1. Results compare flood map and water level

2. PRESENTATION PLAN Introduction: Programme of the week Methodology
Data used
Software 1D (MIKE 11, ISIS, HEC-RAS)
Software 2D (MIKE 21, MIKE 21FM, TELEMAC 2D)
Comparison of software
Conclusions 11 21
21 FM

3. PROGRAMME OF THE WEEK
Prepare data

4. METHODOLOGY

5. DATA USED Study zone → Lower Var (6300 m of river from sea)
- Period → Flood event From 04/11/2011 to 11/11/2011
DEM → 15m resolution
Upper boundary condition → Hydrograph in La Manda bridge
(peak discharge = 1200m3/s)
Lower boundary condition → Sea level
Roughness coefficient → 20 (Strickler) = 0,05 (Manning)

6. SOFTWARE 1D 11

7. Hydraulic structures (e.g. weirs)
SOFTWARE 1D
All based on the equations of mass and momentum conservation
Software
Numerical method
Represents
Principal parameter
Output
Hydraulic structures (e.g. weirs)
Implicit Finite Difference
(6p Abbot)
Unsteady & Steady
Manning's roughness (n)
Topography (cross sections)
Water depth
Flood extent
YES
ISIS
Explicit Finite Difference (Preissmann 4p box scheme)
Steady & Unsteady
(with instabilities)
Manning's roughness (n) --> Parameter k
Flow velocity*
HEC Ras
(Preissmann 2nd order box scheme)
Roughness height (k)
Flow velocity
Finite Volumes
(Roe)
Geometry
Network
Boundary Conditions
Discharge 11
MASCARET

8. Observed Stage and Discharge
Peaks at about 135 hours, and 2.35 m

9. MIKE 11 - Results
Water depth
Discharge 11

10. ISIS - Results
Water depth
Discharge

11. HEC-RAS - Results
Water depth
Flood extent
05/11/ h00

12. SOFTWARE 2D 21
21 FM

13. SOFTWARE 2D Software Numerical method Well adapted to SWE properties
Structured spatial discretization
Optimization of computational points
Time needed
(relative)
Flow regime changes
Structures (e.g. weirs) based on:
Possible mass creation
Finite Differences
(ADI) NO
YES
Good
Stable
Not accurate (e.g. flow regime changes)
Topography or Empirical formulas
Finite Volumes
(Roe)
Reasonable
Stable; not accurate
Topography/ Empirical formulas
TELEMAC 2D
Finite Elements
(SUPG) 21
21 FM
Abily et al. 2016

14. Model Characteristics
MIKE 21- Results
Model Characteristics
Flood map
Specific boundary is applied along the borders
Fill the void with a specific data
Only structured mesh
Run once to simulate IC (10 min)
Create a storage in upstream
Create a pool in downstream
Fill the void with a specific data : Les bords sont définis par 9999 et la mer par -5
Create a storage in upstream : Creation d’un bassin d’alimentation à l’amont pour que le debit soit directement injecté dans le cours d’eau 21

15. Model Characteristics
MIKE 21 FM - Results
Model Characteristics
Flood map
Use structured or unstructured mesh
Water level, discharge and velocities
No weir 1 due to DTM
Have to create a pool
Run once to generate IC (20mn)
Triangle de 100m de côté dans la mer, 25m dans la plaine alluviale et 15 dans le lit mineur
21 FM

16. Model Characteristics
TELEMAC 2D- Results
Model Characteristics
Flood map
Water level and velocities
No weir 1 due to DTM
Hard to implement the weir
Low data flexibility
Use of Bluekenue
(Build mesh + Visualize)
- Parameter file hard to build

17. COMPARISON OF SOFTWARE11
COMPARISON OF SOFTWARE 21
21 FM

18. Comparison of water depth at Napoleon III bridge (1D)
Software
Highest water depth
Time of occurrence
MIKE 11
0.3 m
05/11/ h00
ISIS
4.75 m
05/11/ h00
HEC-RAS
2.5 m
Derived from results shown in prior slides

19. Comparison of water level time-series trend (1D)
MIKE 11
ISIS
HEC-RAS
Quite similar graph shape for all ID model simulations

20. Comparison of water depth at the same time (2D)
Mike 21
Mike 21 FM
Telemac

21. Comparison of velocity at the same time (2D)
Mike 21
Mike 21 FM
Telemac

22. Comparison of velocity at the same time (2D)
Mike 21
Mike 21 FM
Telemac

23. Flood Location (1D & 2D) HEC-RAS and 2D softwares
2D Softwares and HEC-RAS
Telemac 2D and HEC-RAS
Where we see the floods
Mike11: the water level is too low there is no floods. May be too much instabilities in the model.

24. Time of Flood Appearance
Software
When the first flood appears
At CAP 3000
South of the Airport
Mike 21
04/11/ h00
05/11/ h00
TELEMAC 2D
04/11/ h00
04/11/ h30
Mike 21 FM
04/11/ h00
HEC-RAS
05/11/ h00
05/11/11 06h00
The water level is around 0.2m at the begenning of the first flood and reach around 1 to 1.5m at the peak.

25. Time for Simulation Mike 11 15 ISIS 10 HEC-RAS 3 Mike 21 300
Model
Time (min)
Mike 11 15
ISIS 10
HEC-RAS 3
Mike 21
300
Mike 21 FM
200
Telemac 2D
350
Mike21FM_temps de simulation 200min

26. 11
CONCLUSIONS 21
21 FM

27. CONCLUSIONS 2D models are able to represent the floodplain better
Telemac takes more time to simulate but gives more accurate results in comparison to Mike 21 and Mike 21 FM.
- Differences between water levels
- Differences between the time when the flood occurs
- 1D models are greatly affected by cross-section geometry. Real bathymetry data give better results

28. REFERENCES
Abyli et al (2016). Procedia Engineering / 154 / 2016 “High-resolution Modelling With Bi-dimensional Shallow Water Equations Based Codes – High-Resolution Topographic Data Use for Flood Hazard Assessment Over Urban and Industrial Environments” by Abily Morgan, Delestre Olivier, Bertrand Nathalie, Duluc Claire-Marie and Gourbesville Philippe.
HEC-RAS Manual, Hydrologic Engineering Center, River Analysis System
ISIS help.
Roe, P. (1981, October). Approximate riemann solvers, parameter vectors and difference schemes. Journal of Computational Physics 43(2), 357–372.
Abbot et al. (1967). Abbott, M. B. and Ionescu, F.: On The Numerical Computation Of Nearly Horizontal Flows, J. Hydraul. Res., 5, 97–117
Preissmann, A. (1961). Propagation des intumescences dans les canaux et rivieres. In `1er congres de l’Association Franc¸aise de Calcul`, Grenoble, France.
MIKE 21 & MIKE 3 FLOW MODEL FM. Hydrodynamic and Transport Module. Scientific Documentation
“Review of Hydraulic Flood Modeling Software used in Belgium, The Netherlands, and The United Kingdom” Daniel Gilles and Matthew Moore August 15th, 2010 International Perspectives in Water Resource Management IIHR – Hydroscience & Engineering University of Iowa, College of Engineering.
Brooks (1982).Brooks AN, Hughes TJR. Streamline upwind Petrov {Galerkin formulations for convection dominated ows with particular emphasis on the incompressible Navier{Stokes equations. Computer Methods in Applied Mechanics and Engineering 1982; 32:
Hervouet (2007). Hydrodynamics of Free Surface Flows, Modelling with the Finite-element Method. John Wiley & Sons Ltd., West Sussex, England (2007) 340 pp

29. THANK YOU FOR YOUR ATTENTION