Experimental Research On Hydraulic Roughness Of Ecological Revetment.

Revetments are not only the important engineering measures to protect the riverside from washing out, but also the important transitional regions for exchange of substance, energy, and information between river ecological system and land ecological system. So it is important to keep the sustainable development of mankind, economy, and ecological environment. In the future, the destruction of ecological environment, which caused by revetments, should be diminished.Ecological revetment engineering can protect river ecosystem health well, and has been used widely in the channel revetment. The flexible vegetation is a main kind of engineering materials in the ecological revetment engineering, because it grows quickly and can be easily planted and constructed. However, the interrelation between the flexible vegetation and the flow is undetermined, and the systemic study is laggard. To resolve this problem, the effects of vegetation on river characteristics are studied in this thesis through model experiment in flume. In this study, 28 samples of turf and reinforced turf were tested, and vegetation's hydraulic roughness was calculated. The experiment and theoretical study prove that the hydraulic roughness of turf used in revetment ranges from 0.020 to 0.090. The roughness not only depends on the different categories of soil but also on the period of growth and the way of reinforcement. With the flow velocity and duration increasing, the roughness would decrease gradually.