The demand for decent, affordable – and safe – housing for growing urban populations is a nagging problem for financially strapped governments throughout the developing world. According to McKinsey & Co., a third of the world’s urban population – 1.6 billion people – will be hard pressed to obtain decent housing by 2025.
, quickly, by strapping themselves inside the myth that it is always better to build new homes rather than strengthening existing ones.
In Colombia, for example, 98% of all housing subsidies fund the acquisition of a new house or apartment; almost nothing goes to retrofitting existing homes to withstand the forces of nature and the tests of time.
While new construction may be a more attractive way to create schools, hospitals, and other public infrastructure, housing is a bigger, more pressing and complicated problem that may have a simpler solution:
It’s not only a more efficient way to deploy limited government subsidies, but also a strategy to leverage these public funds with another private source in reach of governments: homeowners.
When a family of 10 smooth-coated otters appeared in Singapore’s urban downtown of Marina Bay last year, the city was ablaze with excitement and delight. Who would have thought that these otters would make a dense urban environment like Singapore home? After all, otters were thought to have vanished in the 1970s as Singapore rapidly developed into a dense metropolis.
Was this a fad? Probably. Was this a big deal? Absolutely. In a small city-state where land is considered a scarce resource, This was not the case in Singapore. Between 1986 and 2010, as Singapore’s urban population doubled from 2.7 to 5 million, its green cover also increased from 36% to 50%, all within the confines of just 710 square kilometers. The increase in green cover in urbanized Singapore was seen as a sign that the efforts by the urban planning agency, parks and water management boards had paid off, and a testament that the natural environment could be indeed be integrated effectively into the urban fabric of the city.
Today is World Environment Day. This year, it celebrates the theme of “connecting people to nature,” and invites us to think about how we are part of nature—and how intimately we depend on it.
- New Urban Agenda
- Global Goals
- sustainable development goals
- public space
- urban design
- urban planning
- Sustainable Communities
- Urban Development
- Climate Change
- East Asia and Pacific
- World Environment Day
The city of Medellin has successfully implemented an integrated and multi-sector approach that has included a combination of violence prevention programs and a deep commitment of its people to build a prosperous, inclusive and livable city. For that reason, the experience of Medellin in integral urban transformation and social resilience attracts intense interest from other cities around the world.
This week (May 29 to June 2, 2017), representatives from more than 35 cities are in Medellin sharing different methodologies and experiences with respect to security, coexistence, and resilience. This “Medellin Lab” is the first living laboratory program in Colombia, organized by Medellin’s International Cooperation and Investment Agency (ACI), the World Bank, USAID, and the Rockefeller foundation’s 100 Resilient Cities network.
In this video, Santiago Uribe, the Chief Resilience Officer (CRO) of the City of Medellin, as well as the World Bank’s Senior Director Ede Ijjasz-Vasquez (@Ede_WBG) tell us a bit more about the experience of the Medellin Lab and .
The 2011 World Development Report positioned security as a critical development issue and pointed to the importance of strengthening institutions and governance to provide citizen security, justice, and jobs is crucial to break cycles of violence. Similarly, the World Bank’s flagship report on social inclusion, Inclusion Matters points to the importance of empowering people by transforming institutions to make them more inclusive, responsive, and accountable.
In Cali, Colombia, violence prevention is one of the main aspects of the city’s Resilience Strategy, which recognizes the importance of social inclusion in reducing violence and improving quality of life of the city.
In this video, Vivian Argueta, the Chief Resilience Officer (CRO) of the City of Cali, Colombia, and World Bank Senior Director Ede Ijjasz-Vasquez (@Ede_WBG) discuss Cali’s resilience strategy and its focus on violence prevention.
[Download a newly launched report—Greening Africa’s Cities—to learn more about the interplay between urbanization and sustainability in Africa.]
Take Kampala, Uganda as an example. It is estimated that only 5% of the city’s population is connected to the sewer network, with 95% of the population having access to basic on-site, mostly shared, sanitation. As a result, the volumes of flows entering the city’s Nakivubo wetland channels have increased significantly with contaminated runoff from informal areas and partially treated wastewater from the overburdened sewage works. This has significant negative impacts on human health, wetland and lake ecological function, as well as the cost of water supply to the city from Lake Victoria’s Inner Murchison Bay.
The city is considering rehabilitating the Nakivubo wetland, but it would cost US$53 million upfront, in addition to ongoing maintenance and operating costs of about US$3.6 million per year. Although benefits would include water treatment cost savings of US$1 million and recreational benefits exceeding US$22 million per year, it is now too costly and impractical to restore the wetland to a state where benefits can be achieved.
an additional 100 million people into poverty.
Today, we celebrate the annual World Red Cross and Red Crescent Day. To reduce the impacts of disasters on the poorest and most vulnerable, and build their resilience, it is essential that we collaborate and innovate to bring solutions to the community level. Close coordination with the humanitarian sector is therefore more important than ever before.
