Relative packing ration. The ratio of actual to optimum packing ratio.
A relative packing ratio less than one indicates a packing ratio less than the optimum packing ratio; a value greater than one indicates a fuelbed that is more dense than optimum. Spread rate and fireline intensity do not necessarily reach a peak when relative packing ratio is one, because optimum packing ratio optimizes the intermediate model term reaction velocity, not spread rate or fireline intensity.
