Analysis Of The Expression Ability To Loess Erosion Terrain Using 1"SRTM

1 "SRTM data product has become a high-precision,large-scale new data source for quantitative assessment of the erosional topography over the Loess Plateau and at the same time,it has been used for many different applications in the field of geomorphology.In this context,the two nearresolution DEMs originating from the SRTM and Hc-DEM are widely used.In order to compare the difference of topographic expression between the SRTM data product and the HcDEM generated by 1: 50000 topographic maps in the loess erosion area,10 large samples are selected from south to north in Loess Plateau,China.1" SRTM and Hc-DEM were estimated from two aspects of topographic attributes(elevation,slope,aspect and slope length)and topographic features(peak point,pipeline and watershed boundary)Variation of Data Sources in Loess Erosion Area.The results show that the ability of two DEMs to express Loess erosion terrain is closed,(1)The expression of 1??SRTM on terrain is close to the DEM generated by the 1:50000 topographic map,but overall the DEM generated by the 1?50,000 topographic map has better expression of surface morphology.(2)No matter whether it is on the section of the large area or the sample area,SRTM can express the variability of elevation.Therefore,we can use SRTM to replace Hc-DEM in the analysis of terrain elevation changes.(3)Analysis of surface process: Considering the effect of slope attenuation and slope length expansion in hilly areas based on SRTM,Hc-DEM has better terrain expression than SRTM.(4)Discrete Terrain Elements: The number of peaks and gully density calculated based on Hc-DEM is slightly larger,but the gap between the two is smaller.