1. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Helmut Fischer, Volker Kirchesch, Katrin Quiel, Andreas Schöl Bundesanstalt für Gewässerkunde Influence of global change on the water quality of the Elbe/Labe Einfluss des globalen Wandels auf die Gewässergüte der Elbe

2. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Contents 1. Introduction Position in the model network Factors influencing water quality The water quality model QSim 2. Results Longitudinal development of water quality Model results (validation) Temporal development of water quality 3. Conclusions and outlook

3. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Einleitung: Gliederung Introduction - position of the project in the model network Water management (WBALMO) Water use Energy / Mining (KASIM) Households /business (HAUSHALT WASSER) Industry (INDUSTRIE WASSER) Agriculture / Irrigation Wetlands (MODAM) Development of water technologies Inflow Evaporation Irrigation Wetlands Water suppliers Industry Mining Power plants Nutrient load (MONERIS) Point source: Industry Regionalization of global change Future climate (STAR) Development of agricultural sector (RAUMIS) Economics and demography (REGE) Minimal flow for conservation Transport on inland waterways Point source: Sewage plant Diffuse source: Sealed surfaces Diffuse source: Erosion Diffuse source: Atmospheric Deposition Diffuse source: Drainage Diffuse source: Surface denudation Diffuse source: Groundwater Diffuse source / Sink: Wetlands Land use and regional water balance Hydrological cycle and crop yields (SWIM) Land use (LAND USE SCANNER) Development of energy sector (KASIM) Transport on inland waterways X1X13X15X4X3 X2 Y2 Y1 Y5 Y3 Y4 Y7 Z8 Y8 Z1 Y6 Z6 Z7 Z9 Z5 Z1 Z2 Z3 Z4 Water quality (QSim) Nutrient concentr. Phytoplankton Oxygen

4. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Water use Agriculture / Irrigation Development of water technologies Nutrient load (MONERIS) Point source: dir. ind. discharges Regionalization of global change Future climate (STAR) Development of agricultural sector (WATSIM-RAUMIS) Economics and demography (REGE) Point discharges: WWTP Diffuse Source: imp. surfaces Diffuse Source: Erosion Diffuse Source: Atm. Deposition Diffuse Source: Drainage Diffuse Source: Surface runoff Diffuse Source: Groundwater Sinks: Surface waters/Wetlands Land use and regional water balance Land use (LAND USE SCANNER) Y3 Y8X1 X15 X2 Y2 Y1 Y5 Y7 Y6 Introduction - position of the project in the model network Households / business (HAUSHALT WASSER) Industry (INDUSTRIE WASSER) Wetlands (MODAM) Hydrological cycle and crop yields (SWIM) Water quality (QSim) Nutrient concentr. Phytoplankton Oxygen

5. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Introduction Climate (temperature, light regime, precipitation) model STAR, PIK Discharge (water depth, retention times) model SWIM, PIK Nutrients (inputs, concentrations) model MONERIS, IGB nutrient budget Algal growth and biomass Factors influencing algal biomass and nutrient budget and Models providing input data for QSim

6. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Introduction – the model QSim O2O2 heterotrophic bacteria, nitrifying bacteria phytoplankton diatoms, green and bluegreen algae POC/DOC zooplankton rotifers discharge mussels NH 4, NO 2, NO 3, P, Si dissolved nutrients organic carbon hydraulics generating segments heat- balance planktonic modules benthic modules Schöl et al. 1999, 2002

7. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Longitudinal (Lagrangian) sampling campaigns: chlorophyll a Results Elbe-km Chlorophyll a [µg/l] Summer 2000 26.6. – 5.7. (9 days) low discharge Summer 2005 24.7. – 1.8. (7 days) medium discharge Spring 2006 8.5. – 15.5. (6 days) high discharge 18:00 Elbe 6:00 18:00 tributaries 6:00 High phytoplankton biomass leads to oxygen supersaturation in the Middle Elbe (up to 200% in summer) and and heavy loads of organic matter in the tidal area. n = 3 0 50 100 150 200 0100200300400500600

8. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Chlorophyll a – measured and modelled data Results Sommer 2000 26.6. – 5.7. low discharge 18:00 Elbe 6:00 18:00 tributaries 6:00 Chlorophyll a [µg/l] Elbe-km

9. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Longitudinal sampling campaigns: dissolved phosphorus (ortho-phosphate) Results ortho-PO 4 -P [mg/l] Elbe Tributaries n = 6 Summer 2000 26.6. – 5.7. (9 days) low discharge Summer 2005 24.7. – 1.8. (7 days) medium discharge Spring 2006 8.5. – 15.5. (6 days) high discharge Elbe-km

10. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Sommer 2000 26.6. – 5.7. low discharge Elbe tributaries ortho-PO 4 -P [mg/l] Elbe-km Results Phosphate – measured and modelled data

11. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Results Elbe Tributaries n = 6 SiO 2 -Si [mg/l] Summer 2000 26.6. – 5.7. (9 days) low discharge Summer 2005 24.7. – 1.8. (7 days) medium discharge Spring 2006 8.5. – 15.5. (6 days) high discharge Elbe-km Longitudinal sampling campaigns: silica

12. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Sommer 2000 26.6. – 5.7. low discharge Elbe tributaries SiO 2 -Si [mg/l] Elbe-km Results Silica – measured and modelled data

13. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Longitudinal sampling campaigns: nitrogen (nitrate and total nitrogen) Results n = 6 NO 3 -N, total N [mg/l] Summer 2000 26.6. – 5.7. (9 days) low discharge Summer 2005 24.7. – 1.8. (7 days) medium discharge Elbe-km 0 1 2 3 4 0100200300400500 600 0 1 2 3 4 0100200300400500600 Total-N NO 3 -N Total-N NO 3 -N Elbe Tributaries Spring 2006 8.5. – 15.5. (6 days) high discharge

14. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Sommer 2000 26.6. – 5.7. low discharge Elbe tributaries NO 3 -N [mg/l] Elbe-km Results Nitrate – measured and modelled data

15. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Results Chlorophyll a (1998) measured and modelled (Schöl et al. 2006; measured data by ARGE Elbe) modelled

16. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Results Comparison of phytoplankton composition in the years 1998 and 2003 2003 a warm and dry summer development of cyanobacteria (data by ARGE Elbe)

17. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Results 2003 Measured phytoplankton composition (data ARGE Elbe) 2003 Modelled phytoplankton composition

18. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Results In which direction will the system change if - temperature increases - summer discharges decrease Model runs with database from years 1998 and 2003 Model results slightly more zooplankton only minor change in algal biomass change in phytoplankton composition (increase of cyanobacteria)

19. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Conclusions and Outlook Current state - strong phytoplankton growth (factor ~4) - intense turnover of nutrients (biologically controlled) - heavy organic load (secondary pollution) impairs the oxygen budget of the Elbe estuary - high nutrient loads are problematic for coastal areas Future state - intensification of biological processes - better growth conditions (light, temperature) - stronger nutrient limitation is possible - better conditions for cyanobacteria - open system for invading species (e.g. mussels) Phytoplankton development + +- -

20. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Conclusions and Outlook Further work within GLOWA-Elbe II - Modelling nutrient dynamics and phytoplankton growth in the Czech Elbe section (below Vltava/Moldau). - Calculation of 5 climate scenarios x 4 socio-economic scenarios Future state - intensification of biological processes - better growth conditions (light, temperature) - stronger nutrient limitation is possible - better conditions for cyanobacteria - open system for invading species (e.g. mussels) Phytoplankton development + +- -

21. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Thank You for your attention!

22. GLOWA-Elbe II Statuskonferenz 14. Dez. 2006 Potsdam H. Fischer, BfG Koblenz Longitudinal sampling campaigns: (ortho-phosphate) and total phosphorus Results n = 6 Elbe-km ortho-PO 4 -P, total P [mg/l] Summer 2000 26.6. – 5.7. (9 days) low discharge Summer 2005 24.7. – 1.8. (7 days) medium discharge Spring 2006 8.5. – 15.5. (6 days) high discharge Total-P ortho-PO 4 -P Elbe Tributaries Total-P ortho-PO 4 -P