Determining erosivity potantiel of Mahmuthacılı river basin rainfall

Rainfall erosivity (R-factor) is a very important factor in soil erosion studiesand it has a great influence on soil erosion. Erosion index (EI)is a product of rainfall kinetic energy and rainfall intensity. The calculationof the erosion index (EI)for each individual erosive rainfall event, which is basic to the determination of the rainfall-runoff erosivity factor R of the Universal Soil Loss Equation (USLE) and Revised Universal Soil Loss Equation (RUSLE), is laboriousand time-consuming and requires a continuous record of rainfall intensity. This study aims to evaluate the temporal and spatial distribution of rainfall erosivity and to calculate average annual rainfall erosivity in Mahmuthacılı River watershed. For this purpose, pluviographs data of three rain stations which is close to each other were analyzedand were calculated rainfall durations, kinetic energy and the maximum intensity of each individual erosive rainfall. In the study, the R factor values were calculated separately for both USLE and RUSLE approaches.The R factor value of the Mahmuthacılı watershedhas variedfrom 11,52-47,38 t-mha-1for USLE methodand 102,16-220,99 MJ mm ha-1hour-1year-1 according to the RUSLE method.The average yearly R factor value of the Mahmuthacılı watershed is 24.29 ton-m ha-1for USLE approachand160,00 Mj mm ha-1hour-1year-1for RUSLE method. The R factor values according to USLE and RUSLE methods of all threestations were statistically compared.According to statistic evaluation, the erosive potentials of rainfall were found quite variablein rain stations.2019, 203pages Keywords:Erosivity, RFactor, Erosion, Rainfall, Mahmuthacılıwatershed