以等高线地图为例,提出一种基于空间认知的等高线信息的层次度量方法。首先,分析现有基于Shannon信息论的地图信息度量方法。然后解析地图等高线信息的产生原理,并将等高线信息划分为3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,依据空间信息的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,通过试验初步验证本文所提的等高线信息定量度量方法的合理性和正确性。
Taking a typical map, contour map as example, a methodology is developed 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 mapinformation 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.