In soils, fast preferential flow is limited to infiltration and to small fractions of pore volumes. The viscous flow approach to preferential flow combines these features. The approach is based on thin films whose two parameters—thickness and specific contact area per unit volume of the permeable medium—are deducible from time series of volumetric water contents. Such a time series is the response of the permeable system to an input pulse of known duration and volume flux density. This chapter summarizes the theory, offers a step‐by‐step protocol for determining the two parameters, and applies the approach to water content time series recorded at five depths in a profile of a Mollic Cambisol.

中文翻译：

---

达西规模的优先流：水分时间序列中的参数

在土壤中，快速优先流动仅限于渗透和小部分的孔体积。优先流动的粘性流动方法结合了这些特征。该方法基于薄膜，其薄膜的两个参数-厚度和每单位体积的渗透性介质的比接触面积-可从体积水含量的时间序列推导出。这样的时间序列是渗透性系统对已知持续时间和体积通量密度的输入脉冲的响应。本章概述了该理论，提供了确定两个参数的分步协议，并将该方法应用于在Mollic Cambisol剖面中五个深度处记录的含水量时间序列。