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Multidecadal climate oscillations and climate scenarios for impact analysis climate scenarios for impact analysis on hydrological extremes in Belgium
Patrick WillemsKU Leuven – Hydraulics Division
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Does the river Meuse change,
due to climate change ?
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Is our climate changing?
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Historical climate trends
Historical trend analysisWinter rainfall extreme quantiles Uccle (KMI/IRM, 10 min -> seasonal) 1898 –2007:
10
20
30
s [%
]
Global warming Global warming impactimpact1910s-1920s 1950s-1960s
1990s
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
year [-]
-50
-40
-30
-20
-10
0
10
anom
aly
in e
xtre
mes
winter, 10-year windowwinter, 15-year windowlong-term averageapproximate cyclic variationscyclic variations plus climate changeclimate change effect
Multidecadal Multidecadal climate oscillationclimate oscillation
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Historical trend analysisWinter monthly river flow quantiles Meuse at Monsin since 1925, moving window of 15 years length:
20
25
30
Precipitation, Uccle
River flow, Meuse at Monsin
Multidecadal climate oscillations
1990s
-15
-10
-5
0
5
10
15
20
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000
An
om
aly
[%
]
River flow, Meuse at Monsin
1910s-1920s 1950s-1960s
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Multidecadal climate oscillations
(Anti-)correlations of climate oscillations across EuropeDaily rainfall ECA&D database:
-40
-20
0
20
40
60
80
1880 1900 1920 1940 1960 1980 2000
An
om
aly
[%
]
precipitation, Uccle
precipitation, Bologna
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Multidecadal climate oscillations
Link with large-scale atmospheric circulation:
0
10
20
30
40
50
60
0
5
10
15
Pre
c. a
no
ma
ly [
%]
SLP
an
om
aly
[-]
SLP, Gibraltar - SLP, Haparanda(Sweden)
SLP, Gilbraltar - SLP, Vestervig(Denmark)
precipitation, Uccle
-40
-30
-20
-10
0
-15
-10
-5
Pre
c. a
no
ma
ly [
%]
SLP
an
om
aly
[
-40
-30
-20
-10
0
10
20
30
40
50
SLP
an
om
aly
[%
]
SLP, Reykjavik
SLP, Gibraltar
NAO+ NAO-
NAO+
-
10
20
30
mes
[%]
Multidecadal climate oscillations
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
year [-]
-50
-40
-30
-20
-10
0
anom
aly
in e
xtre
m
winter, 10-year windowwinter, 15-year windowlong-term averageapproximate cyclic variationscyclic variations plus climate changeclimate change effect
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Future climate ?
?
10
20
30
mes
[%]
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
year [-]
-50
-40
-30
-20
-10
0
anom
aly
in e
xtre
m
winter, 10-year windowwinter, 15-year windowlong-term averageapproximate cyclic variationscyclic variations plus climate changeclimate change effect
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Global climate models (GCMs)
European regional climate models (RCMs)
CCI-HYDR project
Belgian Science Policy Office
: climate change scenarios for impact
Climate models
Results for Belgium
: climate change scenarios for impact
analysis on hydrological extremes
in Belgium
• 44 runs with 21 global climate models
• 57 runs with 10 regional climate models
Control period: 1961-1990
Scenario period: 2071-2100
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Statistical downscaling
Large Scale
Dynamical
General Circulation Models
(GCMs)150 – 300 km; seasonally – monthly
Hydrological scale
downscaling
Statistical downscaling
Regional Climate Models
(RCMs)
± 50 km; weekly - daily
± 25 km; daily
river catchment; hourly
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Climate model results
Uccle, mean monthly temperature (1961-1990):
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Climate model projections
Uccle, mean monthly temperature (1961-1990 -> 2071-2100):
summer:+2 to +7°C
winter:+1.5 to +4°C
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Climate change
Temperature rise
Increase in greenhouse gases in the atmosphere
Air moisture at saturation point increases
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Climate model projections
Uccle, monthly mean rainfall (1961-1990 -> 2071-2100):
winter:up to +60%
summer:up to -70%
no. rainy summer days:
up to -50%
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Climate model projections
Uccle, extreme daily rainfall (summer, 1961-1990 -> 2071-2100):
Highest event in 10 years: up to +50%
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Climate scenarios
Uccle, extreme daily rainfall (summer, 1961-1990 -> 2071-2100):
High
Fac
tor
rain
fall
chan
ge [-
]
Mean
Low
Return period [years]
Fac
tor
rain
fall
chan
ge [
-
1.25
1.3
1.35
SHMI-MPI-A2
SHMI-MPI-B2
CNRM-DE6DMI-ECC-A2
Regional climate model simulations
Consistency check with historical trend analysisExample: Uccle, winter daily rainfall extremes:
High = Wet
Climate scenarios
0.95
1
1.05
1.1
1.15
1.2
1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100
Per
turb
atio
n fa
ctor
DMI-ECC-A2
DMI-ECC-B2CNRM-DE5
ICTP-A2HS2 / HS3 / CNRM-DC9
SHMI-HC-B2ETH / HS1
CNRM-DE7 / SHMI-HC22GKSS-A2
GKSS-sn-A2 / METNO-A2SHMI-HC-A2
ICTP-B2DMI25 / KNMI
METNO-B2
Control period(1960-1990)
Scenario period(2070-2100)
Historical trend 30 years blocksize
Historical trend 30 years blocksize: part c.c. increase
Mean = Mild
Low = DryCurrent
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Climate scenarios
Regional differences:Strong north – south variations Europa
minder droog in zomer:
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Impact climate scenarios
Period from 1961-1990 to 2071-2100:• Winter:
� rainfall increase: 0 -> +60%� temperature & evaporation increase:
+1.5 -> 4°C• Summer:
� rainfall decrease: 0 -> -70%� rainfall decrease: 0 -> -70%� number of rainy days: 0 -> -50%� temperature & evaporation increase:
+2 -> 7°C� extreme intensities increase:
2-year event: 0 -> +30%10-year event: 0 -> +50%
• Coastal – polder area:rainfall change +10% higher
• Sea level rise Belgian Coast:20cm -> 2m
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Comparison of downscaling methods
• Two completely different methods/assumptions lead to similar downscaling results!
