Native Text File Differences

[Bruce Campbell]

Hi -- I'm getting different water-level results with GMS 10.4.7 files when I switch from a PEST calibrated binary version to native text files. Here's the workflow:

 

1) Build and calibrate the models using PEST in GMS,

2) Get good results and acceptable calibration, using pilot points for aquifer horizontal hydraulic conductivities (HK) and specific yield (Sy) (for the surficial aquifer),

3) Interpolate the calibrated pilot point HK and Sy data to a 2-D grid created from the 3-D grid (same cell size and alignment) with the same interpolation methods as PEST used, 

4) Replace the parameters (pilot points and drain conductances) in a new set of GMS files with calibrated values,

5) Used the Kriging interpolation method in both the PEST calibration process and when the resulting pilot point set is interpolated to the 2D grid in the native text files,

6) Write the files out as native text, do a forward run, and import results into GMS,

7) Compare key observations from the native text file results to the original binary GMS files.

 

Here's a plot of one of the wells using outputs from the original calibrated binary GMS files.  

 

 

Here's the same well using outputs from the model run using the native text files. 

 

 

I've gone through the process of replacing the PEST variables in GMS with the final calibrated parameters twice and get the same results. 

 

One thing I have noticed is the dataset info differs between the calibrated pilot points and the version that I interpolated to the 2D grid. 

Here's a comparison of the dataset info for one of the pilot point datasets:

 

                     Orig Cal PP       Interp to 2D Grid

Min              1.072                1.072

Max             904.99              734.94

Range          903.91             733.87

Mean          129.78              48.05

Median       50.132             20.75

SD                212.28             77.46

 

Why would these be so different? Both were done using the Kriging interpolation method.

 

Any ideas would be appreciated!

[Michal]

Hi Bruce, it is hard to tell. I suggest you to compare the HK and Sy arrays of the HDF5 and native MF version of your model. See if they are different. They should be exactly same.

You could read the HDF file directly using Python for instance, see the discussion here.

Good luck

Michal