Risico Analyse voor het Waterbeheer (RAW)

FEWS-RISK: A STEP TOWARDS RISKBASED FLOOD FORECASTING
D. Bachmann
D. Eilander, A. de Leeuw, K. de Bruijn, F. Diermanse, A. Weerts, J.
Beckers, P. Gijsbers, M. Ponziani (Deltares, NL)
L. Boelee, C. Hazlewood, E. Brown (HR Wallingford, UK)
FEWS-User Days 2015, Deltares Delft
28. October 2015
Daniel Bachmann
28. October 2015
Common practice in operational flood forecast
System river
Forecasted
process chain
Meteorology
(catchments)
h
Water level
time series
t
Precipitation,
temperature,
wind etc.
Hydrology
(catchment)
Discharge
Hydrodynamic
(river)
Water level
Daniel Bachmann
28. October 2015
How to make a decision based on water levels?
System river
• How will my flood defence line
perform?
h
Water level
time series
t
Crisis
manager
Daniel Bachmann
28. October 2015
• What will be the impacts of
flooding?
Extension by workflow 1
System river and flood
defence line
Forecasted
process chain
In advance
Meteorology
(catchments)
pf = 100%
h
Failure
probability
time series
Hydrology
(catchment)
Hydrodynamic
t
(river)
Water level
Reliability
transformation
Fragility
curve
Daniel Bachmann
28. October 2015
Failure
analysis
(flood defence line)
The concept of Fragility curves (FRC)
Summary of the performance or failure probability of a
structure depending to the load (e.g. water level [m])
Daniel Bachmann
28. October 2015
Determination of Fragility curves (FRC)
INPUT: Geometry, zonation, sub soil, soil
parameter etc.
Daniel Bachmann
28. October 2015
Support for decision makers by workflow 1
System river and flood
defence line
• Where is my weak section given the
hydraulic load?
pf = 100%
h
Failure
probability
time series
• Where and when inspection should
increased or emergency measures
should be taken?
t
Crisis
manager
• Where and when a breach is
probable?
Daniel Bachmann
28. October 2015
What happens if a breach occurs?
System river, flood
defense line, hinterland
• How fast, how much and where the
water will flow?
• How relevant is the protection task
of this section?
Crisis
manager
• When and which emergency
measures should be triggered?
Daniel Bachmann
28. October 2015
National Information system Floodmapping
Predicted hazard: Waterdepth after dike
failure for pre-calculated scenarios
Daniel Bachmann
28. October 2015
What happens if a breach occurs?
System river, flood
defense line, hinterland
• How fast, how much and where the
water will flow?
• How relevant is the protection task
of this section?
Crisis
manager
• When and which emergency
measures should be triggered?
Daniel Bachmann
28. October 2015
Extension by workflow 2
System river, flood
defence line, protected area
Forecasted
process chain
Hydrology
(catchment)
Hydrodynamic
(river)
Water level
Police
Breaching
(flood defence line)
Discharge
Hospitall
School
Transformer
Daniel Bachmann
Flood spreading,
hydraulic values
Impacts to
people, critical
infrastructure
etc.
28. October 2015
Hydrodynamic
(protected area)
Impacts
(protected area)
Support for decision makers by workflow 2
System river, flood
defence line, protected area
• How fast, how much and where the
water will flow?
• How relevant is the protection task
of this section?
Police
Crisis
manager
Hospitall
School
Transformer
Daniel Bachmann
Flood spreading,
hydraulic values
Impacts to
people, critical
infrastructure
etc.
28. October 2015
• When and which emergency
measures should be triggered?
