1. IMPACT ~ Breach Formation (WP2)
Review of The Numerical Model
predictions for Test Case 1

2. Outline Description of the test case Summary of the data
Numerical results comparison
Discussion

3. Description of the Test Case2m 6m 2 1
Homogeneous Embankment
Maximum Cohesive

4. Summary of the Data General
Overtopping failure
Constant upstream water level (up to 450 m3/s)
Free flow downstream (No DS control)
Stage-Area and Volume curves
XYZ Data for 2D models
Geometry
Initial breach dimensions
Material properties

5. Summary of the Data Grading curve
15%
1mm
25%

6. Numerical Results Comparison
Breach outflow
Reservoir levels
Breach invert
Breach width

7. Numerical Results Comparison Breach outflow

8. Numerical Results Comparison Reservoir levels

9. Numerical Results Comparison Breach Invert

10. Numerical Results Comparison Breach width

11. Discussion Test Data Models and Test Results
Actual field test conditions varied significantly from theoretical conditions sent to modellers
Incomplete survey data for the reservoir affected u/s conditions
Models and Test Results
Five 1D models and one 2D model were utilised
Models have been developed mainly for non-cohesive embankments
Wide variation in modelling results (e.g. Peak outflow from 100 m3/s to 1000 m3/s)