1. Water Quality H. Behrendt, M. Grossmann, H. Gömann, U. Mischke, A. Schöll, J. Steidl GLOWA-Elbe GLOWA Status conference 19 May 2005 Cologne Linkages of quantification tools for the estimation of costs – ecological state relationships in the surface waters of the Elbe catchment Tasks of the Working Package Results of Phase I Concept of Phase II Conclusions

2. Water Quality VH I: Integration und -coordination Integrative Methodological Approach GLOWA-Elbe (IMA) Regional actors, decision bodies Frame of Development VH II: Regionalisation of Global Change Global Change Management level VH V: Cross conflict field scenario analysis Management- options Impact- analysis Evaluation VH IV: Conflict field Surface Water Quality Nutrient entry Cost-efficiency analysis Eco-hydrological Indicators Socioeconomic Indicators VH III: Conflict field Surface Water Availability Run off regulation Multi-criteria analysis Eco-hydrological Indicators Socioeconomic Indicators Project advisory board

3. Water Quality Tasks Development of a system of models, for scenario calcula- tions of possible changes of nutrient concentrations and ecological state in the Elbe: due to climate changes and Precipitation Temperature socio-economic development and RAUMISRAUMIS Connections of people WWTP technologies environmental targets (e.g.WFD) Ecological state of the water bodies of the Elbe and coastal zone

4. Water Quality Results phase I: Establishment of a harmonized database for the modeling of nutrient emissions into the total Elbe catchment Begin of cooperation with Czech institutions (e.g. boundaries of Czech subcatchments, unified soil loss map, tile drained areas, statistical data)

5. Water Quality Estimation of the nutrient emissions into the total Elbe catchment: Applicability of the model for areas outside Germany Estimation of nutrient emissions for 184 subcatchments in the Elbe Model calculations for different time periods in the past Long term changes of P- concentrations at Zollenspieker Diffuse P emissions in the Elbe Basin

6. Water Quality Changes of nutrient emissions due to climate Use of precipitation and discharges of WATERGAP 4 for two different climate models Depending on the used climate model the N emissions can increase or decrease up to 15% Scenario calculations on regional changes of discharge and nitrogen emissions for 2025

7. Water Quality Changes of nutrient emissions due to changes of global climate and regional human activities The socio-economic changes in the past influenced strongly the nitrogen emissions The changes due to climate changes are probably low

8. Water Quality Interactions between agricultural activities and nitrogen emissions Only the introduction of a strong N-tax leads to a substantial reduction of N- emissions from agricultural areas. The maximum potential for the reduction of N- emissions is about 1/3 compared to 1999

9. Water Quality GOWA-Elbe Phase II Ecological consequences Human activities Climate changes Costs Find solutions which have large ecological effects with a optimum of costs Nutrient loads

10. Water Quality Linkage between nutrient loads and ecological state of the river Classification of phytoplankton in rivers Tool for the modeling: QSIM

11. Water Quality Classes and linkage between phosphorus and phytoplankton in rivers Classes and linkage between nitrogen/phosphorus and ecological state of the coastal zone?

12. Water Quality Linkage between human activities and nutrient loads Activities in urban areaAgricultural activities Measures for sewers / WWTP / connection of people central versus decentral RAUMIS / SWIM

13. Water Quality N taxe Catchment 1Catchment 2 Bufferst rips Increasing costs Measure x Reduction of N / P load (t/a) Measure Y Costs (€/a) Degree of application Cost – efficient combination of measure? - Scenarios - Bio-economic model Min! (Costs * Degree of application) random condition N / P reduction targetsl Costs and effects

14. Water Quality Conclusions A harmonized database for the total Elbe for the diffuse sources of nutrient entries exists. An enlargement for point sources is needed for the calculation of individual measures. Average changes of climate are compared to human activities of minor importance for the nutrient emissions. But what is the sensitivity of biological indicators and which changes can be expected for extreme changes? Beside the emissions the retention processes determine the nutrient concentrations and ecological state of the water bodies. Measures for changes of retention have to be studied especially for lakes and wetlands. The combination of the model MONERIS with the models RAUMIS and SWIM is realised for the study of agricultural and climate influences on the nutrient emissions and loads. This set of models have to be enlarged by bio-economic and ecosystem models to estimate the costs of different ecological states of the water bodies

15. Water Quality Thank You For Your Attention! WWW.GLOWA-Elbe.de