topoDistance: topoDistance: A package for calculating topographic paths and...

Description Details


The topoDistance package provides functions for calculating topographic distances and identifying and plotting topographic paths. Topographic distances can be calculated along shortest topographic paths or topographic least cost paths. Functions can map topographic paths on colored or hillshade maps and plot topographic cross sections (elevation profiles) for the paths.


Unlike the topographically-corrected distances calculated by some GIS software, which just adjust for elevational changes along a straight-line path between points, topoDistance calculates the distance along the shortest topographic path between points, which is more likely to realistically reflect biological movement on a topographically complex landscape.

Topographic distances are calculated as the hypotenuse of the horizontal and vertical distances between cells on an elevation raster. These distances are assignd to the weights of vertices between the nodes for each cell on a landscape graph, and functions from the gdistance and igraph packages are used to find the shortest path between nodes. For topographic least cost paths, resistance distance weights are multiplied by the topographic distance weights to get topographically corrected least cost path distances.

topoDistance documentation built on Aug. 2, 2019, 5:05 p.m.