The TUFLOW LinkPast, Present and Future

Stephanie Dufourstephanie.dufour@bmtwbm.co.uk

PAST

• Software background

• Thames Embayments Inundation Study

PRESENT

• Flood Modeller -TUFLOW link

• Flood Modeller - ESTRY link

FUTURE

• Tutorial model

• Development & Support

Contents

The Past

The TUFLOW Link – Past

Flood Modeller

• The 1D component first developed in the 1970’s

• Designed to model flows and levels in open channels and floodplains

• First commercially released in 1995

TUFLOW

• The 2D component developed since 1989; the 1D component (ESTRY) since the 1960’s

• Designed to model flow and inundation patterns in floodplains, estuaries, rivers and urban areas

• First commercial sale in 2001

Driver for a linked 1D-2D solution a result of the Environment Agency’s Thames Embayments

Inundation Study (2004)

The TUFLOW Link – Past

Thames Embayments Inundation Study

• Over 100km2 (23 embayments) around London at risk of storm tide flooding during an extreme event

• EA required a modelling tool to predict inundated area following breach / overtopping of defences

• Benchmark testing undertaken on four software packages:

• Flood Modeller (predecessor) Quasi-2D (1D network) model

• LISFLOOD-FP 2D raster routing model

• TUFLOW Fully 2D regular grid hydrodynamic model

• TELEMAC 2D Fully 2D irregular grid hydrodynamic model

The TUFLOW Link – Past

Benchmark Testing

• Testing assessed breach and overtopping scenarios for the Greenwich embayment

• Selection of flood modelling package considered:

• Comparison of predicted flood depths and extents

• Ease of model setup, stability and run times

Test Conclusions

• Flood Modeller and TUFLOW selected in combination as they fulfilled the requirements of the study

• Flood Modeller: fast run times and existing calibrated model of tidal Thames

• TUFLOW: stability and established 1D/2D linking capabilities

• Flood Modeller and TUFLOW codes merged in 2004 as part of Stage 2

The TUFLOW Link – Past

The rest is history !

The Present

The TUFLOW Link – Present

Two link types available

Flood Modeller (1D) -TUFLOW (2D) link

• Original link

• HX Boundary: Head supplied eXternally to TUFLOW

• SX Boundary: Source flow supplied eXternally to TUFLOW

Flood Modeller (1D) – ESTRY (1D) link

• Developed from 2010

• X1DH Connection: eXternal 1D Head supplied to TUFLOW

• X1DQ Connection: eXternal 1D Flow (Q) supplied to TUFLOW

The TUFLOW Link – Present

HX Boundary Link

• Typically used along banks of open channel

• Flood Modeller provides the water level, TUFLOW

returns a flow

• The elevation of the HX boundary determines when the

spill first occurs

• Volume of water entering / leaving the 2D domain is

subtracted / added from the 1D model to preserve

volume

The TUFLOW Link – Present

SX Boundary Link

• Typically used to connect 1D structures to the floodplain

• Flow entering / leaving the 2D domain is calculated by

Flood Modeller taking into account the average 2D

TUFLOW water level along the boundary

• Any 2-noded 1D Flood Modeller unit may be used (i.e.

spill unit)

• A dummy HTBDY unit is digitised at the downstream

end

The TUFLOW Link – Present

X1DH Link

• Typically used where the ESTRY component

discharges to Flood Modeller

• Flood Modeller sends ESTRY a water level

• ESTRY sends a (+/-) flow back to Flood Modeller

• The Flood Modeller unit on the receiving end of an

X1DH connection must be a channel unit

• Link is formed when an ESTRY node is snapped to

a Flood Modeller node

The TUFLOW Link – Present

X1DQ Link

• Typically used where Flood Modeller discharges to

ESTRY

• Flood Modeller sends ESTRY a (+/-) flow

• ESTRY sends a back a water level to Flood Modeller

• Link is formed when an ESTRY node is snapped to a

Flood Modeller node (channel unit)

The TUFLOW Link – Present

Viewing / Checking the Information Exchange

Flood Modeller

• The flow / water level time-series calculated by Flood Modeller / TUFLOW using X1DH or X1DQ link

types may be viewed in the standard results file (*.zzn)

• The flow exchange over an HX or X1DH link type may be viewed by outputting the supplementary results

file (*.zzx)

TUFLOW

• x1d_nodes_check / x1d_chans_check GIS layers containing location of external 1D nodes / channels

• The optional command Write X1D Check Files outputs .csv files containing flow / water level time-series

of flow to and from Flood Modeller

• Volumes of water in / out of 2D domain via X1DH / X1DQ links presented within _MB1D.csv

The Future

The TUFLOW Link – Future

Flood Modeller – TUFLOW Tutorial Model

• Demonstration of all available linking methods

• Full documentation

• Clarity on linking methodology

• Guidance on troubleshooting

• GIS packages and Flood Modeller GUI

• Ability to be simulated license free

• Joint collaboration

The TUFLOW Link – Future

Continued Partnership Approach

• Software Development

• Further integration of TUFLOW with Flood Modeller GUI

• Increase workflow efficiencies

• Ongoing R&D: Ideas from users !

• Software Support

• Joint delivery of technical support services to the Flood Modeller and TUFLOW user

communities

Thank You