Drought Topics

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Drought, Drought

Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region. Although droughts can persist for several years, even a short, intense drought can cause significant damage Living With Drought and harm the local economy.

It is among the earliest documented climatic events, present in the Epic of Gilgamesh and tied to the biblical story of Joseph's arrival in and the later Exodus from Ancient Egypt. http://www.bbc.co.uk/weather/features/bible_drought.shtml Hunter-gatherer migrations in 9,500BC Chile have been linked to the phenomenon, as has the http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html exodus of early man out of Africa and into the rest of the world around 135,000 years ago.

If either of these are reduced, the result is a drought. This can be triggered by an above average prevalence of high pressure systems, winds carrying continental, rather than oceanic air masses (ie. reduced water content), and ridges of high pressure areas form with behaviors which prevent or restrict the developing of thunderstorm activity or rainfall over one certain region. Oceanic and atmospheric weather cycles such as the El Nio-Southern Oscillation (ENSO) make drought a regular recurring feature of the Americas along the Pacific coast and Australia. Guns, Germs, and Steel author Jared Diamond sees the stark impact of the multi-year ENSO cycles on Australian weather patterns as a key reason that Australian aborigines remained a hunter-gatherer society rather than adopting agriculture. Guns, Germs, and Steel by Jared Diamond 1997, pgs 308-309 Human activity can directly trigger exacerbating factors such as overfarming, excessive irrigation A biblical tragedy as Sea of Galilee faces drought Belfast Telegraph , Deforestation, and erosion adversely impact the ability of the land to capture and hold water.

Hydrological drought tends to show up more slowly because it involves stored water that is used but not replenished.

Source: Wikipedia > Drought