地图图形结构分析与概括研究

地图图形往往具有一定程度的空间结构特征，例如树枝状水系，棋盘状街道网等。这些空间结构特征深刻反映了地理现象的特点和规律，是地图图形概括过程中需要突出表现的内容。然而，地理数据库中并没有直接存储图形结构信息，而是隐含地表示于几何图形要素的空间关系之中。这就要求在地图概括处理之前进行图形结构分析。分析了地图图形结构模式及其识别过程，并且探讨了图形结构的概括方法。

Identification and Generalization of Spatial Structures on Map

There are many structural units on maps,such as dendriform drainage and orthogonal streets.Structural patterns reflect the characteristics of geo-graphical phenomena,thus should be represented on map.However,geo-databases usually do not represent structural entities directly. Instead, they are implied by spatial relationship between elementary geometric entities.In many GIS applications,one needs to generalize elementary graphic features so as to derive scale-reduced data set.In such cases,it is necessary to identify the implied spatial structure,so as to represent the implied spatial structure in generalized data sets.Otherwise the spatial structure may be distorted.The classification and identification of structural patterns of spatial distribution were discussed, and the map generalization method based on structure analysis was explored.