Estimation of Rainfall Erosivity Index for Auchi, Edo State, Using Lombardi’s Method

Abstract

The erosivity factor in the universal soil loss equation (USLE) provides an effective means of evaluating the erosivity power of rainfall. This study evaluated the erosivity factor based on monthly and annual precipitation rainfall data of Auchi, Edo State covering a period of 2005 – 2014 using Lombardi method (EI =1.03V_d^1.51).  It was discovered that higher rainfall values resulted in high erosivity index values which was in line with other tropical climates. The average annual erosivity index for the city during the period of study was 587.32 MJ mm/hr. The R² of 0.651 shows that precipitation alone contributed 65.1% of the erosion risk within the study period. The knowledge of impact of rainfall on erosivity is essential in soil erosion risk assessment and for soil and water conservation planning.

Keywords: Erosivity, Kinetic energy, Erosion, Rainfall intensity, Lombardi, Erodibility, Auchi, Soil loss

DOI: 10.7176/CER/11-1-02