沙棘柔性坝拦沙效应的试验研究

在野外试验基地进行了沙棘柔性坝拦沙效应试验。基于试验数据,分析了不同含沙水流条件下沙棘柔性坝对沿程含沙量及出入口悬沙粒径分布的影响,并探讨了沙棘柔性坝的阻力特性。结果表明,沙棘柔性坝对不同含沙水流的拦沙效果显著不同,对原型沙B的拦截效果最好,其次为原型沙A,最后为模型沙。对250~1 000μm粒径范围内的原型沙拦截效果最佳,且原型沙含沙量与中值粒径之间呈现正相关关系,对100~1 000μm粒径范围内的模型沙的拦截效果较好。各不同含沙水流条件下的沿程含沙量主要受沙棘柔性坝阻力的影响。本研究有助于深入理解沙棘柔性坝的拦沙效应,并对沙棘植物柔性坝这一生态工程在砒砂岩区沟道的推广应用提供理论依据。

Experimental study on sediment retention effect by the seabuckthorn flexible dam

A field experiment on the sediment retention by the seabuckthorn flexible dam (SFD) was conducted in the field test base.Based on the experimental data,the impact of the SFD on the longitudinal sediment concentration and the particle size distribution of suspended sediment in the both inlet and outlet were analyzed.Resistance characteristics of SFD were discussed.Results showed that sediment retention effect by SFD on the various sediment-laden flows is obvious,and the best retention effect is caused by SFD on the prototype sand A,the next is on the prototype sand B,and the third is on the model sand.The optimal sediment retention effect is for the prototype sands of 250 ～ 1 000 μm,and the prototype sand concentration is positively related to the median particle size,as well as the model sand of 100 ～ 1 000 μm.Variation of sediment concentration along channel is mainly influenced by the resistance of seabuckthorn flexible dam.