Flood risk management in Switzerland · September 2017 Andreas Götz Flood risk management in Switzerland Know the risk ... and be prepared. IWHR –26. September 2017 Andreas Götz

IWHR – 26. September 2017 Andreas Götz

Flood risk management in Switzerland

Know the risk ...

and be prepared


Content

1. Introduction

2. Dealing with risk

3. Cooperation

Switzerland

„Welcome“

A land of „hills and mountains“. No direct assess to the sea.

Facts and figures

Surface

42’000 km2

Population

8,4 Million

Precipitation

1’450 mm / y

Development 1917 – 2017

Population x 2

Water demand x 6

Energy consumption x 20

Switzerland

Within the past 30 years:

70 % of municipalities and cities were affected by a major natural event!

Specific problems

Switzerland

Many flood control infrastructure is old and engineering standards are

often inadequate.

Space for living and livelihood is

limited

Safe places and those at risk are

close to each other

Access in times of disaster is

difficult

Multi-hazard conditions prevail

Processes are fast, warning time is

short

Reduce existing risks to an acceptable level and to prevent the emerge

of unacceptable new risks.

Today

Sustainable and consistent Security Level

Time

Provide and maintain a sustainable and consistent level of security for

human beings, buildings and infrastructure

Switzerland

Goal

Qa damage limit

Qb hazard limit

HQ1 annual flood

HQ100 100-year flood

EFQ flood occuring for

for extreme meteorological

and hydrological

situations

PMF probable maximum flood

Sustainable security level

Priority 1: Planning measures Priority 2: Structural measures

High protection only for high risks

Economic development takes place in endangered areas

> increasing damages

Flow is accelerated in canalized rivers

> peak discharge increases in the downstream regions

Neglected maintenance of river channel

> hazardous conditions may suddenly change

Intensification of hazards due to external influences

> climate change, ....

Challenges

Unfavorable developments

todayyesterday tomorrow

glacierspermafrost

forests

ecosystems

watercycle slope stability

Effects Increasing

level of summer

droughts

Greater

risk of

flooding

Decreasing

slope

stability

Change in

habitats and

landscape

Challenges

Climate change > impacts on the environment

Extreme events are likely to become intensified.

Outlook 2050: HQ100 could become HQ20

glacierspermafrost

forests

Society

watercycle

water management

agriculture

slope stability

security

Challenges

Climate change impacts on the society

ecosystems

Lesson learnt:

Raising need of coordination among various stakeholders.

Policy

areas

Prerequisites for sustainable management

Water

management Monitoring and early detection

Modelling of climate

Modelling and water regime

Closing knowledge gaps

Closing data gaps

Improving information and coordination

Natural Hazard

Management

Agriculture

Energy

Biodiversity

management

Spatial

Development

Fundamentals for all involved policy areas

Urgent need

Water sector has to take a leading role.

Damages

Risks

Hazards

Runoff/ sediments

Slides

Catchment area

River-condition/

Slope-condition

Measures to Influence hazard

process > Know the hazards

Technical measures (dams,...)

Biological measures

(reforestation, ...)

Maintenance

Crisis Management

Vulnerability

Measures to limit risks and damage

> Know the risks

Respect risks in land use

Emergency planning

Early warning systems

Precipitation/

Geology

Fundamentals

Research

Monitoring

Assessment

Tools and instruments

Urgent need for fundamentals

Challenges

Lesson learnt

We must sharpen the tools

(Analects of Confucius)


1. Introduction


3. Cooperation

Content

Uncontrolled use of forests

Forest area was reduced by

50%

History

18th and 19th century

Mountainous regions:

More erosion

More debris flows

History


In low lands:

More sediment problems

History

19th century

20071876 Law on Forestry

1877 Law on Flood control

Serie of severe events in 19th century

History

19th century

Obligation for Universities to educate engineers and to monitor the

watercycle and the environment.

Channelizing of rivers

History


Increase in safety and usable space > Loss of environment

2007

Event 1987

History

1987: Largest event in Switzerland within 100 years

Huge damages in many places

Doubts about strategy

Event 1987

Assessment of the existing strategy > New approach required

From a pure Defense

against hazards

to

Integrated management

of risks

What can happen?What is allowed

to happen?

Mesures to take?

Assessment

of risks

Evaluation

of risks

Planning

Main questions and answers

From protection against natural hazards to the

management of risks

Hazard assessment is the key for successful risk management.

Provide a basis for spatial planning

Dimensioning of risk reduction measures

Basic information for emergency planning

Awareness raising among the population

low danger

substantial danger medium danger

remaining danger

Assessment of risks

Hazards maps

Evaluation of risks

High protection only for high risks

Avoiding risks

Landuse planning

Limiting risks

Constructive measures, organisational measures,

Transferring risks

Insurance, …

Accepting remaining risk

Use all possibilities to influence risks

Planning

Protect life Safe life

Resilience

Obama: „Yes we can“

Swiss experts: „Yes we do“ 6 fields of action

substantial danger medium danger low danger

1 Knowledge of hazards and risks

Hazard maps for all living areas in Switzerland

1 Knowledge of hazards and risks

Disaster risk reduction (Par. 186 – 189)

„We (=all nations) recognize the importance of comprehensive

hazard and risk assessment.“

„We commit to undertake and strengthen in a timely manner

risk assessment and desaster reduction instruments.“

Main question: What can happen?

