Tunis
URBAN ADAPTATION AND
CLIMATE RESILIENCE
IN THE SOUTHERN MEDITERRANEAN
[email protected]
Anthony G. Bigio, GWU Professor, IPCC Lead Author
Climate change impacts on cities
SLR, marine inundation, storm
surges, coastal erosion
Hurricanes and cyclones
Extreme precipitation events
and urban flooding
Landslides
Droughts, water scarcity
Higher ambient
temperatures
Increased heat-island effect
Heat-waves
Worsened air quality
Bangkok floods, November 2011
Natural hazards and climate change
Source: IPCC Special Report on Extreme Events (SREX), 2012
Definitions of risk and resilience
Risk = Hazard x Exposure x Vulnerability
Hazard: the natural or climatic event
Exposure: n. population, $ assets, square acres ...
Vulnerability: characteristics of assets/people exposed
Resilience
“The ability of a system and its component parts to
anticipate, absorb, accommodate or recover from the
effects of a hazardous event in a timely and efficient
manner, including through ensuring the preservation,
restoration, or improvement of its essential basic structures
and functions” IPPC, SREX Report, Glossary
Key Messages from IPCC 5th A.R.
“City-based disaster risk management with a central focus on
risk reduction is a strong foundation on which to address
increasing exposure and vulnerability and thus to build
adaptation”.
“Urban adaptation provides opportunities for incremental and
transformative adjustments to development trajectories towards
resilience and sustainable development”
“Urban adaptation action that delivers mitigation co-benefits is
a powerful, resource-efficient means to address climate
change” “Ecosystem-based adaptation is a key contributor to
urban resilience”
Source: IPCC Working Group II, Chapter 8, 5th Ass. Report
Urban risk management, adaptation
“Accumulated resilience resulting from the the build-up of
piped water, sewers, drains, health care and emergency
services and standards set and enforced on housing
quality and infrastructure over the past 100-150 years…
helped build the institutions, finances and governance
systems that can support climate change adaptation”
“Can the institutions and political pressures that built the
accumulated resilience shift to resilience building as a
directed process and to respond dynamically and
effectively to evolving and changing climate-related risks?
Source: IPCC Working Group II, Chapter 8, 5th Ass. Report
Differences in urban adaptive capacity
Capacity of cities to adapt to climate change is highly
correlated with the % of residents with adequate
access to urban infrastructure and formal housing
Capacity to “bounce back” of urban centers:
adequate: most cities in high-income countries, 1billion
some: most in middle-income, some in low-income, 1.5b
little: most in low-income, many in middle-income, 1b
Capacity to “bounce forward” of urban centers:
very few, e.g. New York, London, Durban, Manizales
Source: IPCC Working Group II, Chapter 8, 5th Ass. Report
Flood losses in coastal cities
Global yearly flood losses of
US$6billion in 2005 in major
coastal cities are expected to
rise to US$52billion in 2050
due to growing population
and assets exposed, and to
US$1trillion due to climate
change and land subsidence,
if adaptation does not
provide adequate flood
protection to cities.
Source: S. Hallegatte (WB), J.
Corfee-Morlot, C. Green, R. Nicholls,
“Nature Climate Change” 3, 2013
Jakarta
Explosive population growth
source: IMF
Human population growth is a
relatively recent phenomenon,
and one that is occurring at
an extraordinarily fast pace.