The World Bank and the Global Facility for Disaster Reduction and Recovery (GFDRR) have a strong ongoing partnership with the Red Cross Red Crescent—the world’s largest humanitarian network—and in particular the Red Cross Red Crescent Climate Centre.
Better disaster-risk data for timely forecast and rapid financing
Between 2010 and 2017, Chile was struck by 10 major natural hazard events. These disasters affected as many as 340,583 houses and cost $3.6 billion in reconstruction (Ministry of Housing and Urbanism of Chile). Post-disaster assessments point to housing as one of the most affected sectors in the wake of climate-related and other natural hazards—most commonly floods, earthquakes, landslides, and fires. In a 22-year period between 1990 and 2011, minimum losses in the housing sector for 16 countries in Latin America and the Caribbean (LAC) amounted to $53 billion.
In the LAC region, one quarter of the population lives in slums, characterized by the prevalence of substandard housing quality as well as incremental and self-construction of homes. Families living in these informal settlements are at greatest risk to natural hazard impacts. Programs providing new housing do not always reach families in the lowest quintiles; and without access to affordable and well-located housing alternatives, households have no other option than to build informally, and in areas most prone to natural disasters.
There is need for urgent action toward a global solution to leave no area behind because persistent spatial disparities in living standards can adversely affect national unity and social cohesion, foster political instability, and increase the risk of conflict. In identifying priorities, it is essential to remind ourselves that leaving no area behind is NOT equal to “doing the same everywhere.” And to advance on the lagging areas agenda, we must recognize that the heterogeneity of challenges across territories needs to be met with a heterogeneity of policy instruments. To leave no area behind, each local challenge needs to be matched with a specific set of policy instruments. Policies should seek unity, NOT uniformity.
Strengthening the link between research and policy for a combined agenda is critical. Georeferenced data provides a tremendous opportunity for analysis of risk factors. In East Africa, for example, the issue of lagging lands is addressed by work in high-risk and conflict-affected areas, by addressing the underlying drivers of vulnerability and by reducing exposure to hazards of people. In the Horn of Africa, the EU has successfully applied geographical targeting in cross-border areas across the region, collaboration across borders through specific actions, and a regional approach based on research and evidence. In Cali, Colombia, the “Territories of Inclusion and Opportunities,” a land-based strategy addressing multiple risk factors, has been a successful tool in combating poverty, exclusion and violence.
My previous blog post surveyed some of the recent trends in developing global measures of urbanization. In this post, I want to turn to a brief discussion for scholars and practitioners on some possible applications and areas of focus for ongoing work:
[Download draft paper "Bright Lights, Big Cities: a Review of Research and Findings on Global Urban Expansion"]
While there are a number of different maps for documenting urban expansion, each has different strengths and weaknesses in application. Coarser resolution maps such as MODIS can be used for mapping the basic contours of artificial built-up areas in regional and comparative scales. On the other hand, high-resolution maps are best suited for individual cities, as algorithms can be used to identify and classify observed colors, textures, shading, and patterns into different types of land uses. These levels of detail are difficult to use for reliable comparisons between cities as the types of building materials, structure shapes, light reflectivity, and other factors can vary widely between countries and regions.
Nonetheless, there are a number of applications for policymakers in this regard, from identifying and mapping green spaces and natural hazard risks to identifying and tracking areas of new growth, such as informal settlements. However, such approaches to land use detection require careful calibration of these automated methods, such as cross referencing with other available maps, or by “ground truthing” with a sample of street-level photos of various types of buildings and land cover as reference inputs for automation. One solution to this is the use of social media and geo-coded data to confirm and monitor changes in urban environments alongside the use of high-resolution satellite imagery.
Nighttime light maps also have gained traction as measures of urban extent and as ways to gauge changes in economic activity in large urban centers. They are probably less useful for documenting smaller settlements, which may be dimmer or have little significant variation in brightness. It is important to correct these types of maps for “overglow” measurement effects—where certain light may “bleed” or obscure the shapes and forms of very large, bright urban areas in relation to adjacent smaller and dimmer settlements (newer VIIRs maps have made some important advances in correcting this).
(land surface coverage comprised of buildings and roads) and population growth across time and space. This impacts how policymakers may understand and prioritize the challenges cities face and what investments or reforms may be needed. In a new paper, “Bright Lights, Big Cities: a Review of Research and Findings on Global Urban Expansion,” I provide a brief introduction to some of the current approaches for measuring urban expansion and review the comparative findings of some recent studies.
The UN’s World Urbanization Prospects (WUP), perhaps the most comprehensive and widely cited measure of urbanization across the world, draws from a compilation of country-level population totals based on administrative definitions. A key weakness with this set is that since each country defines “urban” differently, it is difficult to accurately compare one country’s urbanization to another, as well as to estimate the urban population of a group of countries or the world itself. Recent work has provided more sophisticated ways to measure urban growth and expansion using both satellite map data and careful application of population data.