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Errors in risk analysis of stochastic modeling

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I'm working on using GMS-MODFLOW to delineate the capture zone stochastically. The conceptual model I'm working on is built based on HUF package (run in HUF Package). As it's a quite large area, but my study area is just a smaller one inside. Therefore, I build smaller coverage to define the study area with specific head boundaries. Then I run MODFLOW and MODPATH again, so the results only come from the smaller study area. 
However, when i was trying to run the stochastic model, which took the recharge rate of the study area as the parameter with different probabilities. I defined the key value of the recharge rate, and run it stochastically, everything went well. I got the results of these realizations. Then i was trying to do the risk analysis, in order to generate the probabilistic capture zone distribution. However, it showed that"MODPATH had errors, cannot read error files", that I can not get the results of the probabilistic capture zone distribution.
Do you have any idea that what's the problem with it? As it's the essential part of my graduate project, it's really important that I should fix the errors ASAP. Your kind help and assistance would be greatly appreciated.
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I've tried to not to redefine the smaller local area, just work on the original large model. I chose the recharge of the small study area as the parameter to be randomized and run stochastic modeling, for example, I run 10 realizations. The results came out successfully and I received the groundwater head simulation results of these 10 realizations. Then I tried to do risk analysis based on these results. This time, there is no error with it. However, I cannot get the probabilistic capture zone distribution graph. Instead, I only received several data files with the name of all the pumping wells in my model. I have no idea how to deal with the data. I tried to export one of the data and open it by Excel, but I don't really understand what it means (it contains lots of 0 and 1).  Can anyone tell me how can I get the probabilistic capture zone distribution picture? I attached the screenshot of my GMS model. Also I attached one of the files. Thanks!



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Thanks for your comments, Alan. I was also thinking these datasets should be contourable. However, I tried several time, i turned on the contour option and set for the color fill, but I cannot get the probability plume. I only got the same color on th screen, without any plume circles. 

May I ask for another question? The model was built on HUF package. The hydraulic conductivities were given by the material types(rather than by layers). If I want to randomize the K value as well, can I just modify the K values in the material module( change them into negative values)? Then run the stochastic model. Or I need to do as the tutorial: indicator stochastic modeling?

Many thanks! 

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Hi Alan,

thanks! Yes I just did like that and it works. But still, I'm not able to contour these datasets. I just feel it's quite strange. Cause I had worked in another model to delineate the probabilistic capture zone plume. After I run the risk analysi, the plume graph just came out on the screen automatically, together with the files. However, in the model I'm working on right now, it doesn't work. I only received the datasets without graph shown on screen. Do you maybe have any ideas about how to contour these datasets? 

Thanks sooo much!

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I don't think there is a problem contouring datasets in GMS. My guess is that the values in the datasets that you are trying to contour do not vary much. For example, maybe there is a value of 1 at the cell where the well is and all of the other cells have a value of 0. I would create a MODPATH model for one of the wells and see how it changes when you change to the various MODFLOW outputs.

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  • 4 months later...
3 minutes ago, Josue Gallegos said:

LeoCN-IL, did you ever figure out why you were getting the modpath error message. I am encountering the same error.

Hi, can you be more specific? Do you mean you cannot continue completing the risk analysis and it was interrupted by the "error" information? If so, maybe try to use the new version of GMS. I upgraded to the latest version (GMS10.2? maybe) and the problem was solved. Of course, you need to make sure there are no other errors with the model you built.

Hope it can give you some idea to solve the problem. Cheers!

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