Open Source Flood Simulation with a 2D Discontinuous Elevation Hydrodynamic Model

<p>A new finite volume algorithm to solve the two dimensional shallow water equations on an unstructured

triangular mesh has been implemented in the open source ANUGA software, which is jointly developed

by the Australian National University and Geoscience Australia. The algorithm supports discontinuouselevation,

or `jumps in the bed profile between neighbouring cells. This has a number of benefits compared

with previously implemented continuous-elevation approaches. Firstly it can preserve stationary states at wetdry

fronts without using any mesh porosity type treatment. It can also simulate very shallow frictionally

dominated flow down sloping topography, as typically occurs in direct-rainfall flood models. In the latter situation,

mesh porosity type treatments lead to artificial storage of mass in cells and associated mass conservation

issues, whereas continuous-elevation approaches with good performance on shallow frictionally dominated

flows tend to have difficulties preserving stationary states near wet-dry fronts. The discontinuous-elevation

approach shows good performance in both situations, and mass is conserved to a very high degree, consistent

with floating point error.

<p>A further benefit of the discontinuous-elevation approach, when combined with an unstructured mesh, is that

the model can sharply resolve rapid changes in the topography associated with e.g. narrow prismatic drainage

channels, or buildings, without the computational expense of a very fine mesh. The boundaries between such

features can be embedded in the mesh using break-lines, and the user can optionally specify that different

elevation datasets are used to set the elevation within different parts of the mesh (e.g. often it is convenient to

use a raster DEM in terrestrial areas, and surveyed channel bed points in rivers).

<p>The discontinuous elevation approach also supports a simple and computationally efficient treatment of river

walls. These are arbitrarily narrow walls between cells, higher than the topography on either side, where

the flow is controlled by a weir equation and optionally transitions back to the shallow water solution for

sufficiently submerged flows. This allows modelling of levees or lateral weirs much finer than the mesh size.

A number of benchmark tests are presented illustrating these features of the algorithm. All these features

of the model can be run in serial or parallel, on clusters or shared memory machines, with good efficiency

improvements on 10s-100s of cores depending on the number of mesh triangles and other case-specific details

Simple

Identification info

Date (Publication)
2015-01-01T00:00:00
Date (Revision)
2018-04-30T07:13:27
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/83863

Cited responsible party
Role Organisation / Individual Name Details
Author

Davies, G.

 1
Author

Roberts, S.

 2
Point of contact
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CSEMD
Owner

Commonwealth of Australia (Geoscience Australia)
Custodian

Commonwealth of Australia (Geoscience Australia)

 Voice
Topic category
  • Environment
Maintenance and update frequency
Not planned

Resource format

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Product data repository: Various Formats

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Data Store directory containing the digital product files

Data Store directory containing one or more files, possibly in a variety of formats, accessible to Geoscience Australia staff only for internal purposes

Keywords

  • External Publication

Australian and New Zealand Standard Research Classification (ANZSRC)

  • Surfacewater Hydrology

Keywords

  • Published_External

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Creative Commons Attribution 4.0 International Licence

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CC-BY

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4.0

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http://creativecommons.org/licenses/

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License

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Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
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https://www.protectivesecurity.gov.au/Pages/default.aspx

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Unclassified
Language
English
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UTF8

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Commonwealth of Australia (Geoscience Australia)

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OnLine resource

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  • html

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Written and developed by Gareth Davies from GA

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Description

Written by Gareth Davies of GA

Metadata constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified

Metadata

Metadata identifier
urn:uuid/193f8fa0-0ebd-e2e8-e053-12a3070affff

Title

GeoNetwork UUID

Language
English
Character encoding
UTF8
Contact
Role Organisation / Individual Name Details
Point of contact

Commonwealth of Australia (Geoscience Australia)

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Type of resource

Resource scope
Document
Name

GA publication: External publication

Alternative metadata reference

Title

Geoscience Australia - short identifier for metadata record with

uuid

Citation identifier
eCatId/83863

Metadata linkage

https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/193f8fa0-0ebd-e2e8-e053-12a3070affff

Date info (Revision)
2018-04-11T00:32:01
Date info (Creation)
2015-06-24T00:00:00

Metadata standard

Title

AU/NZS ISO 19115-1:2014

Metadata standard

Title

ISO 19115-1:2014

Metadata standard

Title

ISO 19115-3

Title

Geoscience Australia Community Metadata Profile of ISO 19115-1:2014

Edition

Version 2.0, September 2018

Citation identifier
https://pid.geoscience.gov.au/dataset/ga/122551

 
 

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