Epa swmm different from pcswmm output pdf#
Parallelized simulation results are not yet available, but preliminary diagnostic tests suggest a speed-up of 20x or more.Ĭlick here to download a static PDF version of the presentation.Ĭlick here to watch recorded presentation on YouTube.
Epa swmm different from pcswmm output full#
Remaining work toward the full release of the SWMM5+ engine includes completing the implementation of an Artificial Compressibility solver for surcharged pipes, as well as expanding the parallelization potential of the solver through the inclusion of a graph partitioning method, BIPquick. The conclusions of this analysis will be available at the time of presentation. The comparative metrics were modified to account for model behavior spatially distributed across the Texas River Basin, ensuring that the models were in agreement at a variety of hydraulically independent sites, as well as temporally for the duration of the 5-month continuous simulation. SWMM5+ and SWMM5 (both Kinematic and Dynamic wave) model outputs were quantitatively compared to the SPRNT output on the basis of Normalized Nash-Sutcliffe Efficiency Index (NNSE), Normalize Peak Time Difference, and Normalized Peak Magnitude Difference. In an ensemble model comparison analysis, the SPRNT 5-month continuous simulation results were used as a baseline. SWMM5+ uses a mass-conservative finite-volume approach for the Saint-Venant equations with explicit Runge-Kutta 2nd order time-marching. SWMM5 represents the Saint-Venant equations as coupled node head and link flow equations using an implicit Euler stencil and Picard iteration with a relaxation factor of 0.5. SPRNT uses a link-node finite-difference form of the full Saint-Venant equations solved with the implicit Preissmann stencil and Newton solution of the resulting nonlinear matrix equation. The established Simulation Program for River Networks (SPRNT), was included in the comparison to provide a range of tolerable disagreement between accepted models. Some discrepancies were expected from the differences in computational approach.
The performance of the new computational engine (SWMM5+) was tested on a large scale river network, the entire HUC-2 Texas River Basin, and compared with SWMM5. The rainfall data were assigned to a single rain gauge. All the GIS data layers representing the subcatchments, outfall, conduits and junctions were imported to the PCSWMM interface to develop the model structure.
A novel parallelized, explicit, finite-volume solver alternative to the established serial, implicit, link-node SWMM5 Saint-Venant has been prepared for alpha release. PCSWMM is a spatial decision support system for EPA SWMM used for stormwater management, wastewater and watershed modelling.