崇陵流域土石山区坡面优先流发育路径研究

Development Path of Preferential Flow on Soil-rock Hillslope in Chongling Watershed

大孔隙优先流对山坡产汇流过程有重要影响。为摸清太行山土石山坡不同坡位点(坡顶、坡中上、坡中、坡中下、坡脚)的大孔隙优先流发育路径规律,以崇陵流域的典型山坡为研究对象,采用亮蓝染色剂开展了野外双环入渗染色剂示踪试验,并从水平方向与垂直方向对比分析大孔隙优先流发育路径。结果表明:(1)从坡顶到坡脚,垂直方向优先流发育减弱,水平方向优先流增强。(2)坡中以下,大孔隙优先流水平发育明显;而坡中以上,垂直方向优先流发育明显,水平方向大孔隙优先流鲜有发育。(3)崇陵流域土山区坡面表层深度20 cm以上很少出现水平方向的优先流侧向补给,为垂直向下的活塞式下渗方式。20 cm以下开始出现水平方向的大孔隙优先流,30~70 cm为优先流发育显著区。以上结论可以为基于优先流的山坡产汇流模拟提供参考。

The preferential flow in macropores usually have importent influence on the process of runoff yield and concentran on hillslopes. In order to research the pattern of macropore preferential flow development paths at different slope locations(top,middle-upper, middle, middle-lower, foot), the typical hillslope in soil-stone zone on the Taihang Mountain was studied. Bright blue stain was used to carry out tracer tests of field double loop infiltration dyes, and the path of preferential flow of macropores was compared in the horizontal direction and the vertical direction. The results show:(1) From the top to foot of the slope, the preferential flow in the vertical direction decreased while the preferential flow in the horizontal direction increased.(2) On the middle-lower slope, the preferential flow in macropores developed significantly in horizontal direction;On the middle-upper slope,the preferential flow developed significantly in the vertical direction while there was hardly any macropore preferential flow development in the horizontal direction.(3) In the soil-rock mountainous area, horizontal preferential flow lateral supply is rarely seen in the surface layer above 20 cm, and piston-type infiltration is mainly vertical. The horizontal preferential flow of macropores began to appear below 20 cm, and the preferential flow developed in 30-70 cm. These conclusions can provide reference for hillside hydrological process simulation.