Evolution in flood modelling based on the example of the...
Transcript of Evolution in flood modelling based on the example of the...
Evolution in flood modelling
based on the example of the Bruce
Highway Crossing over the Eudlo Creek
Anne Kolega, BMT
2019 IPWEAQ Annual Conference, 22 - 24 October 2019
Acknowledgement
• I would like to acknowledge for their support in this project and
willingness to share the presentation:
– Department of Transport and Main Roads
– WSP Australia Pty Limited
Thank you!
Presentation Outline
• Why? - Drivers and benefits of the Evolution of Flood Modelling
• Location
• Data
• Modelling guidelines - ARR 1987, ARR 2016/2019, Monte Carlo
• Modelling approaches - Software Evolution in Eudlo Creek
• Hardware Evolution - TUFLOW Classic versus TUFLOW HPC
• Importance of model calibration
• New 2019 modelling features – TUFLOW HPC Sub-grid sampling / Quadtree
• Summary
• Why have we invested so much
money and effort into hydraulic
modelling
• What are the benefits
• What can we learn from this?
Why? - Benefits of the Evolution of Flood Modelling
Brisbane January 2011
Centenary Highway Mt Ommaney
Why?
January 2011 Flood in Brisbane
Benefits for future assessment - learnings
• More development pressure
• More people living in Australia
• Higher flood risk
• More safety required
• We seek to reduce uncertainties
• Use of additional data collected over the last 30 years - rainfall and river
gauge data
• Significantly increased flood damages
• Affect of climate change is likely to worsen the above
• Better data and more certainty
Presentation Outline
• Why? - Drivers and benefits of the Evolution of Flood Modelling
• Location
• Data
• Modelling guidelines - ARR 1987, ARR 2016/2019, Monte Carlo
• Modelling approaches - Software Evolution in Eudlo Creek
• Hardware Evolution - TUFLOW Classic versus TUFLOW HPC
• Importance of model calibration
• New 2019 modelling features – TUFLOW HPC Sub-grid sampling / Quadtree
• Summary
Location Bruce Highway Crossing over the Eudlo Creek
• Bruce Highway one lane
• Bruce Highway Duplication
• Business Case and Detail
Design of Eastern and
Western Service Roads
• Potential Future Raising of the
Bruce Highway
Presentation Outline
• Why? - Drivers and benefits of the Evolution of Flood Modelling
• Location
• Data
• Modelling guidelines - ARR 1987, ARR 2016/2019, Monte Carlo
• Modelling approaches - Software Evolution in Eudlo Creek
• Hardware Evolution - TUFLOW Classic versus TUFLOW HPC
• Importance of model calibration
• New 2019 modelling features – TUFLOW HPC Sub-grid sampling / Quadtree
• Summary
Data
In the 1990:
• Ground survey
• Contours
• Photos
Now:
• LiDAR covering large areas
• Additional ground survey
• Bathymetry
• Aerial imagery
• Vegetation layers
44
44.5
45
45.5
46
46.5
47
47.5
48
48.5
49
49.5
0 5 10 15 20 25
Presentation Outline
• Why? - Drivers and benefits of the Evolution of Flood Modelling
• Location
• Data
• Modelling guidelines - ARR 1987, ARR 2016/2019, Monte Carlo
• Modelling approaches - Software Evolution in Eudlo Creek
• Hardware Evolution - TUFLOW Classic versus TUFLOW HPC
• Importance of model calibration
• New 2019 modelling features - TUFLOW HPC Subgrid sampling / Quadtree
• Summary
Modelling Guidelines – ARR and Monte Carlo
Reducing uncertainty / Increasing defensibility
?
Time
Flo
w
Monte Carlo
Thousands of
hydrographs per AEP
Vary all major factors
1977 1987
Single hydrograph per duration
per AEP
Time
Flo
w
All inputs fixed
2016/2019
Time
Flo
w
Ensemble 10
hydrographs per
duration per AEP
Vary temporal patterns
Modelling Guidelines – ARR and Monte Carlo
?
Monte Carlo
Thousands of
hydrographs per AEP
1977 1987
Single hydrograph per duration
per AEP
2016/2019
Ensemble 10
hydrographs per
duration per AEP
Hydro
RobustusHydro
Erectus
Hydro
Neanderthalensis
Hydro
Sapiens
Reducing uncertainty / Increasing defensibility
Presentation Outline
• Why? - Drivers and benefits of the Evolution of Flood Modelling
• Location
• Data
• Modelling guidelines - ARR 1987, ARR 2016/2019, Monte Carlo
• Modelling approaches - Software Evolution in Eudlo Creek
• Hardware Evolution - TUFLOW Classic versus TUFLOW HPC
• Importance of model calibration
• New 2019 modelling features – TUFLOW HPC Sub-grid sampling / Quadtree
• Summary
Hydraulic Modelling Approaches – Software Evolution
• Modelling approaches used for Eudlo Creek:
– 1D model
– 1D/2D TUFLOW Classic
– 1:30 scale Physical Model for verification
– TUFLOW HPC
– TUFLOW FV
TUFLOW Numerical Models used in Eudlo Creek
1D/2D TUFLOW Classic
/ HPCGPU Hardware
AD
TUFLOW FVAD / Sediment Transport /
Morphology / Water Quality
Fixed Grid Flexible Mesh
1D ESTRYOpen channel
Pipe network
1D
Why 2D Modelling instead of 1D?
Topography at Bruce Highway over Eudlo Creek
1D Modelling
Basic 1D Network Example
Why 2D Modelling instead of 1D?