At a different time-scale,
demographic growth is projected
to continue throughout the 21st
century before tapering off
Future global warming scenarios
“Without more mitigation, global mean surface temperature
might increase by 3.7° to 4.8°C over the 21st century” IPCC
Summary for Policymakers, WGIII, 5th Assessment Report
Disasters trend in the MENA region
Source: Natural Disasters in the Middle East and North Africa, World Bank, 2014
MENA natural disasters by type
Source: Natural Disasters in the Middle East and North Africa, World Bank 2014
A highly urbanized coastal region
MENA urbanization prospects 2030
Table 1
Urbanization prospects of the nine Southern and Eastern Mediterranean countries
Total Pop. 2005 Urban Pop. 2005 Total Pop. 2030 Urban Pop. 2030 Total increase % Increase of
in thousands
in thousands
in thousands
in thousands
urban population urban population
Algeria
Libya
Egypt
Lebanon
Morocco
Syria
Tunisia
West Bank and Gaza
Turkey
TOTAL
32,854
5,918
72,850
4,011
30,495
18,894
10,105
3,762
72,970
20,804
4,557
31,062
3,473
16,763
10,049
6,603
2,693
49,097
44,726
8,447
104,070
4,925
39,259
29,294
12,529
7,320
92,468
34,096
7,001
51,950
4,435
25,883
18,746
9,417
5,653
71,874
13,292
2,444
20,888
962
9,120
8,697
2,814
2,960
22,777
63.89%
53.63%
67.25%
27.70%
54.41%
86.55%
42.62%
109.91%
46.39%
251,859
145,101
343,038
229,055
83,954
57.86%
Source: "World Urbanization Prospects: the 2007 revision ", United Nations
A projected 58% growth of urban population between 2005 and
2030 will cause huge urban development challenges AND increase
urban exposure to natural hazards and impacts of climate change
Climate Change
Adaptation and Natural
Disasters Preparedness
in the Coastal Cites of
North Africa
Anthony Gad Bigio
Senior Urban Specialist
THE WORLD BANK
OVERVIEW
Study coverage and methodology
Climate downscaling scenarios, probabilistic risk assessments
carried out for Alexandria, Casablanca , Tunis, Bouregreg Valley
Urban risk assessments for 2010 and for 2030, addressing:
seismic & tsunamic risks, SLR, land subsidence, marine
submersion, coastal erosion, flooding, and water scarcity
Economic valuation of potential losses and damages showing
potential costs of over $1billion for each of the cities studied, of
which 20 to 25% due to climate change, rest to natural disasters
Adaptation and Resilience Action Plans prepared, presented to,
discussed with key stakeholders to respond to the main risks
16
OVERVIEW
Institutional support received by the study
National counterparts in Egypt, Morocco and Tunisia fully
involved in the Urban Risk Assessments and the preparation of
the Adaptation and Resilience Action Plans, June 2009-2011
Support of the Marseille Center for Mediterranean Integration,
the Arab Academy for Science ,Technology and Maritime
Transportation (Egypt), and the European Space Agency
Study presented at the following international conferences:
Protecting Deltas Cities (Rotterdam, 2010) MENA Coastal Cities
(Marseille, 2011) Resilient Cities ICLEI Conference (Bonn,
2011), Coastal Cities and Climate Change (Venice, 2011)
17
OVERVIEW
Climate findings and future projections
Increases in ambient
temperatures expected between
1.0C and 1.5C in all cities
Climate downscaling points to
lower total rainfall but more
extreme weather events
Sea-level rise conservatively
estimated at 20 cm by 2030, but
higher levels expected beyond
18
ALEXANDRIA URA
A FRAGILE SITE WITH MULTIPLE RISKS
Alexandria is a linear, congested
city caught between the seafront, lakes and wetlands
City expected to grow from 4.1m
to 6.8m by 2030 (65% rate) with
more pressure on the site
Coastal risks are coupled with
land subsidence, little control
over urban sprawl
19
ALEXANDRIA URA
Marine submersion and coastal erosion risks
2010
2030
20
ALEXANDRIA URA
Coastal erosion aggravated by infrastructure
The Corniche road, recently built on reclaimed sea-shore, has
aggravated storm surges by altering the sea-bed slope
21
CASABLANCA URA
KEY WATER RELATED CHALLENGES
Current population of 3.3m
expected to grow to 5.1 by
2030 (55% increase)
Urban exposure to coastal
erosion and flooding are
high, marine submersion
critical in some areas
Further urbanization may
worsen flooding risks if it is
not “climate-smart”
22
CASABLANCA URA
Tsunami and marine submersion risks
Marine submersion risks
concentrated in the town of
Mohammedia, also exposed to
flooding.
