STR package river slope

[fahad....@uconn.edu]

Hi,

I'm using model muse to run a transient modflow_NWT model. While attempting to calibrate my model, I have a number of observation wells very close to the rivers where I have over-estimation. My question is:

1. Will it help if I alter the river width, slope, etc. geometric properties of the rivers? I'm using the streamflow package (STR). Conceptually what I'm trying to say is, if I change the river width/ slope than it might increase the water carying capacity of the river and more water from the aquifer can be transferred into the rivers, hence, reducing the over-estimation.

2. Is it possible within model muse to write a function (in STR package) so that the river bed slopes will be derived from the Model Top?

Thanks a lot for reading my concerns.

Fahad

[Richard Winston]

1. Increasing the width will increase the conductance between the stream the aquifer which should result in more flow between the stream and the aquifer. Assuming that the stream is gaining reach, that should result in lower heads in the aquifer. Increasing the slope will result in lower heads in the stream if the stream heads are calculated rather than being specified by the user. That should result in more flow from the aquifer to the Stream and lower heads in the aquifer.

2. I can't think of an easy way to directly calculate slope from the model top elevations using a formula in ModelMuse.

Sent from BlueMail

[Chang Liao]

What you are trying to achieve is kind of unreasonable to me.

The slope is defined by the gradient of elevation so a minimal of 2 elevations are needed.

It is unlikely you can define the slope using model top at one point.

Again, you can modify slope, but it appears that is only possible in SFR package instead of STR.

In most cases, modifying the slope can actually remove lots of river bed related elevation issues.

Therefore, I recommend you use SFR package and calculate slope reach by reach instead of segment by segment.

Hope it helps.

[ashutosh singh]

From experience I can say that the aquifer properties effect a lot of the movement of water from the aquifer into the stream/drainage feature.

If you have a discharge value for the stream then change the hydraulic conductivity to match it to the simulated discharge. Also try to observed heads.

This way you will understand the model more!!

//Hpc

--
You received this message because you are subscribed to the Google Groups "MODFLOW Users Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email to modflow+u...@googlegroups.com.
To post to this group, send email to mod...@googlegroups.com.
Visit this group at https://groups.google.com/group/modflow.
For more options, visit https://groups.google.com/d/optout.

[Pedrofit]

I think is possible in Visual Modflow you can put In river elevation a formula like this:

$Bot+$Z+ C ) 

C is the height of the river this need to be measure in the field or by estimation.

I guess in model muse is it possible but I don't remenber the formule maybe is in logical formule..