A quantitative measure of erodibility allows for the prediction of erosion, assisting with the design of structures such as vegetated channels, road embankments, dams, levees, and spillways.
[1] The test consists of mounting a jet tube inside of an enclosed cylinder and releasing a turbulent downpour of water onto a soil specimen at a constant hydraulic head.
If the shear stress applied by the jet stream exceeds the critical shear stress for erosion of the soil, the jet will erode soil particles, causing a scour hole to form.
Fitting the measured erosion rate (Er) to the following equation allows the estimation of the erodibility of the soil (kd) and the critical shear stress (τc), provided that the applied shear stress (τ) is estimated precisely:[2]
[3] One of the results of the test is the jet erosion index (Ji), which can be correlated with the soil erodibility.