Effects of DEM resolution on the accuracy of gully maps in loess hilly areas

Wen Dai, Xin Yang, Jiaming Na, Jingwei Li, Dick Brus, Liyang Xiong, Guoan Tang, Xiaoli Huang

Research output: Contribution to journalArticleAcademicpeer-review

3 Citations (Scopus)

Abstract

Gully maps are important prerequisites for the study of gully erosion and land degradation. Many digital elevation model (DEM)-based methods have been proposed to enable automated gully mapping. However, the accuracy of a gully map derived from a DEM is inevitably affected by the DEM resolution. This study investigates the effects of DEM resolution on the accuracy of gully maps. A series of DEMs with resolutions of 0.1–10 m is employed to map gully areas. The effects of DEM resolution on the error in the mapped gully area and on the position error are described by regression models. The results from two catchments in hilly areas of the Loess Plateau in China are as follows. DEMs with resolutions of 0.5–2 m are the most suitable for gully mapping. Very high-resolution DEMs increase local position errors and over-predict the extents of gullies, whereas DEMs with coarser resolutions cause the downward migration of mapped gully boundaries, resulting in the under-prediction of gully areas. However, the effects of DEM resolution on gully maps are not constant but vary in space. The spatial disparities of the resolution effects are related to the gully morphology. The resolution effects on the gully maps in V-shaped gullies are stronger than those in U-shaped gullies. The findings of this study can be used to select a suitable DEM resolution for gully mapping in loess hilly areas and contribute to understanding the characterization of gullies by using DEMs.

LanguageEnglish
Pages114-125
Number of pages12
JournalCatena
Volume177
DOIs
Publication statusPublished - 1 Jun 2019

Fingerprint

gully
loess
digital elevation model
effect
gully erosion
land degradation

Keywords

  • Accuracy assessment
  • DEM resolution
  • Gully mapping
  • The Loess Plateau of China
  • Uncertainty

Cite this

Dai, Wen ; Yang, Xin ; Na, Jiaming ; Li, Jingwei ; Brus, Dick ; Xiong, Liyang ; Tang, Guoan ; Huang, Xiaoli. / Effects of DEM resolution on the accuracy of gully maps in loess hilly areas. In: Catena. 2019 ; Vol. 177. pp. 114-125.
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abstract = "Gully maps are important prerequisites for the study of gully erosion and land degradation. Many digital elevation model (DEM)-based methods have been proposed to enable automated gully mapping. However, the accuracy of a gully map derived from a DEM is inevitably affected by the DEM resolution. This study investigates the effects of DEM resolution on the accuracy of gully maps. A series of DEMs with resolutions of 0.1–10 m is employed to map gully areas. The effects of DEM resolution on the error in the mapped gully area and on the position error are described by regression models. The results from two catchments in hilly areas of the Loess Plateau in China are as follows. DEMs with resolutions of 0.5–2 m are the most suitable for gully mapping. Very high-resolution DEMs increase local position errors and over-predict the extents of gullies, whereas DEMs with coarser resolutions cause the downward migration of mapped gully boundaries, resulting in the under-prediction of gully areas. However, the effects of DEM resolution on gully maps are not constant but vary in space. The spatial disparities of the resolution effects are related to the gully morphology. The resolution effects on the gully maps in V-shaped gullies are stronger than those in U-shaped gullies. The findings of this study can be used to select a suitable DEM resolution for gully mapping in loess hilly areas and contribute to understanding the characterization of gullies by using DEMs.",
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Dai, W, Yang, X, Na, J, Li, J, Brus, D, Xiong, L, Tang, G & Huang, X 2019, 'Effects of DEM resolution on the accuracy of gully maps in loess hilly areas', Catena, vol. 177, pp. 114-125. https://doi.org/10.1016/j.catena.2019.02.010

Effects of DEM resolution on the accuracy of gully maps in loess hilly areas. / Dai, Wen; Yang, Xin; Na, Jiaming; Li, Jingwei; Brus, Dick; Xiong, Liyang; Tang, Guoan; Huang, Xiaoli.

In: Catena, Vol. 177, 01.06.2019, p. 114-125.

Research output: Contribution to journalArticleAcademicpeer-review

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AU - Dai, Wen

AU - Yang, Xin

AU - Na, Jiaming

AU - Li, Jingwei

AU - Brus, Dick

AU - Xiong, Liyang

AU - Tang, Guoan

AU - Huang, Xiaoli

PY - 2019/6/1

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N2 - Gully maps are important prerequisites for the study of gully erosion and land degradation. Many digital elevation model (DEM)-based methods have been proposed to enable automated gully mapping. However, the accuracy of a gully map derived from a DEM is inevitably affected by the DEM resolution. This study investigates the effects of DEM resolution on the accuracy of gully maps. A series of DEMs with resolutions of 0.1–10 m is employed to map gully areas. The effects of DEM resolution on the error in the mapped gully area and on the position error are described by regression models. The results from two catchments in hilly areas of the Loess Plateau in China are as follows. DEMs with resolutions of 0.5–2 m are the most suitable for gully mapping. Very high-resolution DEMs increase local position errors and over-predict the extents of gullies, whereas DEMs with coarser resolutions cause the downward migration of mapped gully boundaries, resulting in the under-prediction of gully areas. However, the effects of DEM resolution on gully maps are not constant but vary in space. The spatial disparities of the resolution effects are related to the gully morphology. The resolution effects on the gully maps in V-shaped gullies are stronger than those in U-shaped gullies. The findings of this study can be used to select a suitable DEM resolution for gully mapping in loess hilly areas and contribute to understanding the characterization of gullies by using DEMs.

AB - Gully maps are important prerequisites for the study of gully erosion and land degradation. Many digital elevation model (DEM)-based methods have been proposed to enable automated gully mapping. However, the accuracy of a gully map derived from a DEM is inevitably affected by the DEM resolution. This study investigates the effects of DEM resolution on the accuracy of gully maps. A series of DEMs with resolutions of 0.1–10 m is employed to map gully areas. The effects of DEM resolution on the error in the mapped gully area and on the position error are described by regression models. The results from two catchments in hilly areas of the Loess Plateau in China are as follows. DEMs with resolutions of 0.5–2 m are the most suitable for gully mapping. Very high-resolution DEMs increase local position errors and over-predict the extents of gullies, whereas DEMs with coarser resolutions cause the downward migration of mapped gully boundaries, resulting in the under-prediction of gully areas. However, the effects of DEM resolution on gully maps are not constant but vary in space. The spatial disparities of the resolution effects are related to the gully morphology. The resolution effects on the gully maps in V-shaped gullies are stronger than those in U-shaped gullies. The findings of this study can be used to select a suitable DEM resolution for gully mapping in loess hilly areas and contribute to understanding the characterization of gullies by using DEMs.

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KW - Gully mapping

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