International Conference on Stormwater and Urban Water Systems Modeling

International Conference on Stormwater Urban Water Systems Modeling

Thursday and Friday February 19-20, 2009

http://www.computationalhydraulics.com/Training/Conferences/program.html

SWMM 5 Complexity Index

SWMM 5 Complexity Index

The complexity index for SWMM 5 compares a model to the first Extran example in Extran 3, which would be network #1 in this expanded SWMM 5 network. The baseline network has 22 objects and an 8 hour simulation duration. It took 5 minutes to run this network on a IBM AT in 1988.  The purpose of the complexity index is to supply a means of comparison for a present day model.   The complexity equation compares the number of objects in the new model to the number of objects in the baseline model and also factors in any increase in simulation duration.






The complexity index adds up the of raingages, subcatchments, junctions, outfalls, dividers, storages, conduits, pumps, orifices, weirs, outlets, control curves, diversion curves, pump curves, rating curves, shape curves, storage curves, tidal curves, time series, patterns, transects, hydrographs, aquifers, controls, climate objects and snowpacks objects. The complexity index is then multiplied by the number of pollutants for all subcatchments, junctions, outfalls, dividers, storages, conduits, pumps, orifices, weirs and outlets and it also includes the number of landuses times the number of subcatchment objects.

The complexity index is compared to the network #1 by dividing the calculated complexity index by the base line 22 objects and dividing the duration of the new network by the 8 hour duration of the baseline network. The network shown above has a complexity index of 5.2 and runs in less than 1 second on a Intel Dual Core Processor.

The complexity index was 88.5 for sake of comparison for the model USER4.INP in the zip file DATA.ZIP in epaswmm5_qa.zip on the EPA SWMM 5 QA/QC suite of files.   The complexity index was 7.4 for the model USER1.INP in the zip file DATA.ZIP.  The complexity index was 55 for the model USER2.INP in the zip file DATA.ZIP. The complexity index was20.1 for the model USER3.INP in the zip file DATA.ZIP.  The complexity index was 18.5 for the model USER5.INP in the zip file DATA.ZIP.