The Africa Center for Strategic Studies (ACSS) has published a useful map showing the top ten countries in Africa for population displacement. It finds that 71 percent of the continent’s 18.5 million displaced are from Sudan, South Sudan, Somalia, Nigeria, and the Democratic Republic of the Congo (DRC). It observes that each of the five are experiencing serious conflict, and that of the top 10, nine are autocratically governed. (Nigeria is the exception, with credible elections in 2015 that brought opposition leader Muhammadu Buhari to the presidency.)
The ACSS map can be studied in conjunction with the Council on Foreign Relations Sub-Saharan Security Tracker (SST), which tracks violence. It is updated monthly. It shows violence concentrated in Sudan, South Sudan, Somalia, the DRC, the Central African Republic, and Nigeria—the same countries the ACSS identifies as having the largest displaced populations.
The conclusion must be that the internally displaced and refugee flows are directly tied to internal conflict within African states. Elsewhere, on this enormous continent, levels of violence and displacement are low.