Comparison of popular methods for simplifying terrain based on grid DEMs

It is very necessary to construct multi-scale DEMs. And terrain simplification algorithms based on DEMs of high resolution offer an effective solution to approach multi-scale DEMs. Taking Very Important Points and Three- Dimensional Douglas-Peucker as examples, this paper evaluates popular methods for simplifying terrain from dense grid DEMs by extracting and comparing elevation statistical parameters, elevation autocorrelation information, terrain structural characteristics and terrain basic factors. The results show that there are much difference of the DEMs generated by the two methods. Users of DEMs should be aware of the strengths and weaknesses of the different methods in addition to their own special purpose before producing multi-scale DEMs.