Fields outside Benambra, Victoria, Australia suffering from drought conditions.

A drought is an extended period of months or years when a region notes a deficiency in its water supply whether surface or underground water. 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^[1] and harm the local economy.^[2]

This global phenomenon has a widespread impact on agriculture. Lengthy periods of drought have long been a key trigger for mass migration and played a key role in a number of ongoing migrations and other humanitarian crises in the Horn of Africa and the Sahel.

Consequences[link]

Dry earth in the Sonoran desert, Mexico.

Periods of drought can have significant environmental, agricultural, health, economic and social consequences. The effect varies according to vulnerability. For example, subsistence farmers are more likely to migrate during drought because they do not have alternative food sources. Areas with populations that depend on as a major food source are more vulnerable to drought-triggered famine.

Drought can also reduce water quality, because lower water flows reduce dilution of pollutants and increase contamination of remaining water sources. Common consequences of drought include:

• Diminished crop growth or yield productions and carrying capacity for livestock
• Dust bowls, themselves a sign of erosion, which further erode the landscape
• Dust storms, when drought hits an area suffering from desertification and erosion
• Famine due to lack of water for irrigation
• Habitat damage, affecting both terrestrial and aquatic wildlife^[3]
• Malnutrition, dehydration and related diseases
• Mass migration, resulting in internal displacement and international refugees
• Reduced electricity production due to reduced water flow through hydroelectric dams^[4]
• Shortages of water for industrial users^[5][6]
• Snake migration and increases in snakebites^[7]
• Social unrest
• War over natural resources, including water and food
• Wildfires, such as Australian bushfires, are more common during times of drought.^[8]

Globally[link]

Drought is a normal, recurring feature of the climate in most parts of the world. 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.^[9] Hunter-gatherer migrations in 9,500 BC Chile have been linked to the phenomenon,^[10] as has the exodus of early humans out of Africa and into the rest of the world around 135,000 years ago.^[11]

Modern peoples can effectively mitigate much of the impact of drought through irrigation and crop rotation. Failure to develop adequate drought mitigation strategies carries a grave human cost in the modern era, exacerbated by ever-increasing population densities.

Regions[link]

Lake Chad in a 2001 satellite image, with the actual lake in blue. The lake has shrunk by 95% since the 1960s.^[12][13]

Sheep on a drought affected paddock near Uranquinty, New South Wales.

Recurring droughts leading to desertification in the Horn of Africa have created grave ecological catastrophes, prompting massive food shortages, still recurring.^[14] To the north-west of the Horn, the Darfur conflict in neighboring Sudan, also affecting Chad, was fueled by decades of drought; combination of drought, desertification and overpopulation are among the causes of the Darfur conflict, because the Arab Baggara nomads searching for water have to take their livestock further south, to land mainly occupied by non-Arab farming peoples.^[15]

Approximately 2.4 billion people live in the drainage basin of the Himalayan rivers.^[16] India, China, Pakistan, Bangladesh, Nepal and Myanmar could experience floods followed by droughts in coming decades. Drought in India affecting the Ganges is of particular concern, as it provides drinking water and agricultural irrigation for more than 500 million people.^[17][18][19] The west coast of North America, which gets much of its water from glaciers in mountain ranges such as the Rocky Mountains and Sierra Nevada, also would be affected.^[20][21]

In 2005, parts of the Amazon basin experienced the worst drought in 100 years.^[22][23] A 23 July 2006 article reported Woods Hole Research Center results showing that the forest in its present form could survive only three years of drought.^[24][25] Scientists at the Brazilian National Institute of Amazonian Research argue in the article that this drought response, coupled with the effects of deforestation on regional climate, are pushing the rainforest towards a "tipping point" where it would irreversibly start to die. It concludes that the rainforest is on the brink of being turned into savanna or desert, with catastrophic consequences for the world's climate. According to the WWF, the combination of climate change and deforestation increases the drying effect of dead trees that fuels forest fires.^[26]

