11. Profile

A long-section between two nodes: ground, conduit inverts and crowns, node shafts, the HGL at the animated instant, and the maximum-HGL envelope of the run. It answers the question the map cannot: where does the water surface sit against the pipe and the ground along this path?

11.1 Choosing a path

Three ways:

The From and To dropdowns in the view's strip change the path without going back to the map; Swap reverses it. The path between the two nodes is found through the model's links, in either direction, so a profile can run against the flow; it is drawn from the first node station 0. If no chain of links joins the two nodes the view says so.

11.2 What is drawn, and where the elevations come from

The geometry comes from the model file the engine ran, reduced to inverts, crowns, rims, offsets and lengths, by the engine's own rules rather than the drawing's convenience:

A drop structure therefore shows as a step in the invert at the node, and the shaft runs from the node invert to the rim.

11.3 The HGL

Two lines:

The elevation shown is the node's own invert plus depth, which is what the engine reports as the node's head when the two agree; if you have edited a node's invert since the run, the run's depth is drawn on the new invert until you run again (see §11.5).

The HGL is drawn between node heads only; no attempt is made to draw a water surface inside a conduit between nodes, because the .out does not carry one (it carries the link's depth at its midpoint, which is a different thing).

11.4 Controls and export

The same station table is a block of the Model Report (§2.10).

11.5 Which model the profile reads

The geometry is the model open in the editor, as it is now — saved or not, run or not — so a model converted from a storm-sewer file, or one you are still drawing, has a profile straight away. The HGL of a run is the run's: if you edit inverts after a run, the profile shows the edited geometry with the heads the engine computed for the old one until you run again.

The first path offered is the model's first node to its first outfall. A model's 2D sidecar, its DEM and any <model>.2d.out beside it load with the model, so a model reopened after a 2D run draws its terrain and water at once (§11.7).

11.6 The design grade lines

After Analyze (F6, chapter 12) the profile also draws the storm-sewer design's grade lines for every conduit on the path: the Design HGL as a solid violet line from the conduit's upstream HGL to its downstream HGL, and the Design EGL dashed above it by the velocity head V²/2g. Design HGL/EGL in the strip turns them off. These are the standard-step results of the design storm, not a routed hydrograph: compare them with the simulation's Max HGL, not with the HGL at an instant.

11.7 Terrain and 2D water

With a DEM loaded in 2D Setup (§20.3) the profile also draws the Terrain (DEM) along the pipes: the ground sampled every half cell along each conduit's plan path — its nodes and vertices — and laid on the conduit-length stations of the long-section, so the ground between two manholes sits over the pipe that runs under it. The node line is then labelled Rim: where the rims and the DEM agree the two meet at every manhole, and where they do not the gap is the disagreement between the model and the ground.

With 2D results the profile adds the surface water:

After a coupled run the profile carries both halves on one section: the engine's HGL in the pipes, from the coupled run's own 1D results, and the 2D water over the terrain above them. The header names the 1D period and the 2D frame. After a 2D-only run the pipes have no HGL — there was no 1D run — but the terrain and the water are drawn along them.

Section lines

A 2D model has water where there are no pipes. 2D → Draw Profile Line takes clicks on the map as the vertices of a section line; Enter or a double-click finishes it and opens the Profile view along it, stationed by plan distance from the first vertex (marked A on the map, where the line is drawn dashed). The strip gains Along: Pipes / Section line to switch between the two; the node pickers belong to Pipes. Along a section line the plot is the terrain and the 2D water only, Max water switches the dashed maximum, and Export CSV writes station, ground, wse_2d, max_wse_2d for every sample. 2D → Clear Profile Line removes the line.

The water surface is the DEM ground plus the 2D depth: the solver's bed is the DEM resampled to its cells, so on a coarse grid the drawn surface follows the DEM's finer ground rather than the cell's average.