Journals Proceedings

Abstract

This study aims to analyze the influence of surface runoff with rainfall intensity and different slope on the rate of slope erosion that occurs in silty sand soil. The results of the study with 3 variations rainfall intensity of 50 mm / hour, 100 mm / hour and 120 mm / hour, indicating that the effect of surface runoff on rainfall intensity and slope gradient on soil erosion rate is directly proportional. The amount of erosion that occurs based treatment in the laboratory on surface runoff discharge with successive rainfall intensity I50, I100, and I120 at 10° slope respectively are 26285 ml/hour = 36,608 gram/m2/hour, 63375,5 ml/hour = 53,500 gram/m2/hour and 87239,5 ml/hour = 54,150 gr/m2/hour. At the slope of 20°, for surface runoff with successive rainfall intensity I50, I100, and I120 amount of erosion respectively are 34292,5 ml/hour = 4,100 gram/m2/hour, 63375,5 ml/hour = 13,550 gram/m2/hour and 88170 ml/hour = 94,150 gram/m2/hour. Then for the slope of 30°, due to the increment of the surface runoff with intensity I50, I100, and I120 produced the amount of erosion respectively around 35785 ml/hour = 5,650 gram/m2/hour, 86172,5 ml/hour = 23,000 gram/m2/hour and 1033315 ml/hour = 39,250. Based on the results of the regression analysis for the determination of the rate of erosion due to large changes in surface runoff discharge with rainfall intensity is as follows : f(x) = 0,8088X0,3735 and R2 = 0,9459 for slope 10o ; f(x) = 2E-14X3,145 and R2 = 0,9081 for slope 20°, f(x) = 6E-08X1,7548 and R2 = 0,9880 for slope 30°.