Recent events have shown that groundwater flooding is a serious risk to property, infrastructure and social disruption, and is a particular problem for the Chalk of South East England. The nature of this risk is poorly understood, and there is no adequate methodology to assess it. This proposal integrates state-of-the-art models of the soil, unsaturated zone, groundwater and surface water to provide a new modelling tool for risk assessment, and also investigates the use of simpler models for warning of the potential onset of flooding and regional assessment of risk. Experimental data from the NERC Lowland Catchment Research Thematic Programme and historical data from affected areas will be used to test hypotheses and develop and validate the models. The models will be run for future climate states to assess current and future risk using an ensemble of climate models.

Groundwater / surface water interactions, and the controls on water and pollutant flux across the interface of aquifers and rivers, are important factors controlling the chemical and ecological quality of river corridors. An increasing body of research has been published in recent years on processes acting at this interface, which is known as the hyporheic zone (Sophocleous 2002). However, few have adopted a truly multidisciplinary approach, which integrate physical, chemical and biological investigations in the hyporheic zone. There is an opportunity for the UK to take a lead. Understanding processes at the groundwater / surface water interface has been identified as a priority research area the British Geological Survey, CEH and the Environment Agency (Smith 2005); NERC's priorities are currently being reviewed and we expect this area to remain included, as it is in the current science priorities for Sustainable Water Management. In order to understand this system better it is necessary to bring together workers from a range of scientific disciplines. Furthermore, prioritisation of future research requires better engagement between researchers and science end-users. We will establish a Knowledge Transfer Network on groundwater / surface water interactions, with a specific focus on hyporheic processes. The Hyporheic Network will allow researchers to meet with science end-users (and vice versa), in order to disseminate existing knowledge, and to identify the end-user priorities for research in this area. In particular it will bring together hydrologists, ecologists, geochemists, geomorphologists and hydrogeologists in order to identify opportunities for novel cross-disciplinary research. The Hyporheic Network will provide a forum for academics to communicate their research findings directly to interested science end-users, and for those science-users to inform the research community of their priorities. New research teams will be created to develop new and exciting research proposals, in collaboration with end-user groups. The Network will run a series of workshops and meetings that will disseminate recent research and we will provide financial support a number of young researchers to attend these workshops, in order to encourage them to participate. We will develop and maintain a website to distribute reports and information on the hyporheic zone, and we intend that the website will become a portal for international research and information on all aspects of the hyporheic zone. One of the major goals of the network is to write a book on the hyporheic zone, which will turn the latest research into usable advice for river managers. The proposed Network already has commitment from a range of researchers, including hydrologists, ecologist, hydrochemists, hydrogeologists, hydrogeophysicists and geomorphologists. Science end-user groups interested in engaging with the Network include government (both policy makers and regulatory agencies), large industrial companies, consulting companies, non-governmental organisations, and international universities and organisations.

The way in which water flows within a natural river is one of the most complex phenomenon to model and predict accurately in the environment. This is even more so for the flow that occur just beneath the surface of the river bed (in a region termed the 'hyporheic' zone), between the spaces of pebbles and stones that make up the bottom of a river. Efforts to accurately model these flows have been hampered by the fact that obtaining measurements of water velocity from the tiny spaces between pebbles has so far proved an irresolvable problem. But why should this worry scientists? Firstly, stream ecologists now recognise that the hyporheic zone is an important habitat for a diverse range of species. The way flow from above the bed makes its way into the subsurface largely dictates how much oxygen and nutrients are supplied to this habitat. Secondly, fisheries managers have long understood that the probability of salmon eggs laid in river beds hatching will be dependent on a continuous supply of oxygenated water to the grevelly sediments in which they are laid. Thirdly, pollutants in river systems (such as heavy metals) often become attached to microscopic particles called colloids, which tend to follow flow pathways. An understanding of how flow moves within a river bed will thus go a long way to establishing pollutant behaviour. There are thus a broad range of highly important environmental issues that require detailed predictions of how water moves within a river bed, yet there is no way of measuring or modelling this accurately. Using pioneering new approaches this proposal seeks to meet this challenge. The first task is to accurately measure flow within the bed, this significant problem will be overcome using a new micro-PIV (particle imaging velocimetry) technique. This system borrows technology developed for medical applications by employing a small endoscopic digital camera which can be placed within an experimental river bed. By seeding the flow with tiny reflective particles, and providing high intensity illumination from a laser, the endoscopic camera can record how they move within the small gaps found between pebbles in the river bed. Using a special processor, these digital images can be turned into numerical data that accurately records how flow moves across and then into the river bed. Such measurements have never been possible before. The second phase of the project is to use the new understanding made possible by this unique dataset to develop and test a 3-D numerical model that can precisely predict how water will flow above and below the surface of a river bed. This will be achieved using a specially modified computational fluid dynamics (CFD) model. Such models represent the state-of-the-art, yet the issue of subsurface flow has proved too problematic for them to be applied in such environments. However, our team has devised a method whereby the pebbles can be 'blanked out' and the flow predicted around them and into adjacent gaps between pebbles. The advances in measurement and modelling approach that will be used in this project represent real breakthroughs that will unlock the inherent problem of gaining useful data from one of the most challenging of natural environments. Meanwhile, the development of a numerical model that can be widely applied will ensure that this new understanding can be applied and adapted to meet a variety of real world environmental challenges.

