Research Challenges
The key research challenges are focused around the headings below, please click the relevant tab for information on work in that specific area. For the project archive in all of these areas please click here.
Risk & Uncertainty
Decisions about sustainable water management are subject to many sources of uncertainty: about inputs, about the representation of flow and transport processes in predictive models, about the state of the system (particularly in the subsurface) and about future boundary conditions. Thus the way in which science can inform future management policy setting and decision making means that any quantitative predictions should be associated with an assessment of the uncertainty involved. This is difficult, because many of the sources of uncertainty are not simply the result of random variability. More often they result from a lack of knowledge (what are called epistemic uncertainties) that cannot always be represented in simple probabilistic ways. How to deal with this is the subject of the Catchment Change Network, a NERC Knowledge Transfer project led by Lancaster with focus areas in flood risk, diffuse pollution and water scarcity. Associated projects at Lancaster have concentrated on incorporating risk and uncertainty into flood and lake water quality forecasting, inundation modelling, and improving water quality.
Current Projects
Probabilistic Flood Forecasting - Lancaster University has been involved in probabilistic flood forecasting development for more than 20 years with an early flood warning system implemented for the town of Dumfries back in 1991. That system already produced probabilistic forecasts, making use of data assimilation to constrain the uncertainty in making forecasts at the required lead times. More recent developments have shown how the structure of the nonlinearities in the system can be developed from the observations rather than being chosen a priori and then fitted to the observations. Recent work has also shown how models can be developed for water levels rather than discharges, and this has suggested the use of local forecasting since a warning model can be developed for a level sensor at any site at risk of flooding. This is currently being demonstrated for a number of sites around the river Eden catchment.
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Probabilistic Flood Inundation Mapping - Many sources of uncertainty in flood inundation mapping have been ignored or treated very simply in the past. They have also been treated implicitly by agreed protocols based on engineering judgement or limited research studies (20% increase in the 0.01 exceedance probability flood discharge to allow for climate change, the use of zones based on the 0.001 exceedance probability in PPS25, etc). A more detailed consideration of the different sources of uncertainty, particularly in the estimation of design discharges, is likely to lead to identification of significant uncertainty in the risk map. This, however, has two advantages. The first is that the resulting maps are much less likely to be wrong in any particular event. The second is that, providing a measure of confidence in the mapping of flood risk, such maps can inform a risk-based framework for decision making processes, with the mapped risk quantiles allowing both risk accepting and risk averse approaches to decisions (e.g. for planning purposes) within a single assessment. As part of the UK Flood Risk Management Research Consortium we have developed a framework for dealing with assumptions about uncertainty in flood inundation mapping. This takes the form of a hierarchical decision tree. At each stage in the tree assumptions in an analysis must be recorded, providing an audit trail for later evaluation. Case studies include Carlisle, Cumbria (flooded in 2005) and Mexborough, Yorkshire (flooded in 2007). A visualisation tool has been developed to present the results of the calculations to users.
Soil Protection & Biogeochemistry
Soils are vital for the future of life on earth. They store and filter most of the worlds freshwater, are incredibly diverse ecosystems, contain three times more carbon than the earth’s vegetation and are the media in which the crops that we eat grow. But soils need our protection against the threats of soil erosion, drought, sealing and salinization, which result in lower productivity or arable lands and a reduction in ecosystem services that soils provide.
Work in the Lancaster Environment Centre is focused on understanding how soils function and respond to the pressures we place upon them. We are also developing new ways of protecting them for future generations.
Current Projects
Mitigation of Phosphorus and Sediment (MOPS) 2 - This project aims to develop and cost ways of controlling the losses of sediment and phosphorus in overland flow from arable agriculture.
MOPS 2 will focus on the use of ponds and wetlands and the control of erosion in spring crops.
It is a collaborative project between Lancaster University, the Allerton Trust, ADAS and Reading University and isfunded by Defra
The impact of tractor wheelings on soil structure and biogeochemical processes - This project aims understand how tractor wheelings impact on soil structure and how this affects biogeochemical cycling and how these effects may be mitigated against.
It is a collaborative project between Lancaster University, ADAS and a large number of industrial partners. It is funded by the Defra Arable LINK
Coastal Processes
Coastal environments are loci of unique and fragile ecosystems, valuable sources of food, minerals and energy, and densely populated and intensively used by humans. They are subject to continuous change due to natural and man-made influences. The ability to predict the evolution of the coastal environment via the complex feedbacks between its components – flows and waves, sediments, biota, nutrients, and man-made inputs and infrastructure – is vital for the protection of natural coastal habitats and for the planning of future coastal development.
