Buffer Zone Analysis is an analysis method that creates an area of a certain width around a point, line, or Region based on a specified distance. Buffer Zone Analysis is often used in GIS Spatial Analysis, and is often combined with Overlay Analysis to solve practical problems. Buffer Zone Analysis has been applied in agriculture, urban planning, ecological protection, flood control and disaster relief, military, geology, environment and many other fields. For example, in environmental governance, a range with a certain width is often drawn around a polluted river to indicate the polluted area; for example, when expanding a road, a buffer zone can be created for the road according to the road widening width, and then the buffer zone layer and the building layer are overlaid, and the buildings that fall into the buffer zone and need to be demolished can be found through Overlay Analysis.
Buffer Zone Analysis is based on point, line and surface objects, and supports Buffer Zone Analysis for 2D point, line, surface and Network Dataset. When Buffer Zone Analysis is performed on the Network Dataset, the arc segment is used as the buffer zone. Buffer types can be divided into single buffer and multi-buffer. The following takes the simple buffer as an example to introduce the implementation of point, line and surface buffers:
- Point Buffer The buffer of a
point is a circular area centered on the point object with a radius of a given buffer distance. When the buffer distance is large enough, the buffers of two or more point objects may overlap. When you select Union Buffer, the overlapping parts are merged, and the resulting buffer is a complex face object.
- Line buffer The buffer area of a
line is a closed area formed by translating two lines to both sides of the line object in the normal direction of the line object for a certain distance, and joining the two lines with the smooth curve (or flat head) formed at the end of the line. Similarly, when the buffer distance is large enough, the buffers of two or more line objects may overlap. A Union Buffer has the same effect as a point's Union Buffer.
When the Buffer Type of the line data is set to Flat, the buffer widths on both sides of the line object can be inconsistent, so that the left and right buffers are unequal; or a unilateral buffer can be created only on one side of the line object, as shown in the following figure:
- Face Buffer The buffer Generation Method for a
face is similar to that for a line, except that the buffer for a face extends or shrinks only on one side of the face boundary. When Buffer Radius: is positive, the buffer expands outward of the face object boundary; when it is negative, it shrinks inward of the boundary. Similarly, when the buffer distance is large enough, the buffers of two or more line objects may overlap. You can also select a Union Buffer, which has the same effect as a point's Union Buffer.
- Multi-buffer
Multi-buffer refers to the establishment of a buffer of the corresponding amount of data around Geometry according to a number of given buffer radii. For line objects, you can also create a single-sided Multi-buffer, as shown in the following figure:
Related topics
Buffer Zone Analysis Application Example