Showing posts with label How Does the Green Ampt Initial Moisture Deficit Work in SWMM 5?. Show all posts
Showing posts with label How Does the Green Ampt Initial Moisture Deficit Work in SWMM 5?. Show all posts

Friday, July 6, 2012

How Does the Green Ampt Initial Moisture Deficit Work in SWMM 5?

Subject:   How Does the Green Ampt Initial Moisture Deficit Work in SWMM 5?

How Does the Green Ampt Initial Moisture Defiict Work in InfoSWMM and SWMM 5?

by dickinsonre
Subject:   How Does the Green Ampt Initial Moisture Defiict Work in InfoSWMM and 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:

·         Soil Moisture = IMD Max – (FUMax – FU)/Upper Soil Zone Depth
·         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
·         IMD Max is the user defined Initial soil moisture deficit and is a fraction

Figure 1.  How Soil Moisture changes over time.

Figure 2.  Soil Moisture and IMD are related – the Soil Moisture has a maximum of IMDMax.


The Goal of SWMM5 Input Files

 ðŸŒŸ SWMM5 (Storm Water Management Model 5) is a widely used urban hydrology and hydraulic modeling software developed by the United States E...