Hydrodynamic Characteristics Of The Seabuckthorn Plant Flexible Dam Based On Experiments

This paper is based on the research of Joint Fund of National Natural Science Foundation of China and Yellow River Conservancy Commission. Plant flexible dams come into being by planting Seabuckthorn on the slope land of Left Bank, Xiaohuashang reservoir, Hua County, Shanxi Province. A series of field experiments utilizing the advanced Particle Tracking Velocimetry technology are carried out. Then, the meaning from hydraulic angle for the technique of seabuckthorn plant flexible dam, and the changes of seabuckthorn'groupth were discussed. At last, through the flow velocity experments of seabuckthorn plant flexible dam, the influences of seabuckthorn plant flexible dam on the velocity and depth of water flow were analyzed. The main results are as follows.(1) Based upon the experimental design, test facilities is built in May ,2006. Mainly includes the seabuckthorn plant flexible dam, water pool, stilling basins and testbeds. Two systemic water experiments are made in Sep. and Nov., 2006.(2) This paper firstly introduces the technique of seabuckthorn plant flexible dam, then expatiates the sediment trapping mechanism, engineering technology, dam implantation principle and dam design, analyzes its groupth changing process from longitudinal, transverse and vertical, and surveries the grouth of seabuckthorn plant flexible dam. The results show that the grouth of seabuckthorn is all right, the NO.4th is best, and the growth rate and increment of plant height are all more than the diameter of canopy and base diameter.(3) By analyzing and researching the distribution case of the velocity and depth of water flow, it is induced that the plant spacing and the length of flexible dam play a leading role, in which the advantage of length of flexible dam is greater than the plant spacing.(4) Made out a series of experiments with present advanced Particle Tracking Velocimetry technology,then generalized experiment phenomenas and flow state, and also found that energy losses mainly arises in upstream, which is theoretically beneficial to control channel soil and water loss.(5) Through selecting different flow during experiments, it shows that the watertight effect ofseabuckthorn plant flexible dam boosts up when the flow increase. The flow increase has much influence on flow depth of the front and middle part of the flexible dam and the former effect is more significant.(6) Based on the traits of uneven flow in the plant dam, the watertight effect and the deduced flow resistance of seabuckthorn plant flexible dam are theoretically analyzed. It is concluded that the average diameter of the seabuckthorn trunk is more significant than the row spacing. The water resistant effect is urged with the plant upgrowth and time leap. Then, the formula of flow resistances applied by plant is concluded and the influence on flow resistance, which is caused by plant factor and boundary condition are analyzed.