TUFLOW (Two-dimensional Unsteady FLOW) is a two-dimensional (2D) and onedimensional (1D) flood and tide simulation software. It simulates the hydrodynamics of water bodies using 2D and 1D free-surface flow equations. TUFLOW is specifically orientated towards establishing flow patterns in coastal waters, estuaries, rivers and floodplains where the flow patterns are essentially 2D in nature and cannot or would be awkward to represent using a 1D network model. A powerful feature of TUFLOW is its incorporation of the 1D hydrodynamic network software, ESTRY (ie. 2D and 1D domains are linked to form one integrated model). TUFLOW continues to develop and evolve to meet the challenges of hydrodynamic modelling. Its strengths include rapid wetting and drying, powerful 1D and 2D linking options, multiple 2D domains, 1D and 2D representation of hydraulic structures, automatic flow regime switching over levees and embankments, 1D and 2D supercritical flow, effective data handling and quality control outputs. It is suited to modelling flooding in major rivers through to complex overland and piped urban flows, and estuarine and coastal hydraulics. TUFLOW uses GIS to manage, manipulate and present data, and third-party software such as SMS and WaterRIDE to view and animate results.
TUFLOW is originally the product of a joint research and development project between WBM Pty Ltd and The University of Queensland in 1990, to develop a 2D modelling system with dynamic links to a 1D system. Since 1997, considerable improvements in flood modelling capabilities and GIS linkages have been developed. TUFLOWs 2D solution is based on the Stelling solution scheme. It is an finite difference, alternating direction implicit (ADI) scheme solving the full 2D free surface shallow water flow equations. Details on equations, solution methodology, term discretisation, testing and validation can be provided.
- TUFLOW.exe split into two files: TUFLOW.exe and TUFLOW_LINK.dll. These files must remain together within the same folder at all times. When archiving, place in a folder named using the Build ID, eg. 2005-05-AN.
- Pit objects in the 1d_nwk layer and automatic creation of pit channels.
- Use of node attributes to set channel upstream and downstream inverts.
- Use of 1d_nwk Length attribute to add additional storage to a node or to automatically generate a NA (node storage) table. Length attribute on any node must be zero for backward compatibility.
- New command Apply All Inverts to use the upstream and downstream invert attributes to all channels (previously only applied to C, G, S, R and rectangular W channels).
- New command Conveyance Calculation offers an alternative approach to calculating channel conveyance without the risk of conveyance reducing with height.
- Automatic generation of weir channels to represent the overtopping of B, C and R channels. Also includes allowances for representing rails and blockage.
- 1d_nwk Form_or_Bend_Loss attribute now used to model additional dynamic head losses in culverts (previously not used).
- 1d_nwk Form_or_Bend_Loss attribute for B channels can be used to automatically create a BG loss coefficient table or specify an additional loss to a user-defined BG table.
- New .ecf command Structure Losses to either fix structure entrance and exit losses or to adjust them according to the approach and departure velocities in the upstream and downstream channels.
- HX option in Read MI Z Line that uses the same approach for selecting cells along a HX line.
- New Snap Tolerance command for the .tcf and .ecf files that allows changing the search radius used to determine whether two objects are snapped.
- New .tcf Check Inside Grid command to allow objects in 2d_po, 2d_fc and some other layers to extend outside the 2D domain.
- none objects now recognised in .mif layers. none objects occur when attribute data has been entered but no object has been digitised. TUFLOW does not use none objects, but would previously cause problems reading a .mif file if none objects exist
- New Group option for specifying inflow hydrographs. Can drastically reduce the size of the BC_database.csv file.
- Regions now recognised for 1D QT boundaries in 1d_bc layers. The flow hydrograph is distributed equally to all nodes that fall within the region (except H boundary nodes).
- New Rainfall option in the Read MI SA command that allows the application of rainfall depths to all active cells, whether wet or dry, within each SA region. Initial and continuing loss rates can be applied on a material-by-material basis. Note, this fea
ture is undergoing testing and maybe subject to change. In particular, initially high mass errors can occur at the start when the whole model suddenly becomes wet (these are normally small in the overall simulation, but need to be monitored). Very small
- Cell Wet/Dry Depth and Cell Side Wet/Dry Depth depths have been found to assist, as well as using a smaller timestep.
- Mass balance output is available for 2D domains (see Mass Balance Output) and automatically output for 1D domains. Note, this feature is not yet complete and maybe subject to change.
- Two new flood hazard categories (Z2 and Z3) have been added to the Map Output Data Types options.
- Further enhancements to the symbology of the 1d_nwk_check.mif file to show whether nodes are connected to two or more, one or no channels useful for detecting unsnapped nodes and channels.
- Upstream and downstream nodes of a channel are now included as attributes to the 1d_hydprop_check.mif file.
- New 2d_dom_check file that contains a rectangle showing the extent of each 2D domain. Can also generate individual domains using Write MI Domain in the tgc file.
