Pre 2014 Blogs

control-of-hydrologic-parameters-during-simulation (2)

control of hydrologic parameters during simulation

Posted by Steve Pells on September 1, 2011 at 7:48pm

Hi,

I'm using SWMM to model a catchment which is located above a longwall mine - the purpose is to assess if observed changes to stream flows in the catchment are climatic or indicative of mining impacts.

 

Ive established a model which adequately simulates historical streamflows and which successfully uses the aquifers and groundwater flow equation.

 

I would like to simulate the onset of impacts from mining by increasing the "lower groundwater loss rate" value in the aquifer editor.  Is there a way to change such a value mid-simulation?  

 

I have had no success trying to run two separate periods with different "lower groundwater loss rates" for each period as the antecedent conditions for the second (mining) period get mucked up.

 

Any help would be appreciated

Thanks

Steve

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Pump / Force Main System in InfoSWMM and SWMM 5

Posted by Robert Dickinson on November 16, 2010 at 5:14pm

Subject: Pump / Force Main System in InfoSWMM and SWMM 5


The basic system consists of:

· Wet Well and its associated physical parameters,

· Pump Type

· Defined Pump Curve,

· Downstream Pressure Node and

· Downstream Force Main

Figure 1: The Basic System

Step 1: Wet Well Data

Enter the invert elevation, maximum depth of the Wet Well, the physical shape as either a function or shape table and any evaporation or infiltration.

Step 2: Define the Pump Type

The pump type is defined by a Pump Curve and the On and Off elevations:

The four types of pumps are:

· Volume - Flow

· Depth – Flow

· Head – Flow

· Depth - Flow

Step 3: Define the Pump Curve in the Operation Tab

Step 4: Set a Surcharge or Pressure Depth at the Downstream end of the Pump

Any positive Surcharge Depth in the Node will allow the program during the simulation to keep the node under pressure forcing flow through the Force Main.

Step 5: Force Main Data

Define the downstream pipe(s) from the pump as Force Main conduits with either a Hazen Williams or Darcy-Weisbach coefficient (defined in the SWMM 5 options or the Run Manager of InfoSWMM)

Step 6: HGL Plot of the Force Main System

Step 7: Pump Summary in the RPT File

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