Modelling effects of climate g change on hydrology - NVE
Modelling effects of climate g change on hydrology - NVE
Modelling effects of climate g change on hydrology - NVE
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<str<strong>on</strong>g>Modelling</str<strong>on</strong>g> <str<strong>on</strong>g>effects</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>climate</str<strong>on</strong>g><br />
<str<strong>on</strong>g>change</str<strong>on</strong>g> <strong>on</strong> <strong>hydrology</strong><br />
Stein Beldring<br />
Norwegian Water Resources and Energy Directorate
■<br />
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Outline<br />
Global <str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g><br />
Downscaling from AOGCMs<br />
to hydrological impact models<br />
Water resources maps for the<br />
Nordic regi<strong>on</strong> presenting<br />
<str<strong>on</strong>g>change</str<strong>on</strong>g>s from present (1961-<br />
1990) to future (2071-2100)<br />
c<strong>on</strong>diti<strong>on</strong>s<br />
Uncertainty in hydrological<br />
impact simulati<strong>on</strong>s caused by<br />
different emissi<strong>on</strong> scenarios<br />
and <str<strong>on</strong>g>climate</str<strong>on</strong>g> models<br />
Climate <str<strong>on</strong>g>change</str<strong>on</strong>g> impacts <strong>on</strong><br />
glacier covered catchments in<br />
Norway, Svalbard and Bhutan<br />
ACIA: Freshwater discharge to the Arctic<br />
Norwegian Water Resources and Energy Directorate
Norwegian Water Resources and Energy Directorate<br />
3
■<br />
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■<br />
■<br />
Emissi<strong>on</strong>s <str<strong>on</strong>g>of</str<strong>on</strong>g> CO 2 and other greenhouse<br />
gases have disturbed the carb<strong>on</strong> balance<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> the atmosphere<br />
Greenhouse gases affect the<br />
atmospheric absorpti<strong>on</strong> properties <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
l<strong>on</strong>gwave radiati<strong>on</strong>, changing the<br />
radiati<strong>on</strong> balance and warming the lower<br />
troposphere<br />
Increase in temperature leads to an<br />
intensified hydrological cycle, i.e. higher<br />
evaporati<strong>on</strong> and precipitati<strong>on</strong> rates<br />
Climate <str<strong>on</strong>g>change</str<strong>on</strong>g> will lead to <str<strong>on</strong>g>change</str<strong>on</strong>g>s in<br />
mean c<strong>on</strong>diti<strong>on</strong>s, variability and extremes<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> hydrological variables and fluxes, e.g.<br />
snow storage, run<str<strong>on</strong>g>of</str<strong>on</strong>g>f and evaporati<strong>on</strong><br />
These <str<strong>on</strong>g>change</str<strong>on</strong>g>s will influence:<br />
■ the natural envir<strong>on</strong>ment<br />
■<br />
the society (and can either be to its<br />
advantage or disadvantage)<br />
CO 2 c<strong>on</strong>centrati<strong>on</strong><br />
Temperature <str<strong>on</strong>g>change</str<strong>on</strong>g><br />
Norwegian Water Resources and Energy Directorate<br />
4
Range <str<strong>on</strong>g>of</str<strong>on</strong>g> surface warming IPCC 4AR<br />
5<br />
Norwegian Water Resources and Energy Directorate
Multi-model mean projected surface temperature<br />
<str<strong>on</strong>g>change</str<strong>on</strong>g>s relative to the period 1980-1999<br />
B1<br />
A1B<br />
A2<br />
Norwegian Water Resources and Energy Directorate<br />
Source: IPCC
Climate <str<strong>on</strong>g>change</str<strong>on</strong>g><br />
”displacement”<br />
in Norway from<br />
1961-1990 to<br />
2021-2050<br />
and<br />
2071-2100<br />
Source: RegClim<br />
7<br />
Norwegian Water Resources and Energy Directorate
Multi-model mean <str<strong>on</strong>g>change</str<strong>on</strong>g>s in precipitati<strong>on</strong> (mm day –1 ), soil moisture<br />
c<strong>on</strong>tent (%), run<str<strong>on</strong>g>of</str<strong>on</strong>g>f (mm day –1 ) and evaporati<strong>on</strong> (mm day –1 ). Changes<br />
are annual means for the SRES A1B scenario for the period 2080 to<br />
