Syndicate content

cities

There are otters in the city

Ede Ijjasz-Vasquez's picture

Photo by budak via Flickr CC

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, the tension between urban development and biodiversity conservation can be very pronounced. 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.

Mapping and measuring urban places: Are we there yet? (Part 2/2)

David Mason's picture
Photo by Anton Balazh via Shutterstock

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).

Mapping and measuring urban places: Are we there yet? (Part 1/2)

David Mason's picture
Source: Deuskar, C., and Stewart B.. 2016. “Measuring global urbanization using a standard definition of urban areas: Analysis of preliminary results” World Bank
This satellite image shows Sao Paolo's estimated “urban areas” based on a WorldPop gridded population layer. Areas in yellow are areas with at least 300 people per km2 and a known settlement size of 5,000 people. Red areas represent a population density threshold of at least 1,500 people per km2 and a known settlement size of 50,000 people.
There remains a surprising amount of disagreement over precisely what “urban” means despite the ubiquity of the term in our work. Are urban areas defined by a certain amount of artificial land cover such as permanent buildings and roads? Or are they more accurately described as spatially concentrated populations? The answer often depends on what country you are in, as their administrative definitions of urban areas can vary widely across and between these two dimensions.
 
Without a globally consistent measure of urban areas, it can be difficult to track changes in built-up areas (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.

Cleaner streets mean healthier communities: The story of the “Zika Warriors”

Silpa Kaza's picture


Last November, 345 “Zika Warriors” took to the streets of Jamaica to fight the spread of the Zika virus in 30 communities. These local residents trained as vector control aides to prevent Zika primarily by improving waste management in their communities, including cleaning up public spaces and destroying mosquito breeding sites. In addition, they distributed bed nets to pregnant households.

As we observe World Health Day today, we look back with great thanks to the significant reduction in Zika in these communities. Anecdotal evidence suggested that the Zika Warriors significantly stemmed the spread of the virus, especially compared to the 2014 Chikungunya outbreak that led Jamaica to declare a state of emergency.

As a first responder to the pandemic, the Jamaica Social Investment Fund (JSIF) designed this program within an existing waste management program of the World Bank’s Integrated Community Development Project, directly benefitting more than 140,000 citizens.

Urban jungles in jeopardy

Ivo Germann's picture
Why the world’s cities are at risk – and what we can do to make them more resilient



We may not know exactly what the world will look like in two decades, but we know this: it is going to be a world of cities.
 
The global population is becoming increasingly urban, and at an astonishing rate. Each year, urban areas are growing by an average of more than 75 million people – more than the population of the world’s 85 smallest countries combined.
 
For the world’s economy, this is great news, since cities produce 80 percent of global GDP, despite currently being home to only 55 percent of the population. But it is a problem for urban infrastructure, which can’t keep up with such fast-paced growth. As a result, cities, already vulnerable, are becoming increasingly susceptible to natural disasters – from flooding and landslides that can decimate informal housing settlements, to earthquakes that can devastate power grids and water systems.
 
These risks could be disastrous for the urban poor, 881 million of whom currently live in slums (up 28 percent since 2000). And climate change – which is increasing the intensity and frequency of natural disasters – will only exacerbate the problem. For this reason, multilateral and government institutions now see resilience and climate adaptation as integral pillars of development.
 
The Swiss State Secretariat for Economic Affairs (SECO), for example, considers low-emission and climate-resilient economies to be key to global competitiveness. A recent report by the World Bank and the Global Facility for Disaster Reduction and Recovery (GFDRR) found that climate change may force up to 77 million urban residents into poverty by 2030 – unless we take action to improve the resilience of cities around the world.

How to effectively manage metropolitan areas?

Ede Ijjasz-Vasquez's picture
​Today, a quarter of the world’s population lives in urban “agglomerations”—supersized metropolitan areas that cut across jurisdictional boundaries and bring together one or more cities along with their surrounding areas.

These metropolitan areas face a common challenge: effectively coordinating planning, infrastructure development, and service delivery across multiple jurisdictions. This is particularly difficult in developing countries, which often lack the necessary legal, institutional, and governance apparatus to undertake such coordination. The New Urban Agenda issued by the Habitat III conference in 2016 identified metropolitan planning and management as one of the most critical needs to ensure sustainable urbanization.

Fortunately, there is growing evidence and good practice from various countries on how to effectively manage and govern metropolitan areas. To help spread existing good practice and co-create new solutions, the World Bank has been supporting a community of practice (CoP) on metropolitan governance, or MetroLab, which brings together officials from metropolitan areas in both developing and developed countries for peer-peer knowledge and experience sharing.  Since its launch in 2013, MetroLab has held eight meetings in various cities, including Bangkok, Mumbai, New York, Paris, Rio de Janeiro, and Seoul.

