2 d modelling

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Australian Rainfall and RunoffA guide to runoff estimation

ARR Project 15Two Dimensional Simulation

in Urban Areas

Mark BabisterWMAWater , Chair NCWE

Australian Rainfall and Runoff A guide to runoff estimation

WORKSHOP TEAM

The Project 15 workshop members were (* indicate contributing authors to the Project 15 report):

Mark Babister (Project Manager) - WMAwater * James Ball (ARR Editor) UTS * Roger Austin Wallingford Cathie Barton * Warwick Bishop Water Technology * Ben Caddis - WBM Stephen Gray - WMAwater * Rhys Hardwick Jones - WMAwater * Martin Lambert Uni of Adelaide John Macintosh - Water Solutions Andrew McCowan Water Technology * Steve Muncaster Water Technology *

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John Murtagh NSW DECC * Bill Peirson UNSW (WRL) * Brett Phillips Cardno * Habib Rehmann - Golder Monique Retallick - WMAwater * Ted Rigby - Rienco Grantley Smith UNSW (WRL) * Bill Syme - WBM * Stefan Szylkarski - DHI * Chris Thomas Worley Parsons Rhys Thompson Cardno * Eric Valentine - CDU Rudie Van Drye Bill Weeks QLD Main Roads*

WORKSHOP TEAM


OUTLINE

Background

Aim

Approach

Workshop team

Report Structure

Recommendations

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INTRODUCTION

One of 21 research projects to fill knowledge gaps

The next edition of ARR will provide guidance on appropriate usage

The aims of the project, therefore, were to develop guidance on:

model conceptualisation and representation of hydrolog ical and hydraulic processes, inclusive of loss modelling;

influence of the conceptualisation on the input data; influence of the conceptualisation on parameter estimat ion and

the uncertainty in parameter estimation; predictive uncertainty; and analysis of model output.

No promotion of software


IDENTIFIED NEED FOR GUIDENCE

2D models have become tool of choice

2D model better represents storage which challenges aspects of ARR 87 peak burst approach

latest trend in Australian practice is to use 2D models as finely distributed hydrological models

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2D Model Uses Urban Redevelopment


2D Model Uses - Infrastructure

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2D Model Uses - Infrastructure


What is ARR used for? Protection

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2D Model Uses Protection


2D Model Uses Environmental Flows

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AIM

Aim Stage 1 of Project 15 was to consolidate existing knowledge and practice and to highlight deficiencies in the available information.

Stage 2: Testing of emerging areas or areas identified as requiring further research.


AIM

The Stage 1 deliverables defined by the funding agreement with DCC were:

15.1 Assessment of two dimensional models and appro aches for simulation of events in urban areas.

15.2 Development of a methodology for assessing th e performance of these models.

15.3 A report detailing the above work including a detailed scoping of future stages.

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AIM

The Stage 2 deliverables defined by the funding agreement with DCC were:

15.1 Production of a series of peer reviewed paper s that give clear recommendations on the knowledge gaps

15.2 Updating of the stage 1 report to incorporate this work.


APPROACH

Non traditional approach in order to bring together knowledge

series of workshops whose attendees included:

software suppliers experienced 2D model users, clients, and hydraulics experts.

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APPROACH Cont

Produce collaborative report

Initial Wiki approach

Chapter Authors assigned

Group review and technical writer


WORKSHOP TEAM

The Project 15 workshop members were (* indicate contributing authors to the Project 15 report):

Mark Babister (Project Manager) - WMAwater * James Ball (ARR Editor) UTS * Roger Austin Wallingford Cathie Barton * Warwick Bishop Water Technology * Ben Caddis - WBM Stephen Gray - WMAwater * Rhys Hardwick Jones - WMAwater * Martin Lambert Uni of Adelaide John Macintosh - Water Solutions Andrew McCowan Water Technology * Steve Muncaster Water Technology *

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John Murtagh NSW DECC * Bill Peirson UNSW (WRL) * Brett Phillips Cardno * Habib Rehmann - Golder Monique Retallick - WMAwater * Ted Rigby - Rienco Grantley Smith UNSW (WRL) * Bill Syme - WBM * Stefan Szylkarski - DHI * Chris Thomas Worley Parsons Rhys Thompson Cardno * Eric Valentine - CDU Rudie Van Drye Bill Weeks QLD Main Roads*

WORKSHOP TEAM


REPORT STRUCTURE

Chapter no. Chapter Title1 Introduction2 2D Conceptualisation3 Overview of Modelling approaches4 Modelling Process5 Data Requirements6 Model Schematising / Implementation / Assembly7 Calibration Process8 Interpretation of Results9 1D/2D models10 Current Issues with 2D modelling11 Direct Rainfall12 Recommendations and Conclusions

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REPORT STRUCTURE

Chapter no. Chapter Title10 Current Issues with 2D modelling

10.1 Supercritical flow10.2 Adaptive timesteps/run times10.3 Wetting/Drying10.4 Valid Parameter ranges/envelopes10.5 Eddy Viscosity10.6 Very shallow and very deep flow10.7 Numerical precision and accuracy issues10.8 Sub grid features10.9 Structures10.10 Features in urban environments10.11 Resistance/ roughness


DIRECT RAINFALL BACKGROUND

Relatively new approach

Removes need for hydrologic model

Very few published studies (Caddis et al 2008, Clark et al 2008)

No natural gauged catchments with LIDAR data were available until very recently

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RECOMMENDATIONS

Momentum transfer Interaction between flows in the main channel of rivers and on

floodplains and the incorporation of these effects in numerical models,

Connections between 1D and 2D models and momentum transfer,

Testing of commercial software to predict the velocity and hydraulic hazard distribution of a test channel compared to the theoretical distributions.

These models should be tested under the following conditions:

compound channels, meandering channels, and urban areas.


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RECOMMENDATIONS

Obstructions

Buildings

flow obstructions or ineffective flow area,

increased roughness

temporary storage

Testing of modelling of small-scale features beyond the resolution of the model, particularly features likely to control flow behaviour

buildings,

fences, and

walls) .

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RECOMMENDATIONS

Test catchments

At the time of writing no catchment in Australia meets the intensive data requirements set out below for a suitable test data set: pluviograph records,

topographic data (channel cross sections, ALS data etc)

gauged catchment,

calibration data, and

information regarding roughness values.


ACKNOWLEDGEMENTS

Cardno

Charles Darwin University

Department of Environment and Climate Change NSW

Department of Main Roads QLD

DHI Water and Environment

Golder

Rienco

University of Adelaide

University of Technology Sydney

WBM

Wallingford

Water Solutions

Water Technology

WMAwater

Worley Parsons

WRL (UNSW)

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Thank YouThank Youandand

Questions ?Questions ?

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