摘要
为探究黄土中的渗流特征,明确不同初始条件对优先流的影响程度,使用亮蓝和离子染色剂,并控制入渗水量和初始含水率,在黄土高原南部进行染色示踪试验,根据获取的染色剖面图像,从定性和定量2个方面分析了优先流程度。结果表明:亮蓝染色剂在黄土中的染色深度有限,而离子染色剂经显色反应后能很好地示踪水的渗流;黄土高原南部黄土中优先流类型随土层深度从小到大为基质流—非均质指流—高相互作用大孔隙流—混合相互作用大孔隙流;优先流评价指数试坑A(0.55)>试坑C(0.48)>试坑B(0.46),优先流程度由高到低为试坑A—试坑C—试坑B;在其他条件相同时,黄土中更多的入渗水量、更大的初始含水率抑制优先流的发育,使基质入渗深度更大,基质流程度更高,优先流程度降低。研究结果可为黄土地区灾害防治、探明地下水污染机制提供参考。
In order to explore the seepage characteristics in loess, and clarify the influence extent of different initial conditions on preferential flow, a dye tracing experiment was carried out in the southern Loess Plateau, using brilliant blue and ionic dye and controlling the infiltration water and initial water content. According to the obtained dyeing image, the preferential flow extent was analyzed qualitatively and quantitatively. The results showed that the dyeing depth of brilliant blue in loess was limited, while the ionic dye could well trace the seepage of water after color reaction. The type of preferential flow in loess in southern Loess Plateau from small to large with depth was in order as follows: homogeneous matrix flow, heterogeneous matrix flow and fingering, macropore flow with high interaction, macropore flow with mixed interaction. The order of preferential flow indicator was test pit A(0.55)>test pit C(0.48) >test pit B(0.46), and the extent of preferential flow was from high to low: test pit A, test pit C, test pit B. When other conditions were the same, more infiltration water and higher initial water content in loess would inhibit the development of preferential flow, resulting in greater depth of matrix infiltration, higher extent of matrix flow, and lower extent of preferential flow. The study can provide reference for disaster prevention and control in loess area and for proving the mechanism of groundwater pollution.
作者
张旭
卢玉东
王博
曾广豪
吴靓
ZHANG Xu;LU Yudong;WANG Bo;ZENG Guanghao;WU Jing(School of Water and Environment,Chang’an University,Xi’an 710054;Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region,Ministry of Education,Chang’an University,Xi’an 710054;Qinghai Geological Environment Monitoring Station,Xining 810008)
出处
《水土保持学报》
CSCD
北大核心
2022年第6期110-118,共9页
Journal of Soil and Water Conservation
基金
国家自然科学基金重点项目“黄土高原梯田—淤地坝典型区生态服务功能权衡与协同效应”(U2243204)。
关键词
优先流
渗流特征
黄土
染色示踪试验
定量化
黄土高原南部
preferential flow
seepage characteristics
loess
dye tracing experiment
quantitative
southern Loess Plateau
