7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

1/13

Cost effectiveness ofnon-structural measures

Some considerations

Chris Zevenbergen

16/032012

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

2/13

the paradox of optimization

deep uncertainty

context

Content

1/26/13 Presentation Title 2

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

3/13

Cost-Benefit Analysis New Orleans Flood protection System*

1/26/13 Presentation Title 3

Rational design of flood protection systems hampered by

uncertainties arisen from:

the influence of climate change on future weatherextreme events;

impacts of large scale disasters.

* Hallegate, Stanford Universty (2005)

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

4/13

Actual flood risk ?

Risk = P x I

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

5/13

Actual flood risk ?

?

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

6/13

Actual flood risk ?

High risk

Risk= constant

Low risk

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

7/13

Actual flood risk ?

High risk

Risk= constant

Low risk

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

8/13

Actual flood risk ?

Risk= constant

Low risk

High risk

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

9/13

Setting the scene: flood risk management

1/26/13 Presentation Title 9

Current policies in practice (COST C22, 2009): reduce flood probabilities; protection levels do not comply with economic trade-off; extreme events (e.g. overtopping) not taken into account.

Decision makers call for: high ends optimal safety level

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

10/13

buildings &

networks

Flooding system = Complex Adaptive System (CAS)

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

11/13

Decision making: options available?

Standards Risk based approach => what do we accept?

Cost Benefit analysis (CBA) => economic optimization Multi-criteria analysis (MCA) => societal consequences

Effect based approaches/ bottom-up=> tipping points New DDS tools (RDM): exploratory modelling Opportunistic/synergistic adaptation

1/26/13 Presentation Title 11

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

12/13

Costs & benefits: large uncertainties

1/26/13 Presentation Title 12

Cost Benefits

Construc)on Vic)msavoided

M&O Preventeddamage:

-direct-indirect

1st&2ndordereconomic

benefits

7/29/2019 Chris Zevenbergen - "Cost Effectiveness of Non-Structural Measures"

13/13

no one best solution strongly context related deep uncertainty

tend to favor effect based (resilient) approaches need for (new & better) frameworks (social-

economic) for decision makers to be able to act

How to improve sharing of information ? How to scale-up action ?

Conclusions & recommendations