By David Bamford
Droughts are seen all over the world, though their impact varies
The drought now in eastern parts of Africa is the most widespread in many years, affecting countries from the Horn of Africa through Kenya to Malawi, Zambia and Mozambique.
More than 11m people face severe food shortages and dozens have died from hunger-related diseases.
But the term 'drought' is used in different places to characterise a problem that has a wide range of consequences.
The African continent is susceptible to droughts partly because of geography but often also due to poor agricultural practices.
However, in some countries, a drought is little more than a social inconvenience.
In Britain, a drought warning heralds a temporary ban on using garden hosepipes, but little more than that.
Elsewhere, it's been a signal that thousands, or even millions, were likely to die.
This was the case, for instance, in the Ukraine and Caucuses in the early 1920s and 1930s.
In those same decades, and again in 1941, Sichuan province in China was hit three times - in each case 3 million or more died of food and water shortages.
India was badly hit in the mid-1960s and Bolivia in 1983.
Wealthier countries have also been affected.
The American Dustbowl as it was called, in the 1930s saw three waves of drought on the Great Plains of the United States, largely caused by bad farming practices, that forced half a million people to leave.
And in Australia in 1983, dust storms caused by drought blew away the topsoil of the Victoria grain-growing region.
As for Africa, geography combined with poverty has made it highly susceptible to drought, most notably:
In the Sahel in the early 1970s, where the social structures of five countries were all but wiped out;
In Ethiopia in 1974 and again in 1984.
And now, this latest drought affecting a swathe of territory stretching from Somalia to Mozambique.