Jump to content
GMS, SMS, and WMS User Forum
Sylvain

MODFLOW UZF water budget HORT+DUNN

Recommended Posts

Hi,

I have recently started using the UZF package to simulated groudwater flow in a regional model. I firstly developed a steady state model using spatially distributed recharge from a surface model. I was using the «recharge» and the «EVT» package. With this configuration i was able to obtain a water budget with % error < 0.001%. When i replaced the recharge and EVT packages by the UZF, the water budget output file shows a line with a component called «HORT+DUNN» which i suspect to be the surface runoff flow. This component is not well describe in the USGS MODFLOW documentation. The problem is that this volume of water is only present in the «IN» part. In then creates a poor water balance ~1% to 5% error. If i remove it from the balance, the % error is good (> 0.01%).

Any idea of how to deal with this water budget component?

Regards

image.png.93a5242eb770f9645bf4602b5909b444.png

Share this post


Link to post
Share on other sites

Hi,

I agree it is poorly documented. I had to dig into the source codes to figure it out. It seems to be an excess infiltration volume rejected by the model. It can be routed to other packages as described in the ModelMuse documentation:

"If the applied infiltration rate is larger than the vertical hydraulic conductivity, the actual infiltration will be reduced to the vertical hydraulic conductivity. Any remaining potential infiltration will be available to the MVR package as rejected infiltration."

So I guess if you lower your infiltration rate this term should approach zero.

I have no idea why the text description in the budget file states "HORT+DUNN". Maybe somebody else could clarify that.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...