The Online Library of Knowledge

World issues


A near empty reservoir, Western Cape drought, 2018A near empty reservoir, Western Cape drought, 2018Drought is the absence of water for a long period of time in a region where it is not considered to be normal compared to usual conditions. When an area with an arid or semi-arid climate goes without rain for a lengthy period of time, this is not necessarily as a drought, because such conditions are expected. But when a region that has high average annual rainfall goes for a period of weeks or months without rain, it is said to be suffering a drought. Drought is usually caused by below-average precipitation (rain or snow), resulting in prolonged shortages in the supply of water. A drought may last for months or years. Not seen as natural disasters like earthquakes, hurricanes or flooding, which may cause sudden devastation, droughts can be just as catastrophic in the long term.

Shrivelled maize crop after a drought in TexasShrivelled maize crop after a drought in Texas

Types of drought

There are three kinds of drought. Meteorological drought occurs when there is a prolonged period of less than average precipitation. Hydrological drought occurs when the reduced precipitation starts to affect the water supply: rivers, lakes, reservoirs and groundwater. The onset of hydrological drought tends to happen slowly, as stored water becomes used up but is not replenished.

El Niño is Spanish for "the child", and refers to the infant Jesus. This is because the occasional warming of the Pacific Ocean off the South American coast—which causes droughts (and floods) in other parts of the world—peaks around Christmas time.

© 2019 Q-files Ltd. All rights reserved. Switch to Mobile