“Test and punish”?
There’s a debate raging in American schools today: how (and how much) should children be tested?
The No Child Left Behind (NCLB) Act created a system where all children in all schools from grades 3 to 8 must be tested each year. Critics refer to this accountability architecture as “test and punish,” with stakes such as school funding (or closings!), bonuses for teachers, or grade promotion for students all riding on performance. There is evidence that NCLB improved learning outcomes, but improvements came at a high cost: In addition to teaching to the test, this approach can lead to a number of perverse incentives, like keeping weaker students at home on test day, narrowing the curriculum, or downright cheating. Worse, some have said they can serve to mask and contribute to the structural race and class inequalities in the United States.
Can we rely only on satellite? How accurate are these results?
It is standard practice in classification studies (particularly academic ones) to assess accuracy from behind a computer. Analysts traditionally pick a random selection of points and visually inspect the classified output with the raw imagery. However, these maps are meant to be left in the hands of local governments, and not published in academic journals.
So, it’s important to learn how well the resulting maps reflect the reality on the ground.
Having used the algorithm to classify land cover in 10 secondary cities in Central America, we were determined to learn if the buildings identified by the algorithm were in fact ‘industrial’ or ‘residential’. So the team packed their bags for San Isidro, Costa Rica and Santa Ana, El Salvador.
Upon arrival, each city was divided up into 100x100 meter blocks. Focusing primarily on the built-up environment, roughly 50 of those blocks were picked for validation. The image below shows the city of San Isidro with a 2km buffer circling around its central business district. The black boxes represent the validation sites the team visited.
|Land Cover validation: A sample of 100m blocks that were picked to visit in San Isidro, Costa Rica. At each site, the semi-automated land cover classification map was compared to what the team observed on the ground using laptops and the Waypoint mobile app (available for Android and iOS).|
The buzz around satellite imagery over the past few years has grown increasingly loud. Google Earth, drones, and microsatellites have grabbed headlines and slashed price tags. Urban planners are increasingly turning to remotely sensed data to better understand their city.
But just because we now have access to a wealth of high resolution images of a city does not mean we suddenly have insight into how that city functions.
The question remains:
In an effort a few years ago to map slums, the World Bank adopted an algorithm to create land cover classification layers in large African cities using very high resolution imagery (50cm). Building on the results and lessons learned, the team saw an opportunity in applying these methods to secondary cities in Latin America & the Caribbean (LAC), where data availability challenges were deep and urbanization pressures large. Several Latin American countries including Argentina, Bolivia, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama were faced with questions about the internal structure of secondary cities and had no data on hand to answer such questions.
A limited budget and a tight timeline pushed the team to assess the possibility of using lower resolution images compared to those that had been used for large African cities. Hence, the team embarked in the project to better understand the spatial layout of secondary cities by purchasing 1.5 meter SPOT6/7 imagery and using a semi-automated classification approach to determine what types of land cover could be successfully detected.
Originally developed by Graesser et al 2012 this approach trains (open source) algorithm to leverage both the spectral and texture elements of an image to identify such things as industrial parks, tightly packed small rooftops, vegetation, bare soil etc.
What do the maps look like? The figure below shows the results of a classification in Chinandega, Nicaragua. On the left hand side is the raw imagery and the resulting land cover map (i.e. classified layer) on the right. The land highlighted by purple shows the commercial and industrial buildings, while neighborhoods composed of smaller, possibly lower quality houses are shown in red, and neighborhoods with slightly larger more organized houses have been colored yellow. Lastly, vegetation is shown as green; bare soil, beige; and roads, gray.
Want to explore our maps? Download our data here. Click here for an interactive land cover map of La Ceiba.
The submissions – and we at the Global Platform for Sustainable Cities received more than 90 entries from over 40 countries around the world – are very revealing.
What the photographers tried to communicate was a need: both the urgent need for infrastructure that leads to more resilient, sustainable cities, or a need to aspire to greener ideals of building sustainable communities for all.
There is no better day than today, World Cities Day, for us to share with you the 10 finalists – including 3 winners and an honorable mention for climate action – of the photo competition.
In the winning photo by Yanick Folly, one can practically feel the chaos of a city in Benin, the smell of exhaust fumes as cars crawl up alongside motorcycles and pedestrians down narrow alleyways.