Landfill has been the principal method of waste disposal throughout most of the developed world for the last 100 years or more. More than 80% of the UK's waste is currently disposed of to landfill, but changes in legislation and resource management philosophy - in particular the EU Landfill Directive - are already beginning to change this. For example, the Directive requires a reduction in the amounts of biodegradable municipal waste (BMW) being disposed of to landfill in the UK to 75% of 1995 levels by 2010, 50% by 2013 and 35% by 2020. The Directive also requires that wastes are subjected to pre-treatment prior to landfilling, therefore a major role for landfill in the disposal of residual (i.e., post treatment or energy recovery) wastes will remain. Implementation of the EU Landfill Directive will have major implications for the nature of the waste that is disposed of to landfills throughout Europe, and hence for the way in which the receiving landfills should be managed. In particular, the Directive will require the large-scale treatment of municipal solid waste (MSW) to reduce the biological content. European experience suggests that treatment is likely to take one of two forms; either incineration, which has always been unpopular with the public in the UK, or a treatment comprising both mechanical and biological elements, together known as mechanical-biological treatment or MBT. MBT typically involves shredding or grinding of wastes prior to accelerated aerobic (often referred to as composting) or anaerobic degradation. Processing will leave a residue which, though much less biodegradable than MSW, will still produce gas (up to 20% of that from an untreated waste) and have the potential to pollute the environment.It is thought by some that there will be commercial or land improvement uses for the compost-like treated waste residues; however European experience and UK research has shown that it is likely that much of this waste residue will be suitable only for landfill for the foreseeable future. The residual wastes have very different properties to untreated wastes in terms of their mechanical behaviour (which impacts on the physical stability of landfills and hence their risk of landslides and pollution), the amount of gas and fluid which will be produced and the timescales over which gas and fluid production will occur. Unless the properties of residual wastes are understood and appropriate changes in working practice implemented, the consequences in terms of slope failure (landslide), increased risk of environmental pollution and potential loss of life could be severe. The aim of this research is to establish the mechanical and biological properties of waste residues so that design and management policies can be tailored to the waste's properties.

Urban river corridors are experiencing rapid changes in land use and perceptions and offer opportunities to create sustainable, high quality, communities. The hypothesis of the URSULA project (Urban River Corridors and Sustainable Living Agendas) is that there are significant social, economic and environmental gains to be made by integrated and innovative interventions in urban river corridors. We will test this by providing a portfolio of new ideas, new tools and new data to support redevelopment of urban river corridors as places where people want to live and work, now and in the future. We will do this in cooperation with national and local stakeholders, including government, commercial, community and 'non-organised' groups of stakeholders. The key themes of our analysis and way of working are 'people' (living, working), 'river' (ecological goods and services), 'design' (possibilities for intervention and innovation) and 'values' (agents of change, measures of success). We will draw on case studies in Sheffield, the UK and beyond, and test our Outcomes with local stakeholders in Sheffield on the corridor of the River Don and its tributaries. In the design theme we will, with stakeholders, choose a set of new and current ideas which may benefit redevelopment of urban river corridors, for example use of rivers for building climate control, better storm water management, or new urban forms. New field data and design analyses will enable us to understand their potential benefits and impacts. From the field and modelling work in the river theme, a deeper understanding of how urban rivers deliver ecological goods and services to the river corridor will show how the design possibilities can be assessed. The values theme will provide new analyses of the financial and other benefits of urban redevelopment, as well novel tools (e.g. visualisation) to work with stakeholders and understand their preferences. All of these activities will take place within a close cooperation through the people theme with the stakeholder groups, who are central to the project's motivation and measures of success.