Benchmarking SWMM5/PCSWMM 2D Model Performance

The UK Environmental Agency studied the benchmarking of fourteen 2D hydraulic modeling software packages. The objective of their study was to test whether 2D hydraulic modeling packages used for flood risk management are capable of predicting the variables upon which engineering decisions are based (Néelz et al., 2010). Commonly-used 2D Hydraulic modeling packages used for Environment Agency problems were tested including: MIKE21, Infoworks2D, TUFLOW, and JFLOW (Néelz et al., 2010).

It was found that the suitability of the software depends on the mathematical representation of the processes controlling hydraulic movement across a floodplain, the numerical methods used, and the mesh configuration applied (Néelz et al., 2010).

Recently a 2D overland mesh utility was introduced in PCSWMM. Application of this new component was evaluated using the same UK set of 2D hydraulic benchmarking tests used to evaluate the fourteen hydraulic packages. The tests ranged from simple flood analysis to major flood inundation simulations in complex terrain under various initial and boundary conditions, and shallow flows in urban areas with inputs from rainfall and sewer surcharge.

Performance of SWMM5/PCSWMM2D in simulating these test conditions is presented, including model continuity error, stability issues and run time. The effects of shape of the 2D cells, number of nodes/links on the model results are also presented. Additionally, this paper comments on the strengths and challenges faced by modelers conducting 2D hydraulic analyses.