Precondition for an answer: Assessment > Mapping, ...

Anchoring the risk assessment

in the final document

The population must be informed about

the relevant natural hazards.

It‘s important to conserve and promote

the knowledge by a dialogue on risk.

Easily accessible information ensures that

population is aware of existing hazards.

2 Dialogue on risks

Awareness of natural hazards

Involving nature into planning

Space for the rivers

3 Holistic planning of measures

New river bed Flood retention corridor

(evacuation of extreme floods)

Low protection High protection

Land use planning

3 Holistic planning of measures

Space for the rivers

The space required for tomorrow must be secured today

Structural measures have a limited effect on exceptional natural events

Dealing with the residual risks becomes more andmore important

Concepts must be insensitive to excessive loads

Load

Design load

Damage

4 Structures designed to accomodate excess load

Concepts must be adaptive and good-natured

6 Timely identification of hazard events

Timely action at community level

necessitates a

perfect functioning of forecasting and

warning systems

professional interpretation of the

available information.

Careful emergency planning to reduce

damage in case of extreme events

Expert know – how is needed on all administrativ levels


1. Introduction


3. Cooperation

Content

Yunnan Province - Canton Wallis

Sino – Swiss similarities

Mountainous region

In the upper part of a river

(Yangtze River / Rhone River)

Great potential for economic

development

Challenge:

Land use development

Challenge: Climate change

Similar challenges > Cooperation is „win – win“

From flood control to flood management on basin level.

From focus on the development and utilization of water resources to

equal attention to development / protection of water resources.

Sino – Swiss similarities

Need to change the strategies

Prevention and relief of mountainous

disasters, flood control and disasters

mitigation;

Impacts of climate change on water

resources and countermeasures;

Capacity building and personnel

training and exchanges;

Contacts, exchange and cooperation

between research institutes and enterprises

of water resources in both countries.

Areas of cooperation

1. Sino – Swiss MOU 2009

Long term goal:

Develop an Integrated Water

Management System for a River

Basin that

is effective in protecting life and

assets

contributes to the continuing

development of the National

economy

takes account of the impacts of

climate change.

Example 1

Jinsha River Basin - Project

*) See: „Managing Water Resources“ Selected Speeches, CHEN Lei

Principles:

• Basin level

• From flood control to flood

management *)

• From focus on the development and

utilization of water resources to equal

attention to development / protection

of water resources. *)

Example 1


Short term goal 2017

Outcome 1

Improved knowledge of water dynamics.

Outcome 2

Impacts of climate change are identified and analysed.

Outcome 3

Adaptation strategies and measures for water resources

management, flood control and drought relief.

Outcome 4

An international platform for knowledge exchange on water

resources management and climate change adaptation.

Example 1


Develop an Integrated Water

Management System for a River

Basin.

Create the fundament

Main actors:

Experts

First phase 2015 – 2017 Long term goal

Main actors:

Local and provincial stakeholders

Example 1


Example 2

Mountain Torrents Disaster Prevention

Example 2


Voice of Minister Chen Lei

“….Mountain torrents have been the Achilles' Heel of flood control in

China, posing great challenges for us. The Chinese Government has

thus devoted much attention to that and is endeavored to raise our

capacity of flash flood control.

For the unique geographic layout of Switzerland challenging your

country with the same issue, I believe you must have gained rich

experience and effective measures against these hazards.

I sincerely hope both of our sides could have further exchange and

discussion on this. With proper project design and funding, I believe it

will contribute actively to early-warning and prevention capacities of

flash floods in both countries. …..”

Task

introduce advanced technology of mountain torrents disaster

monitoring & hazard management from Switzerland

make a demonstration in a small mountainous basin located in

Danjiangkou City of Hubei Province or Zixing City of Hunan

Province.

Objectives

Improve the mountain torrents disaster prevention capability

Promote cooperation & communication between China and

Switzerland

Example 2


Next steps:

0ctober 2017: Swiss Experts will visit China

RCMT, Wuhan

Danjiangkou City of Hubei Province

Dec 2017:

Clarification of financing (both sides)

Common elaboration of an agreement

2018: MOU-Workshop in Switzerland:

Signature of agreement

Example 2


Damages

Risks

Hazards

Runoff/ sediments

Slides

Catchment area

River-condition/

Slope-condition

Measures to Influence hazard

process > Know the hazards

Technical measures (dams,...)

Biological measures

(reforestation, ...)

Maintenance

Crisis Management

Vulnerability

Measures to limit risks and damage

> Know the risks

Respect risks in land use

Emergency planning


Precipitation/

Geology

Fundamentals

Research

Monitoring

Assessment

Tools and instruments

Research / Exchange on

Processes

Models / Instruments

Monitoring


Exchange

Reason for my visit to IWHR

Inform about activities / exchange

Documents

Flood risk management in Switzerland · September 2017 Andreas Götz Flood risk management in Switzerland Know the risk ... and be prepared. IWHR –26. September 2017 Andreas Götz