1
Water and Dissolved Carbon Flows
(Amazon basin)
Land surface scheme ORCHIDEE - IPSL ESM
Terrestrial biosphere model
ORCHIDEE
Routing of water enabled for
transport of DOC & CO2(aq)
(http://labex.ipsl.fr)
3
Model implementation
Hydrology in ORCHIDEE
Vertical water fluxes, runoff
and drainage simulated at 30
min. timestep
TF
Surfacerunoff
2m,11Layers
I
Deepdrainage
Precipitation, wind, radiation
and temperature taken from
climate forcing files
Also soil properties and
vegetation taken from forcing
files
4
ET
P
New soil C module in ORCHIDEE
For each
layer
CO2
Runoff x DOC, CO2
Between
layers
(De) sorption
Advection / liquid phase transport
Diffusion/ Bioturbation
5
Drainage x DOC, CO2
Decomposition
Heterotrophic respiration
Sources of DOC to the river
FWD
FWD
SCAN
Fadd2can
Fadd2can
SCAN
FTF
FRO
FTF
FFI
SSoil
FFO
SFLOOD
FDR
Uplandsoils
River
Floodplain
6
New fluvial C module into ORCHIDEE
Soil module
Routing module
-  Production and export of DOC
-  Lateral Transfer of DOC and CO2 through fluvial network
-  Decomposition of DOC during transport
-  Evasion of CO2 from the water surface
a)
b)
Hydrology
8
Hydrology in ORCHIDEE
Parametriza@onofthehydrology
Withnewregionalforcingfilefor
floodplainsandswamps
MeanmonthlydischargeatObidos,attheAmazonRiver
Hydrology in ORCHIDEE
FloodingoftheCentralAmazonBasin(averages1995-1997)
Observa@on
CentralAmazonBasin
Area=177x104km²
~30%ofwatershed
Richeyetal.,2002
10
25x104km²=14%oftheCentralAmazonBasin
Hydrology in ORCHIDEE
FloodingoftheCentralAmazonBasin(averages1995-1997)
Observa@on
20
15
10
5
0
Flooded area (10^4 km²)
25
Simula@on
1
2
3
4
5
6
7
Month
8
9
10 11 12
Richeyetal.,2002
Simulatedflooding–Guimberteauetal.,2012
Simulatedflooding–newscheme
11
25x104km²=14%oftheCentralAmazonBasin
Fate of terrestrial DOC export
12
Fate of fluvial C transport in ORCHIDEE
CO2evasion:FCO2=k*∆pCO2*Awater
k=gasexchangevelocity
Transportof
DOC,CO2(aq)
OxidaSonofDOC
DOCCO2(aq)
CO2inputsfromfloodedsoils
(floodplainsonly)
Sources of DOC to the river - Throughfall
Amazonbasin:
Totalfluxto
theground
ThroughfallDOC:
14.4gCm-2yr-1
84.4TgCyr-1
~infiltraSngintotopsoil:
12.1gCm-2yr-1
71.0TgCyr-1
ThroughfallDOC
[gCm-2yr-1]
33
~directexportithrunoff:
2.2gCm-2yr-1
12.9TgCyr-1
0
Directexport
withsurface
runoff
Avg.Annualfluxes1980-2000
14
Sources of DOC to the river - Floodplains
Withrunoff
fromupland
soils
Amazonbasin:
MobilizedDOC
[gCm-2yr-1]
<.5
.5-1
1–5
5–10
10–50
50–100
>100
ThroughfallDOC:
14.4gCm-2yr-1
84.4TgCyr-1
~infiltraSngintotopsoil:
12.1gCm-2yr-1
71.0TgCyr-1
~directexportithrunoff:
2.2gCm-2yr-1
12.9TgCyr-1
DOCfromrunoff:
5.8gCm-2yr-1
34.0TgCyr-1
DOCexports
from
floodplains
Avg.Annualfluxes1980-2000
DOCfromfloodplains:
12.5gCm-2yr-1
-1
73.3TgCyr15
CO2 evasion from the Amazon watershed
16
CO2 – evasion Amazon Basin
AveragemodelledCO2evasionperyear1981-2000
FCO2[gCm-2yr-1]
<1
1...5
5...10
10...50
50...100
>100
FCO2=339TgCyr-1
17
CO2 – evasion Central Amazon Basin
CO2evasion,avg.1995-1997
CentralAmazonBasin
Area=177x104km²
~30%ofwatershed
Richeyetal.,2002
18
CO2 – evasion Central Amazon Basin
20
15
10
5
0
CO2 evasion [Tg C/month]
25
30
CO2evasion,avg.1995-1997
0
2
4
6
8
10
12
Month
SimulatedwithORCHIDOC
Richeyetal.,2002
19
Sediment & POC fluxes in ORCHIDEE
20
Erosion in ORCHIDEE
Regional to global scale modeling based on upscaling from high-resolution forcings
GIS+DEM (high resolution)
Slope steepness
Flow accumulation
Flow direction
River network
ORCHIDEE(coarse resolution)
Daily total runoff (runoff, mm)
Daily maximum 30-min runoff rate (prunoff, mm/s)
Total vegetation cover (cv)
MUSLE (Modified Universal Soil Loss Equation)
Soil carbon
Belowground litter
Total amount of soil that is eroded and transported to
the river network at each ORCHIDEE pixel
Total amount of soil carbon and litter that is eroded and
transported to the river network at each ORCHIDEE pixel
Routing module
Lateral transfer of sediment and carbon between grid cells
MUSLE in ORCHIDEE
Modified Universal Soil Loss Equation
Y = a(Q · qp)b ·K· L · S · C · P
Y: sediment yield (ton) on a storm basis and for the entire study watershed;
(For a certain pixel, Y is the total eroded soil from the pixel itself and the sediment input
from the adjacent upstream pixels)
Q: volume of runoff (m3);
qp: peak flow rate (m3 s-1);
K: soil erodibility factor (t ha h ha-1 MJ-1 mm-1);
L: slope length factor (dimensionless);
S: slope steepness factor (dimensionless);
C: crop management (vegetation cover) factor (0-1,dimensionless);
P: soil erosion control practice factors (0-1,dimensionless);
a, b: location coefficients
Erosion in ORCHIDEE: results as sub-catchment
GIS to extract slope steepness (θ), flow direction, flow accumulation from DEM
DEM: HydroSHEDS products of USGS (http://hydrosheds.cr.usgs.gov), the spatial resolution is 3-seconds (≈90m)
Soil erodibility: ESDAC, http://eusoils.jrc.ec.europa.eu
Annual sediment discharge at each pixel