A rapid model for estimating the reduction in river flows due to groundwater abstraction
Paul Hulme
1*
, Chris Jackson
2
, Keith Seymour
3
Majdi Mansour
4
.
, Katie Wilson
3
, Jane Atkins
3
. Andrew Hughes
2
,
The Environment Agency uses two main modelling techniques for estimating the size and the timing of the reduction in river flows resulting from groundwater abstraction. Firstly analytical equations in the IGARF (Impact of Groundwater Abstraction on River Flows) spreadsheet and secondly regional models from the national groundwater modelling programme.
This paper describes the crucial mechanisms that are needed to estimate the reduction in river flows, presents a model which includes these crucial mechanisms and is quick to build. The method is illustrated on an investigation for the Habitats Directive on the River Leith in
Cumbria.
*lead author mailto:paul.hulme@environment-agency.gov.uk
1 Environment Agency, Solihull
2
3
4
BGS, Keyworth
Environment Agency, Warrington
BGS, Wallingford
15 Impacts of groundwater abstractions on river flows - predictions from regional groundwater models
Rob Soley
1*
, Simon Quinn
2
, Mike Packman
3
, Don Ross
4
& Paul Hulme
5
Regional groundwater resource models are usually built to improve confidence in predicted groundwater abstraction impacts on river flows and groundwater levels. By explicitly representing the three dimensional aquifer system geometry, properties and boundaries, and transient recharge and abstraction pressures, such models provide a robust platform to support
Habitats Directive, Water Framework Directive and other abstraction licensing assessments.
This paper reviews the spatial and temporal patterns of groundwater abstraction impacts predicted by a number of different models and lists the many hydrogeological mechanisms which result in these being more complex than would be suggested by simpler tools and approaches.
*lead author mailto:soler@entecuk.co.uk
1 Entec UK, Cornwall
2
3
4
5
Entec UK, London
Southern Water
Atkins
Environment Agency, Solihull
16 Wetland impact prediction from regional groundwater models
Tim Lewis
1*
, Jan v Wonderen
2
, Ellie Creer
1
, Mark Grout
3
& Ursula Buss
3
Regional scale groundwater resources models have been applied to the assessment of abstraction impacts on sensitive wetland and fen sites throughout East Anglia as part of the Habitats
Directive Review of Consents process. It is acknowledged that these models cannot simulate all the spatial detail of the sites and the associated localised impacts on dependent wetland vegetation. However, by adopting a process of site conceptualisation and careful consideration of specific types of model behaviour, supplemented by ancillary calculations (most notably of changes in soil moisture content), an assessment method has been successfully developed and approved by interested conservation parties.
*lead author mailto:lewit@entecuk.co.uk
1 Entec UK, Shrewsbury
2
3
Mott MacDonald. Cambridge
Environment Agency, Peterborough
M Whiteman
726945212
Page 7 4/15/2020

17 Groundwater modelling in Scotland - a brief history
Majdi Mansour
1*
, Andrew Hughes
2
, Chris Jackson
Ball
3 , Brighid O’Dochartaigh 3
2
, Nick Robins
1
, Alan MacDonald
3
, Derek
and Diarmad Campbell
3
, Chig Okoronkwo
4
, Simon Watson
5
Groundwater in Scotland has been, until recently, an under-rated resource. In the last decade, a number of new abstractions have been developed or existing ones enhanced. Implementing groundwater abstraction licencing through the Controlled Activities Regulation process has accelerated the development of such schemes. Understanding and simulating these groundwater systems, where data are often sparse, is a challenge. This challenge is amplified as often groundwater abstraction occurs from previously unexploited gravel valley deposits in close proximity to large rivers. Using examples of work undertaken for Scottish Water and Glasgow
City Council, BGS’ role in groundwater modelling in Scotland is presented.
*lead author mailto:majm@bgs.ac.uk
1 BGS, Wallingford
2
3
4
5
BGS, Keyworth
BGS, Edinburgh
Scottish Water
Glasgow City Council
18 Using and refining an existing regional groundwater model to assess the impacts of an abstraction on a nearby RSPB reserve
Sarah Gellatly
1*
, Angelo Papaioannou
1
& Chris Green
2
An existing regional groundwater model was refined, updated and recalibrated to asses the local impacts that the resumption of pumping would have on water levels at a nearby RSPB reserve.
The regional model grid was refined locally and boundary conditions were relocated to more accurately reflect the study area. Two layers were added to model the drift deposits, and recharge was altered to account for dampening of the recharge through the drift. Drainage channels were also added to the drift layer and pumping test data were used to aid calibration. A predictive model was set up to run for 20 years to assess the impact of different pumping
1
2 regimes.
