You can select various methods to calculate the amount of time. Click the following links for more information about these methods:
- Friend's Equation
- Alameda Method
- Bransby Williams Method
- Izzard's Formula
- Kinematic Wave
- US Federal Aviation Authority
- TR-55 Methods
Some initial values on the calculator are populated based on the current Inflow:
- Area - Based on the current inflow's Area.
- Catchment Slope - Maximum slope derived from the Outline if a surface file is available. If no surface file is used, defaults to 1:200.
- Catchment Length - The maximum distance between any two points on the outline of the area.
- Runoff Coefficient - The Preliminary or Runoff Coefficient, depending on where the calculator is launched from. Defaults to 0 if it is not specified.
All of these values can be overwritten in the Calculator without affecting the values on the Inflow.