These issues are becoming increasingly important and complex, as on the one hand predicted climate change will bring more variable and extreme weather conditions that will affect the fragile balance between different components of the coastal system, and on the other hand there is an increasing need to exploit natural coastal resources, for example for renewable energy.
We are engaged in fieldwork, laboratory experiments and numerical modelling activities that contribute to the understanding of coastal systems, as well as to the development of new tools and techniques for coastal managers and consultants to enable them to predict and plan for the future.
The real challenge is to describe and predict the complex processes around coastal natural and man-made structures and to predict their influence on natural systems, such as shoreline change, variations in water quality and impacts on coastal ecosystems.
Our research activities cover the following areas: Hydrodynamics: Multi-directional wave transformation around offshore structures, Wave-induced currents around structures, nearshore circulation on complex beaches; Flow-biota interactions: Hydrodynamics of mussel beds and seagrass meadows, effects of spatial heterogeneity on hydrodynamics of benthic organism communities, hydrodynamics and sedimentation in saltmarshes; Sediment transport and morphology: beach changes behind parallel offshore breakwaters; beach changes in front of a new seawall; runnel and ridges dynamics; scour dynamics around offshore wind turbine; Generic tools: Finite-volume numerical models for prediction of nearshore flow; ARGUS video imagery for beach morphology and nearshore flow; forecasting beach volumes by using linear and nonlinear transfer function models; semi-empirical models of flow profile evolution over beds of variable height and roughness.
Our research has been supported by grants from EPSRC, NERC, Wyre Borough Council and the British Council. We collaborate with colleagues from a wide range of disciplines in the UK and around the world, and are active members of collaborative projects, for example using the EU Hydralab experimental facilities.
Current Projects
Supergen Wind Energy Technologies Consortium – Phase II – experimental study of the interactions between wind turbine support structures, the seabed and impacting waves and flows (EPSRC); 2010-2013; Principal Investigator S. Ilic, Co-Investigator A. Folkard (both Lancaster), funding for a PhD studentship and laboratory experiments using the Deep Flume Facility at the University of Hull.
Laboratory flume studies of flow over heterogeneous mussel patches; 2009-ongoing; Principal Investigator A. Folkard, experimental work carried out on the race-track seawater flume at the Dutch Institute for Sea Research (NIOZ) Centre for Estuarine & Marine Ecology, Yerseke, the Netherlands, in collaboration with Dr. T Bouma (NIOZ). Supported by NIOZ and the University of Lancaster
A study of shoreface nourishment using ARGUS video images, funded by the consortium of Wyre Borough Council (WBC), the Environment Agency North West and Stena Line); 2009-2013; funding for a PhD studentship and field studies. (Principal Investigator: S. Ilic)
EU Hydralab IV experiment (2011) - Experimental investigation of nonlinear wave interactions, wave turbulence and rogue waves, in Marintek facility, Trondheim Norway. Team includes: Lancaster University, University of New York, Institute Chernogolovka Russia, LNEC Portugal. The experiment costs and travel and subsistence are covered through the host organisation. (Principal Investigator: S. Ilic).
Water Quality
Surface and groundwater sources are vital for both drinking water and food production, as well as for household and recreational activities. Freshwater is a vital habitat for fish, invertebrates and aquatic plants, and under the European Water Framework Directive we have an obligation to achieve good ecological status for all surface waters by 2015. At present, only 27% of rivers in England achieve that status, and in the UK, 75% of sediment comes from agricultural land use, which equates to 25% of the phosphorus and 6% of the nitrate load. By working with farmers we can identify ways in which we can maximise nutrient uptake by crops and livestock, and thereby food production, whilst minimising nutrient loss into the waterways. This will have a knock-on effect on aquatic and associated habitats by reducing the occurrence of algal blooms, fish kills and eutrophication, and help us achieve good ecological status across the country.
Current Projects
Catchment Modelling Strategies for Faecal Indicator Organisms: Options Review and Recommendations. Working with Aberystwyth University. 2010-12. Department of Environment Food and Rural Affairs - WQ0220.
Delivering healthy water: building the science-policy interface to protect bathing water quality. Working with Stirling University and Abersystwyth University. 2011- 12. NERC - NE/I022191/1.
