Modelling effects of climate g change on hydrology - NVE

<strong>Modelling</strong> <strong>effects</strong> <strong>of</strong> <strong>climate</strong>
<strong>change</strong> on hydrology
Stein Beldring
Norwegian Water Resources and Energy Directorate

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Outline
Global <strong>climate</strong> <strong>change</strong>
Downscaling from AOGCMs
to hydrological impact models
Water resources maps for the
Nordic region presenting
<strong>change</strong>s from present (1961-
1990) to future (2071-2100)
conditions
Uncertainty in hydrological
impact simulations caused by
different emission scenarios
and <strong>climate</strong> models
Climate <strong>change</strong> impacts on
glacier covered catchments in
Norway, Svalbard and Bhutan
ACIA: Freshwater discharge to the Arctic
Norwegian Water Resources and Energy Directorate

Norwegian Water Resources and Energy Directorate
3

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Emissions <strong>of</strong> CO 2 and other greenhouse
gases have disturbed the carbon balance
<strong>of</strong> the atmosphere
Greenhouse gases affect the
atmospheric absorption properties <strong>of</strong>
longwave radiation, changing the
radiation balance and warming the lower
troposphere
Increase in temperature leads to an
intensified hydrological cycle, i.e. higher
evaporation and precipitation rates
Climate <strong>change</strong> will lead to <strong>change</strong>s in
mean conditions, variability and extremes
<strong>of</strong> hydrological variables and fluxes, e.g.
snow storage, run<strong>of</strong>f and evaporation
These <strong>change</strong>s will influence:
■ the natural environment
■
the society (and can either be to its
advantage or disadvantage)
CO 2 concentration
Temperature <strong>change</strong>
Norwegian Water Resources and Energy Directorate
4

Range <strong>of</strong> surface warming IPCC 4AR
5
Norwegian Water Resources and Energy Directorate

Multi-model mean projected surface temperature
<strong>change</strong>s relative to the period 1980-1999
B1
A1B
A2
Norwegian Water Resources and Energy Directorate
Source: IPCC

Climate <strong>change</strong>
”displacement”
in Norway from
1961-1990 to
2021-2050
and
2071-2100
Source: RegClim
7
Norwegian Water Resources and Energy Directorate

Multi-model mean <strong>change</strong>s in precipitation (mm day –1 ), soil moisture
content (%), run<strong>of</strong>f (mm day –1 ) and evaporation (mm day –1 ). Changes
are annual means for the SRES A1B scenario for the period 2080 to
2099 relative to 1980 to 1999.
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Norwegian Water Resources and Energy Directorate

Climate <strong>change</strong>
impacts on
precipitation,
drought and snow
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Norwegian Water Resources and Energy Directorate

Utilization <strong>of</strong> land resources, e.g. deforestation results in significant <strong>change</strong>s <strong>of</strong>
land cover and soil types. These <strong>change</strong>s influence land surface hydrology
through their influence on e.g. albedo, evaporation, soil type, run<strong>of</strong>f generation
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Norwegian Water Resources and Energy Directorate

Description <strong>of</strong> the boundary conditions, including their <strong>change</strong>s and a model <strong>of</strong>
the internal system dynamics. Models for the hydrological cycle transform the
meteorological forcing into the hydrological response <strong>of</strong> a catchment based on
the characteristics <strong>of</strong> the model domain and the relevant hydrological processes.
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Norwegian Water Resources and Energy Directorate

Observed input, output (and state variables) data are necessary
for calibration, validation and running <strong>of</strong> the hydrological model
The primary input variables used in hydrological
modeling are temperature and precipitation
State variables describing the state <strong>of</strong> the
system, e.g. snow or groundwater storage
The output variable in hydrological modeling is usually
the integrated catchment response <strong>of</strong> streamflow
12
Norwegian Water Resources and Energy Directorate

Numerical solution
- Equations continuous in space and time
- Numerical solution only possible in a grid
13
Norwegian Water Resources and Energy Directorate

Dynamical downscaling over limited regions (domains) <strong>of</strong>
the globe with regional <strong>climate</strong> models give more details!
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Typical present day regional model 25 50 km
Norwegian Water Resources and Energy Directorate
Typical present-day regional model 25-50 km
Typical present-day global model 110-300 km

Regional <strong>climate</strong> model domain
Norwegian Water Resources and Energy Directorate

