The use of nighttime lights has become increasingly popular as a way to collect data for use in urban and spatial analysis. It is cost effective, relatively easy to use, and a practical option in areas where it is difficult to gather city-level data on the ground, such as fragile or conflict areas.
Now, a new product developed by the World Bank’s South Asia Urban team in collaboration with the Operational Product unit (ITSOP) makes nighttime lights data much more accessible.
Called the Global Nighttime Lights Urban Extents and Growth Patterns Product, it can provide valuable insights into various areas of analysis, including urban extents estimation, urban and regional growth, urban agglomerations, and economic productivity. And with data available going back to 1992, it can also track regional settlement patterns and urbanization trends over time.
The product builds on previous work for the South Asia Urbanization Flagship report. Various World Bank units have used earlier versions of the product to enrich their analysis, including input for Urbanization Reviews (most recently, the Philippines review) and GSURR’s work on Managing Decline in Europe and Central Asia.
Development of the product was funded by the UK Department for International Development (DFID) and the World Bank’s Multi-Donor Trust Fund for Sustainable Urbanization (MDTF SUD) as part of its global research program on spatial development.
How the new product works
The Global Nighttime Lights Urban Extents and Growth Patterns Product draws its data from nine satellites that are part of the Defense Meteorological Satellite Program (DMSP), maintained by the National Oceanic and Atmospheric Agency (NOAA). These satellites record ground-based light sources such as city lights, forest fires, and gas flares at an intensity that primarily represents outdoor lights emanating from infrastructure and economic activities. They then use images from different nights to get a cloud-free, composite image.
The product can take that data, generate a standard set of statistics derived from night lights for each country, and deliver them in the form of an Excel spreadsheet along with an urban extents shapefile.
A technical guide and simple PowerPoint presentation are also included to provide guidance on how to use the night lights data, as well as its strength and weaknesses. Designed for users with little or no experience in using nighttime lights data, the presentation gives an overview of the different nighttime lights data products that are available for download, their strengths and weaknesses, how they can be used in urban and spatial analysis, and basic guidelines for using them appropriately.
The product is currently available to World Bank staff, with plans to make it publicly available in the future.
An example of how Nighttime Lights data can track urbanization trends over time, as in Mozambique:
The MDTF SUD global research program on spatial development
Based at World Bank headquarters in Washington, the Multi-Donor Trust Fund for Sustainable Urban Development (MDTF SUD) finances global, national and regional initiatives through analytical work for project development, institutional strengthening and knowledge partnerships on urban poverty and sustainable urban development.
It is a partnership of the Swiss State Secretariat for Economic Affairs (SECO), the UK Department for International Development, the Government of Norway and the World Bank.
The MDTF SUD’s global research program on spatial development is an ambitious program of applied research and development of innovative research methodologies to address deficiencies in reliable, cost effective and disaggregated data about the economic, social and spatial dimensions of cities, human settlements and the people who live in them.
Other activities include a survey methodology to measure various dimensions of living standards within cities, which has been developed and tested and is expected to be released publicly this year, and methodologies for using cell phone data to gather data on spatial transformations, mobility patterns and other urban characteristics.
Much of the research will feed into national and city development projects and programs, or provide data and analysis that will be made publicly available through various dissemination channels. Others will feed into research papers and policy notes. And a major subset of the research will inform a World Bank flagship report on Spatial Development of Cities in Africa, scheduled for publication during 2016.