I am new to GIS platform. I am using QGIS. I want to create lines inside map similar to border of country at a particular distance (say 100 KM). My data is in geographic coordinate system.

This is my final goal

  • Its Geographic.
    – victorrr11
    Apr 21, 2021 at 14:02
  • See also here for an answer to a similar question with step-by-step workflow (steps 1 to 7 is preparing data only, you already have that): gis.stackexchange.com/q/383587/88814
    – Babel
    May 21, 2021 at 8:21

2 Answers 2


I would prefer to save the layer as a new file by changing its CRS into a projected one using Right click > Export > Save Features As.... Select a suitable one for your data region. Maybe one of UTMs.

enter image description here

Then use Processing Toolbox > Vector geometry > Buffer tool with negative distance value (-100000 m).

enter image description here

  • Thanks man, this is very helpful.
    – victorrr11
    Apr 21, 2021 at 16:53

Using a m-based CRS you may buffer geometries using negative values, thus "shrinking" them.

The CRS should be based on m (or miles or feet) and not degree since results otherwise wouldn't be equi-distant.

Your Answer

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

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