Download TOLERATE Hydrological scenarios

TOLERATE researchers meeting
23.8.2007, VATT
TOLERATE Hydrological scenarios –
results from Pori
Noora Veijalainen
Suomen Ympäristökeskus
Method

Climate change scenarios
•
•
•
•
From Ilmatieteen laitos
Climate change effects by 2020-2049 (from 1971-2000)
12 scenarios (3 emission scenarios, 1 average of many models,
3 climate models)
Average model scenario with average emission scenario is
called KA A1B and used for further studies



Simulation of 30 years of discharges for Pori with WSFS

Form of the 1/250 flood is calculated from average of the
three largest simulated floods in the 30 year periods
Gumbel distribution fitted to the yearly maximums
1/20, 1/100 and 1/250 year floods of 2020-49 are compared to
baseline period
Regulation

For baseline period the regulation schedules are based
on average observed water levels and discharges

Three alternative regulation schedules for 2020-40
•
Same as baseline
•
•
•
Unrealistic since in reality the schedules are flexible
Slightly altered
•
•
•
Does not work well
Less winter drawdown
Current water level boundaries still in effect as much as
possible
Severely altered
•
No winter drawdown if discharges are large
Results
Change
%
Gumbel
Sligtly altered
regulation
Return
period
Min
250
Severely altered
regulation
Max
KA
A1B
Min
Max
KA
A1B
4.2 %
15.0 %
9.0 %
2.0 %
14.3 %
6.0 %
100
3.4 %
13.8 %
8.3 %
0.9 %
12.9 %
5.3 %
20
1.5 %
11.3 %
6.7 %
-1.4 %
9.0 %
3.6%
Gumbelin jakauma
2000
1800
1600
3
Virtaama (m /s)
1400
1200
Simuloidut 1971-2000
Simuloidut 2020-49 kaa1b 2
19712000_nyky_Gumbel
202049_kaa1b_2_Gumbel
1000
800
600
400
200
0
0.00000
0.78556
Toistumisaika (v)
Pori 1/250 virtaama
1400
Ka 1/250 1971-2000
1200
Ka 1/250 2020-2049
3
Virtaama (m /s)
1000
800
600
400
200
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
Näsijärvi vedenkorkeus
96.00
19712000_nyky_KA
95.80
202049_kaa1b_3_KA
95.60
202049_kaa1b_2_KA
95.40
95.20
95.00
94.80
94.60
94.40
94.20
94.00
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