Stormwater Management Model (SWMM) Information for watershed water quality, hydrology and hydraulics modelers (Note this Blog is not associated with the EPA). You will find Blog Posts and Twitter Embeds on the Subjects of SWMM5, InfoSWMM, InfoSewer, SWMMLive, InfoSWMM SUSTAIN, SWMM4 and SWMM in general.
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Surcharged Node and the Link Connection in SWMM 5
Subject:SurchargedNode and the LinkConnection in SWMM5
A surchargednode in SWMM5 uses this point iteration equation (Figure 1):
dY/dt = dQ / The sum of the Connecting Link values of dQ/dH
where Y is the depth in the node, dt is the time step, H is the head across the link (downstream – upstream), dQ is the net inflow into the node and dQ/dHis the derivative with respect to H of the link St Venant equation. If you are trying to calibrate the surchargednode depth, the main calibration variables are the time step and the link roughness:
1. Mannings's N 2. Hazen-Williams or 3. Darcy-Weisbach
The link roughness is part of the term dq1 in the St Venant solution and the other loss terms are included in the term dq5. You can adjust the roughness of the surchargedlink to affect the node surcharge depth.
Figure 1. The Node Surcharge Equation is a function of the net inflow and the sum of the term dQ/dH in all connecting links. Generally, as you increase the roughness the value of dQ/dH increases and the denominator of the term dY/dt = dQ/dQdH increases.
Figure 2. The value of dQ/dH in a link as the roughness of the link increases.
Soffit Level (pipe technology)The top point of the inside open section of a pipe or box conduit. The soffit is the highest point of the internal surface of a pipe or culvert at any cross-section. The soffit is also referred to as the pipe obvert. So it is not quite the Crown of the Pipe. Here is an image I found that hopefully explains it better.
Engine Error NumberDescription ERROR 101: memory allocation error. ERROR 103: cannot solve KW equations for Link ERROR 105: cannot open ODE solver. ERROR 107: cannot compute a valid time step. ERROR 108: ambiguous outlet ID name for Subcatchment
New InfoSWMM linked 2D Link and 3D Node graphics help you understand one of the most critical outputs in any Stormwater, Combined Sewershed or Sanitary Sewershed Network Model the value and timing of how full the pipes and nodes are over time and how this changes during Wet Weather Flow (Runoff or Infiltration Inflow).These new graphs are included in InfoSWMM v 14.6 and InfoSWMM SA V2 (InfoSWMM SA is not an Esri Extension in ArcMap but uses Arc Engine for GIS processing power) has many new graphical and map display tools that help answer the following modeling questions in a easy to understand group of linked Time Track Graph, 2D Graphs and 2D Thumbnails. If you are modeling a Stormwater Network and need to know the d/D or depth over maximum depth over time and at the peak of the Runoff event you can view linked graphs as shown in Figure 1.If you are modeling a Sanitary Network and need to find the d/D for Rainfall Induced Infiltration and Inflow (RDII) you can see the RDII fl…