Home About Browse Search
Svenska


Effect of DEM-smoothing and -aggregation on topographically-based flow directions and catchment boundaries

Erdbruegger, Jana and van Meerveld, Ilja and Bishop, Kevin and Seibert, Jan (2021). Effect of DEM-smoothing and -aggregation on topographically-based flow directions and catchment boundaries. Journal of Hydrology. 602 , 126717
[Research article]

[img] PDF
11MB

Abstract

It is generally assumed that, in humid climates, the groundwater table is a subdued copy of the surface topography. However, the general groundwater table is unlikely to be affected by the microtopography as seen in high-resolution Digital Elevation Models (DEMs). So far, there has been little guidance on the best resolution DEM to use to determine the shape of the water table or the direction of shallow groundwater flow in headwater catchments. We, therefore, looked at the effects of DEM-smoothing and -aggregation on the calculated flow directions and derived catchment boundaries, and identified areas and landscape features for which the calculated flow directions are particularly sensitive to DEM smoothing or aggregation. For > 40 % of the area of the Krycklan study catchment, the calculated flow directions depend strongly on the degree of smoothing or aggregation of the DEM. The four main landscape features for which DEM smoothing or aggregation strongly affected the calculated flow directions were: local slopes in the opposite direction of the general slope, flat areas, ridges, and incised streambanks. To determine the effects of the changing flow directions on the derived catchment boundaries for the smoothed and aggregated DEMs, we calculated the drainage area for 40 locations, representing the outlets of catchments of varying sizes. The shape and size of the catchments of first-order streams were most affected by the processing of the DEM. These streams were often almost completely smoothed out during the DEM preprocessing steps. These shifts in catchment boundaries and drainage area would have a large effect on the water balance. This study thus highlights the need to carefully consider the effects of DEM smoothing or -aggregation on the calculated flow directions and drainage areas.

Authors/Creators:Erdbruegger, Jana and van Meerveld, Ilja and Bishop, Kevin and Seibert, Jan
Title:Effect of DEM-smoothing and -aggregation on topographically-based flow directions and catchment boundaries
Series Name/Journal:Journal of Hydrology
Year of publishing :2021
Volume:602
Article number:126717
Number of Pages:14
Publisher:ELSEVIER
ISSN:0022-1694
Language:English
Publication Type:Research article
Article category:Scientific peer reviewed
Version:Published version
Copyright:Creative Commons: Attribution 4.0
Full Text Status:Public
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 105 Earth and Related Environmental Sciences > Oceanography, Hydrology, Water Resources
Keywords:Terrain analysis, DEM resolution, Groundwater table, Flow directions, Catchment hydrology, Boreal catchment
URN:NBN:urn:nbn:se:slu:epsilon-p-114249
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-p-114249
Additional ID:
Type of IDID
DOI10.1016/j.jhydrol.2021.126717
Web of Science (WoS)000704794400019
ID Code:26023
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Dept. of Aquatic Sciences and Assessment
Deposited By: SLUpub Connector
Deposited On:04 Nov 2021 15:27
Metadata Last Modified:04 Nov 2021 15:31

Repository Staff Only: item control page

Downloads

Downloads per year (since September 2012)

View more statistics

Downloads
Hits