Enter the erosivity index and the annual rainfall amount into the calculator to determine the R Factor for soil erosion. The R Factor is a key component in the Revised Universal Soil Loss Equation (RUSLE) for predicting soil loss due to water erosion.
R Factor Formula
The following formula is used to calculate the R Factor.
R = E * P
Variables:
- R is the R Factor (ton*in/acre*hr*year)
- E is the erosivity index
- P is the annual rainfall amount (inches/year)
To calculate the R Factor, multiply the erosivity index by the annual rainfall amount.
What is the R Factor?
The R Factor represents the rainfall and runoff erosivity factor in the Revised Universal Soil Loss Equation (RUSLE). It quantifies the effect of raindrop impact and the rate of associated runoff as a factor in soil erosion. The R Factor is influenced by the intensity and duration of rainfall. A higher R Factor indicates a greater potential for soil erosion due to water.
How to Calculate R Factor?
The following steps outline how to calculate the R Factor.
- First, determine the erosivity index (E).
- Next, determine the annual rainfall amount (P) in inches/year.
- Next, gather the formula from above = R = E * P.
- Finally, calculate the R Factor (R) in ton*in/acre*hr*year.
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
erosivity index (E) = 0.5
annual rainfall amount (P) = 30 inches/year
