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WaterGEMS: Trace Alternative Setup

Hi,

I'm looking to setup trace alternatives to run a Trace Analysis on various water sources to determine the percentage of water coming from various water sources in a distribution system. I understand I have to run multiple Scenarios, with each scenario having it's own Trace Element. I have a few questions:

1.) Trace Element: My understanding is that the 'Trace Element' or Source Node based upon which the trace analysis is run, although there are frequently more sources than one. Does this mean that when a simulation is run that all water comes from the source node, and if not, what is the significance of the Source Node? How are the initial Trace percentage and source node related?

2.) Trace Alternative Box: Under the various tabs in the trace alternative box (i.e. Hydrants, Reservoirs), I notice a the 'Trace (Initial)' variable. Based on what information should this be populated?

Thanks,

Mike

Parents
  • Hello Michael,

    1) The trace element is the element from which the trace percentages are tracked. If for example you choose Tank A as your trace element and you graph the calculated trace result at a node out in your network, it will be showing you the percentage of water at that element that originated from the source trace element.

    2) The initial trace property basically allows you to "hot start" a model run. Basically if you happen to know the starting trace percentage at each element, you can enter that (or perhaps copy/paste it from the calculated trace at the end of one run). Otherwise if you use the default of zero, the model will need to be run for a while before an equilibrium is reached.

    Assuming you have WaterGEMS V8i SELECTseries 3 or greater, I would recommend using the Water Quality Batch run tool, as it simplifies the process of performing a trace analysis on multiple sources and helps visualize results in one place. Check out this teaser video for the benefits of the tool:

    Track multiple sources or constituents with Water Quality Batch Run

    Also, here is an article with more details:

    Analyzing concentration of multiple constituents, or a multi-point trace


    Regards,

    Jesse Dringoli
    Technical Support Manager, OpenFlows
    Bentley Communities Site Administrator
    Bentley Systems, Inc.

    Answer Verified By: Sushma Choure 

Reply
  • Hello Michael,

    1) The trace element is the element from which the trace percentages are tracked. If for example you choose Tank A as your trace element and you graph the calculated trace result at a node out in your network, it will be showing you the percentage of water at that element that originated from the source trace element.

    2) The initial trace property basically allows you to "hot start" a model run. Basically if you happen to know the starting trace percentage at each element, you can enter that (or perhaps copy/paste it from the calculated trace at the end of one run). Otherwise if you use the default of zero, the model will need to be run for a while before an equilibrium is reached.

    Assuming you have WaterGEMS V8i SELECTseries 3 or greater, I would recommend using the Water Quality Batch run tool, as it simplifies the process of performing a trace analysis on multiple sources and helps visualize results in one place. Check out this teaser video for the benefits of the tool:

    Track multiple sources or constituents with Water Quality Batch Run

    Also, here is an article with more details:

    Analyzing concentration of multiple constituents, or a multi-point trace


    Regards,

    Jesse Dringoli
    Technical Support Manager, OpenFlows
    Bentley Communities Site Administrator
    Bentley Systems, Inc.

    Answer Verified By: Sushma Choure 

Children
  • Thanks, Jesse. I ran the WQ batch run on a Trace analysis and it seemed to work. I watched the link to the video provided and saw that the results can be viewed graphically and in tabular format. Can I also color code the system junctions by Trace percentage for each Scenario? If so, how would this be done?

    Thanks,

    Mike
  • The max, min and average trace results can be exported to a scenario for color coding purposes. There's a button in the upper-left corner of the Statistics Table:

    This creates new User Data Extensions, which you can set up color coding on.

    Outside of the Water Quality Batch Run tool, you also have the option of setting up separate scenarios with a trace analysis for each separate source, then color code on the standard results such as the time-varying "Trace (Calculated)"


    Regards,

    Jesse Dringoli
    Technical Support Manager, OpenFlows
    Bentley Communities Site Administrator
    Bentley Systems, Inc.

  • (a reply to this thread was moved here)


    Regards,

    Jesse Dringoli
    Technical Support Manager, OpenFlows
    Bentley Communities Site Administrator
    Bentley Systems, Inc.