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Assessment of multiresolution segmentation for delimiting drumlins in digital elevation models

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journal contribution
posted on 30.07.2014, 13:10 by Clemens Eisank, Mike J. Smith, John Hillier
Mapping or "delimiting" landforms is one of geomorphology's primary tools. Computer-based techniques such as land-surface segmentation allow the emulation of the process of manual landform delineation. Land-surface segmentation exhaustively subdivides a digital elevation model (DEM) into morphometrically-homogeneous irregularly-shaped regions, called terrain segments. Terrain segments can be created from various land-surface parameters (LSP) at multiple scales, and may therefore potentially correspond to the spatial extents of landforms such as drumlins. However, this depends on the segmentation algorithm, the parameterization, and the LSPs. In the present study we assess the widely used multiresolution segmentation (MRS) algorithm for its potential in providing terrain segments which delimit drumlins. Supervised testing was based on five 5-m DEMs that represented a set of 173 synthetic drumlins at random but representative positions in the same landscape. Five LSPs were tested, and four variants were computed for each LSP to assess the impact of median filtering of DEMs, and logarithmic transformation of LSPs. The testing scheme (1) employs MRS to partition each LSP exhaustively into 200 coarser scales of terrain segments by increasing the scale parameter (SP), (2) identifies the spatially best matching terrain segment for each reference drumlin, and (3) computes four segmentation accuracy metrics for quantifying the overall spatial match between drumlin segments and reference drumlins. Results of 100 tests showed that MRS tends to perform best on LSPs that are regionally derived from filtered DEMs, and then log-transformed. MRS delineated 97% of the detected drumlins at SP values between 1 and 50. Drumlin delimitation rates with values up to 50% are in line with the success of manual interpretations. Synthetic DEMs are well-suited for assessing landform quantification methods such as MRS, since subjectivity in the reference data is avoided which increases the reliability, validity and applicability of results. © 2014 The Authors.

Funding

This research has been kindly supported by the Austrian Science Fund through the project “KnowLand—Knowledge and Semantics in Landform Classification” (FWF-P23818-N23), and through the “Doctoral College GIScience” (FWF-DK1237-N23).

History

School

  • Social Sciences

Department

  • Geography and Environment

Published in

Geomorphology

Volume

214

Pages

452 - 464

Citation

EISANK, C., SMITH, M.J. and HILLIER, J.K., 2014. Assessment of multiresolution segmentation for delimiting drumlins in digital elevation models. Geomorphology, 214, pp. 452 - 464.

Publisher

© The Authors. Published by Elsevier B.V

Version

VoR (Version of Record)

Publication date

2014

Notes

This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/).

ISSN

0169-555X

Language

en

Exports