morphologie alluviale et dynamique du transport observations
TRANSCRIPT
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Morphologie alluviale et dynamique du transportMorphologie alluviale et dynamique du transport
Observations
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Morphologie alluviale et dynamique du transportMorphologie alluviale et dynamique du transport
Le temps
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Morphologie alluviale et dynamique du transportMorphologie alluviale et dynamique du transport
Les flux
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y = 0.0583x - 1E-08R2 = 0.6966
0.E+00
2.E-08
4.E-08
6.E-08
8.E-08
1.E-07
1.E-07
0.E+00 2.E-07 4.E-07 6.E-07 8.E-07 1.E-06 1.E-06 1.E-06 2.E-06
Q tan m3s 1
3( / )sQ m s
70.06( tan 2.1 10 )sQ Q 70.06( tan 2.1 10 )sQ Q
Les flux
Morphologie alluviale et dynamique du transportMorphologie alluviale et dynamique du transport
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Morphologie alluviale et dynamique du transportMorphologie alluviale et dynamique du transport
L2
(1 )s x
t x s
q z
p z q
(1 )
(1 )t xx
t s xx s
p z z
p q q
A
w
A
La diffusion
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1 sin(t)
qsq0
t
RiverBrahmaputra 1.11E-01 1.25E-01Chao Phraya 7.14E-03 4.55E-02Chiang Jiang 5.88E-02 5.00E-02Ganges 2.13E-02 1.00E-01Hong He 1.67E-01 3.70E-01Huang He 1.03E-02 2.08E-02Indus 2.27E-02 4.00E-02Mekong 1.05E-02 3.33E-02Zhujiang 1.92E+00 2.00E-01
(Métivier & Gaudemer 1999, Castelltort & Van Den Driessche, 2003)
Morphologie alluviale et dynamique du transportMorphologie alluviale et dynamique du transport
Les glaciations
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Chemical weatheringAND Physical erosion
Chemical weatheringAND Physical erosion
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Weathering & ErosionWeathering & Erosion
: grain roughness
: weathering rate
: stochiometric coefficient
S : area production rate
solute pr
pr
Q r S
r
Principle
Working conditions :•1D Problem•Permanent regime (time independant)•No uplift
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Weathering & ErosionWeathering & Erosion
: Surface area production rate
: number of grains per unit time
: surface area per grain
pr gr gr
pr
gr
gr
S n a
S
n
a
gr
/
: total volume of material produced by erosion
: volume per grain
gr grn V
V
Surface production
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Weathering & ErosionWeathering & Erosion
gr grpr
gr gr
a adHS V A
dt
dH H
dt
HAS
D
For cubes we then get
If we take advantage of ahnerts equation for a 1D mountain
Mechanical erosion
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Weathering & ErosionWeathering & Erosion
00
1 1exp aEr r
R T T
solute prQ r S
Temperature
slT T aH
0slT T
0 0 0
exp( )
aEr aH
r R T T aH
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Weathering & ErosionWeathering & Erosion
0 0 0
exp( )
solute aq EH aHq
r D R T T aH
Dissolved Flux
HAS
D
0 0 0
exp( )
aEr aH
r R T T aH
solute prQ r S
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Weathering & ErosionWeathering & Erosion
D= 0.00001 (m)
020406080
100120140160180200
0 1000 2000 3000 4000 5000
altitude (m)
qd
im D= 0.00001 (m)
Dissolved Flux