The Environmental Virtual Observatory pilot (see People & Catchments)
Evaluation of Mitigation Options for Reducing Nutrient Emission to Surface Water and Groundwater at the River Basin Scale. Working with Alterra, Netherlands, Finnish Environment Institute, Finnland and NERI Denmark. 2006-12.
The attenuation of nutrients in the hyporheic zone of river sediments (the zone of transition from groundwater to surface water) is an essential process for maintaining the ecological health of groundwater-fed rivers. However, the interaction of ground-surface water in the hyporheic zones of rivers during baseflow conditions, and its influence on nitrogen transport and transformations are poorly understood at a river reach scale. Furthermore, the predicted changes in temperature and precipitation linked to climate change have put a new urgency on understanding hydrological exchange and biogeochemical processes in the hyporheic zone.
This NERC-funded project is investigating the physical and chemical controls on nitrogen dynamics in the hyporheic zone of a small reach of the River Leith, Cumbria, UK. The project is using a multidisciplinary approach and a variety of conventional and novel methods to explore the physical hydrology, hydrogeophysics and biogeochemistry controls on nitrogen transport.
The project is being conducted with partners at Queen Mary, University of London (School of Geography and School of Biological and Chemical Sciences).
Lost in Translation - Animal diseases are a major environmental, social and economic policy issue not only in the UK but across the globe, with potentially devastating consequences for those communities affected. This project brings together expertise across the natural and social sciences to provide an interdisciplinary understanding of the social, technological and natural dynamics of animal disease management. The analysis focuses on the complexities, risks and uncertainties that are embedded - but rarely exposed - in animal disease containment strategies and examines their impact on land, animal and water resource management. Existing social and natural science databases have been examined during the project, combined with undertaking interviews, focus groups as well as disease-specific and cross-disease workshops. The project is now finished but current and future outputs can be found on our website. This work was funded by the Rural Economy and Land Use Programme (RELU).
Modelling of nutrient biogeochemistry in groundwater-fed River Leith, Cumbria (UK): Automated high temporal resolution (hourly) measurements of total phosphorus (TP), soluble reactive phosphorus (SRP), and nitrate nitrogen (NO3N) have been carried out in the River Leith, a 54 km2, groundwater fed catchment in Cumbria, UK. Additional water quality parameters (turbidity and temperature, specific conductivity, dissolved oxygen and pH), discharge and rainfall monitoring data have been also collected to help understand the hydrological and in-stream controls on the transport of nutrients. High-frequency sampling has been able to capture the complex temporal dynamics of nutrients at full range of flows revealing an existence of non-linear coupling between time series, diurnal in-stream cycling and hysteresis responses in nutrient transfers. This project will advance the understanding of the temporal variation in nutrient processes in groundwater-fed rivers and build into our efforts to reduce diffuse nutrient pollution and improve environmental status of UK rivers.
Nutrient biogeochemistry in freshwater systems. 2010-12. NERC NE/G001707/1
Phosphorus Export and Delivery in Agricultural Landscapes 2 (PEDAL 2)
Underpinning understanding of water connectivity
This project will advance and expand a methodology developed in an earlier project (PEDAL: Phosphorus Export and Delivery from Agricultural Land - PE0113) which considered the delivery of phosphorus (P) in headwater catchments. In addition to considering P delivery, the proposed model will use similar fuzzy-rule based methodologies to estimate DESPRAL P mobilisation (PE0106) for unmonitored catchments, and hence P available for delivery. Expansion of the model in this way will allow predictive estimates of mobilisation and delivery to be made at unmonitored locations. Superimposed upon this structure will be a set of expert-derived rules which modify model output to simulate the likely effect of given mitigation such that estimates of their effectiveness can be made. This will allow environmental managers to target the implementation of mitigation measures (e.g. the programmes of measures to be made operational in WFD River Basins by December 2012).
In addition, a fuzzy-rule based model for faecal indicator organisms (FIOs) will be developed in a similar manner to the improved PEDAL model. The philosophy behind PEDAL is to make estimates that reflect our confidence given the data available for model evaluation using model inputs and parameters that are functionally significant in describing our observations. The resultant fuzzy ranges can, however, be updated when additional information becomes available, thus providing a framework where new information can be incorporated. In this way, the PEDAL approach gives realistic estimates which explicitly take into account factors which make the prediction of diffuse pollution uncertain. Failure to account for uncertainty may lead to ineffective policy decisions made without all available relevant information. The project (2008-2013) is funded by the Department of Environment Food and Rural Affairs.
