2.2 Fluvial Sediments
33
INCREASING
CURRENT
VELOCITY
BED FORMS
ANDINTERNAL
STRATIFICA TION
TRANSPORT
LARGER COMPOSITE
RIVER
BEHAVIOR OF
BED FORMS AND
SYSTEM
SANDANDGRAVEL INTERNALSTRUCTURES
m/s
UPPER
FLOW
REGIME
DIRECTION OF FLOW
c:::======>
ANTIDUNES
LAG
DEPOSIT
GRAVEL BARS
FORESETS IN PLANAR
CROSS-BEDDED GRAVEL
(Gp)
~
HIGH-.....-----1
STAGE~
(RARELY
IN DEEP
WATER)
~ 1-10 m ----l
CURRENT ~~~~~~
" ..- ---------;.,.- STANDING
'" 1.2
'I//I///////1Ji.
w;;/)ii;/A
0.4 -0.7
-WAVE
I - - - 5 m ------l
e---?
~
PLANE
BED (Sh)
~
0----?
LAG
SAND BARS
\I
LOWER
FLOW
REGIME
DUNES
WITH
RIPPLES
PlANAR TABUlAR CROSS-BEDDING (Sp)
0.2-0.3
. !J.
I~
:';;~:~';~": ,.,. 0 .06
0.6 mm
COAR5E SAND
GRAVEL
BOULDERS
DEPOSITION OF
LAMINATED SILT, MUD (F!)
~ SAND TRANSPORT CONTlNUOUS OR INTERMITTENT
~ SAND TRANSPORT ONLY INTERMITTENT
0----:. GRAVEL TRANSPORT CONTINUOUS OR INTERMITTENT
f> GRAVEl ROlLS INTO SCOUR
RIVER SYSTEMS
A , lOW-GRADIENT, MEAND.ERING OR
ANASTOMOSING, PERENNIAL
B , HIGH-GRADIENT, BRAIDED, PERENNIAL
C, HIGH-GRADIENT, EPHEMERAl
C
B
I
I
IA
I
I
I
I
I