2099 relative to 1980 to 1999.<br />
8<br />
Norwegian Water Resources and Energy Directorate
Climate <str<strong>on</strong>g>change</str<strong>on</strong>g><br />
impacts <strong>on</strong><br />
precipitati<strong>on</strong>,<br />
drought and snow<br />
9<br />
Norwegian Water Resources and Energy Directorate
Utilizati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> land resources, e.g. deforestati<strong>on</strong> results in significant <str<strong>on</strong>g>change</str<strong>on</strong>g>s <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
land cover and soil types. These <str<strong>on</strong>g>change</str<strong>on</strong>g>s influence land surface <strong>hydrology</strong><br />
through their influence <strong>on</strong> e.g. albedo, evaporati<strong>on</strong>, soil type, run<str<strong>on</strong>g>of</str<strong>on</strong>g>f generati<strong>on</strong><br />
10<br />
Norwegian Water Resources and Energy Directorate
Descripti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> the boundary c<strong>on</strong>diti<strong>on</strong>s, including their <str<strong>on</strong>g>change</str<strong>on</strong>g>s and a model <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
the internal system dynamics. Models for the hydrological cycle transform the<br />
meteorological forcing into the hydrological resp<strong>on</strong>se <str<strong>on</strong>g>of</str<strong>on</strong>g> a catchment based <strong>on</strong><br />
the characteristics <str<strong>on</strong>g>of</str<strong>on</strong>g> the model domain and the relevant hydrological processes.<br />
11<br />
Norwegian Water Resources and Energy Directorate
Observed input, output (and state variables) data are necessary<br />
for calibrati<strong>on</strong>, validati<strong>on</strong> and running <str<strong>on</strong>g>of</str<strong>on</strong>g> the hydrological model<br />
The primary input variables used in hydrological<br />
modeling are temperature and precipitati<strong>on</strong><br />
State variables describing the state <str<strong>on</strong>g>of</str<strong>on</strong>g> the<br />
system, e.g. snow or groundwater storage<br />
The output variable in hydrological modeling is usually<br />
the integrated catchment resp<strong>on</strong>se <str<strong>on</strong>g>of</str<strong>on</strong>g> streamflow<br />
12<br />
Norwegian Water Resources and Energy Directorate
Numerical soluti<strong>on</strong><br />
- Equati<strong>on</strong>s c<strong>on</strong>tinuous in space and time<br />
- Numerical soluti<strong>on</strong> <strong>on</strong>ly possible in a grid<br />
13<br />
Norwegian Water Resources and Energy Directorate
Dynamical downscaling over limited regi<strong>on</strong>s (domains) <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
the globe with regi<strong>on</strong>al <str<strong>on</strong>g>climate</str<strong>on</strong>g> models give more details!<br />
14<br />
Typical present day regi<strong>on</strong>al model 25 50 km<br />
Norwegian Water Resources and Energy Directorate<br />
Typical present-day regi<strong>on</strong>al model 25-50 km<br />
Typical present-day global model 110-300 km
Regi<strong>on</strong>al <str<strong>on</strong>g>climate</str<strong>on</strong>g> model domain<br />
Norwegian Water Resources and Energy Directorate
Different topography – elevati<strong>on</strong> is not<br />
represented correctly in regi<strong>on</strong>al <str<strong>on</strong>g>climate</str<strong>on</strong>g> models<br />
Distributed HBV hydrological model<br />
• 1 km ×1 km<br />
• 0 – 2256 m a.s.l.<br />
HIRHAM regi<strong>on</strong>al <str<strong>on</strong>g>climate</str<strong>on</strong>g> model<br />
• 55 km × 55 km<br />
• 0 – 1281 m a.s.l<br />
16<br />
Norwegian Water Resources and Energy Directorate
Regi<strong>on</strong>al Climate<br />
Model HIRHAM<br />
17<br />
Norwegian Water Resources and Energy Directorate
Modeling <str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g> impacts <strong>on</strong><br />
water resources in the Nordic countries<br />
■ Two emissi<strong>on</strong> scenarios for greenhouse gases:<br />
■<br />
