7. conclusions

7. Conclusions

1. Major human interventions with significant ecological impact have been identified in all participating countries.

2. The most significant human interventions in the hydrological cycle have been made over the last decades. Today the negative effects of these interventions are recognised and analysed, and restoration activities are initiated. The perception of the importance of an intervention changes over time, as the understanding of the aquatic environment evolves.

3. Key figures and statistics concerning freshwater resources, freshwater abstractions, and major uses by countries are not readily comparable because of the different methods of assessment and calculation in each country. However, comparable data characterising the hydrological cycle, the water balance and water demand are necessary to quantify and judge the human interventions identified in this report, and on the basis of figures which characterise the extent of the impacts (quantity measures), to identify key issues relevant for the EEA.

4. One of the main difficulties in determining the significance of human interventions in the hydrological cycle on a pan-European scale appears to be the lack of appropriate criteria or regional scale for comparison. To that end the use of the regionalisation of the continent by the Biogeographic Regions used for the Natura 2000 process would be inappropriate. From the hydrological standpoint this division of Europe does not seem to be optimal due to the fact that hydrological characteristics vary strongly within a biogeographic region. Interventions in the hydrological cycle are not mainly based on the biogeographic regions itself but rather caused by human pressure (population density etc.) and cultural development. Further, distance between supply and demand, the pressure and the intervention, becomes relevant (e.g. upstream flood control of cities, distant hydropower generation etc.).

5. The report and the selection of the most significant interventions in the hydrological cycle is based on a consultation of experts at AWW (Austria), INAG (Portugal), IOW (France), NERI (Denmark) and NIVA (Norway). Therefore some aspects concerning other countries or regions may have been missed at this stage and will become evident in the further process.