Abstract: An improved algorithm is proposed for dealing with the dangled edges in searching topological polygonal chains. In the algorithm, the laws, which a dangled edge is visited twice on one polygonal chain searching trip while only once for a non-dangled edge, are used to identify and mark dangled edges； and then to ensure the correctness of the search results, the associated incidences of dangled edges are eliminated from the polygonal chain. The test results show that the algorithm can significantly improve the efficiency of the polygonal chains search.

Key words: polygon topology, topology building, dangled edges, polygonal chains

摘要： 针对GIS拓扑多边形链搜索中悬挂弧段的处理问题，提出了一种改进算法。该算法利用在一趟搜索中，非悬挂弧段仅经过一次，而悬挂弧段会经过两次这一规律来识别并标记悬挂弧段；在进行多边形链搜索时，通过避让悬挂弧段以避免将其对应的关联弧段加入多边形链，从而保证搜索结果的正确性。测试结果表明，该算法能明显提高多边形链搜索的效率。

关键词: 多边形拓扑, 拓扑构建, 悬挂弧段, 多边形链