​The most recent meeting took place in Tokyo from January 30 through February 2. Organized by the World Bank’s Tokyo Development Learning Center, the Tokyo MetroLab brought together mayors, city planners, and finance officials from nine developing cities. They were joined by experts from the World Bank, New York’s Regional Plan Association, the Seoul Metropolitan Government, and Advancity—Paris’ Smart Metropolis Hub.

In this video, Lydia Sackey-Addy, one of the participating officials from Accra, Ghana, as well as the World Bank’s Senior Director Ede Ijjasz-Vasquez (@Ede_WBG) and Lead Urban Economist Maria Angelica Sotomayor (@masotomayor) tell us how they are working together to make the Accra metropolitan area more resilient and sustainable for its residents.


 

How can Kenya achieve a sustainable urban future?

Ede Ijjasz-Vasquez's picture
Cities in Africa are growing at unprecedented speeds. In Kenya, about 12 million of the country’s over 40 million people live in urban areas today. However, a child born in 2017 will see Kenya’s urban population double to 24 million by 2035 and more than triple to 40 million by 2050. A World Bank report titled “Kenya Urbanization Review” projects that by that time, about half of Kenyans will be living in cities, and Kenya’s urban population will be nearly as large as the country’s entire population today. Kenya’s urban transition has begun.
 
Despite many advantages including an ambitious program for devolution, the challenges for a smooth urbanization process remain multifaceted for Kenya:
  • Access to services remains low;
  • Informality of human settlements and jobs predominate; and
  • Poorly functioning land markets make investing in housing and infrastructure expensive and inefficient. 
The Kenya Urbanization Review points to some policy recommendations that can help Kenya ensure the smoothest transition possible during its ongoing urbanization process.

In this video, Senior Director Ede Ijjasz-Vasquez weighs in on Kenya’s urbanization challenges, focusing on urban finance, land and planning institutions, and urban governance, as he discusses the main messages of the Kenya Urbanization Review.

Video: Courtesy of Arimus Media

Three misconceptions in the way of better housing policies

Luis Triveno's picture
Also available in: 中文

Photo by Dominic Chavez / World Bank

​While the need for housing is widespread, individually people have different needs—depending on whether they are single, married, senior citizens, families with children, or members with disabilities. Despite the best of intentions of policymakers, "a roof overhead" remains an elusive goal for a large majority of the world’s people. Most households cannot afford even the cheapest house that fits their needs and qualifies as “decent,” and no government alone can close this gap with subsidies. Nor are we on track to build the 300 million new houses needed to close the housing gap by 2030.

What’s missing? At least three misconceptions stand in the way of better housing policies: 
 

Economic growth in Europe: Leaving no region behind

Ede Ijjasz-Vasquez's picture
Economic growth in most countries is driven by a few urban centers that have a high concentration of economic activity. In the EU, 28 capital cities and 228 secondary cities amass 23% of the total population, generate 63% of total GDP, and were responsible for 64% of GDP growth between 2000 and 2013 (EuroStat). These cities are national and regional growth engines. This is of particular importance for lagging region policies, as it indicates that without strong cities, one cannot have strong regions.
 
This importance of cities for regional and national development now serves as a foundation for the dialogue between the World Bank and the European Commission, with respect to the design of the European Regional Development Fund (ERDF) for the 2014-2020 Programming Period. The ERDF is the world’s largest investment program targeting sub-national public infrastructure investments.
 
In this video, World Bank Senior Director Ede Ijjasz-Vasquez and Marcel Ionescu-Heroiu, Senior Urban Development Specialist from Romania Country Office team, discuss the importance of cities in regional and national growth and development, and the role the Bank is playing in the design of the world’s largest sub-national investment fund.

A year of building sustainable communities in 12 stories

Andy Shuai Liu's picture
What are some of the key issues that will shape global development in 2017?

​From addressing the forced displacement crisis to helping indigenous communities, and from implementing the “New Urban Agenda” to enhancing resilience to disasters and climate change, one thing is clear: we must step up efforts to build and grow economies and communities that are inclusive, resilient, and sustainable for all—especially for the poor and vulnerable.
 
In the timeline below, revisit some of the stories on sustainable development that resonated the most with you last year, and leave a comment to let us know what you wish to see more of in our “Sustainable Communities” blog series in 2017.

Pages