June 4, 2011 – Three major North African cities – Alexandria, Casablanca and Tunis - face losses of more than $1 billion each, over the next two decades, as risks of natural disasters intensify with the onset of climate change.
A ground-breaking study shows the increasing environmental threat the three cities face, such as flooding, storm surges and coastal erosion. Morocco’s Bouregreg Valley- an area slated for rapid development - could face major risks unless decision-makers employ climate-smart planning. Particularly, as they develop housing and commercial structures in low-lying, vulnerable areas.
The World Bank-led study, “Climate Change Adaptation and Natural Disasters Preparedness in the Coastal Cities of North Africa,” has been carried out between June 2009 and June 2011 with financial support from the Global Facility for Disaster Risk Reduction and Recovery (GFDRR), the Norwegian Trust Fund Private Sector and Infrastructure (NTF-PSI) and the Trust Fund for Environmentally and Socially Sustainable Development (TFESSD). The Arab Academy of Science, Technology and Maritime Transportation in Alexandria, and the European Space Agency provided analytical support. The Marseille Center for Mediterranean Integration (CMI) has played a key role in the dissemination of the study and public discussion of its findings and recommendations.
The study has been carried out by a consortium of French consulting companies, headed by Egis-BCEOM International and including IAU-RIF and BRGM, in consultation with local partners.
Climate change, under any scenario intensifies the exposure
“Already, these cities experience comparatively high losses from natural disasters such as floods and storm surges,” says Anthony G. Bigio, Senior Urban Specialist at the World Bank, a member of the Intergovernmental Panel on Climate Change (IPCC), and coordinator of the study “Climate change, under any scenario, intensifies the exposure.”
The IPCC has categorized the Middle East and North Africa as the second most vulnerable region in the world to climate change impacts. The risks facing the three cities covered by the study are similar to those faced by many others on the southern Mediterranean coast.
High levels of urbanization and population growth further increase the risks, which place more lives, livelihoods and structures in danger from natural hazards and extreme weather events. In 2010, some 60 million people inhabited the region’s coastal cities and the number is expected to swell to 100 million by 2030. Alexandria, Casablanca and Tunis—home to over 9.5 million people in 2010—can expect a combined population of around 15 million by 2030. The Bouregreg Valley anticipates an influx of more than 140,000 people.
The rapid urbanization also underscores the fact that the region’s coastal cities play an enormously important role—economically, culturally and politically. Disruption and damage from natural disasters would reverberate on a national scale in all the countries.
Similar characteristics but different vulnerabilities
The three cities share a number of similar characteristics, but the study shows that each faces a specific set of unique vulnerabilities and risks.
Alexandria anticipates a 65% surge in population by the year 2030, from 4.1 million to 6.8 million, adding to human density in already vulnerable, low-lying areas. As more people crowd into deteriorating structures in the old parts of the city, informal settlements, which currently house one third of the city’s population, will likely expand. Further settlements are expected in surrounding wetlands and other vulnerable, low-lying areas. The risks of coastal erosion and flooding increase significantly over the next two decades.
Alexandria is expected to adopt a strategic urban plan, which would direct future urban growth, define city limits, and establish a land-use program. It would outline rules for densities, building heights and open space ratios. The plan would need to reflect location-specific assessments of Alexandria’s exposure to natural disaster risks and climate change impacts.
Other recommendations include: more robust early warning systems covering all types of disasters, active management of coastal areas, and improved communication among agencies involved in disaster prevention and response. Water resources management will play an increasingly important role as the impact of climate change grows more visible. Specific goals include greater efficiency in water consumption, better control of runoff and discharge sources, and routine maintenance of the sewage system. Meanwhile, the city could invest in upgraded drainage systems and mobile water pumps to deal with periods of flooding.
