Hi Vivien -- The short answer is, yes, you'll need separate coverages for
each layer for pretty much everything you do with GMS. Make sure your
coverages are set for the different layers in the Coverage Setup dialogue
like the default layer range and the type of observations. Check these
under the MODFLOW -> Observations menu to make sure the observation
coverages are active. Check the MODFLOW -> Parameters dialogue that the
variables you want to use as pilot points are set to pilot points and
pointed to the observation coverage that you want. If you're using the 6.5
beta make sure your variable number (-100, for instance) isn't being used
anywhere else in the model like a cell bottom altitude. This doesn't
matter in the 6.0 version.

Hope some of this helps. I recently calibrated a 16 layer model with pilot
points in most of them, so it can be done!

Good luck. Bruce

------------------------------------------------------------
Bruce Campbell
Hydrologist
US Geological Survey
720 Gracern Rd, Suite 129
Columbia, SC 29210
Off: 803-750-6161 Cell: 803-727-9035
Email: bcampbel@...
-------------------------------------------------------------



Vivien Rudorfer <v.rudorfer@...>
Sent by: gms-users@...
11/08/2007 11:57 PM
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Subject
[gms-users] Pilot Points in 2 Layers






Hi ... I am a student in Australia using GMS and I have a problem that I
hope someone can help me with.

I have a 2-layer model (bottom is confined and top is convertible) that is
bounded by a river defined as a specified head drop (as there is no
information on the flow rate or conductance etc.) on 2 sides and no-flow
bedrock boundaries on the other sides. I have created a solid model of the
geology and mapped this to a grid and have successfully created a flow
model for the site.

However I am now trying to calibrate the model and determine the HK
distribution in each layer but am having no success. I have been using the
GMS tutorials as my guide and going to HELP as well. My problem at the
moment is related to the fact that I have water levels in both of my
layers but I am finding that I can't get the software to recognise that.

This is what I have done:
I have set up a group of 2D scatter points (the pilot points) across the
domain as described in the tutorial (which has only 1 layer
unfortunately). I have a single Observations coverage that includes the
water levels in layers 1 and 2 but when I run it all points are being
treated as though in layer 2 even though some are defined as being in
layer 1. I have also tried using 2 Observations coverages separating the
water levels into separate layers but still no success.

I have been trying different things over the last few days and I think the
essence of my problem is simply (and more generally) how to deal with
pilot points in 2 layers.

My only resource is the tutorials and they have only one HK layer, one
observation coverage and one set of pilot points.

Since I have 2 HK layers do I need to create:
(a) 2 separate observation coverages that separate the observation bores
into layer 1 and layer 2?
(b) 2 separate sets of pilot points?

Thanks ... Vivien



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