1. Toronto, May 6-8, 2008Flood Defence1 Risk assessment in trans-boundary cooperation between the Netherlands and Germany Jan Stijnen

2. Toronto, May 6-8, 2008Flood Defence2 Presentation overview Introduction Study area Risk-assessment method Sensitivity analysis Summary and future plans

3. Toronto, May 6-8, 2008Flood Defence3 Introduction Flood protection in boundary area of Germany and the Netherlands Identify and reduce flood risk for 2 dike ring areas along the Rhine Cooperation!

4. Toronto, May 6-8, 2008Flood Defence4 Introduction Project initiation: 2005 Three phases 1.Communication and identification (2006) 2.Risk-analysis of right-hand side dike ring (2007) 3.Risk-analysis of left-hand side dike ring (2008) Joint method, based on existing software/techniques Time horizons: 2006, 2015 and 2015+

5. Toronto, May 6-8, 2008Flood Defence5 Study area Transboundary dike rings along the river Rhine

6. Toronto, May 6-8, 2008Flood Defence6 Study area Dike ring 48 Dike ring 42 12.5 miles

7. Toronto, May 6-8, 2008Flood Defence7 Scope of the project

8. Toronto, May 6-8, 2008Flood Defence8 Failure mechanisms

9. Toronto, May 6-8, 2008Flood Defence9 Computation of failure probabilities –Overflow –Wave overtopping –Bursting of the soil & piping –Stability of the slope –No structures

10. Toronto, May 6-8, 2008Flood Defence10 Failure mechanisms / probabilities Identification of 10 weak spots, based on Dutch deterministic assessment method and local expert knowledge Probabilistic computation of failure probabilities every 100 meters for wave overtopping only Detailed probabilistic computation of failure probabilities for 10 weak spots

11. Toronto, May 6-8, 2008Flood Defence11 Differences in dike design T = 1250 years T = 500 years

12. Toronto, May 6-8, 2008Flood Defence12 Difference in maintenance

13. Toronto, May 6-8, 2008Flood Defence13 Breach and flood simulation

14. Toronto, May 6-8, 2008Flood Defence14 Breach and flood simulation

15. Toronto, May 6-8, 2008Flood Defence15 Damage assessment Flood simulation Damage and loss of life module Land use

16. Toronto, May 6-8, 2008Flood Defence16 Flood risk Risk = probability  consequence

17. Toronto, May 6-8, 2008Flood Defence17 Cost-benefit analysis of measures Types of (structural) measures: –Dike strengthening –Compartment dikes

18. Toronto, May 6-8, 2008Flood Defence18 Compartment dike

19. Toronto, May 6-8, 2008Flood Defence19 Compartment dike

20. Toronto, May 6-8, 2008Flood Defence20 Sensitivity analysis Verification of sensitivity to assumptions –Critical overtopping discharge –Breach development (width, water level, moment of breach) –Flood wave (shape and height of discharge wave) –Correction of damage and costs

21. Toronto, May 6-8, 2008Flood Defence21 Summary and future plans Cooperation very successfull as a result of the communication and identification phase Much added value because of different partners Project in last phase Final results this summer (symposium)

22. Toronto, May 6-8, 2008Flood Defence22 Thank you for your attention!