An integrated approach to urban planning in Casablanca
Casablanca with a projected population growth of 55% from 3.3million in 2010 to 5.1 million by 2030 -- also faces problems of coastal erosion and flooding. Urbanization claims as much as 1000 hectares a year, with significant consequences for absorption and drainage capacities. Meanwhile, some city edges stretch into low-lying areas that are vulnerable to marine submersion and sea surges. With a concentration of economically important structures located along Casablanca’s coastline, erosion poses a serious concern. A ten-kilometer coastal segment stretching between the eastern end of Casablanca and the Mohammedia power station now faces a strong risk of erosion and submersion; an additional thirty to forty kilometers of coastline segments are also considered at risk. As climate change causes sea levels to rise, vulnerabilities increase in proportion.
The study calls for an integrated approach to urban planning in Casablanca, connecting demographics, growth, economic activity and the environment. In practical terms, such a plan would factor in climate-related vulnerabilities in instances when the city considers alternatives for vacant land or identifies areas for new housing construction. Some slums and overcrowded areas would need to undergo a “de-densification” strategy.
Moroccan institutions can become more effective by removing overlapping ministerial functions and simplifying operations. New information systems, including systems to alert citizens and enterprises of rapidly changing conditions, will also play an important role in lowering risks. The study strongly recommended upgraded systems for surveillance and early warning.
An urgent need to address vulnerabilities along the coastline
The study places special urgency on addressing vulnerabilities along the coastline. Particularly around a stretch of about 40 kilometers that is already vulnerable to erosion and sea surges.
For Tunis, concerns about natural disasters were intensified in 2003. A devastating storm caused significant flooding across the city, with losses running into the hundreds of millions of dollars. The city took steps to improve disaster preparedness, but under most climate change scenarios, more needs to be done.
Tunis anticipates a more modest population growth of 33% over the next two decades- rising to about 3 million by 2030 from 2.2 million in 2010. However, the city faces special risks of its own. In downtown Tunis, land subsidence leaves some buildings tilting dangerously, and seismic risks are amplified by poor soil quality. The coastline is seriously threatened by erosion, requiring reinforced beach defenses.
Topographical data shows that specific areas in the lower downtown area are also vulnerable to marine submersion under certain storm scenarios. By 2030, the frequency of torrential rainfall could increase by 25% under widely accepted scenarios for climate change. Tunis could face an increased recurrence of extreme weather events withshorter cycles of frequency.
Climate-resilient urban planning will be crucial for Tunis in order to manage the increasing risks. In low-lying areas of the city subject to flooding, upgraded drainage systems will be necessary. Illegal housing development at the periphery will need to be contained. In addition, careful zoning, with allowance for green spaces, along with rigorous enforcement of standards, will be critical.
Morocco’s Bouregreg Valley envisions an influx of 140,000 inhabitants and around 90,000 new jobs— in areas subject to a range of natural disasters and climate-related risks. Settlements have been planned for the mouth of the river, and other areas - vulnerable to flooding, submersion and landslides – are slated for construction. The development plan could end up putting more people and structures at risk as natural hazards increase over time. Flooding threats pose a particular concern, with risks increasing from “low” to “very high” in the next twenty years. Climate-smart land use and urban design would mitigate such risks by incorporating flood protection measures and providing earthquake resistant design.
For all urban sites examined by the study, mitigating the risks requires actions in three overlapping spheres: urban planning, institutional reforms including reinforcing capacity, and strengthening infrastructure. Urban design plans will need to steer away from locating communities or enterprises in low-lying areas. Institutions will need to function at higher levels of efficiency and coordination to prevent and lessen damages. They will need improved early warning systems, effective communications, and clearer lines of responsibility. Coastal defenses, drainage systems and other urban infrastructures will require upgrading and reinforcement.
The Bouregreg Valley, which faces large-scale development, constitutes a special case. The investment in climate-smart planning, before buildings and streets are in place, could render significant savings. It could also lower vulnerabilities if the threats are not addressed at the outset of the project.
“The study provides costing tools that will assist cities in identifying potential losses under different scenarios, including taking no action,” says Bigio, who coordinated the study effort. “They have all put together action programs for lessening their risks. The next step is to set priorities and mobilize the necessary investments to move forward and get to implementation.”