Multiscale Analysis of Topographic Surface Roughness in the Midland Valley, Scotland

Abstract

Surface roughness is an important geomorphological variable which has been used in the earth and planetary sciences to infer material properties, current/past processes and the time elapsed since formation. No single definition exists, however within the context of geomorphometry we use surface roughness as a expression of the variability of a topographic surface at a given scale, where the scale of analysis is determined by the size of the landforms or geomorphic features of interest. Six techniques for the calculation of surface roughness were selected for an assessment of the parameter's behaviour at different spatial scales and dataset resolutions. Area ratio operated independently of scale, providing consistent results across spatial resolutions. Vector dispersion produced results with increasing roughness and homogenisation of terrain at coarser resolutions and larger window sizes. Standard deviation of residual topography tends to highlight local features and doesn't detect regional relief. Standard deviation of elevation correctly identified breaks-of-slope and was good at detecting regional relief. Standard deviation of slope (SDslope) also correctly identified smooth sloping areas and breaks-of-slope, providing the best results for geomorphological analysis. Standard deviation of profile curvature identified the breaks-of-slope, although not as strongly as SDslope and it is very sensitive to noise and spurious data. In general, SDslope offered good performance at a variety of scales, whilst the simplicity of calculation is perhaps its single greatest benefit.

Quantitative studies of the morphology of the south Poland using Relief Index (RI)

“…(Table 1). * Area numbering is the same as in Figure 1 The other places (11)(12)(13)(14)(15)(16) are located in a strip of uplands. Sites 11-14 belong to Silesian-Cracow Upland, which is the Palaeozoic-Mesozoic monocline with rocks of varying resistance that form the characteristic structural relief [43].…”

“…Based on a Hobson method [12] developed for measuring surface roughness in geomorphology Sappington et al [13] created a Vector Ruggedness Measure (VRM) to be used in a GIS that incorporates the heterogeneity of both slope and aspect. Other methods were proposed by Jenness [10], who quantifies ruggedness as the ratio of 3-dimensional surface area to planar surface area, or Grohmann et al [14] -surface roughness as an expression of the variability of a topographic surface at a given scale, where the scale of analysis is determined by the size of the landforms or geomorphic features of interest. Another interesting indicator was Topographic Wetness Index (TWI) by Beven and Kirkby [15] which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes [16][17][18][19].…”

A Path Toward the Use of Trail Users’ Tweets to Assess Effectiveness of the Environmental Stewardship Scheme: An Exploratory Analysis of the Pennine Way National Trail

“…A Ruggedness Index was derived from the DEM (Pope, 2009) through calculation of the standard deviation of elevation SDelev (Cooley, Unknown;Ascione et al, 2008;Grohmann et al, 2011). SDelev was selected as it can detect regional relief at a variety of scales and is computationally simple to calculate (Grohmann et al, 2011).…”

“…SDelev was selected as it can detect regional relief at a variety of scales and is computationally simple to calculate (Grohmann et al, 2011). The calculation of SDelev was done using the ArcMap Focal Statistics tool (ESRI, 2011) with a 3 x 3 cell raster window (equivalent to 270 m on the ground).…”

Influence of cell size on volume calculation using digital terrain models: A case of coastal dune fields

“…Resampling was achieved by calculating the mean elevation value for a given resolution. This resampling simulates data acquired by sensors with different spatial resolutions; therefore, it is appropriate that the elevation value is the average of the actual elevations within the cell (Grohmann et al, 2010).…”