The overall objective of the project is to introduce an East-West perspective on past, present and possible future loads of phosphorus and nitrogen in the rivers contributing the largest amounts of the nutrients to the Baltic Sea. Within this general frame, it will be investigated whether :
(i) observed differences in nutrient loads between major Baltic Sea and North Sea rivers primarily reflect differences in the input of nutrients to the studied river basins, or differences in the retention (or transformation) of nutrients in soil, water and sediments;
(ii) time-lagged effects of past loadings can have a substantial impact on the flux of nutrients through large river basins.
In addition, the possible impact of large-scale changes in land-use and agricultural practices on the future riverine load of nutrients to the Baltic Sea will be estimated.
The project is focussed on the flux of nutrients, and factors controlling this flux in the drainage areas of the Daugava, Vistula, Oder, Elbe, Rhine and Meuse rivers. In addition to water quality data, the project will utilize data regarding physical conditions in the studied river basins (precipitation, runoff, topography, soil type) and anthropogenic influence (land-use including agricultural practices, point emissions, atmospheric deposition, river regulation) on the flux of nutrients. Some of these data are point data. Other data will be abstracted from maps and from maps and from statistics for political or administrative units. In all cases, data will be aggregated to subbasins.
To achieve the objectives of the proposed project, three types of studies will be pursued :
(i) emission/immission-based calculations of the flux of nutrients through major Eastern and Western European river basins;
(ii) retrospective studies of the impact of dramatic, large-scale changes in point or non-point source on the riverine export to the sea;
(iii) assessments of the impact of in-stream processes on the overall retention of nutrients in large river basins.
The first type of studies addressed the spatial distribution of the flux of nutrients during periods of moderate temporal variation. The studied river basins represent a great variety of physical conditions, land-use and point emissions, and the estimated spatial distribution will describe average conditions during time periods of 5 to 20 years. In the second type of studies, temporal aspects are in focus. The selected cases represent examples of drastic human interventions in the flux of nutrients, and attention is paid to both immediate and time-lagged effects on this flux. The first type of studies are focussed on the retention of nutrients in reservoirs at hydroelectric power stations.
Funding SchemeCSC - Cost-sharing contracts
51 616 Wroclaw
3720 BA Bilthoven