Sroke特征约束的树状河系层次关系构建及简化方法

Method of Tree-like River Networks Hierarchical Relation Establishing and Generalization Considering Stroke Properties

树状河系作为地图骨干要素之一,其简化效果直接决定地图综合的质量。树状河系简化需要考虑其语义、几何、拓扑和结构等多种特征,而现有方法大多只注重了长度、角度和属性等约束性量化指标,致使简化后的空间分布特征容易被破坏。本文首先研究基于树状河系有向拓扑树(DTT)的特征智能识别方法,然后依据Paiva提出的"180°假设"和"锐角假设",从河口出发,自下游向上游建立顾及河流语义、长度、角度约束的树状河系stroke连接,并据此判断树状河系层次关系,最后提出河系整体选取数量确定方法和顾及密度差异的河系分层剔除选取算法,实现树状河系自动化简化。经样本数据测试,验证了该方法的可靠性,同时经实际数据测试,验证了该方法在树状河系简化中的合理性和有效性。

Tree-like river is one of the key features of map,its simplification effect determines the quality of cartography generalization directly.Simplifying tree-like river need to be considered many characteristics,such as semantic,geometry,topology and structure,but the traditional methods only focus on the quantitive indexes,such as length,angle,which lead to the spatial distribution characteristics of the simplified results were destroyed easily.A new method based on the stroke properties is presented.Firstly,the intelligent identification method of characteristics is studied in this paper on the basis of directed topological tree(DTT).Secondly,according to“180°hypothesis”and“acute hypothesis”which proposed by Paiva and stroke properties,the hierarchical relationship for tree-like river network is established.Finally,the algorithms for setting the whole numbers and hierarchical elimination selection were proposed to realize the automatic simplification of tree river.Results from sample data test verify the reliability and results from actual data verify the rationality and effectiveness of the proposed method.