Buffering

Buffering is the process of  putting an inclusive or exclusive zone around features.  It can be done with points, lines, or areas.  With points you will circles around each point; for lines, you will get a wider line; and with areas, you get a generalized, larger outline.

Point Shapefile

 Points outside a 500 m radius have been eliminated Points within a 500 m radius have been eliminated.
DEM masked with schools from USGS gazetteer database.

This could model the effects of a school drug free zone, for example, or restrictions on sex offenders, or the zoning of adult businesses.

Line shapefile
Only points near roads, with buffer of 250 m on each side of the road.  Only points off roads, with buffer of 250 m on each side of the road.
This could model critical zone along rivers, proximity to roads (or subclasses of roads like interstates) for businesses seeking locations.

Buffering can be done in MICRODEM:


Last revision 8/31/2012