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Residual relief separation: digital elevation model enhancement for geomorphological mapping

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journal contribution
posted on 2013-08-23, 10:13 authored by John HillierJohn Hillier, Mike J. Smith
Geomorphologically mapped data form a primary set of observations that can be used to infer former environmental conditions. Thus, objective and consistent mapping of landforms from remotely sensed data (e.g. satellite imagery, digital elevation models (DEMs)) is paramount for reconstructing palaeoenvironments. This paper proposes a technique, ‘residual relief separation’, to enhance landforms in DEMs prior to visualization and digital mapping. This is applied to a ∼600 km2 region surrounding Lough Gara, Ireland, where drumlins (∼200 m wide) overlie a regional relief of hills (∼10 km wide). Here, residual relief separation uses this difference in width-scale. Regional relief is approximated by a 1 km wide median filter, then subtracted to leave the drumlins in a ‘residual’ topography. In a second step, the residual relief is normalized to allow for amplitude variations in the drumlins across the area (∼5–40 m high). Finally, visualization uses a simple black-to-white colour scale for height. Although not numerically outperforming other visualization techniques, this method performs equally well, and as the data are not ‘illuminated’ there is no azimuthal bias. Additional benefits include the relatively simple calculation, intuitive visual comprehension, no emphasis of noise, and the possibility of using any desired visualization technique after the landscape has been topographically manipulated.

History

School

  • Social Sciences

Department

  • Geography and Environment

Citation

HILLIER, J.K. and SMITH, M., 2008. Residual relief separation: digital elevation model enhancement for geomorphological mapping. Earth Surface Processes and Landforms, 33 (14), pp. 2266 - 2276.

Publisher

© John Wiley & Sons, Ltd.

Version

  • AM (Accepted Manuscript)

Publication date

2008

Notes

This article was published in the journal, Earth Surface Processes and Landforms [© John Wiley & Sons, Ltd.] and the definitive version is available at: http://dx.doi.org/10.1002/esp.1659

ISSN

0197-9337

Language

  • en