This tool calculates the density of edges, or breaks-in-slope within an input digital elevation model (DEM). A break-in-slope occurs between two neighbouring grid cells if the angular difference between their normal vectors is greater than a user-specified threshold value (norm_diff). edge_density calculates the proportion of edge cells within the neighbouring window, of square filter dimension filter, surrounding each grid cell. Therefore, EdgeDensityis a measure of how complex the topographic surface is within a local neighbourhood. It is therefore a measure of topographic texture. It will take a value near 0.0 for smooth sites and 1.0 in areas of high surface roughness or complex topography.

The distribution of edge_density is highly dependent upon the value of the norm_diff used in the calculation. This threshold may require experimentation to find an appropriate value and is likely dependent upon the topography and source data. Nonetheless, experience has shown that edge_density provides one of the best measures of surface texture of any of the available roughness tools.

See Also

circular_variance_of_aspect, multiscale_roughness, surface_area_ratio, ruggedness_index

Function Signature

def edge_density(self, dem: Raster, filter_size: int = 11, normal_diff_threshold: float = 5.0, z_factor: float = 1.0) -> Raster: ...

Project Links

WbW Homepage User Manual Support WbW