急求专业英语翻译!手工的!Modeling the hydraulic effect of transverse dee

急求专业英语翻译!手工的!
Modeling the hydraulic effect of transverse deep zones
on the performance of short-circuiting constructed
treatment wetlands
Short-circuiting, which occurs when a large fraction of water traveling through a system
exits well before the residence time, reduces the performance of constructed treatment
wetlands. Recent field and laboratory observations have shown that short-circuiting within
vegetatedmarsh areas results fromnarrow, continuous fast flowpaths that experience longi-
tudinal dispersion but do not exchange fluid with slow flowing regions of dense vegetation
on either side. Based on these observations, this paper develops an analytic stream tube
model with dispersion to represent flow through the marsh areas of a short-circuiting
constructed treatmentwetland under steady flowconditions. Themodel also includes trans-
verse deep zones, which rapidly dissipate fast flowpath momentum and introduce lateral
mixing through wind-driven circulation.Modeled results reveal that a transverse deep zone
that replaces a portion of a wetlandmarsh can offset the adverse impact of short-circuiting
flowpaths through two separatemechanisms. First, lateralmixing can dilute the water that
has traveled through a fast flowpath. Second, deep zones reduce the probability that fast
flowpaths align throughout the entire wetland. The model results suggest that deep zones
may improve wetland performance when properly sized and located, even when they do
not directly contribute to contaminant removal.
© 2009 Elsevier B.V. All rights reserved.