Buffering Polygon Data

GIS operations often require a point, line or polygon to be 'buffered' for analysis purposes.

The algorithm for buffering polygon data uses the same process as the line buffering algorithm, with one small difference - the polygon buffer is created on only one side of the line which defines the polygon.

The default method is to create a buffer which surrounds the polygon boundary - some GIS software packages also give an option to create a buffer that lies inside the polygon boundary.

Below is an example of the possible outputs of buffering a polygon.

Original Polygon

Outside Polygon Buffer
(50 units)

Inside Polygon Buffer
(50 units)