Uncertainty of Climate Change Impact Uncertainty of Climate Change Impact on on the Flow Characteristicsthe Flow Characteristics

(Tepl(Tepláá Vltava Vltava RiverRiver))

Jan Daňhelka

Czech Hydrometeorological Institute

e-mail: danhelka@chmi.cz

12th Magdeburg Seminar

Český Krumlov, 10th to 13th October 2006

• Climate change uncertainty

• Methods of modeling

• Results

• Medium range modelling

• Conclusion

OUTLINE

Arnell et al. (1999)

Kašpárek in Kalvová et al. (2002)

GCM

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN

rela

tive

chan

ge o

f mon

thly

pre

cipi

tatio

n

A2 50 A2 80 B2 50 B2 80

0

1

2

3

4

5

6

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN

abso

lute

cha

nge

of m

ean

mon

thly

tem

pera

ture

[°C]

A2 50 A2 80 B2 50 B2 80

Study catchment

- Hadley high and low scenario for 2050

- LARS-WG - 50y daily time series (MAP, Tmax, Tmin)

- Different duration of wet and dry spells (max 10 % change)

- Different reference period

- 1961 - 1990

- 1961 - 2003

- 100 random sets

- Hydrological system AquaLog

- Statistical evaluation

Methods

0

10000

20000

30000

40000

50000

0 10000 20000 30000 40000 50000

accumulted observed precipitation [mm]

accumulated simulated precipitation [mm]

LARS-WG

-25

-20

-15

-10

-5

0

5

10

15

20

Temperature [°C]

Observed Tmin Simulated Tmin Difference (OBS-SIM)

LARS-WG

0

5

10

15

20

25N

OV-

65

DEC

-65

JAN

-66

FEB-

66

MAR

-66

APR

-66

MAY

-66

JUN

-66

JUL-

66

AUG

-66

SEP-

66

OC

T-66

Dai

ly fl

ow [m

3 .s-1

]

Observed Simulated

Hydrological model - AquaLog

RESULTS

1000

1020

1040

1060

0 1a 1b 2a 2b 3a 3b 4a 4b

prec

ipita

tion

[mm

]

0

1

2

3

4

0 1a 1b 2a 2b 3a 3b 4a 4b

Ave

rage

Tm

in [°

C]

Annual peakflow occurrence

Flood return period

355 d.p.

1.4

1.5

1.6

1.7

1.8

1.9

2

0 10 20 30 40 50 60 70 80 90 100

exceedance (%)

m3 .s

-1

Recent climate

High climate change scenario

1961-90 1961-2003

Low flows

Coclusion

- uncertainty modeling of climate change impact is necessary(deterministic modeling could lead to wrong results)

- flow exceedance curves are going to change

- mainly low flows simulation shows the need for probability approach

- Flood season - more summer dominance (more research needed)

Thank You for Your Attention

Jan Daňhelka

Czech Hydrometeorological Institute

danhelka@chmi.cz

hydro.chmi.cz/ihc_ips4