Detachment Proportional to Slope Steepness Factor
Not affected by any other variable
This figure shows the slope steepness factor relationship used in RUSLE2.  Detachment is proportional to the slope steepness factor.  It is not a function of anything in contrast to the slope length factor.

However,in actuality the slope steepness is a function of the ratio of rill to interrill erosion but the science isn’t sufficient to develop a working relationship.