Problems to be solved
Across the European Union there are concerns about nitrogen (N) in lowland and upland fresh water systems, estuaries and marine areas. In such systems, additional N inputs can cause rapid aquatic plant growth, leading to eutrophication. The problems of eutrophication are usually associated with lowland, intensively farmed areas where fertilisers provide a significant source of N and/or urban areas where domestic and industrial effluent is discharged to the receiving watercourse and groundwater. However increasing N deposition from the atmosphere has lead to increased problems in upland regions. Whilst management strategies have been implemented to control N in river systems, these have tended to address single issues: either diffuse or point sources, or upland or lowland areas. However, the N concentrations and loads in rivers reflect the integration of the catchments N sources: fertiliser inputs, atmospheric deposition and sewage discharges. Superimposed on these anthropogenic inputs are contributions from the vegetation and materialisation and nitrification of organic N in soils. Thus, given the holistic nature of the N problem, an integrated management approach is required. To support such an approach, modelling tools are needed to assess the likely impacts of land management, N deposition and climatic change on river N concentrations and loads. The INCA project has been designed to assess the impacts of multiple sources of N (N deposition, agricultural and sewage inputs) on water quality in European catchments. As such the project will directly contribute to EC policies including the Nitrate Directive (91/676/EEC) aimed at controlling diffuse nitrate pollution of public water supplies throughout Europe; the EC Habitats Directive (92/43/EEC) which aims to provide for the preservation of rare and valuable remnants of natural habitat in member states, including both terrestrial and aquatic habitat types; the Integrated Pollution Prevention and Control Directive (96/61/EEC) and the proposed Water Framework Directive (COM (97) 49 Final).
Scientific objectives and approach
The INCA project is based on the INCA (Integrated Nitrogen in Catchments) model, a processed based model of plant/soil system and in stream N dynamics which has been developed and tested in 4 UK catchments. Based on mass balance and reaction kinetics, INCA accounts for the multiple sources of N and simulates the principle N mechanisms operating, including mineralisation, immobilisation, nitrification and denitrification. INCA will be applied to assess the impacts of catchments N inputs on water quality at the pan European spatial scale.
Replication of a model application across key ecosystem types throughout Europe will provide
(i) an assessment of the sources and sinks of N and
(ii) estimates of the likely impacts of N deposition, land use and climate change scenarios on the fluxes of N, both within the plant/soil system and the river network. The results will be achieved by the creation of extensive databases describing the hydrology and N dynamics of the study areas and the creation of a generic version of INCA. Application of INCA to different ecosystems will provide some internal testing of the model. Furthermore, the model will be used to evaluate scale-up and connectivity using Monte Carlo analysis and measured N flux estimates at the plot and catchments scales. The model will also be used in conjunction with simple economic models to assess the costs and benefits of N controls in Europe.
The INCA project addresses the problem of providing high quality water in Europe through an improved understanding of river system functioning and the development of a pragmatic scientific and management tool. Thus the INCA model will assist end users such as the European Environment Agency and its national counterparts in the improved management of N in river catchments, which may lead to reduce eutrophication problems in streams, rivers, lakes and marine areas. The results of the project will also provide information for policy makers in the continued development of EC policy regarding the environment. As such the project will contribute to an improvement in water supplies for industrial use, public consumption and benefit environmental conservation thereby enhancing the quality of life for Europeans.
Funding SchemeCSC - Cost-sharing contracts
MK7 6AA Milton Keynes
1018 VZ Amsterdam