Abstract:To determine the relationships between soil detachment capacities and hydrodynamic parameters under Terrace Banks in hexagonal prefabricated net format with different vegetation types, we collected the undisturbed soil samples in Terrace Banks planted with Ophiopogon japonicus, Allium tuberosum and bare land (control) in situ respectively, and conducted the simulated rill flume (4 m long, 0.12 m wide, 0.1 m height) scouring experiments in laboratory. Flume scouring experiments were carried out under the combinations of 3 slopes (15°, 20°, 25°) and 5 flow rates (39.86, 59.98, 79.67, 100.45, 121.16 L/min) with 3 replicates (i.e., a total of 135 scouring experiments). The results showed that soil detachment capacities were significant differences under various vegetations (P<0.05), and ranked as Ophiopogon japonica (2.24 kg/(s·m2)) > bare land (1.34 kg/(s·m2)) > Allium tuberosum (1.09 kg/(s·m2)). The power functions could be used to describe the relationships of soil detachment capacities with shear stress (R2=0.75), stream power (R2=0.73), unit stream power (R2=0.46) and unit energy (R2=0.63). The shear stress threshold presented as τc Ophiopogon japonicus (8.75 Pa) > τc Allium tuberosum (6.47 Pa) > τc bare land (1.93 Pa), indicating that vegetation planted in the Terrace Banks in hexagonal prefabricated net format could enhance the soil resistance to detachment.