D-Infinity Approach

The D-infinity approach is employed to allow flow convergence and divergence to be more faithfully represented than the traditional D8 method so that water movement can be more robustly modeled.

The approach is based on representing flow direction as a single angle taken as the steepest downward slope on the eight triangular facets centered at each grid point.

Upslope area is then calculated by proportioning flow between two downslope pixels according to how close this flow direction is to the direct angles of the downslope pixel.