Daniel Bachmann
28. October 2015
The Rotterdam area and dike rings
Delft
• Western part of the Netherlands at the delta of Rhine
and Maas rivers to the North Sea
• Highly populated area (ca. 1.3 million people)
• High flood protection standards
Daniel Bachmann
28. October 2015
Reliability analysis
• 15 dike sections (14 in Ijsselmonde and 1 in Pernis)
• Pre-calculated fragility curves available
Daniel Bachmann
28. October 2015
Examples fragility curves
• Available fragility curves: km14_1, km47, Pernis
• Manipulated fragility curves: km14_1, km47 (demonstration
purpose); 50 % weaker as determined
Daniel Bachmann
28. October 2015
Hydrodynamic model: Discretization
• Tool: Subgrid software (part of 3di-package)
• 500 km² model domain with ca. 40 000 quad tree
elements (computational elements)
• Quad tree resolution: 100x100 m (min)/400x400 m (max)
• Subgrid resolution: 25x25 m (Lidar-data)
Daniel Bachmann
28. October 2015
Hydrodynamic model: Boundary condition
• 3 Dirichelet-boundary (water level time series 50 h model-time)
• Assumptions (demonstration purpose):
•
•
•
Based on flood event November 2007 (could be also forecasted
data);
Maeslant-Barrier is not closing
25% increase of water levels
Daniel Bachmann
28. October 2015
Impact analysis
• Qualitative impact analysis
• Focus on persons (CBS-data) and critical infrastructure
(OSM-data)
Daniel Bachmann
28. October 2015
Daniel Bachmann
28. October 2015
Customization workflow 1
Daniel Bachmann
28. October 2015
Hydrodynamic analysis without breaching
Computational time: ca. 45 min (Intel Core i53230M CPU 2.60 GHz)
Daniel Bachmann
28. October 2015
Reliability transformation
Water level
time series at
dike sections
Failure
probability
time series
with
thresholds
Daniel Bachmann
28. October 2015
Spatial distribution of dike performance
Daniel Bachmann
28. October 2015
Support for decision makers by workflow 1
• Where is my weak section given the
hydraulic load?
• Where and when inspection should
increased or emergency measures
should be taken?
• Where and when a breach is
probable?
Daniel Bachmann
28. October 2015
Daniel Bachmann
28. October 2015
Customization workflow 2
Daniel Bachmann
28. October 2015
Breach development
Water level
time series at
dike sections
Starting
breach
development
by defined
failure
probability
(here 50 %)
Daniel Bachmann
28. October 2015
Flood spreading breach km14_1 and km47
Daniel Bachmann
28. October 2015
Qualitative Impact analysis: What happens when?
Daniel Bachmann
28. October 2015
Qualitative Impact analysis and evacuation
Daniel Bachmann
28. October 2015
Support for decision makers by workflow 2
• How fast, how much and where the
water will flow?
• How relevant is the protection task
of this section?
Crisis
manager
• When and which emergency
measures should be triggered?
Daniel Bachmann
28. October 2015
Summary
• Extend current operational flood forecast systems with
approaches of strategic flood risk analysis
• Probability of failure
• Impact analysis
• Provide transformed and compact model-base
forecasted information to support decision makers
• Weak spots in the flood defense line (Workflow 1)
• Impacts of flooding (Workflow 2)
• Supports the development and adaptation of emergency
measures in real-time
Daniel Bachmann
28. October 2015
Outlook: Ongoing projects
• Deltares ID-Lab project: Coupling of global forecasting
models as boundary conditions to local models
• Deltares ID-Lab project: Combining real-time sensor
data from a dike (DAM-Live) with fragility curves
• TO2 project Crisis management (program Safe
Society): Integration of ensemble forecast and
quantitative impact analysis
Daniel Bachmann
28. October 2015
Outlook: Coupling to global models
Global forecasts
Forecasted
process chain
Global Forecast
storm surge /
discharge
Police
Hydrodynamic
(river/coastal &overland)
Hospitall
School
Transformer
Flood spreading,
hydraulic values
Impacts to
people, critical
infrastructure
etc.
Local impact forecast
Daniel Bachmann
28. October 2015
local water levels
Inundated area
Impacts
Outlook: Combining with sensor data
Precalculated
fragility curve
Real time dike data,
e.g. seepage line
Daniel Bachmann
28. October 2015
Outlook: Including ensemble forecast
Ensemble forecast for
water level- time series
Precalculated
fragility curve
Ensemble forecast
for breach widthtime series
Ensemble forecast for failure
probability- time series
Daniel Bachmann
28. October 2015
Outlook: Including quantitative impact analysis
Ensemble forecast for flooding
Daniel Bachmann
28. October 2015
More information at the next FEWS-user
days 2016!
Daniel Bachmann
28. October 2015
FEWS-RISK: A STEP TOWARDS RISKBASED FLOOD FORECASTING
D. Bachmann
D. Eilander, A. de Leeuw, K. de Bruijn, F. Diermanse, A. Weerts, J.
Beckers, P. Gijsbers (Deltares, NL)
L. Boelee, C. Hazlewood, E. Brown (HR Wallingford, UK)
FEWS-User Days 2015, Deltares Delft
28. October 2015