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09/06/2015
1
LAS
RICCAR
Using Bias-Corrected Regional Climate
Modelling Outputs for the Arab
Domain to support Hydrological
Modelling
Joel Dahné
Swedish Meteorological and Hydrological Institute (SMHI)
LAS
RICCAR
Future Climate Projections
A core activity within RICCAR is to produce
regionally downscaledregionally downscaledregionally downscaledregionally downscaled future climate
projections for the Arab Region
We need an ensemble of projectionsensemble of projectionsensemble of projectionsensemble of projections because
there is no single answer!
Arab RCM Domain“ensemble” > reproduce results many times using variations in how we go about it
09/06/2015
2
LAS
RICCAR
Future Hydrological Projections
Regional Hydrological Modelling over the Arab
Region is a key component of RICCAR
• (RCP2.6)
• RCP4.5
• RCP8.5
• EC-EARTH
• CNRM-CM5
• GFDL_ESM2M
• RCA4 • VIC
• HYPE
• Python
• ArcGIS
LAS
RICCAR
RCM
(Institute)
GCM Historical
1950-
2005
RCP4.5
2006-
2100
RCP8.5
2006-
2100
RCA4
(SMHI)
EC-Earth
50km✔ ✔ ✔
RCA4
(SMHI)
EC-Earth
25km✔ ✔
RCA4
(SMHI)
CNRM
50km✔ ✔ ✔
RCA4
(SMHI)
GFDL-ESM
50km✔ ✔ ✔
RCA4
(SMHI)
GFDL-ESM
25km✔ ✔
CORDEX-MENA/Arab Ensemble Matrix
Used for Hydrological analysis
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LAS
RICCAR
Requires an interface to overcome RCM biases
Downscaling of RCMs
LAS
RICCAR
Temperature
Precipitation
Example: Bias in EC-EARTH as compared to reference data
09/06/2015
4
LAS
RICCAR
Obs
Direct
RCA3_E5/Ctrl
overestimated
dischange
Example from Torpshammer River Basin in Sweden
(Observations & RCA-ECHAM5) - RCM overestimates precipitation
Direct input of Prec. & Temp. from RCM
control period: 1961-1990
Hydrological model simulations (HBV Model)
LAS
RICCAR
Obs
Direct RCA3
E5/Ctrl
Bias corrected
E5/Ctrl
Bias-corrected input of Prec. & Temp. from
RCM control period: 1961-1990
improved
dischange
Example from Torpshammer River Basin in Sweden
(Observations & RCA-ECHAM5) - RCM overestimates precipitation
Hydrological model simulations (HBV Model)
09/06/2015
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LAS
RICCAR
Some 30 000 subbasinsaverage size 650 km2
Gridded 50 x 50 kmGrid box area 2500 km2
Hydrological Models used for analysis
Main differences
More conceptual �Mode physical
Division into basins � Gridded
Integrated routing, lake/dam routines � routing, lake/dam as modules
Parameterization and calibration
Hype Model VIC Model
LAS
RICCAR
Regionalization, from local to regional model setup
• Calibrate gauged catchments
• Regionalization by nearest neighbor
SoilLandcover
• Calibrated gauged basins (pilot sites)
• Regionalization by linking parameters
to land cover or soil.