Different topography – elevation is not
represented correctly in regional <strong>climate</strong> models
Distributed HBV hydrological model
• 1 km ×1 km
• 0 – 2256 m a.s.l.
HIRHAM regional <strong>climate</strong> model
• 55 km × 55 km
• 0 – 1281 m a.s.l
16
Norwegian Water Resources and Energy Directorate

Regional Climate
Model HIRHAM
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Norwegian Water Resources and Energy Directorate

Modeling <strong>climate</strong> <strong>change</strong> impacts on
water resources in the Nordic countries
■ Two emission scenarios for greenhouse gases:
■
A2 (larger emissions) and B2 (smaller emissions)
■ To global <strong>climate</strong> models :
■ Max Planck Institut für Meteorologie ECHAM4/OPYC3
■
Hadley Centre for Climate Prediction and Research
HadAM3H
■ Dynamical downscaling with two regional <strong>climate</strong> models:
■ Rossby Centre RCAO model (Döscher et al., 2002): Finland,
Latvia, Norway, Sweden
■
RegClim HIRHAM (Bjørge et al., 2000): Iceland, Norway
■ Interface for transferring regional <strong>climate</strong> model results to
meteorological station sites
■
Hydrological models: HBV (Finland, Latvia, Norway, Sweden)
and WaSiM-ETH (Iceland)
Norwegian Water Resources and Energy Directorate

RCM with impacts
emission
scenarios
GCMs:
Hadley
Echam
Statistical Downscaling
RCAO
HIRHAM
Impact
Model
Interface
Hydrological
Model
Interface
Hydrological
Model
Interface
Impact models
Impact models
HBV model
HBV model
Impact models
Impact
Model
Interface
Norwegian Water Resources and Energy Directorate
Impact models
rios
scenar
mpact s
ical im
Hyd
drolog

Hadley A2-Ctrl
The emission scenario /
future emissions matters...
Hadley B2-Ctrl
Larger emissions (A2)
Smaller emissions (B2)
Norwegian Water Resources and Energy Directorate
Source: Rossby Centre, SMHI

Atmospheric circulation and precipitation are related
Source: Tveito and Roald (2005)
Circulation W & SW ”Echam type”
Circulation S & SE ”Hadley type”
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Norwegian Water Resources and Energy Directorate

RCAO-H
RCAO-E
RCAO Hadley RCAO Echam
Winter
Summer
Rossby
Centre
regional
<strong>climate</strong>
scenarios
for
precipitation
<strong>change</strong> (%)
(SRES A2)
22
Norwegian Water Resources and Energy Directorate Source: Rossby
Centre, SMHI

Annual
run<strong>of</strong>f
<strong>change</strong>
(mm)
Hadley/A2
Annual
run<strong>of</strong>f
<strong>change</strong>
(mm)
Hadley/B2
Annual
run<strong>of</strong>f
<strong>change</strong>
(mm)
Annual
run<strong>of</strong>f
<strong>change</strong>
(mm)
Echam/A2 Norwegian Water Resources and Echam/B2 Energy Directorate

Winter
run<strong>of</strong>f
<strong>change</strong>
(mm)
Hadley/B2
Spring
run<strong>of</strong>f
<strong>change</strong>
(mm)
Hadley/B2
Summer
run<strong>of</strong>f
<strong>change</strong>
(mm)
Autumn
run<strong>of</strong>f
<strong>change</strong>
(mm)
Hadley/B2 Norwegian Water Resources and Hadley/B2 Energy Directorate

Change in
annual
maximum
snow store
(%)
Hadley/B2
Change in
annual
maximum
snow store
(%)
Echam/B2
Change in no.
Change in no.
<strong>of</strong> days per
<strong>of</strong> days per
year with
year with
snow cover
snow cover
Echam/B2
Hadley/B2
Norwegian Water Resources and Energy Directorate

Trends in run<strong>of</strong>f for 1941-2002 for
winter (Dec, Jan, Feb) and summer (Jun, Jul, Aug)
Percentage <strong>change</strong> in run<strong>of</strong>f from 1961-1990 to 2071-2100
for winter (Dec, Jan, Feb) and summer (Jun, Jul, Aug)
Norwegian Water Resources and Energy Directorate

Weekly mean discharge Ukentlig vannføring from Norway fra Norge for for 1961-1990 og 2071-2100 and 2071-2100
30000
25000
20000
m 3 /s
15000
10000
5000
0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
week uke nr. no.
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1961-1990 2071-2100 Echam/B2 2071-2100 Hadley/A2 2071-2100 Hadley/B2
Norwegian Water Resources and Energy Directorate