Exceptional storm surges can
submerge a large portion of
the town, expected to increase
by 2030 with sea-level rise
Tsunamic risks are considered
low, with a 22% probability
over 50 years and 1m waves
23
CASABLANCA URA
Water scarcity future constraints
Current urban water supply is
sufficient thanks to the system of
integrated water basins
Bouregreg basin provides 38% and
Oum Er Rabia basin 62% of the
water resource for Casablanca
Demand expected to increase by
1.7 to 1.9% per year to 2030, but CC
could cause a fall in supply of the
Bouregreg basin of up to 40%
24
TUNIS URA
NATURAL, CLIMATE CHANGE RISKS
The 2.2m population expected
to grow to 3m by 2030, with a
33% increase (lowest of all)
Urban coverage expected is
significantly higher due to
demographic transformations
Multiple risks, becoming higher
by 2030, make Tunis the city
most at risk among those
covered by the study
25
TUNIS URA
Urban flooding a primary risk for Tunis
Lack of secondary and tertiary
drainage systems make Tunis
highly vulnerable to flooding
s
After 2003 floods, major works
have been designed, and are
being implemented
However by 2030 further areas
will be subject to flooding, on
account of urbanization and
climate change impacts
26
TUNIS URA
Downtown area of Tunis most threatened
Multiple risks of flooding,
marine inundation, and land
subsidence threaten the
“Basse Ville” of Tunis
Risks expected to worsen
significantly by 2030
High economic, social and
urban heritage values justify
a major effort to rehabilitate
this crucial area of the city
27
URA SUMMARY COMPARISON
Urban risks on the rise in all cities studied
28
Steps to urban adaptation
Source: European Environment Agency
Urban risk assessment for
climate impacts (and
natural hazards !)
Socio-technical
identification of resilience
and adaptation measures
Economic valuation and
adaptation cost curve
No-regret measures,
adaptive management,
periodical updates of
adaptation action plan
Urban adaptive capacity
Source: European Environment Agency
Good governance and
national programs facilitating
local climate action
Democratic and participatory
institutions at local level
Cities’ competences and
authority to regulate climaterelevant issues
Cities’ commitment and the
presence of local champions
Economic resources, knowledge
and information on climate
Urban adaptation tool-kit
European Environment Agency
Gray infrastructure
Green infrastructure
Soft solutions
Source: Bigio, World Bank, 2111
All technical agencies
recognize the importance of
soft or institutional measures
as the most critical ones, which
are also the most costeffective, albeit difficult to
implement
Institutional or soft measures
Authority and resources of
risk-management agencies
Early warning systems for
rapid-onset events, public
information systems
Emergency evacuation plans
and preparedness, civil
protection systems
Hydro-meteorological
services, the technical
capability to predict and
monitor natural hazards and
climate impacts
Coastal resilience
Sea-dikes, levees to control
sea-level rise in critical areas
– within possible limits…
Managed retreat from noncritical, peri-urban areas,
deltas, river estuaries
Beach protection and beach
nourishment programs
Defense works for critical
urban infrastructure: ports,
jetties, power and water
treatment plants
Tunis, La Goulette
Flood risk management
Ballona wetlands state park
From conventional flood
control to an integrated
approach including:
On-site drainage water
retention, water re-use
Structured wetlands and
wetland restoration
Multiple-use urban space
retention ponds
Porous vs. impervious urban
surfaces
Protection of waterways
Transport infrastructure
“Hardening” of transport
systems such as roads and
bridges, underground
metros, surface rail, etc.
Transport infrastructure
critical for post-disaster
emergency response, thus
essential resilience action
Backward and forward
linkages to fuel and power
supply, import and export
functions of urban areas
Melbourne heat-wave
NYC metro, Sandy
Urban energy systems
Flooded power-plant, North Dakota
Climate-safe location of
plants, transformers and
back-up generators
Re-tooling of power plants
to deal with warming water
used for cooling
Integration of supply grids
Reducing dependency on
oil and other fossil fuels
Diversified, decentralized
urban energy production
Urban energy demand
management, smart grids
Buildings and housing
Climate vulnerability of built
environment is highly
correlated to income and
intra-urban differentials
Retrofitting, designing more
climate-resilient and weatherresistant buildings
Informal housing in dev.
