I'm fairly new to QGIS, and I'm trying to create a buffer around the outline of Spain (including the coastline and boarders). When I do so, it buffers all the country from center to the edge, I just need the edge if that makes sense.
You need to do the following:
- Dissolve the detailed administrative boundaries based on a field in the attribute table that has same value
- The output of the dissolve will have only one boundary that covers whole Spain.
- Then you can use buffer to buffer the outline.
- If you need only the mainland without considering the islands, then select the mainland and apply buffer on the selected feature.