摘要
河系简化是地图综合中经常需要处理的任务,其难点主要在于依据上下文环境对河流进行结构化选取,以保持河网密度差异等宏观特征。提出一种新的河流等级规则,依据河流的各级支流的数量确定河流的等级,以反映河流的密度差异;设计一种结合河流等级、长度与所在层次的综合指标进行河流选取;探讨在自动构建河系树的基础上计算河流等级、所在层次等指标的方法;最后使用综合指标进行河流结构化选取试验。结果表明,以新等级规则为基础的综合指标切实可行,能够在一定程度上保持河网密度的区域差异。
It is one of the main tasks to simplify drainages in map generalization. The difficulties lie in selectively omitting some rivers while maintaining the overall characteristics of the drainages. A new rule of ordering river entities based on counting the amount of their tributaries is proposed, which indicated the density differences of river entities among different areas. A complex index that combined length, grade and level is designed for structured river selection. An approach is developed to compute the new grades and complex indexes of river entities, based on structuring river segments into river-entity trees. A case study of drainage network generalization shows that the complex index is effective to combine the length, grade and level of river entities, and maintain the density differences of drainage network to some extent.
出处
《测绘学报》
EI
CSCD
北大核心
2006年第2期191-196,共6页
Acta Geodaetica et Cartographica Sinica
基金
国家自然科学基金项目(40101024)
国家杰出青年科学基金项目(40525002)
"985"工程GIS与遥感的地学应用科技创新平台项目(105203200400006)
关键词
河系简化
密度差异
地图综合
drainage generalization
density differences
map generalization
作者简介
张青年（1968-），男，湖北京山人，博士，副教授，主要研究方向为地图自动综合及GIS应用开发等。E-mail：zqnzsu@163．com