A2 (larger emissi<strong>on</strong>s) and B2 (smaller emissi<strong>on</strong>s)<br />
■ To global <str<strong>on</strong>g>climate</str<strong>on</strong>g> models :<br />
■ Max Planck Institut für Meteorologie ECHAM4/OPYC3<br />
■<br />
Hadley Centre for Climate Predicti<strong>on</strong> and Research<br />
HadAM3H<br />
■ Dynamical downscaling with two regi<strong>on</strong>al <str<strong>on</strong>g>climate</str<strong>on</strong>g> models:<br />
■ Rossby Centre RCAO model (Döscher et al., 2002): Finland,<br />
Latvia, Norway, Sweden<br />
■<br />
RegClim HIRHAM (Bjørge et al., 2000): Iceland, Norway<br />
■ Interface for transferring regi<strong>on</strong>al <str<strong>on</strong>g>climate</str<strong>on</strong>g> model results to<br />
meteorological stati<strong>on</strong> sites<br />
■<br />
Hydrological models: HBV (Finland, Latvia, Norway, Sweden)<br />
and WaSiM-ETH (Iceland)<br />
Norwegian Water Resources and Energy Directorate
RCM with impacts<br />
emissi<strong>on</strong><br />
scenarios<br />
GCMs:<br />
Hadley<br />
Echam<br />
Statistical Downscaling<br />
RCAO<br />
HIRHAM<br />
Impact<br />
Model<br />
Interface<br />
Hydrological<br />
Model<br />
Interface<br />
Hydrological<br />
Model<br />
Interface<br />
Impact models<br />
Impact models<br />
HBV model<br />
HBV model<br />
Impact models<br />
Impact<br />
Model<br />
Interface<br />
Norwegian Water Resources and Energy Directorate<br />
Impact models<br />
rios<br />
scenar<br />
mpact s<br />
ical im<br />
Hyd<br />
drolog
Hadley A2-Ctrl<br />
The emissi<strong>on</strong> scenario /<br />
future emissi<strong>on</strong>s matters...<br />
Hadley B2-Ctrl<br />
Larger emissi<strong>on</strong>s (A2)<br />
Smaller emissi<strong>on</strong>s (B2)<br />
Norwegian Water Resources and Energy Directorate<br />
Source: Rossby Centre, SMHI
Atmospheric circulati<strong>on</strong> and precipitati<strong>on</strong> are related<br />
Source: Tveito and Roald (2005)<br />
Circulati<strong>on</strong> W & SW ”Echam type”<br />
Circulati<strong>on</strong> S & SE ”Hadley type”<br />
21<br />
Norwegian Water Resources and Energy Directorate
RCAO-H<br />
RCAO-E<br />
RCAO Hadley RCAO Echam<br />
Winter<br />
Summer<br />
Rossby<br />
Centre<br />
regi<strong>on</strong>al<br />
<str<strong>on</strong>g>climate</str<strong>on</strong>g><br />
scenarios<br />
for<br />
precipitati<strong>on</strong><br />
<str<strong>on</strong>g>change</str<strong>on</strong>g> (%)<br />
(SRES A2)<br />
22<br />
Norwegian Water Resources and Energy Directorate Source: Rossby<br />
Centre, SMHI
Annual<br />
run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
<str<strong>on</strong>g>change</str<strong>on</strong>g><br />
(mm)<br />
Hadley/A2<br />
Annual<br />
run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
<str<strong>on</strong>g>change</str<strong>on</strong>g><br />
(mm)<br />
Hadley/B2<br />
Annual<br />
run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
<str<strong>on</strong>g>change</str<strong>on</strong>g><br />
(mm)<br />
Annual<br />
run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
<str<strong>on</strong>g>change</str<strong>on</strong>g><br />
(mm)<br />
Echam/A2 Norwegian Water Resources and Echam/B2 Energy Directorate
Winter<br />
run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
<str<strong>on</strong>g>change</str<strong>on</strong>g><br />
(mm)<br />
Hadley/B2<br />
Spring<br />
run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
<str<strong>on</strong>g>change</str<strong>on</strong>g><br />
(mm)<br />
Hadley/B2<br />
Summer<br />
run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
<str<strong>on</strong>g>change</str<strong>on</strong>g><br />
(mm)<br />
Autumn<br />
run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
<str<strong>on</strong>g>change</str<strong>on</strong>g><br />
(mm)<br />
Hadley/B2 Norwegian Water Resources and Hadley/B2 Energy Directorate
Change in<br />
annual<br />
maximum<br />
snow store<br />
(%)<br />
Hadley/B2<br />
Change in<br />
annual<br />
maximum<br />
snow store<br />
(%)<br />
Echam/B2<br />
Change in no.<br />
Change in no.<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> days per<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> days per<br />
