PDC when running a PEST-IES run...

[Groundwater-modeler]

Hi,

I have a model with close to 100 head observations. I ran a prior MC with only 27 workers with noptmax set to -1, this was mostly to generate output files to be able to balance the weights of my observations. Out of this i got pdc for 15 observations (out of which only a few where significantly off target with valid reasons for it).

When I follow up with PEST-IES run with 500 I got PDC in 25 observations. I struggle a bit to understand why? I suppose the randomness when it draws parameter realizations play a role here..? Still, I would expect less PDC from 500 realizations than 27? What am I missing?

Sincerely
David