鹤大高速（G11）低路基边坡土壤优先流特征研究

为了探明盐分在低路基公路边坡土壤中的运移方式,以鹤大高速公路(G11)低路基段边坡土壤为研究对象,引入优先流,来探讨盐分随土壤水分运动的过程。采用亮蓝染色示踪和图像解析方法,分析土壤剖面优先路径水平和垂直分布特征。结果显示:染色区和非染色区的土壤性质存在显著差异,染色区土壤存在较多的大孔隙。在水平剖面上,相同影响半径优先路径数量随着土层深度的增加而减少,同一土层中1.0~10.0mm影响半径的优先路径数量要远远多于10.0mm影响半径的优先路径数量。在垂直剖面上,优先流特征指标染色覆盖率(DC)、均匀入渗深度(UF)、优先流分数(PF-fr)、长度指数(LI)和峰值(PI)分别为40.10%,4.10cm,801.96cm2,74.44%,543.6cm和5。低路基边坡土壤这种重塑的土体中存在较为明显的优先流现象,且优先流对氯盐在土壤中的运移起着重要的作用。优先流指标的提出,为今后量化土壤优先流发生程度提供了一个很好的研究方法。

Characteristics of Preferential Flow in Slope Soils of Low Roadbed Highway

To prove salt transport in roadside soil of low roadbed highway, Heda highway (G11) low roadbed roadside soil was selected as the research object. The preferential flow principle was used to explore the salt transport in the soil water movement process. Analyzed soil profile preferential flow horizontal and vertical distribution characteristics by using brilliant blue dye tracing and image analysis method. The results showed that: Staining area and non-staining area of soil properties had significant differences, staining area had more pore. In the horizontal profile, the number of preferential flow paths with different influence radius decreased with the increase of soil depth. The number of preferential flow paths with 1.0~10.0 mm influence radius in the same layer were far more than the number of paths >10.0 mm influence radius. In the vertical profile, the preferential flow characteristic index as dye coverage (DC), uniform infiltration depth (UF), preferential flow fraction (PF-fr), length index (LI) and peak (PI) were 40.10%, 4.10 cm, 801.96 cm2, 74.44%, 543.6 and 5 respectively. There was obvious preferential flow in roadside soil of low roadbed highway which played an important role in the transportation of salt in soil. The proposed indices provided a good research method to quantify the occurrence degree of soil preferential flow in the future.