Evaluating the impacts of climate change on hydrology and water resources

Phil Graham

Fredrik Wetterhall

Swedish Meteorological and Hydrological Institute

Norrköping

What are our main objectives?

• investigate impacts of climate change on stream

discharge by transferring the climate change signal

from RCMs to hydrological rainfall-runoff models

• identify areas at risk to both changes in flooding

and drought conditions

• conducted in the Nordic Region at varying scale

– continental scale: entire Baltic Sea Basin

– regional scale: entire national territory of Sweden

– basin scale: individual drainage basins in Sweden

Studies at Varying Scales

Link to work package objectives?

• Response surfaces for selected

applications

• Direct use of multiple regional model

projections

• Comparison of outcomes from the two

methods

What have we achieved?

Response Surfaces - Runoff

Lake Mälaren Lule River

RS - Flood Frequency

Lake Mälaren Lake Vänern

RS - Lake Levels

Lake Mälaren

Low levels

RS - Extended Period with Maximum

Discharge

Lake Vänern

Current regulation rules Proposed regulation rules (earlier releases)

WP 6.2 Tasks

6.2.8 construction of response surfaces

6.2.9 scenario impacts and risk

assessment

6.2.11 application of Ensembles

Prediction System

D6.7 & D6.13

Questions for Discussion

• How should we deal with seasonality using

the response surface approach?

• What is the proper level of detail for critical

thresholds?

• What will we actually get from the climate

models (i.e. probabilistic info.)?

• How to choose which transient simulations

to use with direct impacts simulations?

Questions for Discussion

Creating seasonally dependent sensitivity surfaces?

0.6

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1 3 5 7 9 11

Month

Pc

orr

ec

tio

n RCAO-E/A2

RCAO-E/B2

RCAO-H/A2

RCAO-H/B2

Medel

Precipitation Temperature

0

1

2

3

4

5

6

1 2 3 4 5 6 7 8 9 10 11 12

Month

del

taT

(K

)

Questions for Discussion

Creating seasonally dependent sensitivity surfaces?

Precipitation Temperature

0.6

0.8

1

1.2

1.4

1.6

1.8

1 2 3 4 5 6 7 8 9 10 11 12

Month

Co

rre

ctio

n fa

cto

r

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

1 2 3 4 5 6 7 8 9 10 11 12

Month

Co

rre

ctio

n fa

cto

r

Continuous Simulations(transient)

1961-2100

Change in river flow

(10-yr running mean)

compared to 1961-1990

RCA3sres-A2

Continuous Simulations(transient)

1961-2100

Change in river flow

(10-yr running mean)

compared to 1961-1990

RCA3sres-A2

Continuous Simulations(transient)

Work in

Progress!

1961-2100

Change in river flow

(10-yr running mean)

compared to 1961-1990

RCA3sres-A2sres-B2

Modelled Change in

Hydropower Potential

for the Lule River

2071-2100compared to

1961-1990

Modelled Change in

Hydropower Potential in Sweden

2071-2100compared to

1961-1990