Characterization
(VIC Global Input Parameters)
• Hydraulic conductivity
• Elevation
• Soil density
• Water content at wilting point
• Water content at field capacity
Globcover Digital Soil Map of the World
Hype Model VIC Model
Characterization
Landuse Soil type
Arable Coarse
Forest Medium
OpenLand Fine
Wetland Organic
Urban Bare/Shallow
Bare land Submerged/Irrigated
Water
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LAS
RICCAR
River discharge
Runoff from land
Evapotranspiration
Soil water storage
Precipitation
Temperature
Hydrological modelling input and output
HYPE
RCP 4.5 RCP 8.5
Hydro Ensemble
Mean, Max, Min
Creating Future Hydro Projection Ensembles
VIC
HYPEVIC
Hydro Ensemble
Mean, Max, Min
VIC
HYPE
Modelrun 1980 – 2100 Modelrun 1980 – 2100
HYPE
VIC
2*high resolution
VIC
HYPE
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LAS
RICCAR
Future hydro climate projectionsSub-regions
LAS
RICCAR
Maps
Timeserie graphs (to ensembles)
Seasonal graph
(to ensembles)
Graphs relating rcp8.5 ensemble to
High Resolution projections
Hyd-results
• Evapotranspiration
• Soil water storage
• Runoff from land
• River discharge
Climate projections
• 3 RCP 8.5
• 3 RCP 4.5
• 2 RCP8.5, high res
Hyd-models:
• VIC
• HYPE
Time periods:
• 1986-2005
• 2016-2035
• 2046-2065
• 2086-2100
Future hydro climate projectionstype of outcome
Tables
Value Change Agreement
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LAS
RICCAR
Model forcing - RCP 8.5Climate Models: 3-member ensemble
Temperature
Precipitation
Reference
1986-2005
Ensemble
agreement
Change to
2081-2100
> 16 <-16[mm/month]<0.1 >150[mm/month] All - All +
0 35[°C] > 4.0 <-4.0[°C] All - All +
LAS
RICCAR
Evapotranspiration - RCP 8.5Hydro Models: 3-member ensemble
HYPE-m
odel
VIC-m
odel
Reference
1986-2005
Ensemble
agreement
Change to
2081-2100
> 16 <-16[mm/month]<0.1 >150[mm/month] All - All +
09/06/2015
9
LAS
RICCAR
Runoff - RCP 8.5Hydro Models: 3-member ensemble
HYPE-m
odel
VIC-m
odel
Reference
1986-2005
Ensemble
agreement
Change to
2081-2100
> 16 <-16[mm/month]<0.1 >150[mm/month] All - All +
LAS
RICCAR
Mediterranean
Annual HYPE VIC HYPE VIC
Period RCP Runoff Evap
2016-2035 4.5 3% 10% -1% -1%
8.5 9% 17% 0% 1%
2046-2065 4.5 2% 8% -3% -2%
8.5 -2% 2% -7% -7%
2081-2100 4.5 8% 17% -2% -1%
8.5 -13% -10% -14% -15%
Changes to 1986-2005
Pre
cip
ita
tio
n
[%]
Tem
pe
ratu
re
[⁰C
]
Ru
no
ff (
HY
PE
)
[%]
Ev
ap
ora
tio
n (
HY
PE
)
[%]
Seasonal changes 2071-2100 to 1986-2005
RCP 8.5
RCP 4.5
mm
/da
y]
[⁰C
]m
m/d
ay
]
Summary table (ensemble mean)
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LAS
RICCAR
Moroccan Highlands
Annual HYPE VIC HYPE VIC
Period RCP Runoff Evap
2016-2035 4.5 3% 2% -2% -2%
8.5 -7% -9% -3% -2%
2046-2065 4.5 -17% -22% -8% -7%
8.5 -32% -40% -15% -12%
2081-2100 4.5 -23% -28% -11% -10%
8.5 -48% -59% -26% -22%
Pre
cip
ita
tio
n
[%]
Tem
pe
ratu
re
[⁰C
]
Ru
no
ff (
HY
PE
)
[%]
Ev
ap
ora
tio
n (
HY
PE
)
[%]
Changes to 1986-2005 Seasonal changes 2071-2100 to 1986-2005
RCP 8.5
RCP 4.5
mm
/da
y]
[⁰C
]m
m/d
ay
]
Summary table (ensemble mean)
LAS
RICCAR
Ethiopian highlands
Pre
cip
ita
tio
n
[%]
Tem
pe
ratu
re
[⁰C
]
Ru
no
ff (
HY
PE
)
[%]
Ev
ap
ora
tio
n (
HY
PE
)
[%]
Changes to 1986-2005 Seasonal changes 2071-2100 to 1986-2005
Annual HYPE VIC HYPE VIC
Period RCP Runoff Evap
2016-2035 4.5 0% 0% -2% 0%
8.5 -2% 0% -4% 0%
2046-2065 4.5 -5% -1% -7% 0%
8.5 -3% 0% -3% 0%
2081-2100 4.5 -8% -1% -13% -1%
8.5 -7% -1% -10% -1%
Summary table (ensemble mean)
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LAS
RICCAR
Final remarks:
• Bias-correction proved to be more demanding for
the highly variable climate of the region than
expected
• The volume of data processed required a lot of
time, both computational and in man hour
• We are still in the process of identifying what the
main outcomes are