顾及拓扑一致性的水系三维曲线化简

Line Simplification of Three-dimensional Drainage Considering Topological Consistency

鉴于常规曲线化简方法应用于水系曲线化简时难以顾及水系要素的三维特征及其拓扑关系,本文提出了一种顾及拓扑一致性的水系三维曲线化简方法。该方法首先对D-P算法进行三维扩展,实现水系中单条河流三维曲线化简,然后构建水系树结构表达其拓扑关系,最后按照水系树的层次顺序依次进行河流曲线化简和干流与支流的拓扑关系重构。试验结果表明,该方法化简精度高,既能保持水系的三维形态特征,又能保证河流交汇处的拓扑一致性。

In view of the fact that drainage line simplification using conversional methods is usually hard to keep the three-dimensional characteristics and topological relationships,this paper proposes a new method of threedimensional drainage line simplification which maintains topological consistency.It firstly expends the conversional D-P algorithm to three-dimensional in order to keep three-dimensional characteristics during the simplification.Then it constructs tree structures for drainage lines to express their topological relations.Finally,it simplifies river lines and reconstructs topological relations of main streams and their branches according to the hierarchical order of water system tree.The experimental results show that this method has a higher accuracy in simplification and can maintain not only three-dimensional shape characteristics of water system but also the topological consistency at river confluences.