1. Wallingford - May 2002 Dam-break floods and sediemnt movement 1 IMPACT - WP4 Dam-break induced floods and sediment movement IMPACT - WP4 Dam-break induced floods and sediment movement State of the art and need for research Université catholique de Louvain Yves Zech and Benoit Spinewine

2. Wallingford - May 2002 Dam-break floods and sediemnt movement 2 Aims and objectives Improve the prediction of the motion of sediments in association with catastrophic floods

3. Wallingford - May 2002 Dam-break floods and sediemnt movement 3 Solid transport and extreme flows

4. Wallingford - May 2002 Dam-break floods and sediemnt movement 4 Types of catastrophes Dam break Debris flows, mud flows and lahars Floating debris and clogging Glacial lake outburst flood (GLOF) Landslides –Bank failure into the dam reservoir –Obstruction by natural dams

5. Wallingford - May 2002 Dam-break floods and sediemnt movement 5 Former EU researches Natural hazards MITCH Mitigation of climate induced natural hazards January 2001 - 24 months - 13 partners (HR Wall)

6. Wallingford - May 2002 Dam-break floods and sediemnt movement 6 Former EU researches Torrents and sediments THARMIT Torrent hazard control in the European Alps. Practical tools and methodologies for hazard assessment and risk mitigation July 2000 - 30 months - 11 partners (UDT, Cem) EROSLOPE II Dynamics of sediments and water in alpine catchments - processes and prediction June 1996 - 36 months - 10 partners (Cem, UDT)

7. Wallingford - May 2002 Dam-break floods and sediemnt movement 7 Former EU researches Debris DAMOCLES Debrisfall assessment in mountain catchment for local end-users March 2000 - 36 months - 6 partners DEBRIS-FLOW-RISK Debris flow management and risk assessment in the Alpine region October 1996 - 30 months - 9 partners (Cem, UDT)

8. Wallingford - May 2002 Dam-break floods and sediemnt movement 8 Former EU researches Glaciological hazards GLACIORISK Survey and prevention of extreme glaciological hazards in European mountainous regions January 2001 - 36 months - 11 partners (Cem)

9. Wallingford - May 2002 Dam-break floods and sediemnt movement 9 Former EU researches Avalanches and landslides CADZIE Catastrophic avalanches: defence structures and zoning in Europe April 2000 - 30 months - 10 partners (Cem) ALERT Avalanche and landslip early reporting technology December 1997 - 4 months - 2 partners

10. Wallingford - May 2002 Dam-break floods and sediemnt movement 10 Former EU researches Avalanches and landslides (2) Landslide hazards New technologies for landslide hazard assessment and management in Europe July 1996 - 24 months - 11 partners Large-volume landslides Major risk from rapid, large-volume landslides in Europe: the design and testing of new techniques for hazard assessment and mitigation January 1998 - 24 months - 7 partners

11. Wallingford - May 2002 Dam-break floods and sediemnt movement 11 Former EU researches Avalanches and landslides (3) Landslide and avalanche risks Concerted action on forecasting prevention and reduction of landslide and avalanche risks January 1998 - 30 months - 5 partners Mechanisms of landslides Mechanisms of catastrophic landslides January 1998 - 24 months - 6 partners

12. Wallingford - May 2002 Dam-break floods and sediemnt movement 12 Issues of IMPACT WP4 research Extreme flows  intense erosion and solid transport Intense sediment transport  affects flood-wave prediction –Arrival time –Maximum water level –Morphological changes

13. Wallingford - May 2002 Dam-break floods and sediemnt movement 13 Scope of the research Near-field –Severe transient debris flow Far-field –Intense transport –Bank erosion and geomorphic changes

14. Wallingford - May 2002 Dam-break floods and sediemnt movement 14 Near field : problems to be solved Initiation of movement –Vertical effects –Inertial effects –Sediments bulking Propagation –Intense scouring –Debris-flow front

15. Wallingford - May 2002 Dam-break floods and sediemnt movement 15 Far field : problems to be solved Transition from near-field to far-field Geomorphic changes –Bank erosion and failure Tractive forces applied Failure mechanism –Channel widening –Deposition of material De-bulking Distribution of sediments Formation of secondary dams

