HR: 1340h
AN: H43E-1666    [Abstracts]
TI: Can Anything be Done to Improve the Geomorphological Value of off-the-Shelf DEM Products?
AU: * Milledge, D G
EM: d.g.milledge@durham.ac.uk
AF: Durham University, Department of Geography Science Laboratories South Road, Durham, DH1 3LE, United Kingdom
AU: Lane, S
EM: s.n.lane@durham.ac.uk
AF: Durham University, Department of Geography Science Laboratories South Road, Durham, DH1 3LE, United Kingdom
AU: Warburton, J
EM: jeff.warburton@durham.ac.uk
AF: Durham University, Department of Geography Science Laboratories South Road, Durham, DH1 3LE, United Kingdom
AB: Elevation models are a fundamental requirement for distributed, process-based modelling in hydrology and geomorphology. The increased accessibility of high resolution elevation data makes them an easily accessible and potentially powerful tool in many studies. However, the quality of these data are closely linked to the processes used to derive them. These processes are rarely explicit and can be difficult to untangle. The associated errors often propagate into geomorphic variables in a highly non-linear fashion. This study examines the processes of DEM generation, the associated error and its effect on geomorphic variables in relation to modelling shallow landslide processes. Using data collected from digital photogrammetry and Airborne Interferometric Synthetic Aperture Radar (IfSAR), we show that for the same raw data, processing techniques can alter vertical precision in the elevation model by an order of magnitude. We calculate the hydrogeomorphic variables: slope, contributing area, topographic index and probability of slope instability from DEMs with different error properties to demonstrate the resulting variablilty. Based on these results we make a series of recommendations for minimising uncertainty in the DEM generation process with specific reference to airborne IfSAR and digital photogrammetry.
DE: 1640 Remote sensing (1855)
DE: 1818 Evapotranspiration
DE: 1855 Remote sensing (1640)
DE: 1894 Instruments and techniques: modeling
SC: Hydrology [H]
MN: 2007 Fall Meeting