This guide explains how to read Storm Sync Time Area graphs and reports, interpret the isochrone-strip display, and export analysed inflows. Set up the storm, bands, and loss model in the Storm Sync Time Area hydrology guide.

Review graph results #

After analysis, open Graphs → Hydrology Graphs. Under Design Storm → Rainfall Hyetograph, review the rainfall blocks distributed by the selected temporal pattern. In a real Time Area run, this graph’s rainfall matches the rainfall intervals used for each catchment.

Under Catchments, choose a catchment’s Rainfall Excess chart to see separate pervious and impervious panels. Each interval stacks rainfall excess with applied rainfall loss; together, their heights equal the interval rainfall. The Runoff Hydrograph chart shows the resulting catchment flow over time. Use the ARI / Storm Duration checklist to display selected scenarios together. Rainfall Excess is available for Time Area results; Rational Steady produces one design flow and therefore has no hydrograph.

Read the Catchment Hydrology report #

The textual report records the selected loss settings and interval-by-interval rainfall, loss, excess, and band contributions. Compact keeps the peak-flow summary and runoff hydrograph while reducing calculation detail; Detailed adds the full calculation working. Use the Catchment and ARI selectors to change the scenario. Failed scenarios are labelled and are not selected as the default usable result.

Understand the isochrone strips #

The Isochrone Strips overlay is an illustrative display of the configured bands, not a terrain-derived travel-time delineation. MiTS sweeps cuts perpendicular to the catchment’s single Overland Flow line, starting at its drain/outlet end and moving across the catchment boundary. Each strip is sized to match its band’s fraction of the total band area, so the strips tile the boundary. A concave catchment can make one strip appear as multiple separate pieces.

The strip geometry does not change the saved band areas or affect runoff calculations. It does not use terrain elevations or calculate flow paths. Choose Isochrone Strips or Strips + Legend in the Catchment ribbon group. Colours represent each band’s travel time; the palette and legend scale are controlled by Storm Design → Detailing → Time Area Isochrones.

Export an EPA SWMM input file #

The export dialog offers two inflow sources:

• Generate from current settings recalculates the selected ARI and duration from the current project settings.
• Use saved analyzed inflows uses the node inflow hydrographs saved with the selected completed analysis. The open project’s network, storage geometry, and hydraulic settings still provide the EPA SWMM model structure. If saved inflow node marks no longer match the open project, restore the analysed project or export from current settings.

Choose the ARI, duration, mark handling, and output .inp file. Use the saved option when you need the analysed inflow ordinates; use current settings when you intend to generate a new hydrograph from current inputs.

Reference comparisons #

The numerical references check separate cases with separate loss models. Their comparison drafts are available in the Publishing repo: MSMA2 Appendix 2.F2 and legacy PondCAD.