A phenomenon-based approach to upslope contributing area and depressions in DEMs

Abstract

Description of the terrain surface through digital elevation models (DEMs) strongly depends on data collection methods and DEM data structures. For efficiency and availability reasons regular point distributions are most common, which yield artefacts such as depressions and preferential flow directions. These facts need to be considered when natural phenomena are modelled, as is shown for handling depressions and for estimation of flow paths and upslope contributing areas. Analysis of the main reasons for the occurrence of depressions shows that they usually better reflect the terrain than their surroundings. Thus, the most common remedial method of raising depressions is rejected. Algorithms that ‘cut’ a flow path from the depression through its bounding barrier are favoured instead. Several flow routing algorithms are evaluated for their behaviour in regular grids. It is shown that the multiple flow direction (mfd) algorithm that distributes water from a grid cell to the lower of its eight neighbours proportionally to their elevation differences (slope) exhibits correct flow directions and the best rotation invariance. It is suggested that the estimation of upslope contributing areas (TCAs) is undertaken in two steps: first, a high quality flow direction data set is derived by a well‐behaved mfd algorithm or by subgrid modelling of flow paths; secondly, the upslope contributing areas are obtained by counting the upslope elements. © 1998 John Wiley & Sons, Ltd.

A comparison of hillslope drainage area estimation methods using high‐resolution DEMs with implications for topographic studies of gullies

“…Sinks and depressions in DEMs can represent real terrain forms, but most are caused by data errors and need to be corrected prior to routing flow (Rieger, 1998). We assessed several hydrologic‐enforcement methods and their impact on estimated drainage areas and threshold analysis parameters.…”

Effects of LiDAR DEM Smoothing and Conditioning Techniques on a Topography‐Based Wetland Identification Model

“…Fill is perhaps the most commonly used and widely implemented conditioning technique. However, it has been suggested that it is incompatible with LiDAR data due to the inherent assumption that depressions are erroneous data points, rather than reflective of true surface features (Rieger, ; Woodrow et al, ). Fill removes depressions by adjusting the elevation of a depression pixel to match the elevation of the surrounding pixels (Jenson & Domingue, ; Planchon & Darboux, ; Wang & Liu, ).…”

Evaluating preprocessing methods of digital elevation models for hydrological modelling

“…The first breaching methods were introduced by Martz and Garbrecht () and Rieger (, ) and worked by identifying and breaching the lowest outflow in a sink if specific criteria of depth and breach length were meet. Studies by Soille (), Schwanghart and Kuhn (), and Schwanghart et al () propose breach algorithms based on the least cost auxiliary topography.…”