Subject: How Does Green Ampt Cumulative Event Infiltration work in SWMM 5?
This graph shows the values of the internal SWMM 5 parameters for Green Ampt Infiltration for the pervious area of a Subcatchment during a simulation. The parameters are:
· F or FTOT which is the cumulative event infiltration at the start of a time interval in the internal units of feet in SWMM 5,
· FU or current moisture content of the upper zone of the of the soil
· FUMAX which is the saturated moisture content of the upper zone in feet and stays constant during the simulation
Figure 1. How FTOT, FU and F change over time
Figure 2. A closer look at how FTOT or F and FU Change over time in a Green Ampt Pervious Area Simulation.