砒砂岩地区沟道沙棘植物"柔性坝"原型拦沙研究

本文通过实测资料分析得到砒砂岩区土壤侵蚀的基本特点是以冻融风化非径流土壤侵蚀为主,以沟壑中暴雨径流形成的股流为动力核心搬运输移泥沙,重力和风力仅对非径流产沙起加速作用,人类活动对坡面起破坏作用。小流域上、中、下游冻融风化土壤侵蚀的分配比例是76.1％、17.5％和6.4％,说明支毛沟头是土壤侵蚀的关键部位,沟顶坡、沟谷坡和沟床面积分别为22％、75％和3％,沟谷坡产沙量占总产沙量的90％,说明沟谷坡是产沙的关键部位。针对该地区的产沙规律,试验证明在砒砂岩区支毛沟中以沙棘灌木植物作为拦沙的坝型框架材料是可行的,并给出了明确的物理图形,与沟道淤地坝工程相配套,使粗细沙分选、泄流、生态恢复于一体,发挥综合功能。

Field Model Research on Sediment Retention by Seabuckthorn Plant "Flexible Dam" in Gully Channel in the Soft Rock Region

The paper shows that the basic soil erosion characteristics is non-runoff sediment produc-tion in the form of frozen-melting and weathering in the soft rock region after the analysis on observed datum. The core power of sediment transportation is the strand flow caused by rainstorm runoff. And the gravity and wind force just accelerate the non-runoff sediment production. But the human activity damages the slope land. The proportion of frost and weathering soil erosion is respectively 76.1%, 17. 5% and 6. 4% in the upper, middle and lower reaches of a small watershed. This proved that the key soil erosion place is in the gully head section. The proportion of top slope land area, gully slope land and gully bed occupies 22%, 75% and 3% separately. Sediment production on gully slope land takes 90% of the total sediment production. This shows the key sediment production place is gully slope land. Aiming at the sediment production law in the region, the experiment proves that the shrub of seabuckthorn can be used as a frame material for sediment retention in the mini-gullies in the soft rock region. The paper has given a definite physical graph. By combining with warping dam, the flex-ible dam can size coarse and fine sediment, overflow and recovery ecology in the region. So the com-prehensive function will be aroused.