Automatic Generalization Of Contours And Rivers Based On ArcGIS

Cartographic generalization has been one of key reasons to affect the development of GIS, contour generalization becomes the most complex task. In this paper, the generalization system based on ArcGIS of ESRI Company and AML programming language in Arclnfo workstation is designed. The cartographic generalization system can be used to generalize contours and rivers. Although it don't realize completely automation, most tasks can be done by the program, and by means of the interactive method, the results are similar with the results generalized by cartographer.After these line generalization commands are analyzed and compared, the author researches two approaches of contours generalization based on Arclnfo. One method is progressive cartographic generalization, and the process is controlled by structure line. The other method is that generalized contours come from a more simplified TIN; the characteristic points selected from contours with help of Douglas algorithm can be used to create the TIN. The spatial relations between elements are considered when contours are generalized, so contours generalization is associated with rivers generalization.