中文摘要：

小比例尺制图中河流自动渐变绘制是地图制图研究中的常见问题,也是一个技术难点。该文针对当前河流自动渐变研究实用性较差的现状,提出一种基于河流类树结构的河流自动渐变方法：在研究河流复杂树结构基础上,提出了河流类树结构及其构建方法,并从网结构中搜索出主流和支流、河流的流向以及面状水域的处理,在补充河流上下游出图面的长度后,依据河流渐变率实现河流的渐变绘制,并基于MapGIS二次开发,实现了小比例尺地图河流的绘制。结果表明,该算法极大减少了地图制图过程中河流渐变绘制的人工干预,提高了自动化渐变绘制效率,具有可行性。

英文摘要：

It is technologically difficult that the automatic gradual change drawing of rivers in the small scale cartography.For the impractical of the status quo,a gradual change drawing algorithm of river based on treelike structure is put forward in this paper.After a thorough study of the complex structure of river,a treelike structure of rivers and its constructing methods is introduced,and also its searching method of main stream and branch of a river in network structure,the flow of the river,the process of area water.After complement the up and downstream part of the river that is out of the map,the making of the small-scale map is realized based on further development of MapGIS.The results indicate that this algorithm greatly reduces the manual intervention in the river gradual change cartography process as well as improving the platting efficiency.