Drought occurrence and variations in human settlement patterns for representative countries within the UN subregions for Africa. Credit: Earth’s Future (2023). DOI: 10.1029/2023EF003510
A recent study reveals that in 80% of African countries, human settlements move toward rivers and into cities during drought, increasing the number of people living in flood-risk areas. This unsettling pattern may become more pronounced in the future, given that climate change is expected to make droughts more frequent and severe. The intriguing details are available in the study.
“It’s a cycle that exacerbates how many people are negatively impacted by drought, and not only in the ways we might normally expect,” said Serena Ceola, a hydrologist at the University of Bologna in Italy who led the study. “As regional climates change and both droughts and floods become bigger problems, more people will struggle to find a safe place to settle. People may move from one drought-affected place to another or move somewhere that just poses different climate risks.”
For instance, in Somalia, over 3.8 million people were displaced in part by drought over the last three years. Many of these climate refugees sought shelter near rivers, where farming could resume, but heavy rains and flash floods then displaced more than half a million people.
The study was published in the journal Earth’s Future. Before this, research on drought-driven migrations in Africa concentrated on single countries or specific drought events, restricting scientists’ understanding of how drought influences patterns of human settlements at large scales. The new study is the first to examine changes in human settlement patterns associated with droughts on a continental scale.
“We want the whole society to be aware of just how many people are moving from one climate threat to another,” Ceola said.
Nighttime lights can be used to tell where people have settled. Credit: NASA Goddard
Untangling drought
Despite the possibility of droughts pushing people toward rivers or cities for agricultural or economic purposes, the reality might be a bit more complex. Scientists believe that drought can be a significant factor in human displacement, but other influencing factors may include conflict, political violence, and food and job insecurity, all of which can lead to mass migrations.
The researchers focused on drought for its potential impact on several different factors. Their research extended from 1992 to 2013, covering 50 African countries. Nighttime light detection was used to see whether people moved to rivers by examining changes in existing settlements’ luminosities or the development of new settlements.
