CAJ | 학술논문

土壤优先流对包气带水流和污染物运移的影响已引起广泛关注,但大多数研究还停留在定性描述上,缺乏对优先流定量评价的标准.基于室内土柱实验获取的穿透曲线,分析了饱和条件下土壤溶质优先运移的一般规律,采用解析法模拟软件CXTFIT拟合了溶质优先运移的参数,同时结合时间矩方法计算了定量评价优先流的指标PFSP.研究结果表明:时间矩方法中的一阶标准矩μ′_1、二阶中间矩μ_2以及偏态系数S可以定量刻画穿透曲线的特征,从而指示优先流的程度;PFSP能很好地刻画优先流作用的大小.该研究对优先流的定量评价具有重要指导意义.
토양우선류대포기대수류화오염물운이적영향이인기엄범관주,단대다수연구환정류재정성묘술상,결핍대우선류정량평개적표준.기우실내토주실험획취적천투곡선,분석료포화조건하토양용질우선운이적일반규률,채용해석법모의연건CXTFIT의합료용질우선운이적삼수,동시결합시간구방법계산료정량평개우선류적지표PFSP.연구결과표명:시간구방법중적일계표준구μ′_1、이계중간구μ_2이급편태계수S가이정량각화천투곡선적특정,종이지시우선류적정도;PFSP능흔호지각화우선류작용적대소.해연구대우선류적정량평개구유중요지도의의.
Because of its critical effect on field-scale soil water flow and transport of contaminants in soils, more and more research concerns are concentrated on preferential flow. However, few reports are found on quantitative evaluation of preferential flow though there are many reports in literature on qualitative de-scriptions of preferential flow. This paper presents the analysis of the characteristics of preferential trans-port based on the breakthrough curves obtained from soil columns in the lab and the evaluation of its extent based on the time moment analysis and two -region models by CXTFIT. A conclusion is made that the breakthrough curves (BTCs) exhibit different shapes including some with early breakthrough and in-creased tailing curves. This qualitatively indicates the presence of preferential flow and different extent of preferential flow in the different soil columns. By time moment analysis, the first normalized moment (μ'1), the second central moment(μ2), and the skewness (S) were used as reference indices to denote the extent of preferential flow. Using transport parameters determined by the program CXTFIT and the time moments of BTCs, an integrated parameter, PFSP, was calculated to ascertain or compare the extent of preferential flow. The calculation results indicate the value of PFSP could be used to quantify the extent of preferential flow when the breakthrough curves could be obtained. The conclusions in the study offer in-structive implications in evaluation of preferential flow in the field.