The relationship between the rainfall, total losses from the previous area, evaporation and infiltration only rate for SWMM 5

Subject:  The relationship between the rainfall, total losses from the previous area, evaporation and infiltration only rate.

The total loss from a subcatchment pervious area is the sum of the evaporation + infiltration loss.  Typically the evaporation rate is much less than the infiltration rate. SWMM 5 now has too options – evaporation during only dry periods or evaporation during both wet and dry periods.

Figure 1:  An example network that shows the relationship between the rainfall, total losses from the previous area, evaporation and infiltration only rate. 

Figure 2:  The same model with the Evaporation during only Dry Periods turned on