Model of rainfall erosion index for predicting the potential erosion rate by using a rainfall simulator

The intent of this research is to investigate the rainfall erosion index that has the highest correlation to the surface runoff volume and the amount of soil erosion. In addition, the aim of this research is to determine the effective rainfall erosion index to predict soil erosion based on observations. This research was conducted in a hydrology laboratory by using a rainfall simulator. The three methods that were used for analysing rainfall erosion were the formulas of EI30 by Bols, Utomo, and Lenvain. The result is expected to become a consideration in selecting the model of rainfall erosion index due to the rainfall factor as the input of soil erosion prediction. This research provides a temporary hypothesis for obtaining the value of the rain erosivity index with a different value from previous studies with EI30, which leads to the latest model for estimating and predicting from the Bols equation. Based on this research, the rain erosivity index was obtained with a predicting value and final equation of EI30 = 5.128 x (Rain)(1.26) x (Days)(0.47) x (Maxp)(0.53) x (High)(0.61) with the explained value from research analysis being EI30 = 5.128 x (50.002)(1.35) x (23)(0.47) x (622)(0.53) x (12)(0.61). Analysis was then performed with trial and error, and the conclusion of this research is a high rain erosivity index.