| | | State of the art of research regarding river and drainage basin pollution of nutrients |
The drainage basin with all ongoing human activities (such as waste production, leaching of agricultural chemicals etc.) and the coastal waters into which they drain, constitute large-scale ecosystems, that has to be protected from deterioration. Interactions between land activities, fresh water and coastal seas receive increasingly attention. International conferences, (e.g. the `Stockholm Water Symposia' in 1997 and the `Man and River System' conference in Paris in 1998) have been organised within the scope of these issues. The understanding of the dynamics and causes of the large-scale and long-term changes of riverine loads has been regarded as particularly important. The problems of river basin pollution of nutrients that have been addressed include:
Recent research indicates that the main uncertainty is the lack of knowledge of nutrient transformation processes between the root-zone and the rivers (see river runoff section). Attempts to integrate detailed process-oriented models with more simple large-scale approaches are in progress in Scandinavia. Another interesting topic is related to large-scale experiments in Eastern Europe with its dramatic decline in industrial and agricultural production, which has created an unique opportunity to study the river response on such changes (e.g. the Mantra-East project http://www.mantraeast.org; river runoff section).
| | | State of the art of research regarding river and drainage basin pollution of nutrients |