The Need for Resilient Cities in the

Mediterranean in an Era of Climate

and Environmental Change

The Mediterranean Region as a Complex System:

Challenges, Risks and Opportunities

Prof. Oded PotchterDepartment of Geography and the Human Environment, Tel Aviv University, Israel

Email: potchter@post.tau.ac.il

Background• In 1800, only 3% of the world's population lived in urban

areas. By 1950, 30% of the world's population lived in cities.

• Today, 54 % of the world’s population lives in urban areas, a proportion that is expected to increase to 66% by 2050. (http://www.un.org/en/development/desa/news/population/world-urbanization-prospects-2014.html)

• “Managing urban areas has become one of the most important development challenges of the 21st century. Our success or failure in building sustainable cities will be a major factor in the success of the post-2015 UN development agenda,”.(John Wilmoth, Director of UN DESA’s Population Division).

Urban population in Mediterranean countries increased between

1970 and 2010 from 54 to 66 %, with an average growth rate of

3.1 % a year. The south and east Mediterranean is urbanizing

more rapidly than any other region of the world. (Plan Bleu

computations based on UNDESA 2010).

Climatic threats to Mediterranean Cities

• The combined effect of global warming and urban warming.

• Higher Incidence of heat waves.• Higher incidence of cold waves.• Higher frequency of atmospheric anomalies

(storms, unreliable precipitation patterns, drought and desertification).

• Increasing incidence of dust storms due to wars and desertification.

• Sea level rise.

Environmental Hazards, Risks, Shocks and Stresses for City Habitats and Infrastructure

in the Mediterranean

Concentrations of trace metals and Persistent Organic Pollutants

Environmental Hazards, Risks and Stresses for Cities Habitats in the Mediterranean

Sensitivity to flood losses in major coastal cities Temperature Anomalies in the Mediterranean

Climatic conditions in the Mediterranean cities

will become more difficult in the future, as

climate change will severely affect the

environment

Resilience thinking is a new lens for looking a the natural world we are embedded in and the man-

made world we have imposed upon it.”

Source: Ward C (2007) ‘Deisel-Driven Bee Slums and ImpotentTurkeys: The Case for Resilience’.

resilient cities definition: “A Resilient City is one that has developed capacities

to help absorb future shocks and stresses to its social, economic, and technical

systems and infrastructures so as to still be able to maintain essentially the

same functions, structures, systems, and identity.”

Source: Working Definition, ResilientCity.org

Global Warming

• In the twentieth century the average global air temperature

increased by 0.760C, and the linear warming trend over the past

50 years is nearly twice that for the last 100 years. This trend of

rising global air temperature is likely to continue (IPCC, 2015).

• Earth’s 2015 surface temperatures were the warmest since

modern record keeping began in 1880. Globally-averaged

temperatures in 2015 shattered the previous mark set in 2014.

• The 2015 temperatures continue a long-term warming trend,

according to analyses by scientists at NASA (www.nasa.gov).

• Global warming is accompanied by several climatic changes,

such as an increase of specific humidity which is likely to

aggravate the heat stress values (Willett et al., 2008).

The Urban Heat Island (UHI)The UHI is a phenomenon characterizing the urban climate. It can be defined as the difference between temperatures measured in the urban space and those in the non-urban space surrounding it (Oke, 1987).

∆T°C = Turban – T rural

Population and maximum UHI intensity

Source: Fujibe, 2009

The combined effect of global warming and urban warming

• An increase the duration and intensity of heat

waves in cities and prolongation of the hot season

in cities.

• Increases in heat stress within the cities.

• Increased mortality ( the European heat wave in

2003 caused 20 thousand deaths and in 2010 about

30 thousand in Russia).

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Three scenarios: Predictions of urban warming of four cities in Israel for the year 2060

Observation Model Proje ctions with 3 Growth Scenarios

Observation Model Projections with 3 Growt h ScenariosObservation Mo del Projections with 3 Growth Scenarios

Tel Aviv (1,227,000 pop, 2011) Jerusalem (773,000 pop,2011)

Eilat (50,000 pop,2011) Beer Sheva (200,000 pop,2011)

Observation Model Projections wi th 3 Growth Scenarios

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A cold wave in the easternMediterranean Basin 10-14 December 2013

Extreme cold wave event December 2013

Implications of cold waves

• Damage to infrastructure (collapse of the power

lines, roofs, trees and billboards).

• Traffic disruption - Main roads closed.

• Disruption to normal life (closure of public

institutions, schools).

• Disconnection of power causing heating problems.

• Problems in the supply of food and water.

• Aggravation of health problems, higher incidence of

accidents and mortality.

The results of increasing atmospheric anomalies

• Higher incidence of cyclones due to rising seawater

temperatures.

• increase of extreme rain events and amplification of

flooding.

• Potentiel change in air pollution, polluant concentrations.

• Increase in frequency and intensity of dust storms.

• Increased aridity due to temperature rise.

• Increasing aridity due to a decrease in precipitation.

• Increasing desertification.

Atmospheric irregularities

The increasing prevalence and intensity of Cyclones

Increase in the intensity of rain events despite a decrease in overall precipitation

Ayalon River (Tel Aviv) Flooding January 8, 2013

Storm floods January 8 2013

River is formed in a residential neighborhood, near Jerusalem . A few people drowned .

