| Summary: | 博士 === 國立臺灣大學 === 環境工程研究所 === 82 === Two models were developed to describe the solute transfer to
surface runoff. One is a scouring-based model and the other is
a diffusion-based model. The scouring-based model is a two-
stage model. While the first stage is a quick decrease of mass
loss of solute to surface runoff, the second stage is a slow
one. The diffusion-based model assumed that solute transfer
follows the Fick''s law. In this study, a laboratory flume with
a medium packed bed was designed. Four different sizes of
uniform glass beads were chosen to be the media saturated with
three different concentration of potassium chloride before
runoff occurred. In a series of experiments, runoff was passed
at varied flow rates , velocities, and depths over the medium
bed. Runoff samples were taken at the end of flume and
analyzed the concentration of potassium chloride. The
relationships between the dimensionless modeled parameters and
controlled variables were decided by multiple regression. On
the other hand, two different soil conditions were selected to
be the media. One soil condition was passed 9.5mm screen and
the other was passed 4.0mm screen. The same processes of
experiment were performed by using these two soil conditions.
The outflow concentration of soil experiments was simulated by
these two models. The results showed that the simulation of
large soil condition was good, but the fine one was under-
estimated.
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