Experimental study of the effects of riverbank vegetation conditions on riverbank erosion processes

Riverbank erosion is a common natural river process that threatens the security of in-stream structures as well as public and private properties. The impacts of riparian vegetation on the riverbank erosion processes are still unclear. This study conducted flume experiments with artificial riverbanks and living vegetation to investigate the effects of riverbank vegetation conditions on the riverbank erosion process. Two riverbank types, nonvegetation and vegetation riverbanks, with three growth times of vegetation (T = 15, 30, and 60 d) were compared and discussed. The results show that the erosion form on vegetation riverbanks is the individual particles, whereas it is a large block of soil on nonvegetation riverbanks. The equilibrium channel width, riverbank erosion volume, and bed deposition of the vegetation riverbank are lower than those of the nonvegetation riverbank. As the vegetation growth time increases, the equilibrium channel width, riverbank erosion volume, and bed deposition volume decrease. The experimental data also indicate that the temporal channel width of the nonvegetation riverbank is greater than that of the vegetation riverbank; the lower the vegetation growth time, the greater the temporal channel width.