An intrinsic property of the soil expressing its propensity to be eroded by detachment of soil particles and soil aggregates which then become sediment particles in the flowing water. The actual physical processes of detachment are not well understood by scientists so it is usually determined experimentally or empirically. Relative erodibility as used herein is a dimensionless value expressing soil erodibility. A soil with a relative erodibility of 2.0 is twice as erodible as a soil with a value of 1.0.
The variable in WILSIM that can be adjusted to simulate differing rates of erosion for differing surface rock types; examples in the natural landscape would include "soft" sedimentary rock that is susceptible to weathering and erosion as compared to more durable rock that erodes slowly;