Posts

Showing posts from July, 2013

Tributary Area to a Node in SWMM 5 or InfoSWMM

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Note:TributaryArea to a Node in SWMM 5 or InfoSWMM
Here are the steps you neeed to take to calculate the tributaryarea of a node in InfoSWMM:
Step 1:  Use the DB Editor to get the total area in your model using the Data Statistics Tool.


Step 2:  Use the Process options in InfoSWMM to ONLY simulate surface runoff and flow routing.

Step 3. Copy the Node name and Total Inflow Volume from the Juntion Summary Output Table to Excel

Step 4:  Find the Total Wet Weather Flow during the simulation from the Wet Weather Inflow Row in the Flow Continuity Table.
Dry Weather Inflow   0.000  0.000 Wet Weather Inflow  0.782   0.255
Step 5. Make a new column in Excel to calculate the tributaryarea.
The TributaryArea of a Node = Total Inflow Volume / Total Wet Weather Flow * Total Subcatchment Area from Step 1.

How to Set Up an InfoSWMM 2D Simulation Polygon and Mesh

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Subject: How to SetUp an InfoSWMM2DSimulationPolygon and Mesh
Step 1: Create the 2D Database


Step 2: Verify the Creation of the 2D Database


Step 3: Create the background SimulationPolygon for the 2Dsimulation

Step 4: Create the Mesh on the 2DSimulationPolygon

Step 5: Run the combination 1D and 2D network

Step 6: Simulating the network uses up to the number of cores on your computer for the 2D flow.

Step 7:2D plot of the flooded mesh points.


Drainage Wells or a Vertical Exfiltration Trench in InfoSWMM

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Subject:  DrainageWells or a VerticalExfiltrationTrench in InfoSWMM
Note, this is just one way to model an ExfiltrationTrench.  The source for the image below is Rice Creek Watershed
You can make a storage node to simulate the trench with the following characteristics:
·         Functional or Shape Curve to describe the shape of the trench, ·         Infiltration parameters to simulate the infiltration flow out of the bottom or sides of the trench,

Step 1:  Define the shape and geometrical characteristics of the Infiltration Trench

Step 2: Define the soil infiltration characteristics of the trench

Step 3:  Run the simulation.  The Storage Volume Summary tells you the volume infiltrated and the average outflow.

Step 4:  Output Manager will also show the infiltration  outflow, the depth and the volume of the infiltration/storage node.

Step 4:    Infiltration losses out the side and bottom of the orifice.

How to make Multiple Storm Events in InfoSWMM and How to Use them in the Scenario Manager

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Subject:  How to make MultipleStormEvents in InfoSWMM and How to Usethem in the ScenarioManager
Step 1.  Make a new Time Series to hold the data points for your new Rainfall Time Series in the Operation Tab of the Attribute Browser.


Step 2.  Populate the Rainfall Distribution with a SCS Type II Hyetograph with a 1 inch rainfall total


Step 3.  Now Clone the created Rainfall Distribution and make 10, 25, 50 and 100 year stormevents each with 1 inches of rainfall in a cumulative distribution.

Step 4.  Now use the Block Edit command and convert each of the newly created hyetographs to 4, 7, 10, 15 and 20 inch cumulative rainfall totals from the original 1 inch rainfall total (for example).

Step 5.  Now create a Raingage for each of the newly created hyetograph time series using the DB Editor under the Raingage Table in Hydrologic Data



Step 6.  Link the Time Series to the new Raingages and define the type (cumulative), units (inches) and hyetograph interval (15 minutes)


Step 7. Make 4 New Scenari…

Weirs in InfoSWMM and SWMM5

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Weirs in InfoSWMM and SWMM5Subject: Weirs in InfoSWMM  Figure 1 shows the relationship between the weir input data and the upstream and  downstream nodes. ·         Height, ·Crest and ·         Node Invert Elevation  There are four types of weirs and if the weir becomes submerged downstream the Villemonte weir submergence correction is applied (Figure 2).  You can have flow reversal across the weir unless you use a Flap Gate for the weir (Figure 3).  Figure 1:  Definition of Weir Terms Figure 2: Villemonte Weir Submergence Correction Figure 3:  Flow Reversal in a Weir

A Basic InfoSewer Wet Well, Pump and Force Main System

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Note:  A BasicInfoSewerWetWell,  Pump and  ForceMainSystem

How is the St Venant Equation Solved for in the Dynamic Wave Solution of SWMM 5?

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Subject:   How is the St Venant Equation Solved for in the Dynamic Wave Solution of SWMM 5?
An explanation of the four St. Venant Terms in SWMM 5 and how they change for Gravity Mains and Force Mains. The HGL is the water surface elevation in the upstream and downstream nodes of the link. The HGL for a full link goes from the pipe crown elevation up to the rim elevation of the node + the surcharge depth of the node.  The four terms are:
dq2= Time Step * Awtd * (Head Downstream – Head Upstream) / Link Length or dq2= Time Step * Awtd * (HGL) / Link Length Qnew= (Qold – dq2 + dq3 + dq4) / ( 1 + dq1) when the force main is full dq3 and dq4 are zero and Qnew= (Qold – dq2) / ( 1 + dq1) The dq4 term in dynamic.c uses the area upstream (a1) and area downstream (a2), the midpoint velocity, the sigma factor (a function of the link Froude number), the link length and the time step or dq4 = Time Step * Velocity * Velocity * (a2 – a1) / Link Length * Sigma the dq3 term in dynamic.c uses the current midpoin…