year with<br />
year with<br />
snow cover<br />
snow cover<br />
Echam/B2<br />
Hadley/B2<br />
Norwegian Water Resources and Energy Directorate
Trends in run<str<strong>on</strong>g>of</str<strong>on</strong>g>f for 1941-2002 for<br />
winter (Dec, Jan, Feb) and summer (Jun, Jul, Aug)<br />
Percentage <str<strong>on</strong>g>change</str<strong>on</strong>g> in run<str<strong>on</strong>g>of</str<strong>on</strong>g>f from 1961-1990 to 2071-2100<br />
for winter (Dec, Jan, Feb) and summer (Jun, Jul, Aug)<br />
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<br />
30000<br />
25000<br />
20000<br />
m 3 /s<br />
15000<br />
10000<br />
5000<br />
0<br />
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<br />
week uke nr. no.<br />
27<br />
1961-1990 2071-2100 Echam/B2 2071-2100 Hadley/A2 2071-2100 Hadley/B2<br />
Norwegian Water Resources and Energy Directorate
Projected percentage <str<strong>on</strong>g>change</str<strong>on</strong>g> in seas<strong>on</strong>al run<str<strong>on</strong>g>of</str<strong>on</strong>g>f from<br />
1961-1990 to 2071-2100 for central and northern Norway<br />
The box shows the interquartile range (IQR:25-75 percentiles), the<br />
horiz<strong>on</strong>tal line gives the median value and the whiskers extend to<br />
the most extreme data-points which are not more than |1.5| times<br />
the interquartile range from the box<br />
Central and northern Norway<br />
00 200<br />
0 100<br />
00 500<br />
300 400<br />
Norwegian Water Resources and Energy Directorate<br />
Annual Winter Spring Summer Autumn
Weekly mean run<str<strong>on</strong>g>of</str<strong>on</strong>g>f for 1961-1990 and 2071-2100<br />
for elevati<strong>on</strong> bands in catchment Kobbvatn<br />
Kobbvatn (8-500 m asl) weekly mean run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
12<br />
10<br />
8<br />
mm<br />
6<br />
4<br />
2<br />
0<br />
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<br />
week no.<br />
C<strong>on</strong>trol<br />
Scenario<br />
Kobbvatn (500-1000 m asl) weekly mean run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
Kobbvatn (1000-1512 m asl) weekly mean run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
mm<br />
20<br />
16<br />
12<br />
8<br />
4<br />
0<br />
Norwegian Water Resources 0and Energy Directorate<br />
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<br />
week no.<br />
mm<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
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<br />
week no.<br />
C<strong>on</strong>trol<br />
Scenario<br />
C<strong>on</strong>trol<br />
Scenario
Hydrological models - Sources <str<strong>on</strong>g>of</str<strong>on</strong>g> uncertainty<br />
Atmosphere<br />
Land surface<br />
Hydrological<br />
model<br />
Norwegian Water Resources and Energy Directorate<br />
Source: IAHS
Glaciers represent an important storage term in the hydrological cycle<br />
Glacier retreat and advance indicate <str<strong>on</strong>g>climate</str<strong>on</strong>g> variability<br />
Norwegian Water Resources and Energy Directorate
Impact <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g>s in glacier area<br />
Engabrevatn: 52 km 2 , 76 % glaciers, elevati<strong>on</strong> 9-1589 m a.s.l.<br />
Nigardsbrevatn: 65 km 2 , 75 % glaciers, elevati<strong>on</strong> 285-1946 m a.s.l.<br />
Engabrevatn<br />
Norwegian Water Resources Nigardsbrevatn and Energy Directorate
Nigardsbrevatn 1961-1990: C<strong>on</strong>trol – 75 % glaciers<br />
Nigardsbrevatn 2071-2100: Echam/B2 – no <str<strong>on</strong>g>change</str<strong>on</strong>g> in<br />
glacier area<br />
Nigardsbrevatn 2071-2100: 2100: Echam/B2 – no glaciers<br />
40<br />
C<strong>on</strong>trol Glacier covered area not <str<strong>on</strong>g>change</str<strong>on</strong>g>d No glaciers<br />
mflow m 3 /s<br />
strea<br />
30<br />
20<br />
10<br />
0<br />
1 31 61 91 121 151 181 211 241 271 301 331 361<br />
day no.<br />
Norwegian Water Resources and Energy Directorate<br />
Source: Lappegard et al. (2006)
Engabrevatn 1961-1990: C<strong>on</strong>trol – 76 % glaciers<br />
