Estimating Slope From Raster Data:
A Test Of Eight Different Algorithms
In Flat, Undulating And Steep Terrain
Author(s)
J. Tang & P. Pilesjö
Abstract
Eight frequently used slope algorithms based on a DEM (Digital Elevation
Model) have been compared in flat, gently sloping/undulating, and steep terrain
in order to investigate differences in estimated results. The matter of
scale/resolution has not been considered, and the focus has not been on
comparing the estimates with \“ground truth” data but on comparisons between
the different algorithms. Pair-wise statistical tests have been carried out to detect
significant differences between the methods in general, and also between
different terrains. In this way, we make explanations and recommendations
regarding these differences and \“best practice” depending on data/terrain.
Keywords: DEM, slope, algorithm, terrain.
1 Introduction
The estimation of slope from a regularly-gridded DEM is a common procedure
in terrain analysis. Some authors have evaluated the accuracy of various slope
algorithms, using different assessment methodologies. The results of the slope
estimations are always dependent on the generalization/resolution and quality of
the DEM. Even though a number of studies, based on different types of \“ground
truth” data, have been presented, there are no reports with the aim to investigate
possible differences between different slope algorithms and their sensitivity in
different terrain. In this paper, eight frequently used slope algorithms are
evaluated against each other. They are applied in three different terrain forms,
namely flat, gently sloping/undulating, and steep terrain. The estimated slope
Keywords
DEM, slope, algorithm, terrain
Related Book
Other papers in this volume
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