Low amplitude of streambank erosion: distinguishing mass and surface fluvial erosions

The purposes of this manuscript are in two folds e.g.: first, to promote two novel techniques using field-laboratory protocols, each for quantifying surface and mass fluvial erosion, second, to capture and highlight the regime change in the mode of bank erosion from surface to mass fluvial erosion based on real monitoring and measurements on a streambank face. In this study, conduit erosion flume and Photo Electronic Erosion Pin (PEEP) sensor technique were used for monitoring and measuring surface and mass fluvial erosions, respectively. Using those techniques the τ c , sf and τ c , mf , two key parameters which determine the onset of surface and mass fluvial erosion, can be determined successfully. The PEEP sensor can measure the mass fluvial erosion occurred under water, even capture the quasi-continues nature of erosion. More importantly, using these two methods, the presence of two regimes in the low amplitude of bank erosion, e.g. surface fluvial erosion and mass fluvial erosion can be captured. Starting from low to high shear stress, the onset of surface fluvial erosion as well as the transition from surface to mass fluvial erosion can be depicted.