16. Wallingford - May 2002 Dam-break floods and sediemnt movement 16 Overall approach Combine physical experiments with the development and testing of mathematical modelling methods to improve our understanding of these flows

17. Wallingford - May 2002 Dam-break floods and sediemnt movement 17 State of the art Near field –Experimental approach –Physical approach –Numerical approach Far field –Experimental approach –Physical approach

18. Wallingford - May 2002 Dam-break floods and sediemnt movement 18 Near field : experimental approach Regime –Uniform flow, e.g. debris flow (UDT) –Severe transients, e.g. dam break (UCL, UDT, IST, NTU) National Taiwan University

19. Wallingford - May 2002 Dam-break floods and sediemnt movement 19 Near field : experimental approach Solid transport mode –Intense bed load –Debris-flow rheology (UDT) Boundary conditions (water & sediment) UCL

20. Wallingford - May 2002 Dam-break floods and sediemnt movement 20 Near field : experimental approach Material –Light pearls (Taiwan) –PVC pellets (Trento, UCL) –Sand (Beira interior, IST, UCL) National Taiwan University

21. Wallingford - May 2002 Dam-break floods and sediemnt movement 21 Near field : experimental approach Grain-size distribution –Uniform –Graded University of Trento

22. Wallingford - May 2002 Dam-break floods and sediemnt movement 22 Near field : experimental approach Floating debris (Mississippi, Alberta)

23. Wallingford - May 2002 Dam-break floods and sediemnt movement 23 Near field : experimental approach Measurement techniques –Gauges –Interfaces imaging –Particle tracking Tracking of tracers particles Bed material tracking

24. Wallingford - May 2002 Dam-break floods and sediemnt movement 24 Near field : physical approach Sediment inertia –Acting forces Near-field erosion –Mobilisation of granular bed –Scour hole Formation of a debris-flow –Hydraulic jump –Mixture of sediments and water

25. Wallingford - May 2002 Dam-break floods and sediemnt movement 25 Near field : numerical approach Flow description –Analytical (UDT, UCL) –Shallow-water description 1D 2D-H –2D-V Hydrodynamics (ETHZ, Tianjin) Tentative modelling with sediments (NTU, UCL) UCL

26. Wallingford - May 2002 Dam-break floods and sediemnt movement 26 Near field : numerical approach Transport modelling –Uncoupled hydrodynamics & solid transport –Coupled description Sediment inertia Momentum exchanges –Multiphase description

27. Wallingford - May 2002 Dam-break floods and sediemnt movement 27 Near field : former studies University of Trento Uniform debris-flow experiments

28. Wallingford - May 2002 Dam-break floods and sediemnt movement 28 Near field : former studies Mature debris flow

29. Wallingford - May 2002 Dam-break floods and sediemnt movement 29 Near field : former studies Mature debris flow

30. Wallingford - May 2002 Dam-break floods and sediemnt movement 30 Near field : former studies Z (cm) V (m/s) v w u - 0.200.20.40.6 1 2 3 4 5 6 7 Velocity

31. Wallingford - May 2002 Dam-break floods and sediemnt movement 31 Near field : former studies c z cm Concentration

32. Wallingford - May 2002 Dam-break floods and sediemnt movement 32 Near field : former studies Dam-break experiments University of Louvain

33. Wallingford - May 2002 Dam-break floods and sediemnt movement 33 Near field : former studies Mathematical description –Shallow water –Velocity and concentration

34. Wallingford - May 2002 Dam-break floods and sediemnt movement 34 Near field : former studies Numerical results in simplified cases –Finite volumes –Fluxes according to Roe –Non equilibrium UCL

35. Wallingford - May 2002 Dam-break floods and sediemnt movement 35 Near field : former studies Limitations of existing models

36. Wallingford - May 2002 Dam-break floods and sediemnt movement 36 Near field : research programme Laboratory work –Acting forces, flow resistance –Dam-break flows : near-field features

37. Wallingford - May 2002 Dam-break floods and sediemnt movement 37 Near field : research programme Acting forces, flow resistance (UDT) –Uniform material Months 1-18 –Graded material Months 18-32  Benchmark

