Intersection

The Intersection operation computes the spatial intersection between the objects of two layers. The objects of the input layer that have intersection with the objects of the overlay layer will be cut and included in an output layer.

It is accessed through:

    Processing > Vector Processing > Intersection...

1. Input Layer (A):   select the input layer
• Only Selected: optionally, check this box  to apply the intersection over the selected objects on Map Display.
2. Overlay Layer (B): select the overlay layer to intersect with. 
•  Only Selected: optionally, check this box to apply the intersection only over selected objects on Map Display.
3. Attributes Selection: select the attributes from A and B that will appear at the resulting layer. They will be prefixed by 'A_' and 'B_".
4. Output: inform where to save the result by clicking on:
•   to select the output directory and also inform the new layer name to store the result, or
•  to select the output Data Source
• Inform the new Layer Name to store the intersection result (when the repository is  a data source).
5. Click OK to perform the operation or Cancel to close the interface.

Tips:

If the Input Layer and the Overlay Layer are in different SRSs (Spatial Reference System) the geometries of the Overlay layer will be converted before executing the operation. If only one of then have an unknown SRS a message will be issued, since no conversion will be possible and the result might be incorrect.

The option to use only selected objects from the Input and/or Overlay layers is under development.