Floods in shopping mall

- Wind storm damage(Tel Aviv) 7 January 2013

Storm floods 4th October (Israel) 2014

רוב בלפור בבת ים

כביש נסחף בחולון

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Extreme hail storm – Upper Galilei

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Storm damage- A 100 m strip of forest ripped apart

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Storm Damage

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A tiled roof which has been re-located two

streets away from its original location

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סימולציות רוח

• Urban flow simulation on GTX 470

• CFD analysis for flows thought the city

• Wind blow roof off building

• Pass way effect

• Pass way effect 2 אישה עפה מהרוח ברמת גן

• Flying materialפגיעת חפצים מעופפים

Sea level rise

Predictions for numbers of people affected by flooding

in 2080 under circumstances of unmitigated emissions.

Geographical implications of sea level rise

• Flooding along coastal areas

• The disappearance of island states ( such as Tuvalu, Micronesia, Solomon Islands).

• Delta river flooding and the disappearance of agricultural areas and global food reserves

Population immigration

Predicted impact of sea level rise in:

Egypt Bangladesh

The Nile Delta is one of the oldest intensely cultivated

areas on earth. It is very heavily populated, with

population densities up to 1600 inhabitants per square

kilometer. Only 2,5% of Egypt's land area, the Nile

delta and the Nile valley, is suitable for intensive

agriculture. Most of a 50 km wide land strip along the

coast is less than 2 m above sea-level and is protected

from flooding by only a 1 to 10 km wide coastal sand

belt, shaped by the discharge of the Rosetta and

Damietta branches of the Nile. Erosion of the

protective sand belt is a serious problem and has

accelerated since the construction of the Aswan dam.

Potential impact of sea level rise: Nile Delta

Massive cement tetrapods lie along the beach in Baltim, on Egypt's Mediterranean coast. The huge blocks

are a stopgap to prevent erosion, but the sea is steadily overtaking them. The first stages of this wall have

been almost completely overtaken by sand; only their moss-covered tops remain visible. Without action, the

other rows will soon disappear as well. Nicholas Linn for Newsweek

Venice Carnival 2015: Participants try to keep their costumes dry on flooded St

Mark's Square

Source: http://www.ibtimes.co.uk/venice-carnival-2015-revellers-try-keep-their-costumes-

dry-flooded-st-marks-square-1486241

Sea Level Rise: Venice Going Under.

Venice's last line of defence: New anti-flood system aims to protect historic Italian city from rising waters

Israel coast lin 18,000 B.P

High resolution software to assess sea level rise in different scenarios (Hebrew University of Jerusalem)

High resolution software to assess sea level rise in

different scenarios

The city of Tel Aviv after a 2 m sea level rise Haifa Bay after a 2 m sea level rise

Characteristics of Resilient Cities• Heat wave resilient

- Mitigation of the urban heat island by adaptation of environmental-climate-related planning.

- Water and energy supply in an emergency. - Preparing and educating the population for

dehydration heat stroke scenarios

• Cold wave resilient - Keeping transportation routes open- Maintaining food and energy supply in an emergency.

- Heating houses and public buildings when power lines are down

- Preparations for the operation of key institutions

Preparation of resilient cities

• Atmospheric disturbances resilient (storm winds, intense precipitation)

- Strengthening Infrastructure.- Preparation of drainage and infiltration systems.- Removal of obstacles (pruning trees, billboards, antennas,

etc.)

- Preparation of forecasting and warning system.

• Sea level rise- Constructing models to predict future floods.- Prohibition of construction in low places along th e

coastline- Raising coastal infrastructure ( e.g ports, jetty, roads)

- Readiness for sea storms and tsunamis

Difficulties in legislating for policy change towards resilient city adaptations

• Lack of geographical and historical analogies from the past

• Controversy over economic implications of policy

adaptation

• Lack of environmental awareness

• Conservatism of decision-makers

• Politicians have more pressing issues to relate to

Resilient Urban Design — 11 Principles• Embrace density, diversity and mix of uses, users, building types, and public spaces.

• Prioritize walking as the preferred mode of travel, and as a defining component of a healthy

quality of life.

• Develop in a way that is transit supportive.

• Focus energy and resources on conserving, enhancing, and creating strong, vibrant places, which

are a significant component of the neighborhood’s structure and of the community’s identity.

• Provide the needs of daily living, within walking distance (a 500 m radius).

• Conserve and enhance the health of natural systems (including climate) and areas of

environmental significance, and manage the impacts of climate change.

• Enhance the effectiveness, efficiency and safety of their technical and industrial systems and

processes, including their manufacturing, transportation, communications and construction

infrastructure and systems to increase their energy efficiency, and reduce their environmental

footprint.

• Will grow and produce the resources they need, in close proximity (200 kilometer radius).

• Will require the active participation of community members, at all scales in the development

plans.

• Plan and design for redundancy and durability of their life safety and critical infrastructure

systems. Planning and design of these systems will aim for levels of redundancy and durability

that are commensurate with the increasing environmental, social, and economic stresses

associated with the impacts of climate change and peak oil.

• Develop building types and urban forms with reduced servicing costs, and reduced

environmental footprints.

http://www.unisdr.org/files/26462_handbookfinalonlineversion.pdf