Engabrevatn 2071-2100: Echam/B2 – no <str<strong>on</strong>g>change</str<strong>on</strong>g> in<br />
glacier area<br />
Engabrevatn 2071-2100: 2100: Echam/B2 – no glaciers<br />
40<br />
C<strong>on</strong>trol Glacier covered area not <str<strong>on</strong>g>change</str<strong>on</strong>g>d No glaciers<br />
stream mflow m 3 /s<br />
30<br />
20<br />
10<br />
0<br />
1 31 61 91 121 151 181 211 241 271 301 331 361<br />
day no.<br />
Norwegian Water Resources and Energy Directorate<br />
Source: Lappegard et al. (2006)
Norwegian nati<strong>on</strong>al<br />
catchment database<br />
• Water system areas<br />
• River basins<br />
• Rivers<br />
• Lakes<br />
Bayelva<br />
DeGeerdalen<br />
Norwegian Water Resources and Energy Directorate
Bayelva catchment<br />
Svalbard<br />
Archipelago<br />
55 % glacier cover<br />
36<br />
N<br />
0 1 km<br />
Norwegian Water Resources and Energy Directorate
Bayelva glacier volume per HBV elevati<strong>on</strong> z<strong>on</strong>e 1st September 1999<br />
Initial glacier volume (m)<br />
20<br />
622<br />
40<br />
50<br />
463<br />
60<br />
50<br />
399<br />
344<br />
100<br />
100<br />
60<br />
290<br />
236<br />
186<br />
50<br />
131<br />
0<br />
68<br />
22<br />
Norwegian Water Resources and Energy Directorate<br />
m a.s.l.
Bayelva glacier volume per HBV elevati<strong>on</strong> z<strong>on</strong>e 31st December 2049<br />
Initial glacier volume (m)<br />
Net accumulated mass balance (m) 1999 - 2049<br />
20<br />
-8<br />
622<br />
0<br />
-109<br />
40<br />
50 -30<br />
50<br />
-40<br />
60<br />
-48<br />
60 -57<br />
100<br />
-67<br />
100<br />
50 -77<br />
-87<br />
-100<br />
Norwegian Water Resources and Energy Directorate<br />
463<br />
399<br />
344<br />
290<br />
236<br />
186<br />
131<br />
68<br />
22<br />
m a.s.l.
Bayelva HBV model<br />
Bayelva annual maximum streamflow 1980-2049 MPI HBV model<br />
20<br />
18<br />
mean annual flood 1990-2007<br />
16<br />
14<br />
12<br />
m 3 /s 10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
Norwegian Water Resources and Energy Directorate<br />
1980 1990 2000 2010 2020 2030 2040 2050
DeGeerdalen and Water system area 419<br />
Weekly mean run<str<strong>on</strong>g>of</str<strong>on</strong>g>f Distributed HBV model<br />
DeGeerdalen and Water system area no. 419<br />
12<br />
10<br />
8<br />
mm/day<br />
6<br />
4<br />
2<br />
0<br />
1 5 9 13 17 21 25 29 33 37 41 45 49<br />
week no.<br />
Norwegian Water Resources and Energy Directorate<br />
DeGeerdalen obs.run<str<strong>on</strong>g>of</str<strong>on</strong>g>f 1991-2006 DeGeerdalen obs.met.1970-2006<br />
Hadley c<strong>on</strong>trol 1961-1990 Hadley A2 2071-2100
Svalbard 1 km 2 grid based HBV model<br />
Norwegian Water Resources and Energy Directorate<br />
Source: Norwegian Polar Institute
Svalbard 1 km 2 grid based HBV model<br />
Norwegian Water Resources and Energy Directorate
Svalbard 1 km 2 grid based HBV model<br />
Norwegian Water Resources and Energy Directorate
Svalbard 1 km 2 grid based HBV model<br />
Norwegian Water Resources and Energy Directorate
Hindu Kush-Himalayan regi<strong>on</strong> Bhutan<br />
Norwegian Water Resources and Energy Directorate
Punakha Dz<strong>on</strong>g<br />
Norwegian Water Resources and Energy Directorate
1349 Wangdirapids 1981 – 2100<br />
Mean annual streamflow (m 3 /s) based <strong>on</strong> HBV model and input data<br />
from <str<strong>on</strong>g>climate</str<strong>on</strong>g> projecti<strong>on</strong> Echam B1 – time-variant glacier covered<br />
areas with initial ice volumes modified by model mass balance results<br />
for glacier covered grid cells<br />
Norwegian Water Resources and Energy Directorate
1349 Wangdirapids 1981 – 2100<br />
Mean annual streamflow (m 3 /s) based <strong>on</strong> HBV model and input data<br />
from <str<strong>on</strong>g>climate</str<strong>on</strong>g> projecti<strong>on</strong> Echam B1 – c<strong>on</strong>stant glacier covered areas<br />
Norwegian Water Resources and Energy Directorate
Hydrological impacts <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g> in the Nordic countries<br />
■<br />
■<br />
■<br />
■<br />
■<br />
■<br />
