SMS:Floodway Delineation Workflow

SMS has the ability to delineate a floodway. Certain datasets and project features are required in order to complete this process.

Required data and project features.
Geometry – 2D mesh, UGrid, or scatter set. Depth and velocity datasets for the given geometry. Defined centerline of the river or channel. A defined cross section coverage in the given area.

To compute volumes in SMS, use the following steps:

1. Load data files.

1. Gather and open image files. Images are imported into the GIS module in SMS. 1. Open local images. Load images from local computer files using the File | Open... command. Alternatively, drag and drop the file into the Graphics Window in SMS. 2. Import images from the web. 1. Import static images. Use the File | Import from Web command. Select a location in the Virtual Map Locator. Set a projection for the project using the Display Projections dialog. Use the Data Service Options dialog to select a web service or catalog. Use the Advanced options if needing to access a unique or unavailable data source. Save the data file and import the data into SMS. 2. Import dynamic images. Use the File | Add Online Maps command. Select a location in the Virtual Map Locator. Set a projection for the project using the Display Projections dialog. Use the Data Service Options dialog to select a web service or catalog. Save the data file and import the data into SMS. 2. Gather and open geometric data files. 1. Import map data. Use the File | Open... command to import map data such as Map files, boundary ID files, or boundary XY files. Alternately, drag and drop the file into the Graphics Window in SMS. 2. Import GIS data. Use the File | Open... command to import GIS data files such as Shapefiles, MIF/MID files, Lidar files, or raster files. Alternatively, drag and drop the file into the Graphics Window in SMS. 3. Import scatter data. Use File | Open... to open files with scatter data such as scatter point files, ASCII dataset files, binary dataset files, tabular data files, or XYZ files. Alternatively, drag and drop the file into the Graphics Window in SMS. Use the File Import Wizard to specify how to import the data. 4. Import CAD data. Verify the CAD file type is readable by SMS before importing it. SMS can import DXF and DWG files. Use the File | Open... command to launch the Open dialog (or drag and drop) to import the CAD files. The data should load in layers into the Project Explorer. 5. Review and set object projections. Right-click on an object in the Project Explorer and select the Projection command. Set the horizontal and vertical projection using the Object Projection dialog. To set a global projection, use the Horizontal Projection dialog.

2. Select the desired "delta" dataset
The delta dataset with the spatially varied elevation needs to be active to calculate volumes. The dataset can be on of the following: 2D Mesh 2D Scatter Set UGrid/Quadtree

3. Load or define the polygon for the delta volume area.

A polygon on an map coverage is needed to compute volumes. 1. Use an existing map coverage or create a new map coverage. 1. Create new coverage from scratch. Select Map Data in the Project Explorer and use the New Coverage right-click command. Use the New Coverage dialog to create a new coverage by selecting the desired coverage type, and naming the coverage. 2. Create new coverage from an existing coverage. Use the Duplicate command on an existing coverage. This will copy any feature objects on the coverage. Use the Rename command to give the coverage a new name. Change the coverage type. 2. Import a polygon for the delta volume. If there is a file with with the define polygon available, use this option. Use the File | Open menu command to open a file containing a polygon. Depending on the file type, the polygon may need to be converted to a map coverage. 3. Define the polygon for the delta volume. Use this option if a new polygon needs to be defined. 1. Create enclosed arcs for polygon area. 1. Create feature arcs, nodes and vertices. In the Map module, create feature objects in the active coverage. Use the Create Feature Arc tool to create arcs in the map coverage. Begin creating a new arc by clicking in the Graphics Window at either arc end. If clicking on an existing feature node, vertex or arc, the new arc will snap to that object. Double-click or press the Enter key to terminate the arc. Use the Create Feature Node tool to create additional nodes alone or to split arcs. 2. Modify arcs. Feature arcs often need to be edited after initial creation. 1. Create additional vertices on arcs. Use the Create Feature Vertex tool to add vertices along arcs. 2. Refine the arc shape. Use the Select Feature Vertex tool and the Select Feature Node tool to move/edit existing arcs and refine the shape by dragging the nodes/vertices. Use the Select Feature Arc tool to move entire arcs . 3. Split arcs. An existing arc can be split by: 1. Converting a vertex to a node. Use the Select Feature Vertex tool and right-click on a vertex along an arc. Select the Convert to Node command to split the arc into two arcs. 2. Add a node the arc. Use the Create Feature Node tool to add a node on an arc in order to split it into two arcs. 3. Add a new connecting arc. Use the Create Feature Arc tool to start or end a new arc on an existing arc to split the existing arc into two arcs. 4. Use the Split Arcs Tool. Right-click on an arc using the Select Feature Arc tool and select the Split Arc(s)... command. Use the Split Arcs Tool to divide arcs. 5. Split overlapping arcs using the Clean Options dialog. Select overlapping arcs using the Select Feature Arc tool. Use the Feature Objects | Clean command to bring up the Clean Options dialog. Select the Intersect selected arcs option (for selected arcs) or Intersect arcs option (for all overlapping arcs) to split the arcs. 4. Merge arcs. Two arcs that share an end node can be merged together. Select the shared node using the Select Feature Node tool. Right-click on the node and select the Convert to Vertex command to merge the arcs. If desired, the Select Feature Vertex tool can be used to select and delete the new vertex. 5. Smooth arcs. The variability or roughness of an arc can be reduced. Right-click on an arc using the Select Feature Arc tool and select the Smooth Arc(s)... command. Use the Smooth Arcs Tool to reduce the variability of the arc. 6. Prune arcs. Concave sections of the arc can be removed. Right-click on an arc using the Select Feature Arc tool and select the Prune Arc(s)... command. Use the Prune Arcs dialog to remove concave sections. 7. Extend/trim arcs. Extend or shorten an arc to match an existing arc's length. Using the Select Feature Arc tool, select two intersecting arcs. Right-click on an arc using the Select Feature Arc tool and select the Extend/Trim Arc... command. Use the Trim/Extend Arc dialog to select the target arc and source arc. 2. Build polygons. Polygons are not created automatically when arcs are enclosed. To create polygons: Use the Feature Objects | Build Polygons command.

4. Make certain the Volume option is on.
Select the File | Info option... menu command. In the Selection Information dialog, make certain Volume is turned on. If desired, unselect quantities that are not of interest. If wanting to create a file with computed volume, turn on the Echo to File option.

5. Compute volume in the Select/Delete Data dialog.

Using the Select Polygons tool, select the polygon(s) that covers the computation region. Use Select/Delete Data... command in the Feature Objects menu. Compute volume in the Select/Delete Data dialog. Leave the Data Domain setting as Inside polygon(s). Select the geometry in the tree on the lower right. "Elements" if the geometry is a mesh. "Triangles" if the geometry is a scatter set. "Cells" if the geometry is a UGrid. SMS will switch the module to the geometry module and select the elements, cells, or triangles inside the polygon(s).

6. View results.
The volume will be reported in the Status Bar at the bottom of the Graphics Window. The Echo to File option in the Selection Information dialog allows for the results to be saved to a file or displayed in a separate window.