countries up to 50% of city:
provision of on-site
infrastructure, slope
stabilization, drainage
Protecting public health
IPCC, AR5, WGII, 2014:
Reducing local air pollution
from energy systems
Providing access to
reproductive health service to
contain population growth,
related emissions
Shifting consumption away
from animal products and
related GHG emission
Designing transport systems
that promote active transport
and reduce use of motorized
vehicles
Urban planning in existing cities
Designing or transforming
urban public spaces
Green street canopies,
parks, also carbon sinks
Waterfront redevelopment
combining adaptation with
urban regeneration
Managed retreat of
neighborhoods subject to
high levels of risk
Protecting urban built
heritage from impacts
Planning future urban growth
Directing urban growth
away from at-risk areas via
land-use plans and main
transportation investments
Green barriers to contain
sprawl, protect agricultural
areas, food production
Promoting “right” density
and urban form for
resilience, mitigation and
sustainable development
APPORTIONING URBAN RISK
Varying proportions of urban risk causes
41
ALEXANDRIA
Urban planning responses
GOPP to orient future urban
growth away from areas at
risk via the forthcoming
Master Plan to 2030
Critical areas of Abou Qir
and El Max to be protected
from marine submersion,
flooding risks
Strategic Urban Plan to
include climate-resilient
urban development plans
42
ALEXANDRIA
Infrastructure investments required
Build further sea defenses to limit
coastal erosion and marine
submersion due to storm surges
Promote reuse of waste water for
agricultural purposes in lieu of Nile
water to reduce future demand
Conduct seismic micro-zoning, and
deeepen the understanding of
tsunamic risks and of the vulnerability
of the housing stock
43
ALEXANDRIA
Adapting institutions to manage urban risks
Strengthening monitoring and early warning systems, in order
to better protect the city against extreme weather events
Preparation and self-protection against fast-impacting
phenomena, via information and education campaigns
Insuring against natural risks, via publicly supported schemes
that would protect public as well as private investments
Improving the capacity to integrate the forecasting of (fastonset) natural risks with (slow-onset) climate change impacts
44
CASABLANCA
Urban planning responses
Protection of green areas and
waterways to improve urban
environmental quality
Managed retreat of the housing
threatened by coastal erosion,
greater limits on high-end
coastal real-estate projects
Eco-neighborhoods to be
planned for the future urban
expansion, with on-site
drainage systems
45
CASABLANCA
Infrastructure investments required
A major drainage channel to the
West of the city is required to
increase flood protection
Sea dikes will be needed to
protect Mohammedia against
marine submersion risks
Coastal erosion protection,
water leakages control, water
conservation and waste-water
reuse systems are all necessary
measures
46
CASABLANCA
Regulatory, preparedness responses
Casablanca should increase
its level of protection against
storm surges and tsunamis
with early warning systems
Integration of data on rapidonset and slow-onset events
should be improved
Civil society to be more
integrated in the preparedness
systems at local level
47
TUNIS
Urban planning responses
Containing urban sprawl is a
critical challenge for 2030, by
increasing densities
Orient future growth away
from risk areas and promote
eco-neighborhood concept
Special urban rehabilitation
plan for down-town Tunis
Integrate green areas to
mitigate ambient heat
48
TUNIS
Infrastructure investments required
Flood protection for downtown area, the Sebkahs and
various urban watersheds
Coastal erosion control
measures between La Marsa
and La Goulette, between
Radès and Oued Seltene
Pumping stations for the North
and South Lakes required
Rehabilitation of central areas
affected by subsidence
49
TUNIS
Improved preparedness, emergency response
Seismic risks to be further addressed with a national risk map,
a local micro-zoning map taking into account geological data
Land subsidence and the vulnerability of building stock to
earthquakes should be investigated. Early warning systems to
earthquakes should also be put in place in Tunis
50
ECONOMIC ANALYSIS RESULTS
Robust measures, adaptation cost curves
The study internalizes the uncertainty related to the climate
change projections, emphasizes the need to focus on “noregret” measures, valid under many scenarios. It also provides
a cost-benefit analysis of response measures recommended
51
OVERVIEW
STUDY REPORTS AVAILABLE AT:
beta.cmimarseille.org/
citiesclimatechange
52