Abstract: Based on the data accumulated during the 9 years from 2000 to 2008 on rainfall processes in the Nüerzhai small watershed in Wuling Mountains of Northwest Hunan, rainfall erosivity was calculated and analyzed. With the calculation of Model EI₃₀ as baseline, Model EI₁₀,EI₆₀ and CREAMS was used for assessing single rainfall, daily rainfall and rain intensity of a half-month time step and daily rainfall in Wuhan to explore applicability of various models in this watershed. Results show that the mean rainfall erosivity was 5 423.06 MJ·mm·hm^-2·h^-1, and occurred mainly in the period from April to August.Power-law relations were observed between single rainfall and single rainfall erosivity, monthly rainfall and monthly rainfall erosivity, and yearly rainfall and yearly rainfall erosivity.Among the models, EI₃₀ was the most suitable one. The half-month time step daily rainfall and rain intensity model was modified into a half-month time step daily rainfall model, and made more applicable with its parameters specified.Non-linear multi-parameter models were also very applicable to assessment of rainfall erosivity of the watershed. However, further study is to be done to select more accurate parameters suitable to the watershed.

Key words: rainfall erosivity, model, applicability, Northwest Hunan, the Nüerzhai small watershed