A Research On The Topographical Information Content Of DEMs & Topographical Analysis Applicability——Take Example For 1:50000 Scaled DEMs In The Loess Plateau

Currently, DEMs of different scale level were constructed under NSDI production project. The existing DEMs have played a key roll in various fields of our national economy. Being a sub-research project of national nature science fund project "The Uncertainty of DEMs and Their Influence to Applications", this research focus mainly on the concept, theory and methodology of DEM spatial information content. By means of information content quantitative index, the accuracy and applicability of DEM is revealed. The basic concept of terrain information content is proposed after an overall review of existing research achievement. Applying a series of analysis and data processing method, like math-analysis, mathematical statistics, comparative, error visualizing, this paper carefully investigated the terrain information content characteristic of DEMs of 1:50000 map scale of Loess Plateau Area. Taking slope gradient, aspect, curvature and stream channel networks as examples, an overall analysis was made to explore the accuracy and application feasibility in this paper.Experiment results show: ㏕he theory and method of Information content could play an important role in the case study on the accuracy and application of DEM. (2)In the loess plateau area, there are much difference between 5m resolution DEMs of 1:10000 map scale and 25m resolution DEMs of 1:50000 map scale while gathering terrain characteristic information, and yet the spatial structure of DEM error have discipline and measurability on statistics. (?The results could offer fundamentals and methods to people on their work to research the terrain information content of DEMs with different scale level. It also can be assistance to establish concerned criterion and standard.