Implement pilot points without flopy

[BJEANNOT0]

Hello,

I want to do a parameter estimation with Pest++ and would like to use pilot points in order to reduce the number of parameters. I was thinking about using pyemu for pilot points interpolation.

However, reading the documentation of pyemu, it seems that the use of pyemu for pilot points has been thought in a workflow that contains flopy==>modflow==>pest++. As far as I am concerned, the model I want to use pest++ on is not modflow, therefore I do not use flopy.

Therefore, my question is the following. Is it possible for me to use pyemu for pilot point interpolation although i am not using flopy nor modflow ? In detail, my problem is a the following : Considering a mesh with nn nodes and ne elements, with a mesh file that enables me to access to coordinates of center of elements, i want npp = 200 pilot points to be defined on the domain (which is not a square but a real domain). Among them, there are nkpp = 3 pilot points i want at specific locations.

Then, I want to be able to use the value of parameters at these 200 locations in order to interpolate values of parameters at each element.

I provide sample code below and attach sample inputs (a mesh file and a file containing locations whee i absolutely want a pilot point to be located). Could you please get me started on the way to use pyemu for this purpose ? I would like -to define pilot points uniformly on the domain, with 3 of them at specific locations -to use the value of parameters at the pilot points in order to interpolate the value of parameters at each elment of my mesh.

Thanks in advance for your help ! Here is the file containing the code :

Pilot_points.txt

Here are the inputs : mesh.txt known_pilot_points.txt

[jtwhite79]

If you are using thePstFrom class, it can do unstructured pilot points. the key is you need to pass the spatial reference as a dict of node-tuple(xy) pairs so that it look up the location of nodes as needed. Then you can pass pp_space as a dataframe of pilot point name-xy info. There is an example of using a unstructured modflow model here:

https://github.com/pypest/pyemu/blob/a474ebd76d6822fed895957aaa52110bf0ab866c/autotest/pst_from_tests.py#L3020

admittedly Im no good with unstructured models but hopefully that will help you get going. There is likely better unstructured grid support in PEST groundwater utilities...

[BJEANNOT0]

Thank you ! I will look into it. As you say, I also investigated PEST groundwater utilities and I may end up using PLPROC as well. I will post again when i manage to provide satisfactory results.

Bets regards,

[briochh]

Hi @BJEANNOT0, did this issue get sorted? @rhugman-intera, recently implemented some functionality for DISV grids in MF6 (#393 and #387) with a suggestion that DISU might support might not be too painful. If you were heading down the MF6 path.