Topographic parameterization in continental hydrology: a study in scale

Armstrong, Robert N. and Martz, Lawrence W. (2003) Topographic parameterization in continental hydrology: a study in scale. Hydrological Processes, 17 18: 3763-3781. doi:10.1002/hyp.1352

Author Armstrong, Robert N.
Martz, Lawrence W.
Title Topographic parameterization in continental hydrology: a study in scale
Journal name Hydrological Processes   Check publisher's open access policy
ISSN 1099-1085
Publication date 2003-12-30
Sub-type Article (original research)
DOI 10.1002/hyp.1352
Open Access Status Not Open Access
Volume 17
Issue 18
Start page 3763
End page 3781
Total pages 19
Place of publication Chichester, West Sussex, United Kingdom
Publisher John Wiley & Sons
Language eng
Abstract Digital elevation models (DEMs) are useful and popular tools from which topographic parameters can be quickly and efficiently extracted for various hydrologic applications. DEMs coupled with automated methods for extracting topographic information provide a powerful means of parameterizing hydrologic models over a wide range of scales. However, choosing appropriate DEM scales for particular hydrologic modelling applications is limited by a lack of understanding of the effects of scale and grid resolution on land-surface representation. The scale effects of aggregation on square-grid DEMs of two continental-scale basins are examined. Base DEMs of the Mackenzie and Missouri River basins are extracted from the HYDRO1k DEM of North America. Successively coarser grids of 2, 4, 8, … 64 km were generated from the ‘base’ DEMs using simple linear averaging. TOPAZ (Topographic Parameterization) was applied to the base and aggregated DEMs using constant critical source area and minimum source channel length values to extract topographic variables at varying scales or resolutions. The effects of changing DEM resolution are examined by considering changes in the spatial distribution and statistical properties of selected topographic variables of hydrological importance. The effects of increasing grid size on basin and drainage network delineation, and derived topographic variables, tends to be non-linear. In particular, changes in overall basin extent and drainage network configuration make it impractical to apply a simple scaling function to estimate variable values for fine-resolution DEMs from those derived from coarse-resolution DEMs. Results also suggest the resolution to which a DEM can be reduced by aggregation and still provide useful topographic information for continental-scale hydrologic modelling is that at which the mean hydraulic slope falls to approximately 1%. In this study, that generally occurred at a resolution of about 10 km.
Keyword Digital elevation model
Hydrological modelling
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Queensland Alliance for Agriculture and Food Innovation
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Created: Thu, 09 Jun 2016, 21:36:09 EST by Robert Armstrong on behalf of Centre for Plant Science