Tutorial: Create a Triangulation-Based Contour Map

Estimated time: 4 minutes.

Contour maps illustrate elevations or other measured data in the study area using lines or colored intervals. "Triangulation-Based" contours are constructed using the same technique you would draw contours by hand, using a "Delaunay" triangulation technique. (See Creating a Grid Based Contour Map in the next lesson for another contouring method.)

! This lesson assumes that you have completed the previous lesson. We are just going to change a few settings to create a new map.

1. With the Maps_Soil_Properties.RwDat file still loaded into the RockWorks datasheet, locate the Utilities program grouping in the menu ribbon, and select Maps | Triangulation Contours.
   
2. Data Columns: Be sure the following columns are selected. If the wrong column title is displayed, just click on the down-arrow and scroll up or down to the correct column title.
   1. X (Easting): Easting
   2. Y (Northing): Northing
   3. Z (Elevation): Elevation
      
3. Click on the Triangulation Contours tab.
   1. On the Contours tab...
      1. Colored Intervals: Check this option, and click on its tab to access the settings.
         1. Scheme:
            • With Min -> Max selected, try clicking on the small color button on the left edge of the palette bar, and choose a color. Do the same for the color button on the right side - you'll see a gradation of colors
            • Another method for choosing a scheme is to click on the large color palette bar - you'll see a popup list of some pre-configured color schemes.
            • In this exercise we will just use the default Cold -> Hot (Medium) palette. This means that lower elevations will be color-filled with cold colors (purples, blues), and higher elevations with hot colors (orange, red).
         2. Interval Type will default to Gradational. Insert a check in the Confirm Interval checkbox.
      2. Contour Lines: Insert a check here, and click on the tab.
         1. Intervals
            • Regular: Choose regular contour intervals to get contours at regular intervals (e.g. every 5 meters).
              • Confirm Intervals: Check this.
         2. Labels: Check this to include contour labels. The default settings should be fine.
         3. Omit Zero Contour: Unchecked
         4. Omit Low Values: Unchecked
         5. Omit High Values: Unchecked
         6. Omit Segments Near Faults: Unchecked
         7. Color & Styles
            • You’ll see the default line style for labeled and unlabeled contours. You can adjust these if you like.
            • Smoothing: Set this to 1.
            • 
              
   2. Triangle Network: Uncheck this.
      
   3. Interpolate Edge Points: This prompt should NOT be checked. The program will build contours only to the given map points, not all the way to the edge of the map area.
      
4. Set up the other map layers:
   1. Background Image: Unchecked.
   2. Labeled Axes: Checked. Since you set this up for the previous map, the settings will be remembered.
      
   3. Map Overlays: Checked. This will allow us to overlay the point symbols on this contour map.
      1. Point Symbols: Checked. The Symbols and Symbol Labels from the previous map should still be activated.
         
   4. Other 2D Files: Unchecked.
      
   5. Peripherals: Check this, so that we can activate a color legend and other map peripherals.
      1. Color Legend: Check this. You will see the legend displayed in the preview pane to the left. Click and drag to reposition the legend relative to the map. To resize the legend, hold down the SHIFT key as you click on a corner of the legend preview and drag.
      2. North Arrow: This should be on by default. Click this tab to choose an arrow design.
      3. Scalebar: This should also be on by default.
         
   6. Border: Unchecked.
      
5. Click the Continue button at the bottom of the window to create the map.

   Because you activated the "confirm intervals" options, the program will display a window summarizing the Z (elevation) values found in the datasheet, and some recommended labeled and unlabeled contour intervals (top) and color-contour intervals (bottom).

6. Click OK to accept these.

   RockWorks will scan the datasheet, determine the location coordinates for each sample site, and build line contours and color-filled contour intervals to represent the surface elevations. It will overlay point symbols and labels to illustrate the control point locations, and it will annotate the border with titles, ticks, and coordinate labels. The color legend, north arrow, and scale bar will be appended. The completed map will be displayed in a new RockPlot2D tab on the screen.

   Let's keep a copy of this map opwn while we make a grid-based contour map in the next lesson.

7. Click on the Edit | Copy to New Window menu option. You will see a new, stand-alone RockPlot window, displaying the triangulation contour map.
   
8. Click on the small Save button to save this map.
   Type in the name: Triangulation Contours   and click Save.
   
9. Move this window to the upper-right corner of your screen or to another monitor. (To move a window, just click-and-hold on the RockPlot title bar, and drag the window to a new location.) Or, minimize the window if you need the space.
   
10. Click back in the original map window, and close it using the upper-right X button. You can answer No to the save-file prompt.
    

  Triangulation-Based Contour Maps

  Back to map menu     |     Next (grid-based contours) 

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