Yanick Folly (Benin) – Winner
The photo is also a reminder that cities are made of people. Any set of solutions for “sustainable cities” will have to make sense to a city’s inhabitants, who tread its streets daily.
In other photos, the aspiration is palpable.
Many of the photographers are nationals of developing countries from all over the world. Yet quite a few of them shared photos of cities we regard as environmentally friendly: Singapore, Amsterdam, London, and Paris... We saw many photos of parks in developed countries, and heard the same message: These green spaces and pedestrian walkways are what we want in a city.
Adedapo Adesemowo (UK / Nigeria)
We received photos of what many of us may categorize as rural areas, but we should reconsider these preconceptions: some “cities” in developing countries are little more than makeshift towns.
So, it is all the more reason why we are excited about this winning photo by Oyewolo Eyitayo from Nigeria. You might think this is an uneventful photograph of a typical urban suburb. Except that the half dirt roads are lined with solar panels.
Oyelowo Eyitayo (Nigeria) – Winner
- photo contest
- photo competition
- sustainable cities
- Global Platform for Sustainable Cities
- Sustainable Communities
- World Cities Day
- Urban Development
- Social Development
- Climate Change
- Latin America & Caribbean
- The World Region
- Middle East and North Africa
- South Asia
- East Asia and Pacific
- Lao People's Democratic Republic
- United Kingdom
Photo: Deutsche Welle | Flickr Creative Commons
As in many regions, countries in Latin America and the Caribbean are underinvesting in infrastructure—spending in the sector is only about half of the $300 billion needed annually to encourage growth and reduce poverty. Addressing this issue involves the successful interaction between public officials and leading infrastructure actors, particularly in the private sector. Stimulating such public-private dialogue is a priority for the Inter-American Development Bank (IDB) Group, a technical partner of the Global Infrastructure Facility (GIF). Along with other partners, our recently established PPP unit supports governments, international financial institutions, and the private sector to develop infrastructure projects.
It was therefore a privilege for me to moderate a panel on country infrastructure programs in Latin America at the GIF’s annual Advisory Council meeting in April 2017. We covered three countries—Colombia, Argentina and Peru—at different stages of PPP market development. The findings were encouraging and illustrate a path forward for other countries in the region:
The availability and quality of such agriculture risk information is hugely important for farmers, and the potential impact of bad information can be quite costly, leading the farmer to make wrong decisions and eventually lose revenue. Information systems that have unreliable sources and/or poor data processing protocols, produce unreliable results, no matter how complex the data processing model is. In other words, one can have “garbage in – garbage out.” Information is integral to agriculture risk management, not only in the short term to hedge against large adverse events, but also in the medium and long term to adapt to climate change and adopt climate smart agriculture practices. Climate-smart agriculture programs and agriculture risk management policies are toothless unless farmers have reliable information to implement changes on the ground.
Investing in agriculture risk information systems is a cost-effective way of making sure that farmers--and other actors along the food supply chain-- make the right decisions. But agriculture risk information systems in most countries suffer from lack of capacity and funding. Mexico, a country with an important agriculture sector, does not have information on market prices of agriculture products like maize, which is why a new Bank project aims to strengthen their capacity in this area. Mexico is not alone. Argentina solved this same problem recently with World Bank support, creating a market price information system for basic grains.
Invited to think of Buenos Aires, most would probably think of elegant cafés, beautiful architecture, passionate football fans, and buzzing streets. Invited to think harder, you might also think of its villas (slums), street children, and other less gleeful views. But no matter how hard you try, very few would associate Buenos Aires with Indigenous Peoples. Yet,
What do they do? What conditions they are living in? What is happening to their unique cultures and languages? Are they losing connection with their ancestral lands? Is the special legislation protecting their collective rights relevant in the cityscape? In sum, how is the city changing them and, inversely, how are they shaping the urban landscape? These and other questions were at the heart of the dialogue I had with graduate students from across the Latin America region in FLACSO – University of Buenos Aires, last week, on the occasion of the presentation of the report Indigenous Latin America in the Twenty-First Century, in Buenos Aires.
Villa 31, an iconic urban settlement in the heart of Buenos Aires, is home to about 43,000 of the city’s poor. In Argentina, paradoxically, urban slums are called ‘villas’ – a word usually tied with luxury in many parts of the world.
Photo credit: Ministry of Transport, Argentina