High
Mean
Low
Direct precipitation results + quantile based climate factors
Extended weather typing technique (28 Jenkinson-Collison weather types + effect temperature rise)
1 day10 min 1 day10 min
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• Day -> hour (river), 10-min (sewer system)• Based on quantile perturbations:
– change in rain storm frequency and rain storm intensity– dependent on return period rainfall intensity, season, weather type, …
• Time horizons till 2030, 2050, …, 2100
CCI-HYDR Perturbation Tool
Month i Month i Month i
Wet day frequencyperturbation
Wet day intensityperturbation
Combined perturbation
Time series
Time series
High = Wet
Mean = Mild
Low = Dry
DailyHourly10min
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CCI-HYDR Perturbation Tool
• Preserves physical consistency (dependency) between seasons and variables (precipitation, temperature and ETo)
Day-Winter1.4
Day-Summer1.4Winter Summer
0.4
0.6
0.8
1
1.2
0.8 1 1.2 1.4 1.6 1.8
Eto Perturbation [-]
Rai
nfal
l Per
turb
atio
n [-
]
High Mean Low
0.4
0.6
0.8
1
1.2
0.8 1 1.2 1.4 1.6 1.8
Eto Perturbation [-]
Rai
nfal
l Per
turb
atio
n [-
]
ETo change factor ETo change factor
Pre
cip.
cha
nge
fact
or
Pre
cip.
cha
nge
fact
or
High Mean Low
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Hydrological impact modelling
Rainfall, ETo
Rainfall-runoffNAM, PDM: conceptual
Spatially distributed:SCHEME (KMI/IRM), MIKE-SHEWetSpa (VUB)
River hydrodynamics
Physico-chemical riverwater quality
WetSpa (VUB)
MIKE11InfoWorks-RS+ quasi 2D overstromingen
Spills
Calculation nodesnumerical scheme
Right floodplainLeft floodplain
Bridge over tributary(culvert + weir)
MAIN RIVER
TRIBUTARY
MIKE11 EcoLab
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• New method for testing the accuracy of the rainfall-runoff models in making extrapolations to more extreme rainfall conditions:
Hydrological model testing
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• Data-based checking of the model structure:
Hydrological model testing
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• Data-based checkingof the shape of the tail of the extreme value distribution:
Hydrological model testing
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• Data-based checkingof the shape of the tail of the extreme value distribution:
Hydrological model testing
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Impact of climate scenarios on hourly runoff peaks:
Hydrological impact
40
60
80
varia
tie p
ieka
favo
eren
(%))
)
High Mean Low
Cha
nge
in r
iver
pea
k flo
ws
[%]
High Mean Low
-40
-20
0
20
0.1 1 10 100
Terugkeerperiode (jaar)
varia
tie p
ieka
favo
eren
(%))
)
Return period [years]
Cha
nge
in r
iver
pea
k flo
ws
[%]
precip.increase ETo
increase
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• Impact of climate scenarios on hourly runoff peaks:
Hydrological impacts
(-70%) - (-50%)(-49%) - (-30%)(-29%) - (-22%)(-21%) - (-13%)(-12%) - 0
Low scenario, Runoff peaks RUNOFF PEAKS
01% - 22%23 %- 24%25 %- 32%33% - 37%
High scenario, Runoff peaks
Climate 2100, Flanders
→ Change in flood risks is highly uncertain→ Runoff peaks due to rainfall/ETo change decrease in low
scenario and increase in high scenario (up to 35%)→ Major influence due to sea level rise (Scheldt tidal river)
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• Impact of climate scenarios on low flows extremes:
Hydrological impacts
Low scenario, Runoff peaks LOW FLOW PEAKS
(-88%)(-87%) - (-68%)(-67%) - (-63%)(-62%) - (-55%)(-54%) - (-48%)
Low scenarioLow scenario, Runoff peaks LOW FLOW PEAKS
(-88%)(-87%) - (-68%)(-67%) - (-63%)(-62%) - (-55%)(-54%) - (-48%)
Low scenario
High scenario, Runoff peaks
Climate 2100, Flanders
(-35%) - (-32%)(-31%) - (-24%)(-23%) - (-21%)(-20%) - (-15%)(-14%) - (-10%)
High scenarioHigh scenario, Runoff peaks
Climate 2100, Flanders
(-35%) - (-32%)(-31%) - (-24%)(-23%) - (-21%)(-20%) - (-15%)(-14%) - (-10%)
High scenario
→ Low flow risks increase significantly in all scenarios→ May increase problems rel. water quality, navigation, drinking water production,
irrigation, industrial cooling water availability, groundwater table decreases, groundwaterquality decreases (oxygen reactions), ecological state river valley changes, ...
