Loading ...
Sorry, an error occurred while loading the content.
 

Boundary Conditions

Expand Messages
  • David Mitchell
    Hello All, I would like to know if the boundary conditions I used are correct for my model? I ve assigned the following: 1) a constant head boundary for the
    Message 1 of 4 , Dec 1, 2005
      Hello All,

      I would like to know if the boundary conditions I used are correct for my model? I've assigned the following:

      1) a constant head boundary for the coast to the east
      2) a constant head boundary for the western most part of the domain, where no natural boundary condition exists.
      3) a no flow (Neuman) boundary to the north and south.

      Groundwater flows from west to east.


      Thanks,

      David


      ---------------------------------
      Do you Yahoo!?
      Take your Mail with you - get Yahoo! Mail on your mobile

      [Non-text portions of this message have been removed]
    • Bron Smolski
      Hi David, From your (scant) description of the problem the boundaries seem to be OK. Few more comments are in CAPITALS below Cheers Bron ... From:
      Message 2 of 4 , Dec 1, 2005
        Hi David,

        From your (scant) description of the problem the boundaries seem to be
        OK. Few more comments are in CAPITALS below

        Cheers
        Bron

        -----Original Message-----
        From: gwmodel@yahoogroups.com [mailto:gwmodel@yahoogroups.com] On Behalf
        Of David Mitchell
        Sent: Thursday, 1 December 2005 6:52 PM
        To: gwmodel@yahoogroups.com
        Subject: [gwmodel] Boundary Conditions

        Hello All,

        I would like to know if the boundary conditions I used are correct for
        my model? I've assigned the following:

        1) a constant head boundary for the coast to the east - OK - GENERALLY
        THE COAST = CONSTANT HEAD UNLESS YOU HAVE TO SIMULATE WAVE/TIDES
        2) a constant head boundary for the western most part of the domain,
        where no natural boundary condition exists. OK - PROVIDING YOU HAVE AN
        IDEA ABOUT THE ELEVATION OF THE GROUNDWATER TABLE AND THIS GW TABLE IS
        NOT FLUCTUATING TOO MUCH WITH TIME (DURING SIMULATION PERIOD)
        3) a no flow (Neuman) boundary to the north and south. OK - IF THEY
        WERE SET ALONG THE STREAMLINES OR THE HYDROGEOLOGICAL BOUNDRIES

        Groundwater flows from west to east.


        Thanks,

        David
      • aaronlapine386
        Hi Bron, If you have the luxury of historical data, how best to select constant head boundaries? I would assume you should expand your model extent to reduce
        Message 3 of 4 , Jun 22, 2006
          Hi Bron,
          If you have the luxury of historical data, how best to select
          constant head boundaries? I would assume you should expand your
          model extent to reduce the impact of the boundaries...correct?
          Would you use the calculated gradient to interpolate the expected
          head for each end of your model? Any assistance would be
          appreciated.

          Thanks,
          Aaron


          --- In gwmodel@yahoogroups.com, "Bron Smolski" <bron.smolski@...>
          wrote:
          >
          > Hi David,
          >
          > From your (scant) description of the problem the boundaries seem
          to be
          > OK. Few more comments are in CAPITALS below
          >
          > Cheers
          > Bron
          >
          > -----Original Message-----
          > From: gwmodel@yahoogroups.com [mailto:gwmodel@yahoogroups.com] On
          Behalf
          > Of David Mitchell
          > Sent: Thursday, 1 December 2005 6:52 PM
          > To: gwmodel@yahoogroups.com
          > Subject: [gwmodel] Boundary Conditions
          >
          > Hello All,
          >
          > I would like to know if the boundary conditions I used are
          correct for
          > my model? I've assigned the following:
          >
          > 1) a constant head boundary for the coast to the east - OK -
          GENERALLY
          > THE COAST = CONSTANT HEAD UNLESS YOU HAVE TO SIMULATE WAVE/TIDES
          > 2) a constant head boundary for the western most part of the
          domain,
          > where no natural boundary condition exists. OK - PROVIDING YOU
          HAVE AN
          > IDEA ABOUT THE ELEVATION OF THE GROUNDWATER TABLE AND THIS GW
          TABLE IS
          > NOT FLUCTUATING TOO MUCH WITH TIME (DURING SIMULATION PERIOD)
          > 3) a no flow (Neuman) boundary to the north and south. OK - IF
          THEY
          > WERE SET ALONG THE STREAMLINES OR THE HYDROGEOLOGICAL BOUNDRIES
          >
          > Groundwater flows from west to east.
          >
          >
          > Thanks,
          >
          > David
          >
        • Smolski
          Aaron, My comments are in CAPITALS below. Cheers Bron ... From: gwmodel@yahoogroups.com [mailto:gwmodel@yahoogroups.com] On Behalf Of aaronlapine386 Sent:
          Message 4 of 4 , Jun 23, 2006
            Aaron,
            My comments are in CAPITALS below.
            Cheers
            Bron

