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.
