Simple dem-based methods to delineate channel networks for hydrogeomorphological mapping

Kohei Matsunaga, Tomoki Nakaya, Toshihiko Sugai

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

To delineate channel networks from DEMs regardless of landform type, this article proposes a new method using slope-weighted flow accumulation. To validate the method, SRTM-3, a global DEM dataset with a resolution of approximately 90 m, was used for analysis of the Loess Plateau, China. Channel networks delineated with and without slope-weighted flow accumulation were derived in both uplands and hilly lands for comparison. In the weighted flow accumulation method, the thresholds for delineating the channels were defined by detecting a turning point in the frequency distribution of the weighted flow accumulation function or by visual similarity with drainage channels extracted from topographic maps. The channel networks delineated with weighting showed closer correlation with a topographic map than the channel networks without weighting, despite the differences in thresholds. Moreover, the channel networks delineated with weighting represented the differences between landform types, while the channel networks without weighting did not. Weighting on the basis of the slope angle shows promise as a general channel delineation method which reflects the actual topography due to its hydrogeomorphological functions.

Original languageEnglish
Pages (from-to)87-103
Number of pages17
JournalTransactions in GIS
Volume13
Issue number1
DOIs
Publication statusPublished - 2009 Apr 1
Externally publishedYes

Keywords

  • Channel network
  • DEM
  • Hydro geomorphology
  • Slope angle
  • Thres hold

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)

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