华北土石山区草地过滤带布设方式对坡面产流产沙的影响

为治理华北土石山区坡耕地水土流失,提出坡面草地过滤带优化布设方式,以该区典型的土壤石灰岩母质发育的褐土为研究对象,在9°坡度、90 mm/h雨强条件下,利用室内人工降雨试验,分析草地过滤带的布设方式(坡下片状、坡下条状、坡上片状、坡上条状)对坡面侵蚀的影响。结果表明:(1)坡下条状布设方式可以有效延缓坡面初始产流时间,相比其他3种布设方式初始产流时间延长了1.3～1.6倍,且坡下条状布设方式可增加坡面径流入渗,减少产流量,在累计产流量上,坡下片状坡上条状坡上条状坡下条状。(2)坡上布设方式下的累计产沙量是坡下布设方式的10～23倍,坡上布设方式的产沙率随时间变化波动明显,坡上布设方式下的产沙率是坡下布设方式的3～35倍,当在坡下布设草地过滤带时对泥沙的削减效益最优。(3)坡下布设可以抑制细沟侵蚀的发育,坡下条状布设方式可以有效控制细沟产生的数量和沟长,护坡效益最优。

Effect of Grassland Filter Belt on Runoff and Sediment Yield on Slope in Earth-rocky Mountainous Area in North China

In order to control soil and water loss of sloping land in Earth-rocky Mountainous Area in North China, and to propose the optimal layout pattern of slope grass belt was put forward, the typical soil limestone parent material developed cinnamon soil in this area was taken as the research object. Under the condition of 9° slope and 90 mm/h rainfall intensity, the indoor artificial rainfall test was used to analyze the layout pattern of grassland filter belt (upslope, downslope, sheet, strip) on the slope The results showed that: (1) The strip layout under the slope could effectively delay the initial runoff generation time of the slope, which was 1.3~1.6 times longer than the other three layout. And the strip layout under the slope could increase the runoff inflow and infiltration of the slope and reduce the runoff generation. As for the cumulative discharge, the upslope > strip > sheet > downslope. (2) The cumulative sediment yield under the arrangements on the slope was 10~23 times that under the arrangement on the slope. The sediment yield under the arrangement on the slope fluctuated obviously with time, and the sediment yield under the arrangement on the slope was 3~35 times that under the arrangement on the slope. The sediment reduction was the best when the grass filter belt was laid under the slope. (3) The layout under the slope could inhibit the development of rill erosion, and the strip layout under the slope could effectively control the number and length of rills, and the benefit of slope protection was the best.