Effects of vegetation root on erosion degree under different arrangements of river banks.

With environmental protection becoming more and more important in recent years, the suitability of traditional regulation methods in rivers such as bank protection and river cutoff begins to be challenged. The regulation methods combined with ecology have become an important goal in natural rivers nowadays. In this research, a series of flume experiments were conducted to discuss the effect of bank erosion on vegetation roots between bare and vegetated banks.

The experimental parameters of flow discharge, water depth,  and channel slope are 0.014 , 9.5 cm, and 0.001, respectively. A kind of vegetation, Vigna radiate, is planted in cultivation boxes for 1 – 2 weeks and then moves into the channel as the vegetated banks. A laser scanner is set up on the flume channel to record the variation of initial and final topography. The results show that the erosion ratios of bare and vegetated banks are 40.24 % and 24.34 %, respectively. The root system of vegetation has a function of anti-erosion on river banks. In addition, we observe the exposed roots formed a protective layer along the flow direction on the bank over a period of time after beginning the experiment. The protective layer by roots helps the river bank resist water erosion and reduce the amount of erosion in the covered area.