Changes in run<str<strong>on</strong>g>of</str<strong>on</strong>g>f depends <strong>on</strong> the spatial distributi<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
atmospheric pressure fields as modeled by the Echam and Hadley<br />
global <str<strong>on</strong>g>climate</str<strong>on</strong>g> models.<br />
Regi<strong>on</strong>al differences in <str<strong>on</strong>g>change</str<strong>on</strong>g>s in annual streamflow, with a<br />
decline in southern areas and an increase in most northern areas.<br />
Significant <str<strong>on</strong>g>change</str<strong>on</strong>g>s in the seas<strong>on</strong>al distributi<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> streamflow:<br />
■ increase everywhere in the winter<br />
■ increase in mountainous basins and in northern areas in the<br />
spring, while a moderate decline e is expected in low-lying basins s<br />
in southern and central parts<br />
■ decrease will occur almost everywhere in the summer<br />
■<br />
increase in autumn streamflow, with the excepti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> low-lying<br />
lying<br />
basins in the east and south which will experience a decrease<br />
There will be more floods in the winter, especially in low-lying<br />
basins, while spring floods will decrease and occur earlier<br />
Late autumn floods are likely to become both more frequent and<br />
more severe<br />
Uncertainty regarding the future hydrological regime may be<br />
quantified Norwegian by Water c<strong>on</strong>sidering Resources results and from Energy multiple Directorate hydrological model<br />
runs driven by <str<strong>on</strong>g>climate</str<strong>on</strong>g> scenarios from several GCMs and RCMs
Hydrological impacts <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g> in Svalbard<br />
■<br />
■<br />
■<br />
■<br />
■<br />
■<br />
■<br />
Glacier mass balance and glacier covered areas decrease<br />
Maximum snow storage increases in north-eastern parts and<br />
decreases in southern and western parts<br />
Number <str<strong>on</strong>g>of</str<strong>on</strong>g> days with snow cover decrease<br />
Annual run<str<strong>on</strong>g>of</str<strong>on</strong>g>f increases, but <str<strong>on</strong>g>change</str<strong>on</strong>g>s in glacier covered area may<br />
lead to decreased annual run<str<strong>on</strong>g>of</str<strong>on</strong>g>f<br />
Winter, e,spring gand autumn u run<str<strong>on</strong>g>of</str<strong>on</strong>g>f increases<br />
Summer run<str<strong>on</strong>g>of</str<strong>on</strong>g>f:<br />
■<br />
■<br />
Decrease in areas without glaciers<br />
Increase in glacier covered areas<br />
Annual maximum streamflow increases, but reducti<strong>on</strong> in glacier<br />
covered area may lead to a decrease<br />
Norwegian Water Resources and Energy Directorate
Climate <str<strong>on</strong>g>change</str<strong>on</strong>g> impacts <strong>on</strong> the flow regimes <str<strong>on</strong>g>of</str<strong>on</strong>g> rivers in<br />
Bhutan during the period 2011 – 2100 based <strong>on</strong> Echam B1<br />
■<br />
■<br />
■<br />
Increase in temperature<br />
Minor <str<strong>on</strong>g>change</str<strong>on</strong>g> in precipitati<strong>on</strong><br />
it ti<br />
Decrease in snow storage<br />
■<br />
Melting <str<strong>on</strong>g>of</str<strong>on</strong>g> glacier ice leads to decrease in glacier covered areas after<br />
2050<br />
■ Minor <str<strong>on</strong>g>change</str<strong>on</strong>g> in run<str<strong>on</strong>g>of</str<strong>on</strong>g>f from presently glacier covered areas until 2050<br />
■ Decrease in run<str<strong>on</strong>g>of</str<strong>on</strong>g>f from presently glacier covered areas after 2050<br />
caused by melting and disappearence <str<strong>on</strong>g>of</str<strong>on</strong>g> ice<br />
■<br />
Increase in run<str<strong>on</strong>g>of</str<strong>on</strong>g>f from areas where glacier ice is still present by the<br />
end <str<strong>on</strong>g>of</str<strong>on</strong>g> the century<br />
Norwegian Water Resources and Energy Directorate
Norwegian Water Resources and Energy Directorate 10.11.2011<br />
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