Using Buffer Zones in GIS Application Objects (Especially for GATE-Geospatial 2022)

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Buffering is another method of reclassification. A buffer is a polygon created through reclassification at a specified distance from a point, line, or area. Buffering is based on location, shape, and orientation of an existing object.

Creation of Buffers

Buffering creates a new theme with new polygon features based on a constant measure from features in a source theme; buffers around points are circles, around lines are ‘corridors’ (snake-like with rounded ends) and around polygons are ‘donuts;’ buffers can be created based on:

  • A single set width
  • Multiple widths where more than one buffer is created around each feature
  • Varying width based on an attribute field- this irregular buffering is used for example in stream reaches

How Are Buffers Created?

The software measures outward a certain distance from a point, line or polygon and it then converts that whole area to a polygon. You can place buffers around point objects, such buffers are known as wellheads. You can decide to make this type of buffer either a single distance measure or in multiples. Multiple buffers are known as doughnut buffer.

Image Shows Doughnut Buffer and Wellhead Buffer

For example, if you put a buffer around a wellhead as a safety corridor, you can create several levels of safety corridor – 100,200, and 300 meters. These might be classified as modest, medium, and high risk based on a safety officer՚s experience. In a GIS application, buffer zones are always represented as vector polygons enclosing other polygon, line or point features.

Figure Shows a Buffer Zones Around Polygon, Line or Point

Applications of Buffer Zone

  • Protection zone
  • Neutral zone
  • Inclusion zone
  • Sampling scheme

Developed by: