Tutorial: Create a 3D Aquifer Model

Estimated time: 4 minutes.

We are going to take a slight detour at this time to create a model of the water level data in the borehole project.  These surfaces will be used in the next lesson to constrain the T-Data model.

An aquifer model is created by interpolating 2 grid surfaces (.RwGrd): one for the water level top and one for the base.

! You must be using RockWorks in Trial mode, or have a Standard or Advanced license to run this modeling program.

Before continuing, be sure you have opened the sample project, and established the project dimensions, as discussed in earlier lessons.

1. Re-enable all of the boreholes in the project, if necessary, by clicking on the Edit | Enable All Boreholes toolbar button or selecting that menu option.
    
2. Look at the aquifer data:
   1. Back at the Borehole Manager, click on any borehole to make it active. 
   2. Click on its Water Levels button to view the aquifer data.   
   3. Note how this table contains only 4 columns:
      • Aquifer Name:  Since you can include multiple aquifers in your database, the first column defines which aquifer's data you are entering. The names are defined in the Aquifer Types Table. You can click on this button, above the data listing, to see the types table.
      • Date of Sample:  Just like the T-Data, water levels are also flagged with dates.
      • Depth to Top: Measured depth from the borehole surface to the aquifer top.
      • Depth to Base: Measured depth to the aquifer base.
   4. At the top of the Water Levels table, there is a From Elevation / From Collar button - you can use this in your own work to define whether the water level depths (for all holes) are referenced to the ground surface elevation or the collar elevation, both listed on the Location table.
       
3. Establish the modeling settings:  Select the Aquifers | Model menu option.

1. • Choose Aquifers:
     • Single Aquifer: Choose this option, and be sure this is set to Aquifer 1.
       
       
   • Surface Modeling (Gridding) Options: Click on the Options button to the right to define how the surfaces will be modeled. 
     • Method (Algorithm): Choose the  Inverse Distance option.  This tells the program to use the Inverse-Distance gridding method to interpolate the aquifer surfaces. The default settings for this algorithm will be fine.
     • Dimensions: This item (upper-right) should be set to be Based on Output Dimensions. 
     • Smooth: Check this option to smooth the resulting surfaces.
     • All remaining Additional Options can be left unchecked.
     • Click the OK button to close the Gridding Options window.
   • Hide Thin Zones: Leave this setting unchecked.  (In your own work it can be used to hide portions of the aquifer model that are below a user-defined thickness.)
   • Plot Logs: Leave this setting unchecked. 
   • Reference Cage: Unchecked.
   • Include Aquifer Legend: Unchecked.
     
     
   • Rules & Filters: : Look for the Rules & Filters pane along the right side of the options window.
     • Date/Time Filtering: Be sure this is checked.
     • Exact:  Click in this radio button.
       • Click in the prompt to set this date to 2/14/2007 (or, if you're not in the U.S. your dates may appear as 14/2/2007). 
          
4. Click Process at the bottom of the Aquifer Modeling window. 

RockWorks will read the aquifer top and base depths, determine true elevations, and create a grid model for each that represents the water level surface.  The upper surface will be stored under the name "2_14_2007_top.RwGrd," named automatically by the program (the name will be formatted as "14_2_2007.RwGrd" if that is your date format).  The lower surface will be stored under the name "2_14_2007_base.RwGrd".  You'll use these RwGrd files in the next lesson.

Once the surfaces are interpolated and stored on disk, the program will create a 3D view of aquifer and display it in a RockPlot3D window.

5. If you would like to take a moment to investigate this view (zoom, rotate, expand the "2/14/2007 Water" item in the data tree, turn portions on/off, etc.) feel free to do so. 
    
6. Save this 3D view by choosing File | Save and typing in the name:  aquifer model 2-14-07   The program will store this under the file name "aquifer model 2-14-07.Rw3D".
    
7. Close this RockPlot3D window by clicking in its upper-right Close box. 
    

Creating Water Level Models
 

  Back to T-Data menu     |     Next (isosurface diagram) 

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