Differences in topographic characteristics computed from 100- and 1000-m resolution digital elevation model data

Abstract

Abstract:Topographic characteristics computed from 100-and 1000-m resolution digital elevation model (DEM) data are compared for 50 locations representing varied terrain in the conterminous USA. The topographic characteristics are three parameters used extensively in hydrological research and modelling Ð slope (S), speci®c catchment area (A s ) and a wetness index computed as the logarithm of the speci®c catchment area divided by slope [ln(A s /S)]. Slope values computed from 1000-m DEMs are smaller than those computed from 100-m DEMs; speci®c catchment area and the wetness index are larger for the 1000-m DEMs compared with the 100-m DEMs. Most of the dierences between the 100-and 1000-m resolution DEMs can be attributed to terrain-discretization eects in the computation of the topographic characteristics and are not the result of smoothing or loss of terrain detail in the coarse data. In general, the terrain-discretization eects are greatest on at terrain with long length-scale features, and the smoothing eects are greatest on steep terrain with short length-scale features. For the most part, the dierences in the average values of the topographic characteristics computed from 100-and 1000-m resolution DEMs are predictable; that is, biases in the mean values for the characteristics computed from a 1000-m DEM can be corrected with simple linear equations.

Effect of Contour Intervals and Grid Cell Size on the Accuracy of DEMs and Slope Derivatives

“…This gives the users more flexibility in selecting the proper resolution based on the purpose of using the results. This agrees with findings reported by Wolock and McCabe (2000) and Kienzle (2004), who stated that when the sampling density decreases (as the terrain becomes flatter), coarser DEMs can be used for the analysis of slope.…”

Evaluation of digital channel network derivation methods in a glaciated subalpine catchment

“…For D8, as DEM cell size increases mean slope increases. While the effect is slight, it contrasts with findings of prior studies (Zhang and Montgomery, 1994;Wolock and McCabe, 2000).…”

Slope Scaling Effect and Slope-Conversion-Atlas for Typical Water Erosion Regions in China

“…(2) The similarity and difference of slope conversion atlas in different sample areas coexist under the same resolution. Except for SPSR, the similarity between different sample areas is relatively large, which is closely related to the resolution and the landform type, and is consistent with the experiments from local experts [23,29]. During the process of conversion, the proportion of conversion from DEM30 and DEM90 to the middle and low grades of DEM10 (0 • -25 • ) is large.…”