Gridded digital elevation data, often referred to as DEMs, are one of the most widely
available forms of environmental data. Topographic analysis of DEMs can take many
forms, but in hydrologic and geomorphologic applications it is typically used as a
surrogate for the spatial variation of hydrological conditions (topographic indices) and
flow routing. Here we report on a new flow routing algorithm and compare it to three
common classes of algorithms currently in widespread use. The advantage of the new
algorithm is that unrealistic dispersion on planar or concave hillslopes is avoided, whereas
multiple flow directions are allowed on convex hillslopes. We suggest that this new
triangular multiple flow direction algorithm (MD1) is more appropriate for a range of
flow routing and topographic index applications.
2007. Vol. 43, W04501- p.