Abstract: The buffer construction of line object in GIS usually uses the parallel algorithm. But, when the baseline is complex, the algorithm brings about many intractable problems, when the baseline is a line group, there are more problems to solve. By splitting baseline into segments, it constructs buffers of segments respectively, and then combines them, those complicate cases can be avoided. In order to improve efficiency, it constructs topological relation between point, line, polygon and extensively uses vector algebra for computing, while it discusses some special cases.

Key words: Geographic Information System（GIS）, buffer construction, topological relationship

摘要： GIS线目标缓冲区的构建通常采用平行线算法。但是当基线复杂时，会带来许多难以处理的问题，当基线为线群时更加难以解决。通过将基线分解为线段，分别构建线段的缓冲区并进行合并，可以避免这些复杂的情况。为了提高实现效率，构建了点、线、面间的拓扑关系并大量采用了向量代数的方法进行计算，同时对某些特殊情形进行了讨论。

关键词: 地理信息系统, 缓冲区构建, 拓扑关系