Help!

[Guest terry]

i have a tow questions!

First is it is possible to clip a polygon filter to a fence model?

Second How i can export my lithology model to Modflow or GMS!!

Thanks

[Molly]

Hi Terry,

You'll need to clip the solid model (.MOD file) first, then build the fence diagram using the clipped MOD file: Use the Utilities | Solid | Filters | Polygon Clip to clip an existing solid model. Then select Use Existing Model and specify the clipped model name in the Fence diagram application menu you're using.

Lithology models are solid models (3D models), and you probably want to export surfaces (2D grid models) to your groundwater modeling program. RockWorks can generate a grid model of the uppermost (or lowermost) elevations of a specific lithology type in a model, using the Lithology | Superface (or Lithology | Subface) menus.

Molly Mayfield

RockWare Inc.

[Alison]

Terry,

Molly is correct that typically, stratigraphic grids are exported as ASCII files and imported into MODFLOW models as layer boundaries.

However, if you do want to get actual lithology values into a MODFLOW model, then you can export a list of xyz and lithology G-values through the Solid -> Export to ascii menu option. If your MODFLOW model has the same spacing and layer thickness as your MODFLOW model, then there is probably a way to get it into your MODFLOW model (you would need to contact GMS technical support for more information about how to populate a model with lithology data).

If you have a list of xyz values for the cells in your MODFLOW model, you can get the lithology g-value for the closest cell to each point using the Solid -> Statistics -> Residuals tool in the Utilities. This will require that you populate a 4^th column with fictitious values (I would recommend 0s) to use for the G(observed) input column.

Please let us know if you have additional questions.

Thanks,
Alison

[Guest terry]

Thnks Sir, I am asking about exporting all the model to modflow , for building the groundwater flow model of study area, because im working in a alluvial aquifer and i use the technique of "Using Lithologic Modeling Techniques for Aquifer Characterization and Groundwater Flow Modeling", i find in a study that its possible to export the composite lithology model as slices as shown in the figure below!

[Alison]

Terry,

Without seeing the full article, and knowing which MODFLOW interface this person was using, its hard to know exactly how he got the lithology data into the MODFLOW model. If you want to contact me directly with a copy of the article, or additional information, I may be able to help you further. My email address is alison @rockware.com.

Thanks,

Alison

[Guest terry]

Thank you Alison,

I am very grateful for your help I will send this article.

[Alison]

Terry,

In the paper you've referenced, I believe that the user extracted horizontal slices from the solid model as GRD files through the Solid --> Convert --> Extract Grid tool in the RockWorks Utilities. He then probably exported each grid as an ASCII XYZ file (where Z represents material type) through the Grid --> Export menu item. It is important to note that he kept the xy spacing for his MODFLOW model exactly the same as his lithology model, which made the data import into Groundwater Vistas very easy.

I don't know exactly how you would go about doing this in GMS. There may be a similar process that you could follow. I would recommend that you contact AquaVeo technical support and explain that you have lithology data that you’ve like to import into a MODFLOW model. Once you’ve determined which format is needed for this specific product, we can tell you how to go about reproducing this format from RockWorks.

Best Regards,

Alison

[Guest terry]

ok Sir i receive your e-mail, i understand that the model is divided in grid every grid present a X, Y, Z with Z is the G-value ( in my case i have 161 layer every layer have a 5 m of thickness), i can export each layer as an ASCII XYZ file (where Z represents material type), but the problem how put that in Modflow (Modflow flex) and how the software will know which elevations of each layer?

[Alison]

I would recommend that you include the elevation in the name of the extracted grids and ASCII file.

I do not know what the work flow would be for you to import this type of information in to VMOD Flex. I would recommend that you first contact Schlumberger technical support to see how they would recommend you import this type of lithology data into a model. The software may include import options other than a layer by layer import.