Why 2D Modelling instead of 1D?
2D Model Example
Better coverage representation
(vegetation cover or elevation)
Requires significantly less engineering judgment to
get the correct answer
2D Modelling Results
Physical Model in Eudlo Creek
Model Configuration with Roughness Elements
Model Bridge Structure Pre-duplication of Highway 1983
Model Bridge Structure for Highway Duplication
Bill Syme comment:
• No one believes a computer model
(except for the modeller)
• but everyone believes a physical
model
(except for the modeller)
Presentation Outline
• Why? - Drivers and benefits of the Evolution of Flood Modelling
• Location
• Data
• Modelling guidelines - ARR 1987, ARR 2016/2019, Monte Carlo
• Modelling approaches - Software Evolution in Eudlo Creek
• Hardware Evolution - TUFLOW Classic versus TUFLOW HPC
• Importance of model calibration
• New 2019 modelling features – TUFLOW HPC Sub-grid sampling / Quadtree
• Summary
Hardware Evolution -TUFLOW Classic versus HPC
• 1D versus 1D / 2D
• TUFLOW Classic / HPC
• TUFLOW HPC
Central Processing Unit (CPU)
VS
TUFLOW Classic
TUFLOW HPC + GPU Module
Central Processing Unit (CPU) Graphic Processing Unit (GPU)
Hydraulic Modelling Hardware Evolution - CPU vs GPU
VS
Cell Count
7,500 cells
31,000 cells
125,000 cells
750,000 cells
3,100,000 cells
12,500,000 cells
Classic CPU(pre 2017 standard)
0:12 hr
0:15 hr
1:32 hr
15:19 hr
146:0 hr
≈48 days
Speed-upRatio
4
5
23
51
81
86
• Cell Size
• 20m
• 10m
• 5m
• 2m
• 1m
• 0.5m
HPC GPU(current standard)
0:03 hr
0:03 hr
0:04 hr
0:18 hr
1:47 hr
13:18 hr
Presentation Outline
• Why? - Drivers and benefits of the Evolution of Flood Modelling
• Location
• Data
• Modelling guidelines - ARR 1987, ARR 2016/2019, Monte Carlo
• Modelling approaches and software available and used for Eudlo Creek
• TUFLOW Classic versus TUFLOW HPC
• Importance of model calibration
• New 2019 modelling features – TUFLOW HPC Sub-grid sampling / Quadtree
• Summary
Importance of model calibration
• Model calibration was undertaken
for all models TUFLOW Classic, FV
and TUFLOW HPC
• Various historic events were
assessed: 1983, 1992, 1999, 2012,
2013 and 2015
• Good calibration was achieved
for both models
Presentation Outline
• Why? - Drivers and benefits of the Evolution of Flood Modelling
• Location
• Data
• Modelling guidelines - ARR 1987, ARR 2016/2019, Monte Carlo
• Modelling approaches and software available and used for Eudlo Creek
• TUFLOW Classic versus TUFLOW HPC
• Importance of model calibration
• New 2019 modelling features – TUFLOW HPC Sub-grid Sampling /
Quadtree
• Summary
TUFLOW HPC Sub-grid Sampling / Quadtree Features
Sub-grid Sampling TUFLOW GPC Quadtree
Sub-grid Sampling
Cell volume elevation point
Cell face elevation point
Current Cell Volume / Face Schema
TUFLOW HPC Sub-grid Sampling / Quadtree Features
• Mesh refinement
• Maximum cell division of 2
across adjacent cells
• Requires user input on where to
refine mesh => easier workflow
than flexible mesh
• Adjustable resolution =
refinement only where necessary
= efficient memory utilisation
TUFLOW HPC Sub-grid Sampling / Quadtree Features
Three Tier Quadtree Nesting Benchmark
5m Single domain 5m – 2.5m – 1.25m quadtree domain
TUFLOW HPC Sub-grid Sampling / Quadtree Features
Single Domain(current standard)
0:03 hr
0:03 hr
0:04 hr
0:18 hr
1:47 hr
13:18 hr
• Cell Size
• 20m
• 10m
• 5m
• 2m
• 1m
• 0.5m
Speed-upRatio
1.3
3.6
4.1
3.5
HPC Single vs Quadtree Simulation Speed-up
Cell Size
20m / 10m / 5m
10m / 5m / 2.5m
5m / 2.5m / 1.25m
2m / 1m / 0.5m
Quadtree(future standard)
0:03 hr
0:05 hr
0:26 hr
3:47 hr
over 300 times faster than CPU
using a single domain!
TUFLOW HPC Sub-grid Sampling / Quadtree Features
Presentation Outline
• Why? - Drivers and benefits of the Evolution of Flood Modelling
• Data
• Modelling guidelines - ARR 1987, ARR 2016/2019, Monte Carlo
• Modelling approaches and software available and used for Eudlo Creek
• TUFLOW Classic versus TUFLOW HPC
• Importance of model calibration
• Future modelling features – TUFLOW HPC Subgrid sampling and Quadtree
• Summary
Summary – Evolution Flood Modelling
Individual development – no common goal
• Evolution in data available
• Evolution in guidelines – Australian Rainfall and Runoff
• Evolution in Hardware
• Evolution in Software
• Evolution in Flood Modelling
Summary Key points and Benefits
• Better data and more certainty
• Better inform development to reduce flood risk and improve safety
• Use of additional data collected over the last 30 years - rainfall and river
gauge data
• Simulate larger areas with more certainty
• Aim to reduce flood damages
• Better inform the effect of climate change