            -----Original Message-----
            From: gwmodel@yahoogroups.com [mailto:gwmodel@yahoogroups.com] On Behalf
            Of aaronlapine386
            Sent: Friday, 23 June 2006 10:53 AM
            To: gwmodel@yahoogroups.com
            Subject: [gwmodel] Re: Boundary Conditions

            Hi Bron,
            If you have the luxury of historical data, how best to select
            constant head boundaries?
            AS YOU SAY BELOW, IDEALLY THEY SHOULD BE FAR ENOUGH FROM THE CENTRE OF
            YOUR MODEL (WHERE I ASSUME YOU HAVE WELLS, PITS ETC) SO THE IMPACT OF
            WHATEVER YOU WANT TO DO DOES NOT EXTEND TO THE BOUNDARIES, OR IF THIS IS
            NOT POSSIBLE THAN THE IMPACT DOES NOT AFFECT TOO MUCH YOUR SIMULATION
            RESULTS. WHAT IS SIGNIFICANT OR INSIGNIFICANT IMPACT DEPENDS ON THE
            PURPOSE OF THE SIMULATION.

            I would assume you should expand your
            model extent to reduce the impact of the boundaries...correct? YES SEE
            ABOVE



            Would you use the calculated gradient to interpolate the expected
            head for each end of your model? YES AND NO. YOU HAVE TO ALSO LOOK AT
            THE TOPOGRAPHY OF THE AREA. THE HEAD CALCULATED THAT WAY MAY END UP
            BEING LONG WAY ABOVE THE GROUND SURFACE OR THE ELEVATION OF THE CREEK
            BEDS (EVEN DRY) AND THIS MOST LIKELY WOULD NOT BE CORRECT.
            LOOK AT THE TOPOGRAPHY, AND OFF COURSE GEOLOGY, OF THE AREA AND THEN
            DECIDE ON THE ELEVATION OF YOUR CONSTANT HEAD BOUNDARY.



            Any assistance would be
            appreciated.

            Thanks,
            Aaron


            --- In gwmodel@yahoogroups.com, "Bron Smolski" <bron.smolski@...>
            wrote:
            >
            > Hi David,
            >
            > From your (scant) description of the problem the boundaries seem
            to be
            > OK. Few more comments are in CAPITALS below
            >
            > Cheers
            > Bron
            >
            > -----Original Message-----
            > From: gwmodel@yahoogroups.com [mailto:gwmodel@yahoogroups.com] On
            Behalf
            > Of David Mitchell
            > Sent: Thursday, 1 December 2005 6:52 PM
            > To: gwmodel@yahoogroups.com
            > Subject: [gwmodel] Boundary Conditions
            >
            > Hello All,
            >
            > I would like to know if the boundary conditions I used are
            correct for
            > my model? I've assigned the following:
            >
            > 1) a constant head boundary for the coast to the east - OK -
            GENERALLY
            > THE COAST = CONSTANT HEAD UNLESS YOU HAVE TO SIMULATE WAVE/TIDES
            > 2) a constant head boundary for the western most part of the
            domain,
            > where no natural boundary condition exists. OK - PROVIDING YOU
            HAVE AN
            > IDEA ABOUT THE ELEVATION OF THE GROUNDWATER TABLE AND THIS GW
            TABLE IS
            > NOT FLUCTUATING TOO MUCH WITH TIME (DURING SIMULATION PERIOD)
            > 3) a no flow (Neuman) boundary to the north and south. OK - IF
            THEY
            > WERE SET ALONG THE STREAMLINES OR THE HYDROGEOLOGICAL BOUNDRIES
            >
            > Groundwater flows from west to east.
            >
            >
            > Thanks,
            >
            > David
          Your message has been successfully submitted and would be delivered to recipients shortly.