436
:;:::: --:Ql
N
....
50
v
40
0
0
"C
~
x
....J 30
-x
. .
E
I
0 20
';J
co
....
....
Q)
10
Q)
CI:
Chapter 9
t t
b
.... 124
121
0
()
0
c
....
0
Denudation and Mass Transport
1000
co
-800 E
E
....
-
600 g
2
400 ~
c
c
co
c
200 ~
~
. .
0 ~LlZLaz~~~~~~~~~~~~~~~~~~~O
10
10
Chemical denudation rate
20
(mm/ka)
:-:·:·670
M 600 )[:II! 470 Brahmaputra
t
1000
~
Relief ratio Hma.lL
1500
Hmax of
~
~ - t - - loeal relief
NE
~~--------------------~------~
~
t: , ~ ~ I I I , I ~ ~ i , , ; ~ ~
11
I
I
I
I"C C
c:t
I
I
I
I E :~
. . . . I: I 1120 g'
L
max, length of drainage area
300 ~
Cl
C c
Q)
....
ß 2 'e.
Ql
ltI
C.
E 'Vi
o
c
a
J2
Q)
'> .... c
Q)
~ 80
....
Mechanical denudation rates (mm/ka)
E
200~
c
o
';J
~ 60
:J
C
Q)
'0
co
(,l
c
co
40
'5 20
Q)
~
o
Ql
c
'N
0
~
Cl
C
:l Cl Ql
>- c ~
ltI
()
.... ltI
0 ~
Fig. 9.12. Mean mechanical and chemical denudation rates, DR", and DR.,h (here for rock density 2.7
glcm 3 ), in the drainage areas of major world rivers,
DR",e values correlate relatively weH with the relief
ltI
~
Ql
"C
....
C
tf)
:l
~
ltI l'J
.... ltI >0
(:[ ~
....
ä:
:l
ltI
:l E ~
~
...J ~ ltI
E
>- ltI
0
C .D
~
Ql 0
...J
3
2
... ..
Ql
()
C
Ql
.... ~
C. ltI
Ql ...J
C ..;
0 Cf)
1
100
o
Q)
rJ)
(,l
;;::
'ü
Q)
Co
Cf)
ratios (shaded eolumns) and, to a minor degree, with
annual runoff (dotted lines), (Drawn after data from
Summerfield and Hulton 1994), DR",e of the YeHow
river is calculated from its modem river load