QGIS – Dissolving Using Attribute Field and Area in QGIS

Question

How can I dissolve a shapefile with polygons and keep the information of the polygons that have the bigger area in QGIS?
example:
two polygons with the same field values but one of them is bigger than the other –> dissolve into one polygon that contains the attribute values of the bigger polygon.

Answer 1

If the polygons you want to dissolve or merge located inside the bigger polygon , then try to use Eliminate sliver polygons located under Vector → Geoprocessing tools → Eliminate sliver polygons:

• Select the polygon layer you want dissolve/merge
• Select the Area field from the attribute table (Selection Attribute)
• Use the <= to select only the polygons less than the bigger polygons area
• Write the threshold area of the bigger polygon
• Select Merge by largest area
• Run the tool