Risk-based policy analyses in water protection zones. Partnership award. 2008-11. EPSRC 07000967
Sensitive Catchment Integrated Modelling and Prediction (SCIMAP): Lancaster University is developing further and integrating the risks from fine sediment, phosphorus and nitrogen losses from catchments using the SCIMAP approach pioneered by Durham and Lancaster Universities. Integrating sediment and nutrient risk in catchments is essential in order to target land use and land management actions and to mitigate damage to ecosystem health. The work will pave the way for the identification of how multiple land use combinations might achieve multiple benefits by ensuring that resources are focused on those parts of catchments that generate and propagate most risk whilst reducing the need for regulation in the parts of catchments that are not critical in generating diffuse sediment and nutrient risk. The outcomes from this research will provide evidence and form recommendations for the policy makers and governing bodies that can help target measures in catchments to deliver Water Framework Directive targets.
Uncertainty Assessment of Phosphorus Risk to Surface Waters. 2006-12. Environment Agency Science Project SC030176.
People & Catchments
As an essential component of healthy ecosystems, water in all its forms is vital for the people, plants and animals that live on the earth. In order to safeguard our health and that of the environment, it is crucial for us to couple our scientific knowledge of water, soil and atmospheric processes with social science understandings of how people engage with the environment. The People and Catchments theme of CSWM exists to bring such understandings to bear on the water-related grand challenges that affect us locally, nationally and internationally by exploring a range of topics such as strategies for land and water management and community engagement with flood risk. Many of the research projects carried out under the People and Catchments theme therefore place a strong emphasis on bringing researchers together with local residents, businesses and stakeholders, such as charities, local government and policy makers, with the aim of creating real world impacts through research.
Current Projects
The Environmental Virtual Observatory pilot is a project which is bringing together environmental data, models and visualisation tools to assist environmental decision making. The aim of the Local Landscape work package, which Prof. Phil Haygarth of CSWM is leading, is to develop exemplars that illustrate the opportunities and benefits of working with local communities to explore new dialogues, visualizations, and model technologies related to the understanding of local environmental soil and water issues. The work is based in three river catchments across the country; the Tarland in Scotland, the Dyfi in Wales and the Eden in England and involves researchers from CSWM, Aberyswyth and Newcastle Universities and the James Hutton Institute. The project is working closely with the Defra Demonstration Test Catchments project based on the river Eden. Researchers in CSWM along with Newcastle University and the Eden rivers trust are responsible for engagement with the local communities of farmers and residents taking place in the Morland subcatchment of the River Eden to collaboratively develop a pilot visualisation tool for the local area. To be kept up to date with our work in the Eden, please visit our blog.
Subsurface Processes
Understanding the mechanisms that control water and chemical fluxes within the subsurface environment is essential for catchment management. Shallow subsurface processes can influence the magnitude of flood events within a catchment and the susceptibility to soil erosion. Deeper subsurface processes control the recharge to an aquifer, impact on baseflow generation and can dictate the migration of contaminants in a catchment. Within the river corridor, the exchange between surface and subsurface flow can have immense impact on the surface water quality and ecosystem health.
Much of our research is focussed on understanding the role of physical and biogeochemical heterogeneity on pathways within the subsurface, from shallow soils to deep groundwater. As we improve our knowledge of this we can begin to develop appropriate parameterisation of models that are necessary for exploring optimal catchment management strategies.
One of the significant challenges of studying the subsurface is the difficulty in making observations, at an appropriate scale, that can capture the temporal and spatial variability of properties and states. We have been developing geophysics-based tools at Lancaster for over 20 years to help tackle such a challenge. The field of hydrogeophysics has emerged as a branch of hydrology that sees the utilisation of geophysics for solving hydrological problems. Whilst much of the earlier work in this field concentrated on mapping subsurface hydrological units, we are now beginning to formally incorporate geophysical data (alongside other data) in hydrological model parameterisation and calibration. We see exciting opportunities to develop these data assimilation methods, particularly as we move to measurements over larger areas (as we move from plot to field to catchment scale).
Current Projects
New Process Models
A random particle tracking model of hillslope hydrology
- Despite the long history of the continuum equation approach in hydrology, it is not a necessary approach to the formulation of a physically-based representation of hillslope hydrology. The Multiple Interacting Pathways (MIPs) model is a discrete realisation that allows hillslope response and transport to be simultaneously explored in a way that reflects the potential occurrence of preferential flows and lengths of pathways. The MIPs model uses random particle tracking methods to represent the flow of water within the subsurface alongside velocity distributions that acknowledge preferential flows and transition probability matrices, which control flow pathways. An initial realisation of this model is presented here in application to a tracer experiment carried out in Gårdsjön, Sweden. The model has been used as an exploratory tool, testing several hypotheses in relation to this experiment. It is currently being extended to the whole Gårdsjön catchment and to other data sets.