*lead author mailto:sgellatly@slb.com
Schlumberger Water Services, Shrewsbury
Environment Agency Wales, Bangor
19 Lumped modelling of the Mendips karstic Limestone
Rik Ingram 1* , Nancy Proudfoot 1 , Maria Walford 2 , Jim Grundy 2 , Claire Cook 1 , Mike Carey 1
The conceptual model of the karstic Carboniferous Limestone aquifer of the Mendip Hills and north Somerset has been investigated using physically-based lumped models. The models improve quantitative understanding of water balances at the spring catchment scale. Uncertainty in the role of the unsaturated zone, particularly the weathered epikarst, in storing and transmitting groundwater recharge to conduits and the water table was specifically examined.
Statistical methods were employed to determine the model parameter sets best able to replicate observed data within appropriate acceptability criteria. The advantage of using physically based models as opposed to ‘black-box’ models is that statistical uncertainty can be directly related to specific hydrogeological processes, increasing confidence in model use.
*lead author mailto:ingrr@entecuk.co.uk
1
2
Entec UK, Shrewsbury
Environment Agency, Exeter
M Whiteman
726945212
Page 8 4/15/2020

20 Recharge estimation for regional groundwater modelling in the UK
Dirk Liss
1*
, Dave Johnson
2
, Simon Quinn
1
, Jan van Wonderen
3
& Tim Power
1
Recharge calculations based on a daily soil moisture balance models define the resource available for most groundwater models. A switch in recent years from the Penman-Grindley methodology to the Food and Agricultural Organisation approach has improved the representation of soil properties in these calculations. The Meteorological Office algorithm for calculating potential evapotranspiration inputs has also changed and rain gauge data processing on individual models is being streamlined towards the use of nationally derived grids. A range of infiltration, bypass and runoff-recharge mechanisms have been conceptualised and modelled incorporating simple representation of unsaturated zone storage and flow processes. This paper reviews recharge modelling developments across the UK and assesses their impacts on resource
1
2
3 estimates.
*lead author mailto:lissd@entecuk.co.uk
Entec UK, London
Environment Agency, Solihull
Mott MacDonald
21 Spatial heterogeneity of recharge through Quaternary deposits
Geoff Parkin
1*
,Federico Fragala
1
, Mairead Glennon
1
& James Glover
1
Management of regional groundwater resources requires detailed quantitative knowledge of recharge rates. Across large areas of Britain, recharge is mediated through Quaternary deposits which are highly heterogeneous due to the glacial depositional environment and subsequent geomorphological action. This results in complex hydraulic responses governed by interactions between topography and the hydraulic properties of soils and underlying deposits. This paper explores the ‘natural’ spatial scales of recharge processes from the hill slope to the landscape scale, and how these are represented in recharge models, with a case study example of the
Permian sandstone aquifers of the Eden valley, Cumbria. The findings have implications both for estimation of broad scale recharge parameters for water resources assessment, as well as identification of potential ‘hot-spots’ of diffuse agricultural pollution of groundwater.
*lead author mailto:geoff.parkin@newcastle.ac.uk
1 Newcastle University
22 Climate change predictions and groundwater source yield implications
Paul Davison 1* , John Faherty 1 & Mark Whiteman 2
A number of studies to assess the impacts of climate change on groundwater recharge and deployable output are presented. These include examples from a range of hydrogeological settings including the Chalk, Permo Triassic Sandstone and Limestone, and geographically coverage includes the South coast, the South West, the Midlands and Northumbria. The 2020’s time slice was considered because it is aligned with water resource planning timescales. Studies that used distributed groundwater models were compared to estimates based on lumped spreadsheet models. The conclusions of the paper include that a source’s resilience to climate change may depend on aquifer type and whether the deployable output for a source is physically or licence constrained. Recommendations for further work included the use of the probabilistic
UKCP09 scenarios.
*lead author mailto:paul.davison@entecuk.co.uk
1
2
Entec UK, Shrewsbury
Environment Agency, Leeds
M Whiteman
726945212
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23 How to get your model results used: A guide to stakeholder engagement.
Andrew Hughes
1*
Herman Karl
5
, Jan van Wonderen
2
, John Rees
1
, Keith Seymour
3
, Desmond Manful
4
&
The usage of modelling results by their intended audience is an important aspect of undertaking any project. However, providing the appropriate results in the correct way to key stakeholders is not a straightforward task. Fortunately, there is a growing body of work about approaching the engagement of stakeholders in a way to maximise the impact of modelling results. Using the lessons learnt from a number of recent workshops, suggestions for best practice are presented and their relative merits discussed. Particular attention is paid to the best ways of communicating the results of predictive simulations to a range of stakeholders.