(-54%) - (-48%)(-54%) - (-48%)
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Hydrological model testing
MIKE-SHE
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• Impact on peak flow extremes 2071-2100:
Model intercomparison
HighMeanLow
30 to 70% increase
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• Impact on low flow extremes 2071-2100:
Model intercomparison
HighMeanLow
40 to 70% decrease40 to 70% decrease
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Some papers
• Ntegeka V., Willems P. (2008), ‘Trends and multidecadal oscillations in rainfall e xtremes, based on a more than 100 years time series of 10 minutes rainf all intensities at Uccle, Belgium ’, Water Resources Research, 44, W07402
• Baguis P., Roulin E., Willems P., Ntegeka V. (2009), ‘Climate change scenarios for precipitation and potential evapotranspiration over central Belgium ’, Theoretical and Applied Climatology, 99(3-4), 273-286
• Baguis P., Roulin E., Willems P., Ntegeka V. (2010), ‘Climate change and hydrological extremes in Belgian catchments ’, Hydrol. Earth Syst. Sci. Discuss., 7, 5033-5078
• Willems P., Vrac M. (2011), ‘Statistical precipitation downscaling for small-sca le hydrological impact investigations of climate change ’, J. Hydrol., 402, 193–205
• Van Steenbergen, N., Willems, P. (2012), ‘Method for testing the accuracy of rainfall -runoff models in • Van Steenbergen, N., Willems, P. (2012), ‘Method for testing the accuracy of rainfall -runoff models in predicting peak flow changes due to rainfall change s, in a climate changing context ’, Journal of Hydrology, 414-415, 425-434
• Dams, J., Salvadore, E., Van Daele, T., Ntegeka, V., Willems, P., Batelaan, O. (2012). ‘Spatio-temporal impact of climate change on the groundwater system ’, Hydrol. Earth Syst. Sci., 16, 1517-1531
• Vanuytrecht, E., Raes, D. Willems, P. (2011), ‘Considering sink strength to model crop production under elevated atmospheric CO2 ’, Agricultural and Forest Meteorology, 151(12), 1753-1762
• Vanuytrecht, E., Raes, D., Willems, P., Geerts, S. (2012), ‘Quantifying field-scale effects of elevated carbon dioxide concentration on crops ’, Climate Research, 54, 35-47
• Vansteenkiste, Th., Tavakoli, M., Ntegeka, V., Willems, P., De Smedt, F., Batelaan, O. (in press), ‘Climate change impact on river flows and catchment hydrolog y: a comparison of two spatially distributed models ’, Hydrological Processes; doi: 10.1002/hyp.9480
• Willems, P., Olsson, J., Arnbjerg-Nielsen, K., Beecham, S., Pathirana, A., Bülow Gregersen, I., Madsen, H., Nguyen, V-T-V. (2012), ‘Impacts of climate change on rainfall extremes and urban drainage ’, IWA Publishing, 252p., Paperback Print ISBN 9781780401256; Ebook ISBN 9781780401263
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More floods?
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More low flow problems !
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• Drier summers may have severe impact• Mean water availability in Flanders and Brussels is very
limited: 1480 m3/(person.year)– International standards:
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Water availability
Study prof. K. Walravens U.Gent:
On some locations in Flanders the deep groundwater reduced with more than 140 m below the natural levels
Topography, isolines of aquifer piezometric level and piezometric level –
area in the “Sokkel” Aquifer in Southwest Flanders (view from the South)
“Sokkel” systemIn the main depression area of Southwest Flanders the groundwater abstraction needs to be reduced to about 25% of the current abstraction permission (anno 2000), in order to improve the situation and to avoid that the aquifer levels will further reduce on the long term (next 50 years)
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Water quality
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More info
Research project CCI-HYDR on“Impact of climate change on hydrological extremes (peak and low flows) along rivers (Scheldt and Meuse basins) and urban drainage systems in Belgium”(for Belgian Science Policy Office):
http://www.kuleuven.be/hydr/CCI-HYDR
Impact studies:Instituut voor Natuur- en Bosonderzoek (INBO):http://http://www.inbo.be
Vlaamse Overheid:Waterbouwkundig Laboratorium: http://www.watlab.beVlaamse Milieumaatschappij:http://www.milieurapport.behttp://www.watertoets.be/publicaties