The UK's Disasters Emergency Committee (DEC) says at least 16 million people in Somalia, Kenya, Ethiopia and South Sudan need food, water and medical treatment.
It blames drought and conflict for the crisis - so what can be done?
Patrick Thomson, Lead Researcher for the Smith School of Enterprise and the Environment's Water Programme at Oxford University has a plan to help.
The innovation is a UK aid funded water pump.
More top news
Wednesday's weather forecast for the west of the region
Wednesday's weather forecast for the east of the region
A sad day dawned at RAF Odiham as the Army said a fond and final farewell to its Lynx helicopters.