130
or"
1 c~ 1
h xt
----+--+p=O
R.H. Charlier and Chr. P. De Meyer
(70)
o! ~ ~y~ . ~ ,
$~
51 ° b 5_1
/~J'l,
[~, -,<
F- d x
Fig 28 :
(a) Profile Schematization
(b) Plan view
where "
S~ = longshore sand transport
h
= height of the schematized beach profile
p
= transversal sand transport
t
= time
The equation of motion may be derived from Fig. 29 "
The following conditions are set :
1. The longshore transport is a function of the coastline direction only and of no
other parameters.
2. This function can be differentiated for any of its values.
3. The second order and higher terms may be neglected.
The first condition leads to:
$1 = $1 (c0
(71)
The theorem of Taylor-Maclaurin, together with the second condition, yields •
S 1 (a) = Sol + c~
+--o~
+..
(72)
da c~=o 2
\d°~2 )a=o