河网线要素与DEM综合的三维Douglas-Peucker算法

The Three Dimensional Douglas-Peucker Algorithm for Generalization between River Network Line Element and DEM

目前三维Douglas-Peucker(3D_DP)算法主要应用于单一类型的DEM综合。本文引入"弯曲调节指数"来改进3D_DP算法,提出了一种三维空间河网要素与DEM综合的新方法,即将河网线矢量提取成三维离散点数据集(增加高程属性),与DEM三维离散点数据集合并,在河网层次化选取基础上,利用改进的3D_DP算法对合并数据集进行综合操作。通过试验结果的对比和分析表明,该方法通过弯曲调节指数的调节使河流自身所具有的弯曲形态与地形的主要特征得以同时保留,试验效果良好,实现了三维空间河网要素与DEM数据在同一简化因子作用下的综合,提升了地图综合的质量。

At present,the three dimensional Douglas-Peucker（3D_DP）algorithm is mainly used on generalization of a single type of DEM.This paper introduces the＂bending adjustment index＂to improve the 3D_DP algorithm,and puts forward a new method for generalizing river network and DEM in three-dimensional space.In this method,river network line vector data are extracted into 3Ddiscrete point data sets which are added elevation attributes,and then they are merged with the 3D discrete point data sets of DEM.The generalization operations are made by the improved 3D_DP algorithm after the hierarchical selection of river networks.Through the contrast and analysis of the experimental results,the well experiment results have been achieved.Under the role of bending adjustment index,the overall distribution form of the rivers and the main terrain features can be reserved reasonably on the generalization.The river network and DEM data were generalized under the same simplified factor in this method.It improves the quality of the cartography generalization.