ABSTRACT
Alluvial meandering rivers show a rich pattern of
channel migration (Figure 1). Ikeda et al. (1981) intro-
duced the simple algorithm for computing meander
migration shown in Figure 2. Let s and n = stream-
wise arc-length coordinates along and normal to the
centerline, respectively, channel half − width = b,
centerline radius of curvature = R
, depth-averaged
streamwise flow velocity = u¯(s, n) and the migration
rate of the channel normal to the centerline = n˙
. Now
consider the difference u¯ defined as
u¯ = u¯
|
− u¯
|
(1)
where n = ±(b − ε) denote near-bank positions just
inside the bank boundary layer. In the Ikeda-Parker-
Sawai model (Ikeda et al., 1981, referred to as IPS
below), the relation for migration rate is
n˙
=
Eu¯ (2)
where E is a dimensionless parameter. Figure 2 illus-
trates the principle of the algorithm: the bank nearest
the locus of high velocity erodes, and the opposite
bank deposits.
