Jump to content
GMS, SMS, and WMS User Forum

Importing XYZ data and attribute (pressure)


Recommended Posts


I'm relatively new to the GMS software and have performed a few of the basic tutorials Aquaveo provides. 

I have XYZ data that provides spatial reference to every observed pressure points/head values. These points are evenly spaced/gridded. I would like to create a MODFLOW simulation with these pressure data. To my understanding, the best way about creating this model would be to generate a raster that stores XYZ and P data (GeoTIFF). Theoretically, I'd like to create a 3D grid that stores these X, Y, Z, and P data. From there I'm going to need to create an IBOUND layer that specifies the head based on the P value. 

I've successfully performed these simulations in 2D space but am unable to comprehend where to start in the 3D space. See the attached screenshot for an example of a longitudinal cross-section of a 2D simulation. 

Can someone provide me some insight on how to begin setting up this model? Let me know if there are further things I need to clarify.


Link to comment
Share on other sites

If I understand it right, you have raster dataset of measured heads and you basicaly want your model to reproduce these as close as possible. Why not just convert the raster data to points a treat each point as observation point? Then you can formulate the inversion problem as usual.

Link to comment
Share on other sites

Hi Michal,

Thanks for your response. I actually just have a gridded point dataset. I was wondering if the best option would be to convert it to a raster.

Otherwise, if I can keep this dataset as a gridded point dataset, then that's one less data processing step which is fine by me. What I'm modeling here (theoretically) is hyporheic exchange on the surface and subsurface of a stream bed. Once I run MODFLOW I will generate flow paths to visualize the hyporheic exchange.

What you see in the above screenshot is one longitudinal section of the entire dataset with three distinct locations which represent a boulder on the surface of the bed. In the full data set, I have surface observations regularly spaced at 5mm with an observed location (XYZ) and a modeled pressure value from a flume for every single observation. Note, it is a complete 3D data set. I am able to bring in this dataset as a shapefile then convert it to a feature object (is this a good next step?). My next big hurdle I'm facing is snapping these observation points to a grid cell center where I want one observation point per grid cell (5mm resolution).

Can you provide some insight into how I might do that and then assign each grid cell the respective pressure value for that point?


Link to comment
Share on other sites

Hi T,

I didnt understand what you do, so forget my last comment :). I dont know much about this topic. It would be nice if GMS would allow us to do "Interpolate to modflow layers" command with RIV package (to prepare the river bottom/elev dataset and head), but i think only Head in GHB package could be distributed this way. If you decide to model it with RIV, which would be my choice, you need to prepare the package outside GMS.

Link to comment
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.

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.


  • Create New...