World poverty revealed by satellites

The analysis of the nocturnal radiance it can be a valuable tool to estimate the degree of well-being and poverty worldwide. The study conducted by the International Institute for Applied Systems Analysis in Laxenburg (Austria) and published in Nature further demonstrated the theory, focusing however on the relationship between unenlightened areas and poverty. In developing countries – the researchers explain – areas with low levels of light radiance generally indicate areas with a limited degree of development:

While previous research has focused more on the relationship between enlightened areas and economic development, we found that actually the opposite also works and that unlit areas are a good indicator of poverty – Steffen Fritz, one of the authors of the study

To outline what can in fact be considered one world poverty mapscholars have combined night satellite images acquired in 2015 with information on the Geospatial Wealth Index – calculated by the Demographic and Health Surveys (DHS) program – relating to settlements in 49 countries (31 African, 10 Asian and 8 in the Americas), for a total of 2.4 million families.

By luminous radiance is meant the flux of light radiation per unit area. The specific unit of measurement is the nit.

The images are those captured by VIIRS DNB (Visible Infrared Imaging Radiometer Suite Day-Night Band), a satellite sensor for night light launched in 2012 and capable of photographing almost the entire Earth at night with a resolution of about 750 meters in the 500-900nm spectral range. In fact, VIIRS DNB allows you to estimate nocturnal radiance with a level of precision at the neighborhood level. The researchers also used data from the World Settlement Footprint (WSF), currently the largest database encompassing all human settlements worldwide.


Proven that there is a clear association between the increase in the percentage of unenlightened communities in a country and the decrease in the level of economic well-being, the study shows that 19% of urban settlements world cup it does not emit luminous radiance: most of this large chunk of the earth is in Africa (39%) And Asia (40%). Considering only rural settlements, the percentage is 65% in Africa and 40% in Asia.

In addition, non-illuminated infrastructures are also found in various countries of the Middle East and Europe. The data relating to European continent16% of the settlements without radiance – it may surprise but the researchers put forward a couple of hypotheses on the reasons: it could be the combined effect of the measures to limit energy consumption implemented by governments, citizens and companies, combined with the observation of a non-negligible percentage of inhabitants who live in rural areas. North America and South America, on the other hand, albeit with some exceptions, have relatively low levels of unlit infrastructure, a circumstance partly explained by the high degree of urbanization in South America and by the high per capita energy consumption in South America. North America.


Creating a map of poverty without then enhancing it risks turning out to be an operation for its own sake. For this reason, the researchers provide insights that even world governments should keep in mind. The study indeed shows the areas of the Earth that require more than others an intervention to improve living conditionsin line and according to the paths indicated by the United Nations itself that make the availability of accessible, sustainable, reliable and modern energy for all.

The study spatially highlights the areas that need to have a fast track in terms of aid and infrastructure investments and, if carried out, could be used to monitor progress towards the SDGs (Sustainable Development Goals). The methodology is in fact suitable for evaluating how developing countries carry out the electrification process and how developed countries reduce the consumption of light energy.

Top image: credits Pixabay

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