*lead author mailto:aghug@bgs.ac.uk
1
2
3
4
5
BGS, Keyworth
Mott MacDonald, Cambridge
Environment Agency, Warrington
Stuttgart University
USGS-MIT
24 How the models are being delivered - the National Groundwater Modelling System for England and Wales (NGMS)
Mark Whiteman 1* , Rolf Farrell 1 , Peter Gijsbers 2 , Marcel Ververs 2 & Clare Wilson 3
NGMS is a map-based, client-server system for holding groundwater and recharge models and supporting documentation. Models can be run, new scenarios created and data rapidly viewed or exported in time-series or spatially. NGMS enables models to be used for making day-to- day operational decisions and for water resource management. The system is being used to improve representation of groundwater in Catchment Abstraction Management Strategies (CAMS) and to forecast the potential impacts of climate change upon water resources. Use of the system provides greater standardisation of data formats, model codes and methods used by the
Environment Agency without stifling technological progress.
*lead author mailto:mark.whiteman@environment-agency.gov.uk
1 Environment Agency, Leeds
2
3
Deltares, The Netherlands
Entec UK, Leamington Spa
25 Regional groundwater models – the external advisor’s viewpoint
Jane Dottridge
1
, Jan van Wonderen
1*
& Alistair Wyness
2
The role of external advisor in the modelling programmes provides a unique overview of the projects, especially through involvement in projects in different regions and aquifers. The advisors provide technical support to the Agency’s project teams, thus contributing to development of expertise, comparison and consistency of approach, sharing of good practice and problem solving techniques, and benefits realisation. In addition, the independent opinion is required for all projects funded under the Agency’s capital programme. The paper comments on the strengths and areas for improvement of the groundwater modelling programme from the
1
2 external advisors viewpoint.
*lead author mailto:Jan.VanWonderen@mottmac.com
Mott MacDonald, Cambridge
URS, Manchester
M Whiteman
726945212
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26 Modelling the Vale of St Albans: Karstic Flow, Parameter Estimation and Dual
Porosity
Adam Taylor
1*
, Norline Martin
2
& Travis Kelly
3
Atkins has been working with the Environment Agency to develop a new groundwater model for the Vale of St. Albans. Although several models cover parts of this area, the new model is geographically centred on the River Colne and Lee catchments in order to represent groundwater interactions between the two surface water catchments. This paper will consider the parameter optimisation and model refinements which have informed the conceptual and numerical model development. The focus will be on how improvements have been made, particularly in problematic sub-catchments, comparing model outputs with those from previous models.
*lead author mailto:admbtaylor@yahoo.co.uk
1
2
3
Groundwater Modelling Solutions
Atkins,
Environment Agency, Reading
27 Pest controlled: responsible application of inverse techniques on UK groundwater models
Gemma Black
1*
& Alastair Black
2
The inverse modelling code PEST (Doherty, 2004) is a tool for model parameter estimation
(during calibration), sensitivity analysis and predictive error analysis (to assess uncertainty).
Despite the successful use of inverse techniques in other countries these methods have not been widely adopted for UK regional groundwater modelling. This is partly due to the challenge of adequately representing the complicated conceptual models involved and also to wariness over perceived ‘machine-led' modelling. The PEST algorithm has been tried and tested worldwide and such concerns can be addressed. This paper presents examples of how PEST has been responsibly applied to significantly improve model calibration, provide robust sensitivity data and credibly estimate uncertainty.
*lead author mailto:gblack1@shrewsbury.water.slb.com
1
2
Schlumberger Water Services, Shrewsbury
Entec UK, Shrewsbury
28 A glimpse into a virtual future: What groundwater modelling could be like in a decade?
Chris Jackson
1*
, Andrew Hughes
1
, Holger Kessler
1
, Denis Peach
1
, John Bloomfield
2
and Majdi
Mansour
2
& Andrew Spink
3
Given the pace of technological change over the last few decades, it is difficult to predict how modelling may develop. However, it is worth applying a forward look to groundwater modelling. The challenge posed by the Water Framework Directive has still to be fully met by groundwater modellers. Better linkage with surface water models is required using technologies such as OpenMI. Based on the lesson learnt implementing object-oriented techniques and linking groundwater models with 3D geological representations, a vision of groundwater modelling for the next decade is presented. The relationship to BGS’ recently launched
Environmental Modelling Platform project is discussed.
*lead author mailto:crja@bgs.ac.uk
1
2
3
BGS, Keyworth
BGS, Wallingford
Birmingham University
M Whiteman
726945212
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