Tutorial #6. Buffer Command

Researchers often find the command to be useful. As its name implies, this command creates a buffer of a specified distance around polygons, lines, or points. The buffer's width is a radius having relevance to the particular research question at hand and is defined by the researcher. For example, if a researcher is interested in mapping the right-of-way for a pipeline project, he or she would simply create a buffer around the transect line at the desired distance. The command would then produce a linear polygon with the defined width (for example, if the pipeline right-of-way was 500 meters on either side, the polygon would have an overall width of 1km and it would be perfectly bisected by the transect line, 500 meters falling on either side).

The simple figure below illustrates how a buffer (outlined by the blue line) is created for one polygon (the green circle). Buffers have many uses, one of which is as a quick, simple, and accurate method of assessing the proximities of selected features to other features in the area (for example, how close rockpile fields are to habitation sites). They can also be used to demarcate land around sensitive archaeological sites or fragile environmental areas. Select to see a view that illustrates a more complicated buffer in which Zone 2 habitation sites are buffered at 2km.

Buffer: in spatial information systems a buffer zone, or simply buffer, is a polygon enclosing an area within a specified distance from a point, line, or polygon. Accordingly, there are point buffers, line buffers, and polygon buffers. Buffers are useful for proximity analysis, for example, finding all stream segments within 300 feet of a proposed logging area.