为了探究工程措施水平阶和鱼鳞坑对工程堆积体陡坡坡面减流减沙和产沙过程的影响, 采用径流冲刷试验, 在流量为40 L/ min, 坡度24b、28b、32b范围内对工程堆积体陡坡坡面产流产沙过程进行模拟研究, 结果表明: 水平阶 和鱼鳞坑在产流前期具有滞缓坡面径流、增加土壤水分入渗的作用; 在产流之后两种措施对坡面径流的拦蓄能力微 弱, 甚至起到放大的作用; 其中鱼鳞坑使坡面径流强度随放水时间的延续出现两次峰值, 其坡面土壤剥蚀率变化过 程也出现两次峰值, 即产流后第6 min 和24 min; 水平阶使径流强度随放水时间的变化呈现阶梯式变化, 变化的时 间点不同坡度不尽相同; 产流后期, 水平阶和鱼鳞坑出现水毁现象, 土壤入渗率出现负值, 表明产流前期的土壤水补 给径流, 导致坡面侵蚀加剧; 鱼鳞坑和水平阶使累积产沙量和累积径流量的幂函数相关性降低。对于陡坡坡面排水 渠的设计不仅要考虑最大径流量还要考虑坡面措施的放大作用, 对于陡坡坡面径流调控体系而言, 工程措施防护效 益的时效性值得考虑。

In or der t o investig ate the effects o f eng ineer ing measures fish2scale pit and lev el ter race on the reduct ion of over land flow and sediment by the steep slope of eng ineering accumulat ion, in this paper, the r unoff sco ur ing experiments w ere used to simulate the runo ff and sediment pro cess in t he steep slo pe o f eng ineer ing accumulat ion with the flow of 40 L/ min and slo pe of 24b, 28b, and 32b . The results showed that ( 1) fish2sca le pit and lev el terr ace can reduce slo pe r unoff and incr ease soil wat er in2 filtr atio n at the early stag e of the pro ductio n flow; ( 2) the intercept ion ability of two measures decr eases aft er the pr oductio n flow and the tw o measur es even hav e adver se effects; ( 3) fish2scale pit can r esult in tw o peaks in runoff intensity w ith t he con2 tinuatio n o f dischar ge time, and soil ero sion rate has two peaks as w ell, w hich o ccur after 6 and 24 minutes o f pr oduction f low ; ( 4) lev el ter race can lead to the staged v ariation of r unoff intensity w ith dischar ge time; ( 5) the w ater log ging phenomeno n ap2 pears in the level ter race and fish2scale pit in the later per io d of product ion flow , so il infiltr ation rate is neg ativ e, w hich indicates that soil w ater r echarg es to r unoff in the early stag e o f pro ductio n flow and leads to the increasing of slo pe erosio n; and ( 6) fish2 scale pit and level ter race have low ered the co rr elation o f pow er function o f cumulativ e sediment y ield and runoff. For the dr ain2 ag e design of st eep slope, the maximum runoff and am plification effect o f slope measures are needed to be considered. For the runoff reg ulation system of steep slo pe, the timeliness of the protective benefit of eng ineering measures is needed to be considered.

/ 十二五0 国家科技支撑计划课题/ 农田水土保持关键技术研究与示范0 ( 2011BAD31B01)