Modelling of Climate Change Impacts on River Flow Regime and Discharge of Danube River Considering Water Management Effects

Modelling of climate change impacts on river flow regime and discharge of Danube River considering water management effects

Judith Stagl Anastasia Lobanova, Fred Hattermann, Hagen Koch, Shaoshun Huang

18 July 2013 International SWAT Conference, Toulouse, France Motivation

• Investigate the impacts of climate change on the water regime of the Danube river

• Highly managed watershed -> Include water management

• Climate change impacts vs. impounding effects of reservoirs

• Application of eco-hydrological Indicators to bridge the gap to biodiveristy Observed Trends Climate Projections for Danube basin

Models: ENSEMBLES 2009; 14 GCM/RCMs, A1B Scenario Multimodel mean 2021–2050 relative to 1971–2000 Climate Projections for Danube basin

Models: ENSEMBLES 2009; 14 GCM/RCMs, A1B Scenario Multimodel mean 2021–2050 relative to 1971–2000 Danube Tributeries

Cumulated annual mean discharge of the Danube river 3 Qave/Year [m /s] Tisza

7000 Prut Siret Ialomita 6000 Arges Yantra Olt 5000 Iskar Jiu Timok Morava (CS) 4000 Sava Tamis/Timis Sava Tysa/Tisza/Tisa 3000 Tysa/Tisza Drau/Drava Sío Ipel/Ipoly 2000 Drava Hron Vah Raab/Rába 1000 Morava/March Enns Inn Traun Inn 0 Isar Naab 694 604 432 155 2497 2282 2125 1880 1766 1708 1382 1170 1103 Lech [river km] The Danube River – different regimes

Runoff regime (Pardé) for selected gauges in the Danube basin

m.a.s.l. <100 100 200 300 400 500 1000 1500 2000 2500 >3000

Name, Research Domain 7 Water management – Iron Gates I and II

• total volume of 3.2 billion m3 • total length of 270 km • for hydropower generation but also used for the flow regulation • Volume < 3% of the average annual flow -> impounding effects minor significant • -> provide a daily and weekly flow regulation Monthly discharge from 1992-1999

350000 Novo Selo - downstream 300000 Bazias - upstream

250000

200000

150000

100000

50000

0 1992 1993 1994 1995 1996 1997 1998 1999 Danube – outlet Ceatal Izmail Preliminary results

Danube - Selected subbasins

Tisza

Relative Volume Difference: -0.9 % Nash-Sutcliffe Efficiency: 0.62

A. Lobanova Mures

Relative Volume Difference: 3.9 % Nash-Sutcliffe Efficiency: 0.68

A. Lobanova Scenarios (ENSEMBLES) – for Mures

Deviations [%] in monthly mean discharge of Mures River compared to 1971-2000

% %

Scenario period 2021-2050 Scenario period 2071-2100

Models: ENSEMBLES 2009 9 GCM/RCMs, A1B Scenario

A. Lobanova Outlook

• Parametrisation/Calibration for different sub-catchements • Improvement of storages and routing (adjustment of curve numbers)

• Integration of largest reservoirs • Evaluation of different climate scenarios ENSEMBLES and also new ones (CORDEX) • For nature conservation: application of specific eco-hydrological indicators

Thank you for your attention

Danube Canyon Iron Gate