Effect of Rainfall Duration and Soil Moisture on Changes of Splash Erosion

The first step form soil erosion is the soil splash that this step creates by the raindrops effect on soil surface. The raindrops can separate the soil particles and they cause the change of soil structure and increase soil erosion. Therefore, the study of effectiveness factors on splash erosion are including rainfall erosivity and soil erodibility can be effective in control of splash erosion. Two variables of rainfall duration and initial soil moisture can be have more effect on amounts of splash erosion that these have been less considered. for this purpose, the present study to the effect of rainfall durations with rates of 5, 10, 15, 20, 25 and 30 min and initial soil moistures with rates of 20 and 40 percent studied on splash erosion in rainfall intensity of 30 mm h-1 and scale of splash cup. The results showed that the variables of rainfall duration and initial soil moisture had significant on the rates of total and net splash in time unit and level of 99 percent. Whereas, the interaction effect of initial soil moisture and rainfall duration had not significant on total and net splash in time unit. The results also showed that, there was the inverse and significant correlation between rainfall duration and total and net splash in time unit, because the total and net splash in unit time decreased with increasing rainfall duration in both moistures of 20 and 40 percent. The study of obtained results showed that the effect of initial soil moisture of 40 percent had more on total and net splash in time unit toward initial soil moisture of 20 percent