Return flow in rivers due to navigation traffic


Bhowmik, N. G., R. Xia, B. S. Mazumder, and T. W. Soong.  1995. Return flow in
rivers due to navigation traffic.  Journal of Hydraulic Engineering 121(12):914 918. 
Reprinted by U.S. Geological Survey, Environmental Management Technical Center,
Onalaska, Wisconsin, May 1997.  LTRMP 97-R005. 5 pp.  (NTIS #PB97-176010)


ABSTRACT

Movement of navigation traffic (barge-tows) in restricted waterways such as the Illinois
or Mississippi Rivers can generate rapid return flow and water-level depression
(drawdown) between the barge and the shoreline.  Consequently, the velocity
distribution in the zone between the barge and the shoreline changes temporarily in
space and time.  The objective of the present study is to use existing models to compute
the average return flow and the lateral return flow distribution, and compare them with
the observed data to test the validity of these models.  Field data were collected from
the Illinois River at river mile 35.2, near Kampsville.  In this analysis, it was found that
all the existing models underestimate the average return flow velocity by as much as
30%.  It was also found that the exponential return flow distribution across the width
between the barge and the shoreline described by the existing models are not supported
by the field data.  An examination of the field data indicates that the return flow due to
the movement of navigation traffic may have a parabolic-like distribution.  Therefore, it
may be necessary to develop a more realistic model to predict the return flow in natural
rivers due to the movement of navigation traffic.


KEYWORDS

Illinois River, Mississippi River, navigation,  return flow, traffic impacts