چکیده
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The purpose of this paper is to use the application of the multilinear lag cascade model as a
contaminant transport model through river networks. Monocacy River and Antietam Creek data,
which were collected by USGS with different reach lengths and discharge conditions, have been used
in the current study. It was found that the multilinear discrete lag-cascade (MDLC) model is capable
of reconstructing contaminant breakthrough curves. A complete study was performed to estimate
the reach length for use in the accurate simulation, and it was concluded that by assuming a uniform
flow through the reach, the length unit should be obtained by applying Pe¼ 12. Moreover, by using
temporal moment matching, explicit relationships for MDLC model parameters (k, n, and τ) and
based on conventional advection-dispersion equation (ADE) parameters (D, u, x) were extracted.
MDLC parameters of the field breakthrough curves were extracted, and it was found that the
increase of Pe number caused an increase in delay time and the number of cascades. However, the
residence time was obtained to be fixed. Additionally, by assuming the dispersivity parameter (D/u) is
constant, the changes in the MDLC parameters were investigated by velocity variation, and new
relationships were proposed to estimate the parameters under different hydraulic conditions. Using
presented equations provided in this study for residence time (k), cascade number (n), and delay time
(τ), the sensitivity analysis was performed, and it was found that the parameters of velocity (u),
dispersion coefficient (D), and velocity (u) have the most important effect in calculation of them,
respectively.
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