Introduction: This set of blogs uses the 1000 year rainfall/runoff/hydraulics model that you can download at http://swmm2000.com/forum/topics/1000-year-simulation-with-rainfall-in-swmm-5 to show the inner workings of SWMM 5 and by extension InfoSWMM and H2oMap SWMM using a QA/QC version of SWMM 5 with extended graphics. I always hope that seeing the inner workings of a SWMM 5 feature helps to understand the code, sensitivity and importance of a parameter. It also helps show sometimes when a parameter is not important. In this example, the components of the total losses in SWMM 5 which are the infiltration from the pervious area and the evaporation from the impervious and pervious area are shown (Figure 1)
Discussion: The total losses (Figure 1) are:
1. The infiltration only losses from the pervious area,2. Evaporation losses from the pervious and impervious area weighted by areal coverage
3. The total losses which are the sum of the evaporation plus infiltration losses
a. In a continuous simulation the times of infiltration only loss is less than the total losses due to the times when evaporation only is occurring from the depression storage of the Subcatchment
b. The Statistics assume an inter-event time of 0 hours to capture all of the one hour saved time increments
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| Figure 1. The total losses include both evaporation and infiltration for a 100 Year SWMM 5 Simulation |
