I am new to GIS and also QGIS tool.

There are two layers imported into the qgis project. Layer-1 (green) has attributes ID, area, code Layer-2 (brown) has attributes station, shp_area, name.

I want to divide the polygons by overlapping and then add a new field value with the divided polygon's respective area. Other fields will remain the same of Layer-1 For e.g. Along the border of one polygon (brown border), a larger polygon (green) was divided into two polygons. The total area before division was 125sqm. After division (shown in red), the areas respectively became 70sqm and 55sqm.

I want to do this in the entire shapefile and store the new output (divided green areas) as Red-layer.

A sample Input(left) and Output(right)

  • 6
    Vector > Geoprocessing Tools > Union will do the job.
    – wiltomap
    Nov 19, 2015 at 14:11
  • 3
    Wiltomap: May I suggest giving this as a formal answer so we can mark up the question as answered?
    – Hairy
    Nov 19, 2015 at 15:28

1 Answer 1


This operation is called union or intersection. Intersect will keep only the area of overlap while union keeps the non overlapping geometries. The tools are located in Vector > geoprocessing menu.

Once you've created the new feature, update the area of the polygons with the field calculator.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.