Using a spatial overlay

Spatial Overlay forms a new layer containing the attributes from two or more layers. For example, you can overlay a layer containing land-ownership polygons and a layer containing vegetation polygons to analyse where the types of vegetation are located on each property. If you want to overlay specific shapes from the layers, select them before you begin the Spatial Overlay.

  1. From the Analysis menu, click Overlay.
  2. In the Overlay Wizard, enable the Spatial option and click Next.
  3. In the Available Files/Layers list, enable the check mark next to the layers that you want to combine.
    • If you want to select layers from another file, click Browse, locate and select a file from the File Selector window, and click Open.
    • If you want to overlay only the selected shapes in each layer, enable the Overlay only the selected shapes of the input layers check box.
  4. Click Next.
  5. Choose a layer from the Layer list box.
  6. Select an attribute that you want to include in the new layer from the Input Attribute list.
  7. Click Add.
  8. Repeat step 5 to step 7 for each layer. If you want to change the order of an attribute, select it in the Attribute table and click the up or down arrow buttons.
  9. If you want to change the names of an attribute, double-click it and type a new name.
  10. Click Next.
  11. In the Output Options area, enable one of the following options:
    • Union: includes all shapes in their entirety from all the input layers
    • Intersection: includes only the overlapping areas of the shapes from the input layers
  12. Enable any of the following check boxes:
    • Use a Mask to Limit Output: uses a layer to limit the area. Choose a layer from the list box.
    • Using Only Selected Shapes: includes only the selected shapes as the mask
    • Use a Named Region to Limit Output: uses an existing named region as the mask. For more information about Named Regions, see Creating a named region.
  13. In the Output Layer area, select a layer type for the new layer from the Type list box.
  14. Enable one of the following options:
    • Display: shows the results without saving the new layer
    • Save: saves the new layer in the project. Choose a file from the File list box and choose a layer from the Layer list box.
    • If you want to display the results in the view pane, enable the Display saved results check box.
  15. Click Finish.
Parent topic: About the Overlay wizard
Next topic: Using a statistical overlay

© PCI Geomatics Enterprises, Inc.®, 2026. All rights reserved.