Estimating uncertainty in reactive transport modelling (X1t, X2t)

[sam.bingham]

Hi all,

I use X1t and X2t to predict phosphate concentrations from both dissolution reactors and within groundwaters. These models include lots of parameters, all of which have uncertainty associated with them. However, I am not sure how to estimate the uncertainty on the phosphate concentration that the RTM predicts. I could calculate it by propagating the error through the fundamental equations that the RTM use (SI, advection, dispersion, etc.), but I was wondering if there is a more straight-forward method through?

Thanks for your help,

Sam Bingham 

[sam.bingham]

Any ideas?

[JohanFourie]

From 1 user to another:

GWB does not have the facility to include statistical distribution of parameters. 

Option 1: Manually run various scenarios with consideration of the statistical distribution of the most sensitive parameters. Let say the 50, 66 and 95 percentile of a parameter. 

Option 2: Write a code in Chemplugin that run several models for you with consideration of the statistical distribution of your parameter (which might even be a water balance component). I have not done it myself but think it is a great idea - but one would probably need a lot of time for the development of the code.

If you have several parameters with several different distribution functions, I would say first try to simplify your conceptual model as much as possible...….