Projected percentage <strong>change</strong> in seasonal run<strong>of</strong>f from
1961-1990 to 2071-2100 for central and northern Norway
The box shows the interquartile range (IQR:25-75 percentiles), the
horizontal line gives the median value and the whiskers extend to
the most extreme data-points which are not more than |1.5| times
the interquartile range from the box
Central and northern Norway
00 200
0 100
00 500
300 400
Norwegian Water Resources and Energy Directorate
Annual Winter Spring Summer Autumn

Weekly mean run<strong>of</strong>f for 1961-1990 and 2071-2100
for elevation bands in catchment Kobbvatn
Kobbvatn (8-500 m asl) weekly mean run<strong>of</strong>f
12
10
8
mm
6
4
2
0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
week no.
Control
Scenario
Kobbvatn (500-1000 m asl) weekly mean run<strong>of</strong>f
Kobbvatn (1000-1512 m asl) weekly mean run<strong>of</strong>f
mm
20
16
12
8
4
0
Norwegian Water Resources 0and Energy Directorate
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
week no.
mm
30
25
20
15
10
5
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
week no.
Control
Scenario
Control
Scenario

Hydrological models - Sources <strong>of</strong> uncertainty
Atmosphere
Land surface
Hydrological
model
Norwegian Water Resources and Energy Directorate
Source: IAHS

Glaciers represent an important storage term in the hydrological cycle
Glacier retreat and advance indicate <strong>climate</strong> variability
Norwegian Water Resources and Energy Directorate

Impact <strong>of</strong> <strong>change</strong>s in glacier area
Engabrevatn: 52 km 2 , 76 % glaciers, elevation 9-1589 m a.s.l.
Nigardsbrevatn: 65 km 2 , 75 % glaciers, elevation 285-1946 m a.s.l.
Engabrevatn
Norwegian Water Resources Nigardsbrevatn and Energy Directorate

Nigardsbrevatn 1961-1990: Control – 75 % glaciers
Nigardsbrevatn 2071-2100: Echam/B2 – no <strong>change</strong> in
glacier area
Nigardsbrevatn 2071-2100: 2100: Echam/B2 – no glaciers
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Control Glacier covered area not <strong>change</strong>d No glaciers
mflow m 3 /s
strea
30
20
10
0
1 31 61 91 121 151 181 211 241 271 301 331 361
day no.
Norwegian Water Resources and Energy Directorate
Source: Lappegard et al. (2006)

Engabrevatn 1961-1990: Control – 76 % glaciers
Engabrevatn 2071-2100: Echam/B2 – no <strong>change</strong> in
glacier area
Engabrevatn 2071-2100: 2100: Echam/B2 – no glaciers
40
Control Glacier covered area not <strong>change</strong>d No glaciers
stream mflow m 3 /s
30
20
10
0
1 31 61 91 121 151 181 211 241 271 301 331 361
day no.
Norwegian Water Resources and Energy Directorate
Source: Lappegard et al. (2006)

Norwegian national
catchment database
• Water system areas
• River basins
• Rivers
• Lakes
Bayelva
DeGeerdalen
Norwegian Water Resources and Energy Directorate

Bayelva catchment
Svalbard
Archipelago
55 % glacier cover
36
N
0 1 km
Norwegian Water Resources and Energy Directorate

Bayelva glacier volume per HBV elevation zone 1st September 1999
Initial glacier volume (m)
20
622
40
50
463
60
50
399
344
100
100
60
290
236
186
50
131
0
68
22
Norwegian Water Resources and Energy Directorate
m a.s.l.

Bayelva glacier volume per HBV elevation zone 31st December 2049
Initial glacier volume (m)
Net accumulated mass balance (m) 1999 - 2049
20
-8
622
0
-109
40
50 -30
50
-40
60
-48
60 -57
100
-67
100
50 -77
-87
-100
Norwegian Water Resources and Energy Directorate
463
399
344
290
236
186
131
68
22
m a.s.l.

