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

Hydrological Processes

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DOI: 10.1002/(SICI)1099-1085(20000430)14:6<987::AID-HYP980>3.0.CO;2-A

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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 - slope (S), specific catchment area (A(s)) and a wetness index computed as the logarithm of the specific 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; specific catchment area and the wetness index are larger for the 1000-m DEMs compared with the 100-m DEMs. Most of the differences between the 100- and 1000-m resolution DEMs can be attributed to terrain-discretization effects 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 effects are greatest on flat terrain with long length-scale features, and the smoothing effects are greatest on steep terrain with short length-scale features. For the most part, the differences 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. Copyright (C) 2000 John Wiley and Sons, Ltd.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 - slope (S), specific catchment area (As) and a wetness index computed as the logarithm of the specific catchment area divided by slope [In(As/S)]. Slope values computed from 1000-m DEMs are smaller than those computed from 100-m DEMs; specific catchment area and the wetness index are larger for the 1000-m DEMs compared with the 100-m DEMs. Most of the differences between the 100- and 1000-m resolution DEMs can be attributed to terrain-discretization effects 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 effects are greatest on flat terrain with long length-scale features, and the smoothing effects are greatest on steep terrain with short length-scale features. For the most part, the differences 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.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Differences in topographic characteristics computed from 100- and 1000-m resolution digital elevation model data
Series title:
Hydrological Processes
DOI:
10.1002/(SICI)1099-1085(20000430)14:6<987::AID-HYP980>3.0.CO;2-A
Volume
14
Issue:
6
Year Published:
2000
Language:
English
Publisher:
John Wiley & Sons Ltd
Publisher location:
Chichester, United Kingdom
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Hydrological Processes
First page:
987
Last page:
1002
Number of Pages:
16