SMS:TUFLOW Coverages

TUFLOW models use several types of Feature coverages. Feature coverages are used in SMS to represent geometry and associated attributes as points, arcs, and polygons. Unlike most models used in SMS, TUFLOW uses coverage data as model inputs.

TUFLOW coverages can be associated with 2D Geometry Components and TUFLOW Simulations by creating links to the coverage in the component or simulation. The use of links allows multiple simulations or geometry components to share coverage data. Sharing data between simulations reduces required disk space for the simulation and makes it easier to update several simulations with the same changes.

In addition to the coverages listed below, TUFLOW models can use Area Property Coverages to define where to use specific material properties using polygons.

Contents

• TUFLOW 1D/2D Connections Coverage

  1D/2D connections are used with the 2D BC coverage to link 2D and 1D domains.

Two types of arcs can be created in a 1D/2D connection coverage: 1D/2D connection arcs (CN) and Flow vs. Head Connection arcs (SC).

1D/2D Connection arcs are written to a 2d_bc layer file for TUFLOW input (see 2d_bc_layers in the TUFLOW documentation). One end of the connection arcs must end at the same location as a 1D Flow/2D Water Level Connection (HX) in a TUFLOW BC coverage. The other end of the connection arc must end at the same location as a network node in a TUFLOW network coverage.

• TUFLOW 1D Cross Section Coverage

Cross section coverages are used to define open channel cross section data for 1D networks. Cross section geometry is generally extracted from a TIN and may be edited by hand if desired.

Cross sections are created by creating arcs in a cross section coverage. SMS can automatically create cross section arcs from a 1D network.

After cross section arcs are created, the elevations for the arc can be extracted from a scatter set (TIN) by right clicking on the coverage and selecting “Extract from Scatter” from the menu. This will extract the cross-section data from the active dataset on the active scatter set. Values are extracted at each triangle edge in the scatter set and each node or vertex on the cross section arc.

After cross sections have been created, the materials from an area property coverage may be mapped to the cross-sections. This is done by right clicking on the coverage and selecting, “Map Materials from Area Property Coverage.”

Individual Cross sections may be viewed and edited by double clicking on an arc, or by selecting an arc and choosing Feature Objects->Attributes. This will bring up the cross-section attributes dialog (see TUFLOW Cross Section Attributes).

All the cross-sections in the coverage are stored in a cross section database. The cross section database may be opened by right clicking on the coverage and selecting “Properties” (see Editing Cross Sections).

• TUFLOW 1D Network Coverage

1D domains are made up of a network of channels and nodes. Channels represent the conveyance of the flowpaths and nodes represent the storage of inundated areas (TUFLOW Users Manual). Channels are created using arcs and the arc endpoints are the nodes.

There are a variety of channel types including open channels, weirs, and culverts (pipe networks). The channel also has a variety of attributes depending upon the channel type. The channel type and attributes are defined in the Channel Attributes dialog.

There are two types of nodes generic nodes, and inlets. Generic nodes can be used to specify storage and can be used to set channel invert elevations. Inlet nodes are used to get flows from a 2D domain into a 1D pipe network below the 2D domain. The node type and attributes are defined in the Network Node Attributes dialog. The TUFLOW documentation sections 4.5.1.3: Connecting Pits and Nodes to 2D Domains and 4.5.3: 1d_nwk Attributes list some new TUFLOW features that SMS now supports. SMS's Network Node Attributes dialog has several new additions to the Create Connection to 2D Domain (SX) section. These new options allow you to control elevations at the connections, how many cells are connected, and the method for selection of additional cells (Grade or Sag). Each option correlates fairly directly to a TUFLOW field and some are labeled as such to make lookup easy.

The TUFLOW documentation sections 4.5.1.3: Connecting Pits and Nodes to 2D Domains and 4.5.3: 1d_nwk Attributes list some new TUFLOW features that SMS now supports. SMS's Network Node Attributes dialog has several new additions to the Create Connection to 2D Domain (SX) section. These new options allow you to control elevations at the connections, how many cells are connected, and the method for selection of additional cells (Grade or Sag). Each option correlates fairly directly to a TUFLOW field and some are labeled as such to make lookup easy.

• TUFLOW 2D/2D Links Coverage

A 2D/2D Links Coverage is used to setup TUFLOW to use multiple 2D domains. See Linking 2D Domains.

• TUFLOW 2D Flow Constriction Shape Coverage
• TUFLOW 2D Spatial Attributes Coverage

Spatially varied attributes can be defined using the 2D spatial attributes coverage. The values for the attributes are assigned to polygons. TUFLOW assigns the values from the polygons to the cells that exist within the polygon.

The two available spatial attributes are initial water levels and weir factors.

Assigning spatially varied initial water levels may be necessary to ensure that water bodies have water in them initially.

• TUFLOW 2D Z Lines (Advanced) Coverage
• TUFLOW 2D Z Lines/Polygons (Simple) Coverage
• TUFLOW Boundary Conditions Coverage
• Clip Region Read TIN Z pts Coverage
• TUFLOW Grid Extents Coverage
• TUFLOW Water Level Lines Coverage
• TUFLOW Water Level Points Coverage