- Further changes to the _messages.mif file to de-clutter it! More changes are also planned in this regard.
There have been a number of changes and new utilities for preparing data and post-processing results. Sms_to_mif.exe has been replaced by TUFLOW_to_GIS.exe, which offers extended capabilities including generation of longitudinal profiles that can optionally show nearby calibration levels. It also can now handle over a million cells (yes, someone has cracked the 1,000,000 mark!).
Several MapBasic utilities are being made available that include a bulk .mif file exporter and an improved time-series graphing tool.
2D/1D Dynamic Links
The dynamic linking capability between 2D and 1D domains is a major strength of TUFLOW. With the adaptation of TUFLOW to floodplain modelling, the need for more flexible and complex linking was identified. The advanced linking functions developed have been extensively applied to a wide range of models varying from major river systems to fine-scale urban flood models to coastal storm tide inundation. The types of links available are described below. Joining of 1D and 2D Models (External Links) External 2D/1D links are applied along any part of the 2D TUFLOW and ESTRY are the computational
engines for carrying out 2D and 1D
In their PC form, they do not have their
own graphical user interface, but utilise
GIS and othedomains perimeter(s) of active cells. In its simplest form, the assumption is the water level along a link is horizontal. More complex linking allows sloping water surfaces based on interpolation between 1D nodes. External links can be at any orientation, start completely dry, and wet and dry during a simulation. Nesting 1D Models Inside 2D Models (Internal Links) Internal links are used to model flow within the 2D domains, but not represented by the 2D solution. This may be a small culvert through an embankment or a complex underground pipe network. Multiple 2D Domains The study area can be broken up into any number of 2D domains, with each domain having its own orientation and cell resolution. These domains are linked to form one overall model. 1D Waterway linked with 2D Floodplain An extension of the external links is the modelling of a waterway in 1D and overbank areas in 2D. This is useful where the drain, creek or river is too coarsely represented by the 2D topographic resolution and is better represented by 1D cross-sections. The 1D channel is carved through the 2D domain using GIS layers. As for other links, the 2D cells along the banks of the 1D channels can wet and dry at any point during a simulation.
Software Structure TUFLOW and ESTRY are the computational engines for carrying out 2D and 1D hydrodynamic calculations. In their PC form, they do not have their own graphical user interface, but utilise GIS and other software for the creation, manipulation and viewing of data. These software are: A GIS that can import/export .mif/.mid files (MapInfo Interchange Format files). MapInfo is recommended. 3D surface modelling software running inside the GIS (eg. Vertical Mapper) for the creation and interrogation of a DTM, and for creating 3D surfaces of water levels, depths, hazard, etc. SMS (Surfacewater Modelling System) or WaterRIDE for the viewing of results and creation of flow animations. A text editor such as UltraEdit. UltraEdit has been colour customised especially for TUFLOW free-formatted simulation control files. Spreadsheet software such as Microsoft Excel for managing tabular data (eg. time varying boundaries, 1D crosssections, etc). MIKE 11 and ISIS cross-section editors are sometimes used for managing and editing 1D cross-sections. TUFLOW and ESTRY read the cross-section data text formats of these software. Software Structure TUFLOW and ESTRY are the computational engines for carrying out 2D and 1D hydrodynamic calculations. In their PC form, they do not have their own graphical user interface, but utilise GIS and other software for the creation, manipulation and viewing of data. These software are: The above combination of software offers a very powerful and economical system for 2D/1D hydraulic modelling.
As for the input data, TUFLOW uses third-party software for viewing results. The recommended software are SMS and WaterRIDE for viewing and animating results, Microsoft Excel or similar for graphing, and MapInfo/Vertical Mapper GIS for high quality mapping and interactive time-series graphing. TUFLOW outputs SMS, WaterRIDE and GIS formatted files containing a variety of data, such as water levels, velocity vectors, depths, unit flow, energy head, flood hazard categories, froude number and several other data types. DTMs, aerial photos and other GIS data are displayed in the background. Computer animations showing the rise and fall of the flood are generated using SMS or WaterRIDE. High quality mapping for reporting, plans and public displays are produced using GIS. MapInfo is used to interactively select and graph time-series results from the 1D and 2D domains.
Major Advantages of TUFLOW Software
The TUFLOW software continues to develop and evolve to meet the challenges of hydraulic modelling. Its strengths are rapid wetting and drying, powerful 1D and 2D linking options, multiple 2D domains, 1D and 2D modelling of hydraulic structures, treatment of levees and embankments, effective data handling, 1D and 2D supercritical flow and quality control outputs. TUFLOW is applicable for modelling flooding in major rivers through to complex overland and piped urban flows, and estuarine and coastal hydraulics. TUFLOW uses GIS as its primary method of data management, manipulation and presentation. The use of GIS allows easy inclusion of model topography changes to assess floodplain impacts. TUFLOW is proudly Australian made and owned.