Flow Characteristics and Rill Erodibility in Relation to the Rainfall Intensity in a Marl Soil

Rill erosion which occurs as a result of runoff concentration on a hillslope is one of the major soil erosion types in arid and semi-arid regions, especially where plant cover is poor. For this reason, understanding the factors affecting them is a high priority. Rill erodibility indicates the ease of soil particles detachment and transport by water shear force in a rill. The study was conducted to investigate the effect of rainfall intensity on the flow characteristics and rill erodibility (Kr) in a marl soil. A laboratory experiment was carried out in ten rainfall intensities from 10 to 100 mm.h-1 at three replications. Soil samples were taken from a semi-arid region in west of Zanjan and placed into a flume with 0.4 m × 9 m in dimensions. Rill erodibility (Kr) was determined using the WEPP model at three artificial rills. The results showed that flow characteristics (velocity, discharge and shear stress) and rill erodibility were affected significantly by rainfall intensity (P