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.
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Tuesday night's weather for the east of the region
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