The user defines a three-dimensional surface file that GeoFluv™ will use as the reference surface from which the fluvial geomorphic surface will be designed. This surface file could be an existing Approximate Original Contour map, a pre-disturbance map, or any other surface from which the user wants to begin the design.
The Select Pre-Disturbed Surface T-Mesh File (.FLT, .TIN) dialog box appears when the Pre-Disturbed Surface button is left-clicked.
The user can type the file name into the File Name field or browse for the file by left-clicking the Browse button to the right of the File Name field. Left-clicking the browse button will open another dialog box that will display file selections and the directory path. The user can search for the surface file in various directories and left-click the Open button when the desired 3-D surface file is found. When Open is clicked in the file search dialog box, the search dialog disappears and the file name is entered into the File Name field in the Select Design Surface T-Mesh File (.flt) dialog box. The user can then click Open on the Select Design Surface T-Mesh File (.FLT) dialog box and details of the file loading will be listed: Loadings edges . . ., the number of points and triangles that were loaded will be listed. Regrade will also conduct an automatic save of the file and the path will be stated.
When the Pre-disturbed Surface file has been accepted, the file name is listed below the Pre-Disturbed Surface button, and GeoFluv™ reads the head and base level elevations from the Pre-Disturbed Surface file for the main channel that the user has sketched and displays these elevations in the "Data for main channel:" fields above the Pre-Disturbed Surface button. GeoFluv™ designs the main channel from this information and the settings on the Channels tab. The elevation at the heads of all other channels have their defaults set by the Pre-Disturbed Surface. The elevations along the GeoFluv Boundary are also set from this surface. This in turn sets the elevations of the main ridges and subridges and subridge valleys that intersect the GeoFluv Boundary.