Least-cost Path in GIS Using an Accumulated Cost Surface and Slopelines

One of the most interesting and potentially useful applications of geographic information systems is the computation over a mapped space of the fastest, shortest, least-cost, or least-impact routes, given a map of the area with its frictions, costs and impediments. The problem is compared to the refraction of light, and a general solution is discussed, with algorithms to implement these. The problem is broken down into the computation of an accumulated cost surface integrated about a destination, and the generation of slope lines, which are the least-cost paths. Examples are presented from the sport of orinteering.