|Martz, Lawrence - UNIV OF SASKATCHEWAN|
Submitted to: Environmental Systems Research Institute Users Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 26, 1999
Publication Date: July 26, 1999
Interpretive Summary: The scientific and engineering communities rely heavily on computer models to quantify hydrologic and environmental processes and impacts. Advances in computer technology and availability of landscape topography in digital format, called Digital Elevation Models (DEM), provide greatly expanded application potentials. However, as with most data, DEMs have short comings and limitations that must be understood before using the data in water resources modeling. This paper reviews capabilities and limitations of DEMs for water resources modeling support. Specifically, issues of data availability, quality and resolution, as well as capabilities and limitations in automated derivation of topographic landscape features from DEMs, are discussed. Also, the latest research results regarding the derivation of distributed subcatchment properties are discussed. It was generally concluded that the increasing quality and resolution of new DEM products and new computer processing methodologies will lead to an increased use of DEM in water resources investigations.
Technical Abstract: Topography plays an important role in the distribution and flux of water and energy within natural landscapes. The automated extraction of topographic parameters from DEMs is recognized as a viable alternative to traditional surveys and manual evaluation of topographic maps, particularly as the quality and coverage of DEM data increases. The capabilities and limitations of DEMs for use in water resources model applications are reviewed. Specifically, data availability, quality and resolution are discussed from an application perspective. Issues related to the automated extraction of topographic and drainage information from DEMs is presented. These include the identification of drainage in the presence of pits and flat areas in the DEM, the determining role of channel source definition in drainage network configuration, and network analysis capabilities for raster networks. Findings on the latest research results regarding the reduction of distributed subcatchment properties into a representative value for the subcatchments are also presented. Increasing quality and resolution of DEM products, new raster processing methodologies and expanding GIS capabilities and linkages with water resources models are expected to lead to a heavier reliance on DEMs as a source of topographic and surface drainage information.