For nearly 30 years, researchers have been using satellite images of the earth at night to study human activities. It is also recognized that these images - commonly known as night radiance or night light - can help map issues such as economic growth, poverty and inequality, especially in areas where data are scarce.
Data map
In underdeveloped places, the level of light is often low, while in underdeveloped places, it means that there is no bright light at night.
In general, researchers are more interested in using data collected from areas with light, while areas without light are usually ignored. However, the International Institute for Applied Systems Analysis (IIASA), in its new study to be published in nature communication on May 5, has paid special attention to data from unlit areas to estimate global economic well-being.
"Previous work has focused more on the relationship between lighting areas and economic development, and we found that it is actually the opposite. Non lighting areas are a good indicator of poverty. By identifying these non lighting areas, we can carry out targeted poverty alleviation and focus on improving energy access," said Steffen Fritz, the author of the study and director of IIASA's strategic initiative project.
The researchers used the unified geospatial wealth index of households in Africa, Asia and the Americas calculated by the population and Health Survey (DHS) program. It is reported that the index places a single family on a continuous scale of relative wealth from poorer to richer. Then they combined the data with satellite images of global night lights in these countries and found that 19% of the earth's total residential footprint had no detectable artificial radiation associated with it. Most of the matte settlement footprints were found in Africa (39 per cent) and Asia (23 per cent). If we only consider the dark infrastructure in rural areas, these figures rise to 65% in Africa and 40% in Asia. In almost all countries, the results show that there is a clear link between the increase in the percentage of unlit communities in a country and the decline in the level of economic welfare.
"Based on the percentage of unlighted settlements detected using night light satellite images, we can map and predict the wealth level of about 2.4 million households in 49 countries in Africa, Asia and the Americas, with an overall accuracy of 87%. Surprisingly, there are also a relatively large number of unlighted settlements in developed countries, especially Europe." Ian McCallum, head of the IIASA new data ecosystem research group for sustainable development, who led the study, pointed out that "there may be several reasons for this result, including that the satellite passed after midnight, but it may also be due to the conscious energy-saving and cost-saving policies of European homeowners, governments and industries."
The researchers point out that government agencies usually give priority to expanding power supply in cities rather than rural areas. However, rural electrification has great prospects in improving welfare and in household income, expenditure, health and education Can also have a significant positive impact. The United Nations sustainable development goals include, inter Alia, access to affordable, reliable and sustainable modern energy for all. Although this goal is being achieved and substantial progress has been made in the past 20 years, there are signs that it will be difficult for the government and industry to keep pace with the expected population growth. Especially in sub Saharan Africa, projections show that more than 300 million people will still live in extreme poverty by 2030.
The impact of the covid-19 pandemic may push another 88 million to 115 million people into extreme poverty by 2030, which will delay the United Nations poverty reduction goal by about three years. However, research like this can help track the electrification process in developing countries and the reduction of light energy consumption in developed countries.
Shonali Pachauri, head of the transformative institutional and social solutions research group, concluded: "If applied in the long term, the approach we use in our research can provide an opportunity to track well-being and progress towards sustainable development goals. On the policy side, it can help to better understand global energy policies and help formulate assistance policies by ensuring that we have access to remote rural areas that may be energy deficient. In addition, it can help to test the sustainability and environmental management of lighting in developed countries Signs of reason. "