Climate change scenarios for hydrological impact analysis ...CORDEXbe... · Climate change...
Transcript of Climate change scenarios for hydrological impact analysis ...CORDEXbe... · Climate change...
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Climate change scenarios
for hydrological impact
analysis (floods, droughts)
Parisa Hosseinzadehtalaei, Hossein Tabari,
Els Van Uytven, Patrick Willems
KU Leuven - Hydraulics Section
Climate change impact analysis
GCMs
RCMs
Urban hydrological
impact models
Statistical
downscaling
incl. bias
correction
Large ensemble (>200): CMIP5
Reduced ensemble:
CORDEX
Climate scenarios
Coarse resolution climate models
-> need for downscaling + bias correction
Thanks to CORDEX.be
GCMs
RCMs
LAMs
Statistical
downscaling
incl. bias
correction
Large ensemble (>200): CMIP5
Reduced ensemble:
EURO-CORDEX
Climate scenarios
High resolution (2.8 4 km)
convection permitting models
Urban hydrological
impact models
Changes in precipitation extremes
Influence of number of model runs?
Hosseinzadehtalaei P, Tabari H, Willems P (2017) Uncertainty assessment for climate change impact on intense
precipitation: How many model runs do we need? International Journal of Climatology, 37(S1), 1105-1117
Climate model based variance analysis for extreme precipitation:
At least 10-15 runs needed for
obtaining unbiased & reliable
change factors
Climate scenarios
GCMs
RCMs
LAMs
Statistical
downscaling
incl. bias
correction
Large ensemble (>200): CMIP5
Reduced ensemble:
EURO-CORDEX
Climate scenarios
Urban hydrological
impact models
CORDEX.be runs
-> downscaling
CORDEX.be runs
-> downscaling + lower bias for precipitation extremes
Tabari H, De Troch R, Giot O, Hamdi R, Termonia P, Saeed S, Brisson E, Van Lipzig N, Willems P (2016)
Local impact analysis of climate change on precipitation extremes: are high-resolution climate models needed
for realistic simulations? Hydrology and Earth System Sciences 20: 3843-3857
Coarser resolution
models, daily
LAM fine resolution models, hourly
Tabari H, De Troch R, Giot O, Hamdi R, Termonia P, Saeed S, Brisson E, Van Lipzig N, Willems P (2016)
Local impact analysis of climate change on precipitation extremes: are high-resolution climate models needed
for realistic simulations? Hydrology and Earth System Sciences 20: 3843-3857
Saeed S, Brisson E, Demuzere M, Tabari H, Willems P, van Lipzig N (2017) Multidecadal convection permitting
climate simulations over Belgium: Sensitivity of future precipitation extremes. Atmospheric Science Letters
18(1): 29-36
Coarser resolution
models, 3-hourly
LAM fine resolution
models, 15min
CORDEX.be runs
-> downscaling + lower bias for precipitation extremes
ALARO model
Changes in precipitation extremes
Tabari H, De Troch R, Giot O, Hamdi R, Termonia P, Saeed S, Brisson E, Van Lipzig N, Willems P (2016)
Local impact analysis of climate change on precipitation extremes: are high-resolution climate models needed
for realistic simulations? Hydrology and Earth System Sciences 20: 3843-3857
Relative changes till 2071-2100:
Strong (potential) dependency of climate
change factor on time & spatial scale
CCLM model
LAM fine resolution, hourly
Coarser resolution models, daily
Changes in precipitation extremes
Higher changes for higher return periods & shorter durations:
Changes in precipitation extremes
Higher changes for higher greenhouse gas concentrations:
Conclusions
Because at least 10 to 15 different models should be considered for
obtaining reliable climate change factors
& no large ensemble of super resolution climate model runs available yet:
hydrological impact modellers have to rely on:
combining available climate change projections from:o GCMs (large ensemble available; CMIP5)
o RCMs (smaller ensemble available; EURO-CORDEX)
