中文摘要：

在讨论高程准确性、高程序正确性、高程特征保持性和模型概念的基础上，分析了DEM机械建模生成中的理论和实践局限，提出了特征建模目标和数字综合途径，论述了DEM数字综合原理，并给出了1：5万和1：1万两种DEM系列综合例图。实验表明，只有在表示出全部地形特征的可靠DEM基础上进行数字综合，才能在指定分辨率上表示出所需地形特征的DEM。

英文摘要：

This paper is based on the discussion of three fundamental characteristics of the ground （elevation accuracy, validity of elevation order, and the preservation of elevation features） and the concept of the model, then analyzes major theoretical and practical shortcomings of the DEM generated in the mechanical model in depth. Finally we proposes and discusses objects for feature modeling and the way of digital generalization, and discusses the principles of DEM digital generalization. We also give the 1 ： 5 0000 and 1 ：1 0000 two series of DEM generalization maps, which achieve the desired results. Experimental results clearly show that： Only with digital generalization based on reliable DEMs expressing all terrain features, we can express DEM of required terrain feature on designated resolutions. That is no generalizing, there will be no DEM. The excellent consistency of theoretical analysis and experimental results, makes this paper believe that objects for feature modeling and digital generalization will bring qualitative change to DEM, and will be a promising new way to solve hundred-years problem of combination and generalization of contours and water portfolio.