Page 75 - 2017地大报告电子书

环境学院发展报告

J for the Hamaker constant, rather than the

commonly used value of − 6.0 × 10 − 20 J,
appears to be more appropriate to represent

solely the effect of the van der Waals forces
and to predict the film conductivity. In

comparison with the commonly used van
Genuchten-Mualem model, the EMFX-K

model significantly improves the prediction of
hydraulic conductivity under dry conditions.

The sensitivity analysis result suggests
that the uncertainty in the film thickness

estimation is important in explaining the
model underestimation of hydraulic conductivity for the soils with fine texture, in addition to the

uncertainties from the measurements and the model structure. High quality data that cover the
complete moisture range for a variety of soil textures are required to further test the method.

论文链接：https://doi.org/10.1016/j.jhydrol.2017.03.063

6.Single-well push-pull test in transient Forchheimer flow field
作 者：QuanrongWang; HongbinZhan *; YanxinWang.
JOURNAL OF HYDROLOGY 卷 : 549 页 : 125-132 出版年 : JUN 2017

摘 要 :Using the single-well push-pull (SWPP) test to quantify in situ aquifer characteristics
associated with solute transport (dispersion coefficient, geobiochemical reaction rates), the

accuracy of parameter estimation was not only dependent on the solute transport models but also
the groundwater flow models. However, many previous studies on the SWPP test were based

on assumptions over-simplifying the flow field, namely, groundwater flow followed Darcy’s
law; flow was in the steady state during the entire test duration; the wellbore storage could be

negligible. In this study, we have carefully examined such assumptions by developing a new finite-
difference model of the SWPP test under the transient Forchheimer flow condition, considering

the wellbore storage. The SWPP test included an injection phase, a chaser phase, a rest phase, and
an extraction phase. The results showed that the concentration of the steady-state flow solution

was greater than that of the transient flow solution at the beginning, and its peak value was
also greater than that of the transient flow solution. The difference between the breakthrough

curves (BTCs) of the transient flow SWPP model and the steady-state flow SWPP model was

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