38. Wallingford - May 2002 Dam-break floods and sediemnt movement 38 Near field : research programme Dam-break flows : near field (UCL) –Uniform material Months 1-9  Benchmark Various water levels Various sediment levels

39. Wallingford - May 2002 Dam-break floods and sediemnt movement 39 Near field : research programme Mathematical modelling (UCL) –1D model: months 1-10 Velocity distribution (Concentration distribution)

40. Wallingford - May 2002 Dam-break floods and sediemnt movement 40 Near field : research programme Mathematical modelling (UCL) –2D-V model: months 21-32

41. Wallingford - May 2002 Dam-break floods and sediemnt movement 41 Near field : research programme Validation of codes (UDT, UCL, Cem) –Debris flow Months 11-12 –Dam-break flow in the near field Months 11-12

42. Wallingford - May 2002 Dam-break floods and sediemnt movement 42 Far field : experimental approach Numerous data from real cases –Lawn Lake dam failure (Colorado, 1982) –Lake Ha!Ha! dike failure (Quebec, 1996)

43. Wallingford - May 2002 Dam-break floods and sediemnt movement 43 Far field : experimental approach Bank failure experiments –River meandering –River braiding Breaching processes UCL

44. Wallingford - May 2002 Dam-break floods and sediemnt movement 44 Far field : physical approach Transition from near- to far-field –Sediment de-bulking –Front-plug piping and overtopping National Taiwan University

45. Wallingford - May 2002 Dam-break floods and sediemnt movement 45 Far field : physical approach Valley widening –Bank scouring –Bank collapse Sediment re-distribution –Bed deposition

46. Wallingford - May 2002 Dam-break floods and sediemnt movement 46 Far field : numerical approach Extension of shallow-water equation –Two-phase flow description River width adjustment 3D de-coupled modelling –Bends Does not match the dam-break problem

47. Wallingford - May 2002 Dam-break floods and sediemnt movement 47 Far field : former studies Bank erosion experiments University of Louvain

48. Wallingford - May 2002 Dam-break floods and sediemnt movement 48 Far field : former studies Bank erosion experiments

49. Wallingford - May 2002 Dam-break floods and sediemnt movement 49 Far field : former studies Submerged sand Dry sand Humid sand 37° 85° Principle experiments

50. Wallingford - May 2002 Dam-break floods and sediemnt movement 50 Far field : former studies

51. Wallingford - May 2002 Dam-break floods and sediemnt movement 51 Far field : former studies Bank failure mechanism 50° 37° 85° V bank

52. Wallingford - May 2002 Dam-break floods and sediemnt movement 52 Far field : former studies 6 cm 19 cm 50° UCL

53. Wallingford - May 2002 Dam-break floods and sediemnt movement 53 Far field : former studies UCL

54. Wallingford - May 2002 Dam-break floods and sediemnt movement 54 Far field : former studies Numerical result (without water)

55. Wallingford - May 2002 Dam-break floods and sediemnt movement 55 Far field : former studies Limitation of numerical description –Need for 2D approach –Need for coupling Limitation of physical description –Bank-failure mechanism : 3D features –Rheological aspects of bank failure –Suspended load and re-suspension

56. Wallingford - May 2002 Dam-break floods and sediemnt movement 56 Far field : research programme Laboratory work –Dam-break in an initially prismatic valley (UCL) Months 13-20 –Similar tests in large- scale model (Châtelet) –Large-scale enlargement (Châtelet) Months 24-31

57. Wallingford - May 2002 Dam-break floods and sediemnt movement 57 Far field : research programme Numerical modelling –Extension of 2D-H model (UCL) Bank erosion Months 12-20

58. Wallingford - May 2002 Dam-break floods and sediemnt movement 58 Far field : research programme Validation (UCL, UDT, Cemagref, IST) –Benchmarks Laboratory tests WP2 Norwegian dam Lake Ha!Ha!

59. Wallingford - May 2002 Dam-break floods and sediemnt movement 59 IMPACT - WP4 Dam-break induced floods and sediment movement IMPACT - WP4 Dam-break induced floods and sediment movement State of the art and need for research Université catholique de Louvain Yves Zech and Benoit Spinewine