Hydrogeophysical data fusion
- We are developing Bayesian data fusion algorithms that allow us to bring together multiple geophysical datasets and data types in the formation of a single coherent geophysical model of the subsurface. The algorithms recognise the inherent uncertainty in measurements and models and provide a probabilistic measure of geophysical states within a 3D volume. Information quantification permits the assessment of data worth, which can help improve survey design as we seek to reduce uncertainty. Linking with appropriate petrophysical models then permits the characterisation of the subsurface in terms of hydrological states (e.g. water content) or properties (e.g. hydraulic conductivity). Much of our current work is funded by the EU FP7 project modelPROBE and focuses on a number of European contaminated test sites.
Hydrogeophysical characterisation of permeability
- Supported by funds from the US National Science Foundation, we are exploring the use of electrical measurements for the estimation of hydraulic conductivity in aquifers. Spectral induced polarisation provides electrical spectroscopic measures that are strongly influenced by electrical charge conduction and storage along the surface of charged grains, and thus can be affected by similar textural factors that influence hydraulic permeability. With colleagues in the US we are investigating these links and attempting field based studies to examine the usefulness of these tools for mapping hydraulic conductivity fields in the subsurface.
Mass transfer in aquifers
- Chemical transport in the subsurface can be controlled by the reactivity of the grain surface in a porous medium but also by the pore structure. Where dead-end pores exist, chemical diffusion may occur, thus leading to an apparent retardation of contaminant migration. As part of a US Department of Energy project which is examining the migration of uranium at the Hanford site in eastern Washington State, we are studying the link between electrical spectroscopic properties of porous media and the mass transfer processes. Our aim is to establish petrophysical links between the two, which can then be exploited for field scale investigations.
Surface Water Processes
Lakes and rivers, and other surface waterbodies – reservoirs, wetlands, streams etc. – are vital elements of the global water and nutrient cycles, in relation both to in-catchment processes, and in terms of their integrated effects at national and global scales. Within themselves, they also support high biodiversity and deliver a wide range of ecosystem and hydrosystem services – water supply, leisure amenity, flood protection etc. and are one of the most important and iconic aspects of many very highly valued landscapes around the world. As the convergence of increases in calls on their usage, delivery of eutrophying nutrients and potentially destabilising climate changes intensifies, understanding which can lead to management which sustains their water quality and ecological health becomes increasingly valuable.
The challenges faced in this area of our work are to gain a more fully joined up understanding of the inter-relationships between the physical, chemical and biological processes which determine waterbodies’ health and to deliver this understanding in a way which facilitates solution of real problems and setting of policy regarding the management of surface waterbodies in the UK and worldwide.
In this area, we carry out fieldwork-driven research, which incorporates theoretical modelling and laboratory analyses. This work is carried out primarily with our co-located colleagues in the Lake Ecosystems Group at the UK Centre for Ecology and Hydrology Lancaster Laboratories, but has involved collaboration with many other groups worldwide.
Our research activities cover the following areas: Turbulent mixing in stratified lakes: determination of energy budgets derived from heat and wind energy inputs, and the chemical and biological implications of their physical manifestations in the water column; Nutrient budgets and pathways in lakes: determination of lake-wide budgets of nutrient delivery, cycling and outflow via a combination of physical and chemical sampling methodologies; Flow-vegetation interactions: both in standing and flowing water – determination of the effect of vegetation on hydrodynamics and thus conveyance, bed material resuspension and nutrient transport, and of the effect of flow on vegetation and thus vegetation distribution and colonisation.
Our research has been supported by grants from NERC, the Australian Research Council and the Royal Society.
Current Projects
Using thermal microstructure profiles to determine the history of turbulent mixing in a lake water column; Principal Investigator A. Folkard, ongoing project pump primed by NERC 2009-2010.
Heterogeneity of phosphorus budgets in Esthwaite Water, a small temperate lake; Principal Investigators A. Folkard, I. Jones (CEH Lancaster), Faculty PhD studentship supporting E. Mackay 2007-2011, project ongoing
Determining the flow resistance of vegetation in small streams and ditches, Principal Investigator A Folkard, funded by University of Lancaster