APPLICATION OF RAINFALL INTENSITY – KINETIC ENERGY RELATIONSHIP FOR SOIL LOSS PREDICTION

Abstract

In order to explore the consequences of rainfall intensity – kinetic energy relationships for soil loss, climatologically data for monthly and yearly rainfall depth over period of 30-yrs for Mosul city which is located at northern Iraq, were analyzed for the rainfall erosivity index (EI30). The modified Fourneir erosivity (MFI) model was used as an indicator for the combination effect of kinetic energy(E) and maximum rainfall intensity at 30 minute (I30) on the soil loss. The results showed that EI30 index was varied within a year and between years of the rainfall records and was ranged from 25.1 to 411.9 metric unit with average 140.3metric unit .The monthly distribution of EI30 showed that the rainfall erosivity was very sever in four months (50% of rainy months ) through any year of recorder data and December to March was found to be the most erosive months in the studied region. Regression analysis for EI30 with mean annual rainfall depth showed that the natural log law is the best suitable mathematical function judged their relation and 83.3% of the changes in EI30 were due to variation in the rainfall depth.