Integrating the full US EPA SWMM5 engine, PCSWMM accounts for various hydrologic processes that produce runoff from urban areas. These include:
• time-varying rainfall
• evaporation of standing surface water
• rainfall interception from depression storage
• infiltration of rainfall into unsaturated soil layers
• percolation of infiltrated water into groundwater layers
• interflow between groundwater and the drainage system
• nonlinear reservoir routing of overland flow
PCSWMM application that includes natural channels withuser-defined channel geometry.
Spatial variability in all of these processes is achieved by dividing a study area into a collection of smaller, homogeneous sub catchment areas, each containing its own fraction of pervious and impervious sub-areas.Overland flow can be routed between sub-areas, between sub catchments, or between entry points of a drainage system.
PCSWMM also contains a flexible set of hydraulic modelling capabilities used to route runoff, RDII, DWF, and/or external inflows through the drainage system network of pipes, channels, storage/treatment units and diversion structures. These include the ability to:
• handle networks of unlimited size
• use a wide variety of standard closed and open conduit shapes as well as natural channels
• model special elements such as culverts, storage/treatment units, flow dividers, pumps, weirs, and orifices
• apply external flows and water quality inputs from surface runoff, groundwater interflow, rainfall-dependent infiltration/inflow (RDII), dry weather sanitary flow (DWF), and user-defined inflows
• utilize either kinematic wave or full dynamic wave flow routing methods, including 2-D capabilities for floodplain routing
• model various flow regimes, such as backwater, surcharging, reverse flow, and surface ponding
• apply priority-based, dynamic control rules to simulate the operation of pumps, orifice openings, and weir crest levels.