Hydrology module

Inputs

• Catchment properties: area, flowpath length, elevations / slope proxy
• IDF data for required return periods and standard durations
• Method settings:
• Tc method
• Rational vs SCS area threshold
• ARF enablement (if used)
• CN (for SCS) or \(C\) coefficient (for Rational)

Steps

1. Enter/verify catchment row(s).
2. Enter/verify return period IDF table.
3. Select Tc method and compute \(T_c\).
4. Run peak computations.
5. For SCS runs, generate hydrograph outputs and review the time series.

Review checklist

• Tc values are within plausible ranges for the terrain.
• Intensity retrieved from the correct IDF segment.
• Method branch is correct for the catchment area threshold.
• Peak values are reasonable and monotonic with return period.