Across much of Africa, drought is driving people living in rural settlements closer to rivers and cities, according to new study published in the journal Earth’s Future.
Researchers from Sweden’s Uppsala University and Italy’s University of Bologna conducted a continent-wide analysis of human settlements in Africa and found that drought has driven migration in 80 percent of African countries, but particularly those in South Africa and in the Horn of Africa.
The study, “Drought and Human Mobility in Africa,” warns that this human migration will likely intensify as climate change leads to more severe and frequent droughts.
“It’s an aggravating cycle of how many people are adversely affected by drought, and not just in the ways we usually expect,” Serena Ceola, a hydrologist at the University of Bologna and lead author of the study, said in a press release.
“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.”
Ceola and her co-authors said they chose to study Africa because it is one of the most drought-prone continents and human migration is more prominent there compared to other parts of the world. They looked at the effects of drought in 50 countries between 1992 and 2013.
“We want the whole society to know how many people are moving from one climate threat to another,” said Ceola.
As well as contributing to overcrowding in urban centres, the study warns that this large-scale drought-induced migration is leaving more people vulnerable to deadly floods.
For example, the International Organization for Migration reported earlier this year that the number of displaced people in Somalia had reached 3.8 million, partly due to ongoing drought conditions. Many of these climate refugees sought refuge near rivers where agriculture could resume, but the UN Refugee Agency reports heavy rains and floods that subsequently displaced more than half a million people.
WHERE AND WHY DROUGHT EXCITS PEOPLE
Ceola and her co-authors found that people facing drought conditions tend to move near rivers so they can access water for agricultural activities and to cities because they offer different economic opportunities when drought makes farming too difficult .
The researchers used satellite detection of nighttime light to track when settlements moved toward rivers during drought conditions, as well as annual World Bank census data by country to track populations in urban centers. However, they cautioned that their results may underestimate the number of people forced to migrate by drought because settlements too small or poor to produce enough nighttime light for detection would have been left out of the study.
During the period they studied, in about half to three-quarters of the 50 countries included in the study, settlements moved closer to rivers, and one-third to half of the countries experienced urban population growth.
Seventeen countries experienced drought, and up to 65 percent of these countries saw increased human movement toward rivers during drought years compared to pre-drought years.
The cycle was particularly strong in Burundi, Mozambique and Zimbabwe in East Africa. Chad in Central Africa? Guinea and Guinea-Bissau in West Africa. and Namibia and Swaziland in South Africa. In South Africa, every country studied saw drought-related migration to rivers during the study period.
While drought-induced migration leads to its own problems, Ceola and her colleagues write that human mobility and migration “also represent increasingly important strategies” for adapting to climate change and reducing disaster risk. as the climate crisis continues to reshape the lives of people around the world.
“Policymakers need data and detailed information to implement strategic planning, support sustainable development and increase the resilience of people living in vulnerable areas,” said Ceola. “Similarly, people living in these areas need to be aware of the risks and have the opportunity to move freely to safer locations.”