124
R.H. Charlier and Chr. P. De Meyer
For values of I-~JLo between 0.025 and 0.030 there is a transition zone where
either type of profile might exist.
~60
1:40
1:20
1:10
1:a
'1:6
1:4
1:2
,, .
|
•
!
',
,,
A
A A
~0~
~0
0
Prof|les ~
PtO(ilell
o AA~
O~ • ACI eG
0 A
•
0
•
O
•
0
O
A
Q
A
a
•
0
IL °
0
• •
Nayok
Q
0
o Hector (19S4)
A J~aqleson, Glenne Qnd Or~cup ~19G3|
(2 NOyQk (197'0)
IS Ram=n and [atarlvpvll~a {|973)
• van Hilum (1974)
• Thompson (19T6]
'
!
i
s
s
A
l,
;
s
J
J
0 4
.0 6 .O 8 .10
.Z
4
.6
~8 1.0
Z.
4.
6.
8,
Ho
wT
IO
Fig. 23 : Beach slope versus fall velocity parameter
The above tests were carried out with regular waves and constant water level.
Watts and Dearduff (1954) observed that water level variation influences the
profile development.
Later, Iwagaki and Noda (1962) observed that grain size influences the critical
value of the wave steepness for a bar or step profile. On the basis of model
experiments they concluded that the criterion for bar formation varies roughly
between Ho/Lo = 0.025 for Ho/Dso < 300 and HULo = 0,01 for Ho/Dso > 1000.