DSD-INT 2014 - Delft-FEWS Users Meeting - Floodrisk management & Delft FEWS Workshop, Caroline...

October 2014

HR Wallingford Deltares Collaboration

Developing an operational flood-risk-forecasting toolkit

C. Hazlewood, E. Brown, L. Boelee, B. Gouldby, J. Lhomme A. de Leeuw, F. Diermanse, D. Bachman

© HR Wallingford 2014 October 2014 Delft-FEWS User Days

HR Wallingford

Specialise in engineering and environmental hydraulics, and in the management of water and the water environment

Formed 1947 Privatised 1982 Limited by guarantee Non profit distributing Independent Over 280 staff £25m turnover

© HR Wallingford 2014

Flood forecasting typically focuses on hazards e.g. river flows, water levels Flood risk management considers wider system performance e.g. defence failures; floodplain extents, depths & velocities; consequences; etc. Opportunity for richer ‘live’ information: What type of action can I take to mend a

weak spot? Where should I enforce my flood defence

system? Which areas should I evacuate first? Which least-cost areas could be actively

inundated to save other areas? October 2014

Why do we need something new?

Delft-FEWS User Days


Develop an operational flood-risk-forecasting toolkit

Toolkit of models in Delft-FEWS shell: hydrology river system (1D) dynamic breach growth rapid flood spreading (2D) impact assessment (risk to life, critical

infrastructure, economic consequence)

Move to: risk-based approach probabilistic e.g. rainfall ensembles,

defence performance October 2014

Collaboration Aims



Application of toolkit

Not one size fits all

Select important processes (and hence capability) for your catchment fluvial vs coastal urban vs rural flood risk infrastructure e.g. storage,

defences, pumps, barriers, etc.

Flexibility to use hierarchy of data and models - simple assumptions, generic datasets, detailed modelling October 2014 Delft-FEWS User Days


Risk model framework

October 2014 Delft-FEWS User Days



October 2014

Hydrological models e.g. WFLOW: A distributed hydrological modelling platform which includes derivations of SBM, HBV96, gr4h/d, a dynamic wave model, an associated flood mapping model HR Wallingford gridded model - computationally efficient, semi-distributed hydrological model providing spatially coherent estimates of river flow and groundwater level. (Counsell, 2014)




October 2014

River models - MASCARET Open Source 1D open-channel hydraulic software Originally developed by EDF, now managed by a consortia (Goutal and Maurel 2002; Goutal et al, 2012)





Reliability models/data e.g. Library of fragility curves for all asset types (> 60)

Tools such as: RELIABLE (Kortenhaus et al, 2008; FLOODsite), Hydra-Ring (Deltares)

Section 16

0.0

0.2

0.4

0.6

0.8

1.0

0.0 2.0 4.0 6.0 8.0 10.0

Water level (m OD)

Pro

babi

lity

of fa

ilure

Total

Uplif ting

Piping

Sliding

Overturning

Reinforcement failure

Shear failure

Piping toe

Crest level

Indication extremew ater level

Numerical Integration

Structure-specificFault tree

Limit state equationFailure mode 1



Limit state equationFailure mode ..n

Structure-specific parameters, probability

distribution functions and ranges

Structure-specific fragility curve



October 2014

Breach model - AREBA Rapid breach growth - predicts flood hydrograph and breach widths and depths for surface, headcut and piping failures (Van Damme et al, 2012)




October 2014

Inundation model - RFSM-EDA Rapid Flood Spreading Model Explicit Diffusion wave with Acceleration terms Impact zones with volume-level and level-width curve Minimal loss of accuracy in topography description Developed by HR Wallingford (Jamieson et al, 2012)




October 2014

Impact models - economic assessment

Depth-damage curves for residential and commercial property, agriculture, key infrastructure e.g. FIAT (Deltares), Impact Calculator (HRW)

-1-0.75-0.5

-0.250

0.250.5

0.751

1.251.5

1.752

2.252.5

2.753

0 250 500 750 1000 1250 1500

Dept

h M

etre

s

Damage £/m2

Depth Damage Curve

HighSuscept ibilityBand

LowSuscept ibilityBand

Indica tiveSuscept ibility




October 2014

Impact models - risk to life Agent-based modelling of the dynamic interaction of the flood wave from a breach or dam break with people, vehicles and property



Example outputs - flood likelihood (ensemble 1)



Example outputs - flood likelihood (ensemble 2)



Example outputs - flood damage (€, $)



Example outputs - defence risk (€, $)



Example outputs - Life safety



Scoping Study

Develop FEWS model adaptors Stage 1 - develop initial adaptors and

simple model linking (proof of concept) Stage 2 - extend capability to capture

dynamic interactions (model coupling) Stage 3 - incorporate more sophisticated

risk capability

Pilot system Trial methods at two locations in close

liaison with end users

October 2014

Project Steps



Questions - nature of information

What information would help your decision making? flood lead times, safest/quickest evacuation routes, knowing areas that can be

inundated to save other areas, weak defences, defences at risk of breach, defences at risk of overtopping probable flood extents, depths, velocities risk to people (injuries, fatalities) risk to critical infrastructure (power stations, transport, hospitals, etc.) economic risk, environmental risk

Would you use probabilistic information?

Would you use uncertainty information?



Questions - nature of system

How would you want the system to operate? e.g. in FEWS, stand-alone, ability to plug in wider models, web-link

What are the system requirements? e.g. computational speed, robustness, data storage and management

How would you like the outputs to be communicated? e.g. target audience, online, mobile phones

What functionality would help to make it even more useful to you? e.g. mapping, visualisation, animations, inter-activeness re effectiveness of

measures


Howbery Park, Wallingford, Oxfordshire OX10 8BA, United Kingdom www.hrwallingford.com

October 2014

DSD-INT 2014 - Delft-FEWS Users Meeting - Floodrisk management & Delft FEWS Workshop, Caroline...

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