Which factor(s) of RUSLE must be changed to recalculate risk when the construction duration has changed?

• A. A
• B. C
• C. R
• D. LS

Answer: (C)

The key idea is that only the soil surface protection changes when construction duration changes. In the RUSLE product A = R × K × LS × C × P, the factors R, K, and LS are properties of the rainfall, soil, and terrain and do not depend on how long construction lasts. The factor that captures how well the surface is protected, such as temporary cover, mulch, or other control measures, is the cover-management factor. If the site remains the same in rainfall, soil, and slope, but the duration of exposure changes, you adjust the cover-management factor to reflect the changed protection. Longer exposure typically means less cover, so C would change to indicate higher potential erosion; shorter exposure with good cover would lower C. The other factors stay the same unless their underlying conditions change.