Bayelva HBV model
Bayelva annual maximum streamflow 1980-2049 MPI HBV model
20
18
mean annual flood 1990-2007
16
14
12
m 3 /s 10
8
6
4
2
0
Norwegian Water Resources and Energy Directorate
1980 1990 2000 2010 2020 2030 2040 2050

DeGeerdalen and Water system area 419
Weekly mean run<strong>of</strong>f Distributed HBV model
DeGeerdalen and Water system area no. 419
12
10
8
mm/day
6
4
2
0
1 5 9 13 17 21 25 29 33 37 41 45 49
week no.
Norwegian Water Resources and Energy Directorate
DeGeerdalen obs.run<strong>of</strong>f 1991-2006 DeGeerdalen obs.met.1970-2006
Hadley control 1961-1990 Hadley A2 2071-2100

Svalbard 1 km 2 grid based HBV model
Norwegian Water Resources and Energy Directorate
Source: Norwegian Polar Institute

Svalbard 1 km 2 grid based HBV model
Norwegian Water Resources and Energy Directorate

Svalbard 1 km 2 grid based HBV model
Norwegian Water Resources and Energy Directorate

Svalbard 1 km 2 grid based HBV model
Norwegian Water Resources and Energy Directorate

Hindu Kush-Himalayan region Bhutan
Norwegian Water Resources and Energy Directorate

Punakha Dzong
Norwegian Water Resources and Energy Directorate

1349 Wangdirapids 1981 – 2100
Mean annual streamflow (m 3 /s) based on HBV model and input data
from <strong>climate</strong> projection Echam B1 – time-variant glacier covered
areas with initial ice volumes modified by model mass balance results
for glacier covered grid cells
Norwegian Water Resources and Energy Directorate

1349 Wangdirapids 1981 – 2100
Mean annual streamflow (m 3 /s) based on HBV model and input data
from <strong>climate</strong> projection Echam B1 – constant glacier covered areas
Norwegian Water Resources and Energy Directorate

Hydrological impacts <strong>of</strong> <strong>climate</strong> <strong>change</strong> in the Nordic countries
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Changes in run<strong>of</strong>f depends on the spatial distribution <strong>of</strong>
atmospheric pressure fields as modeled by the Echam and Hadley
global <strong>climate</strong> models.
Regional differences in <strong>change</strong>s in annual streamflow, with a
decline in southern areas and an increase in most northern areas.
Significant <strong>change</strong>s in the seasonal distribution <strong>of</strong> streamflow:
■ increase everywhere in the winter
■ increase in mountainous basins and in northern areas in the
spring, while a moderate decline e is expected in low-lying basins s
in southern and central parts
■ decrease will occur almost everywhere in the summer
■
increase in autumn streamflow, with the exception <strong>of</strong> low-lying
lying
basins in the east and south which will experience a decrease
There will be more floods in the winter, especially in low-lying
basins, while spring floods will decrease and occur earlier
Late autumn floods are likely to become both more frequent and
more severe
Uncertainty regarding the future hydrological regime may be
quantified Norwegian by Water considering Resources results and from Energy multiple Directorate hydrological model
runs driven by <strong>climate</strong> scenarios from several GCMs and RCMs

Hydrological impacts <strong>of</strong> <strong>climate</strong> <strong>change</strong> in Svalbard
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Glacier mass balance and glacier covered areas decrease
Maximum snow storage increases in north-eastern parts and
decreases in southern and western parts
Number <strong>of</strong> days with snow cover decrease
Annual run<strong>of</strong>f increases, but <strong>change</strong>s in glacier covered area may
lead to decreased annual run<strong>of</strong>f
Winter, e,spring gand autumn u run<strong>of</strong>f increases
Summer run<strong>of</strong>f:
■
■
Decrease in areas without glaciers
Increase in glacier covered areas
Annual maximum streamflow increases, but reduction in glacier
covered area may lead to a decrease
Norwegian Water Resources and Energy Directorate

Climate <strong>change</strong> impacts on the flow regimes <strong>of</strong> rivers in
Bhutan during the period 2011 – 2100 based on Echam B1
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Increase in temperature
Minor <strong>change</strong> in precipitation
it ti
Decrease in snow storage
■
Melting <strong>of</strong> glacier ice leads to decrease in glacier covered areas after
2050
■ Minor <strong>change</strong> in run<strong>of</strong>f from presently glacier covered areas until 2050
■ Decrease in run<strong>of</strong>f from presently glacier covered areas after 2050
caused by melting and disappearence <strong>of</strong> ice
■
Increase in run<strong>of</strong>f from areas where glacier ice is still present by the
end <strong>of</strong> the century
Norwegian Water Resources and Energy Directorate

Norwegian Water Resources and Energy Directorate 10.11.2011
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