Buffer analysis is based on the point, line, surface entities based on the automatic establishment of a certain width within the scope of the buffer polygon layer, and then establish the layer and the target layer of the superposition, analysis and get the desired results. It is one of the spatial analysis tools used to solve the proximity problem. The proximity describes the degree of proximity of the two objects in the geospatial.
The production of the red zone
1, based on the point of the elements of the buffer, usually point to the center, to a certain distance radius of the circle.
2, based on the line elements of the buffer, usually the line as the central axis, from the central axis of a certain distance from the parallel band polygon.
3, based on the edge of the polygon border buffer, outward or inward expansion of a certain distance to generate a new polygon.
The significance of buffer analysis
Buffer analysis is one of the important spatial analysis functions of geographic information system. It is widely used in transportation, forestry, resource management and urban planning. For example, the separation of protected areas around lakes and rivers, the choice of automobile service area, Residential area away from the establishment of the buffer zone of the street network.
The role of the buffer is to solve the problem of speed does not match, high-speed cpu and memory, memory and hard drive, cpu and io speed does not match the problem, and the introduction of the buffer, such as we read information from the disk, we first The read data on the buffer, the computer and then read the data directly from the buffer, and other buffer data read after the disk to read, so you can reduce the number of disk read and write, plus The operation of the buffer on the computer is much faster than the operation of the disk, so the application of the buffer can greatly improve the speed of the computer.
The buffer is a memory area that is used between the input and output devices and the CPU to cache data. It allows low-speed input and output devices and high-speed CPU to coordinate the work, to avoid low-speed input and output devices occupy the CPU. Liberate the CPU, so that it can work efficiently.