Calculates the t_slope value for the Multiresolution Index of Valley Bottom Flatness (Gallant and Dowling, 2003) based on input DEM resolution. MRVBF identified valley bottoms based on classifying slope angle and identifying low areas by ranking elevation in respect to the surrounding topography across a range of DEM resolutions. The MRVBF algorithm was developed using a 25 m DEM, and so if the input DEM has a different resolution then the slope threshold t_slope needs to be adjusted from its default value of 16 in order to maintain the relationship between slope and DEM resolution. This function provides a convenient way to perform that calculation.
mrvbf_threshold(res)numeric, DEM resolution
numeric, t_slope value for MRVBF
mrvbf_threshold(res = 10)
#> [1] 27.9632