基于复杂树结构的河流渐变自动绘制算法

An Algorithm for Single- line Stream Automatically Shading

地图制图和GIS可视化中的河流自动渐变是水系要素表达的重要方面，同时又是一个技术难点。文章针对当前河流自动渐变研究较少的现状，提出一种复杂树递归算法的河流自动渐变方法。该算法深入研究了复杂树结构的构建和河流渐变中存在的上下游流向、主支流搜索、面状水域流人流出等复杂问题，实现了河流渐变自动绘制，并进行了实践测试。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。

Single - line stream automatically shading is an important aspect of map - making and GIS visualization, and also is a great difficulty in realizing. At present, the study on single -line stream automatically shading is very few, so this paper puts forward a method based on the complex - tree recursion algorithm. The method deeply discussed many complex spots in single - line stream automatically shading, such as building complex - tree structure, flowing orientation, searching main and branch stream, flowing in and out of regional - water and so on. The method realized single - line stream automatically shading, and also practised in different items. The results have shown that the method has obviously reduced the manual work in shading single -line stream, improved the efficiency, and possessed feasibility.