The Reaches in SWR: Surface-Water Routing Process pane is on the MODFLOW Features tab of the Object Properties dialog box.
This pane is used to define reaches in the SWR process. The reaches are normally numbered automatically. You can use a vertex value to override the automatic numbering.
There are two tabs on this pane: Steady and Transient.
Steady Tab
The Steady tab defines those aspect of the reach that do not change through time.
Type of routing (IROUTETYPE): IROUTETYPE defines the surface-water equation used in each reach.
Reach length (RLEN): RLEN is the length of reach within this finite-difference cell. The length of a reach can exceed the finite-difference cell dimensions because of the meandering nature of many one-dimensional surface-water features. The length is used to calculate the reach conductance for this reach for several leakage options. RLEN can be defined as any value for reaches defined as IGEOTYPE = 4 and 5
Multilayer (KRCH): If this checkbox is checked, the reach can span multiple layers. The geometry data is used to determine the layers spanned by the reach.
Grouped (IRGNUM) and Group number (IRGNUM): If the Grouped check box is checked all the reaches defined by this object will be assigned to the value specified in Group number. Otherwise, each reach will be assigned to a separate group.
If Save observations in the SWR: Surface-Water Routing Process pane of the MODFLOW Packages and Programs dialog box has been set to SAVE_SWROBSERVATIONS or SAVE_SWROBSERVATIONS_ALL, You can select the types of observations to be defined by this object. After running MODFLOW, the observation data can be plotted along the length of the stream in the SWR Observations pane of the Data Visualization dialog box.
Connections: Connections are automatically assigned to all reaches defined by the same object. There are three ways to define connections with other objects. If the Connection Method is set to Object, select the other object in the table in the Objects column. For polyline objects the reaches at the end points of the lines that are closest to one another will be the ones that are connected. For polygons, the closest two reaches defined by the objects will be connected. If the Connection Method is set to Specific reach, select the reach number in the table. If the Connection Method is set to Overlapping reaches, select another object in the table in the Objects column. Connections will be defined by all reaches defined by the other object that are in the same cell as a reach defined by the object being edited.
It is not necessary to specify the reach connections in both objects that are connected. When the SWR input file is generated, ModelMuse will automatically define the reverse connection if needed.
Connections between multiple objects can be made in one step using the Link Streams dialog box.
Connections can be displayed using the SWR Reach Connections of the Data Visualization dialog box.
Transient Tab
The Transient tab defines those aspect of the reach that change through time.
Starting time and Ending time are explained in the help for the MODFLOW Features tab.
Geometry (IGEONUMR): Geometry is the Name of the reach geometry or this reach as defined in the SWR Reach Geometry dialog box.
Vertical Offset (GZSHIFT): The same reach geometry can be used for multiple reaches. For example, if a reach cross section is used and it has only been measured at a few places, you might want to use the same shape for the cross section but have it offset vertically at different locations along a stream. GZSHIFT lets you do this. You can use a function that will give different values along the length of a polyline to specify GZSHIFT. InterpolatedVertexValue is one such function.
Reach Type (ISWRBND): Reaches can be either active, inactive, or specified stage reaches.
Stage (STAGE): If you have chosen to specify stage by object, a column for the stage will be present. The stage must be specified for all reaches in the first stress period. This acts as the initial stage. For other stress periods, the stage can be specified for specified stage reaches and for reaches that use either level- or tilted-pool reservoir routing. See also: Stage in SWR: Surface-Water Routing Process.