o LAMs (few models and runs available; CORDEX.be)
to be further downscaled applying statistical methods
where statistical downscaling assumptions have to be applied with caution and validated as much as possible
Applications
Changes in precipitation extremes -> Changes to design storms (design of urban drainage systems):
0
10
20
30
40
50
60
70
-100 -50 0 50 100
Rai
nfa
ll in
ten
sity
[mm
/h]
Time [min]
historical climate
mean climate scenario
high climate scenario
Applications
Changes in precipitation, temperature, ETo statistics -> Perturbed historical time series (river catchment
hydrological impact analysis: floods, droughts, ):
Spills
Calculation nodes
numerical scheme
Right floodplainLeft floodplain
Bridge over tributary(culvert + weir)
MAIN RIVER
TRIBUTARY
Climatic change signals:
Climatic Perturbation Tool:
Hydrological & hydraulic impact models:
Impact results:
Current climate
Climate scenarios
>200 GCMs CMIP5 (RCP based) for Uccle: change for 100 years (2000 -> 2100):
Change in mean monthly temperature:
Strong increase in temperature
(mainly in summer)
Current climate
Climate scenarios
>200 GCMs CMIP5 (RCP based) for Uccle: change for 100 years (2000 -> 2100):
Change in mean monthly rainfall:
Winter: increase in rainfall
Summer: strong decrease in rainfall
Climate scenarios
>200 GCMs CMIP5 (RCP based) for Uccle: change for 100 years (2000 -> 2100):
Change in number of wet days:
Current climate
Summer: strong decrease in number of rainy days
Climate scenarios
>200 GCMs CMIP5 (RCP based) for Uccle: change for 100 years (2000 -> 2100):
Change in rainfall intensity for 20-year storm:
Increase in extreme rainfall intensities
Current climate
Applications
Changes in precipitation, temperature, ETo, statistics: Climate Perturbation Tool
Month i Month i Month i
Wet day frequency
perturbation
Wet day intensity
perturbation
Combined perturbation
Time
series
Time
series
Perturbs historical series to high/mean/low climate scenarios
Time scales: daily, hourly, 10-minutes
Based on quantile perturbations:
change in rain storm frequency and rain storm intensity
dependent on return period and season
Time horizons till 2030, 2050, , 2100
High = Wet
Mean = Mild
Low = Dry
Daily
Hourly
10min
High/mean/low climate scenarios, tailored for
hydrological climate change impact analysis
High / Wet
Mean / Mild
Low / Dry
IMP
AC
T
Floods
Low flows
Hydrological impact analysis
Rainfall, ETo
Rainfall-runoff
River
hydrodynamics
Physico-
chemical river
water quality
PDM, NAM, VHM:
conceptual
Spatially distributed:
MIKE-SHE
WetSpa
Modflow
InfoWorks (RS, ICM)
MIKE11
+ floodplains
Spills
Calculation nodes
numerical scheme
Right floodplainLeft floodplain
Bridge over tributary(culvert + weir)
MAIN RIVER
TRIBUTARY
Our recent CORDEX.be papers on the topic:
Tabari H, De Troch R, Giot O, Hamdi R, Termonia P, Saeed S, Brisson E, Van
Lipzig N, Willems P (2016) Local impact analysis of climate change on
precipitation extremes: are high-resolution climate models needed for realistic
simulations? Hydrology and Earth System Sciences 20: 3843-3857
Saeed S, Brisson E, Demuzere M, Tabari H, Willems P, van Lipzig N (2017)
Multidecadal convection permitting climate simulations over Belgium:
Sensitivity of future precipitation extremes. Atmospheric Science Letters
18(1): 29-36
Hosseinzadehtalaei P, Tabari H, Willems P (2017) Uncertainty assessment for
climate change impact on intense precipitation: How many model runs do we
need? International Journal of Climatology 37(S1): 1105-1117
Hosseinzadehtalaei P, Tabari H, Willems P (2017) Precipitation intensity
durationfrequency curves for central Belgium with an ensemble of EURO-
CORDEX simulations, and associated uncertainties. Atmospheric Research
200: 1-12; doi:10.1016/j.atmosres.2017.09.015
Contact:[email protected]