地图上等高线信息度量的层次方法研究

地图信息定量度量是地图学研究一个基础问题，亦是评价地图设计、地图综合、制图质量的一个重要依据。本文以等高线地图为例，提出了一种基于空间认知的等高线信息的层次度量方法。首先，分析了现有基于Shannon 信息论的地图信息度量方法。然后解析了地图等高线信息的产生原理，并将等高线信息划分为三个层次，分别为单条等高线信息度量层次（即元素层次）、基本地貌单元邻接等高线信息度量层次（即邻域层次）、全局地图等高线信息度量层次（即整体层次）。在此基础上，依据空间信息多样性和差异性特征，分别建立了各层次信息定量度量方法。最后，通过实验初步验证了本文所提的等高线信息定量度量方法的合理性和正确性。

A Hierarchical Approach to Measuring the Information Content of the Contours in a Map

Quantitative measurement for map information is one of the basic research issues in the field of theoretic cartography. It is recognized as an indicator for evaluating the efficiency of both map design and map generalization as well as the practical value of a map. Taking a typical map, contour map as example, this paper develops a methodology for measuring the information content of the contours in a map in a hierarchy. Existing methods of measuring the information content of a map are first summarized, which are almost based on Shannon information theory. Then, the sources of contour map information and its nature is discovered. It is found that the information of a contour map is able to be described into three levels, namely, element level, neighborhood level and global level. At the element level, it means the information of a contour line; at the neighborhood level, it refers to the information of basic geomorphic unit; and at the global level, the distribution information of whole geomorphology in a contour map is indicated. Moreover, all levels of information are measured from the nature of information source, i.e. variability and diversity. Finally, some practical examples are provided to illustrate the proposed methods in this paper.