Representation of Eroded Geomorphological Features on the Digital Elevation Model(DEM)

The eroded geomorphological feature lines such as plateau edge lines and gully edge lines alone with the discontinuous terrain are obviously existing in the gully area of the southern Loess Plateau,but the representation of this topographical feature in the DEM surface lacks of necessary research for how to represent that topographical feature lines.This paper selects Changwu County as the study region,and digitizes the 1∶50 000 topographic maps(including contours,elevation points and rivers thematic layers) and its hand-drawn topographic features lines(including plateau sidelines,gully edge lines and the slope toe lines).This research established four rules grid DEMs with 10 m resolution,respectively using multi-element structuring TIN method and Hutchinson interpolation method,in the case of with or without topographic feature lines participation interpolation,and comparative analysis terrain attributes such as the surface elevation,slope and curvature characteristics between the four DEMs,by map algebra and frequency statistics method.The results show that,in ANUDEM interpolation(Hutchinson algorithm) case,representation of topographical feature in the DEM surface with topographical feature lines can be significantly improved,avoiding the flat triangle and taking into account both the smoothness and continuity of the terrain features,while topographical feature lines have useless impact on the DEM established by TIN.