By far the largest part of Australia is desert or semi-arid lands commonly known as the outback. A 2005 study by Australian and American researchers investigated the desertification of the interior, and suggested that one explanation was related to human settlers who arrived about 50,000 years ago. Regular burning by these settlers could have prevented monsoons from reaching interior Australia.^[27] In June 2008 it became known that an expert panel had warned of long term, maybe irreversible, severe ecological damage for the whole Murray-Darling basin if it does not receive sufficient water by October.^[28] Australia could experience more severe droughts and they could become more frequent in the future, a government-commissioned report said on July 6, 2008.^[29] Australian environmentalist Tim Flannery, predicted that unless it made drastic changes, Perth in Western Australia could become the world’s first ghost metropolis, an abandoned city with no more water to sustain its population.^[30]

East Africa currently faces its worst drought in decades,^[31][32] with crops and livestock destroyed.^[33] The U.N. World Food Programme recently said that nearly four million Kenyans urgently needed food.^[34]

Causes[link]

A Mongolian gazelle dead due to drought .

Ancient Meso-American civilizations of the Mayans and Aztecs likely amplified droughts in the Yucatán and southern Mexico by clearing rainforests to make room for pastures and farmland.

Generally, rainfall is related to the amount of water vapour in the atmosphere, combined with the upward forcing of the air mass containing that water vapour. 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 (i.e. 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 Niño-Southern Oscillation (ENSO) make drought a regular recurring feature of the Americas along the Midwest 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.^[35] Another climate oscillation known as the North Atlantic Oscillation has been tied to droughts in northeast Spain.^[36]

Human activity can directly trigger exacerbating factors such as over farming, excessive irrigation,^[37] deforestation, and erosion adversely impact the ability of the land to capture and hold water.^[38] While these tend to be relatively isolated in their scope, activities resulting in global climate change are expected to trigger droughts with a substantial impact on agriculture^[39] throughout the world, and especially in developing nations.^[40][41][42] Overall, global warming will result in increased world rainfall.^[43] Along with drought in some areas, flooding and erosion will increase in others. Paradoxically, some proposed solutions to global warming that focus on more active techniques, solar radiation management through the use of a space sunshade for one, may also carry with them increased chances of drought.^[44]

Types of drought[link]

Ship stranded by the retreat of the Aral Sea.

As a drought persists, the conditions surrounding it gradually worsen and its impact on the local population gradually increases. People tend to define droughts in three main ways:^[45]

1. Meteorological drought is brought about when there is a prolonged period with less than average precipitation. Meteorological drought usually precedes the other kinds of drought.
2. Agricultural droughts are droughts that affect crop production or the ecology of the range. This condition can also arise independently from any change in precipitation levels when soil conditions and erosion triggered by poorly planned agricultural endeavors cause a shortfall in water available to the crops. However, in a traditional drought, it is caused by an extended period of below average precipitation.
3. Hydrological drought is brought about when the water reserves available in sources such as aquifers, lakes and reservoirs fall below the statistical average. Hydrological drought tends to show up more slowly because it involves stored water that is used but not replenished. Like an agricultural drought, this can be triggered by more than just a loss of rainfall. For instance, Kazakhstan was recently awarded a large amount of money by the World Bank to restore water that had been diverted to other nations from the Aral Sea under Soviet rule.^[46] Similar circumstances also place their largest lake, Balkhash, at risk of completely drying out.^[47]

Drought protection and relief[link]

The effects of the drought brought on by El Niño. Waiting for water distribution (Ebeye, Marshall Islands.)

Strategies for drought protection, mitigation or relief include:

• Dams - many dams and their associated reservoirs supply additional water in times of drought.
• Cloud seeding - an artificial technique to induce rainfall.^[48]
• Desalination of sea water for irrigation or consumption.
• Drought monitoring - Continuous observation of rainfall levels and comparisons with current usage levels can help prevent man-made drought. For instance, analysis of water usage in Yemen has revealed that their water table (underground water level) is put at grave risk by over-use to fertilize their Khat crop.^[49] Careful monitoring of moisture levels can also help predict increased risk for wildfires, using such metrics as the Keetch-Byram Drought Index^[8] or Palmer Drought Index.
• Land use - Carefully planned crop rotation can help to minimize erosion and allow farmers to plant less water-dependent crops in drier years.
• Outdoor water-use restriction - Regulating the use of sprinklers, hoses or buckets on outdoor plants, filling pools, and other water-intensive home maintenance tasks.
• Rainwater harvesting - Collection and storage of rainwater from roofs or other suitable catchments.
• Recycled water - Former wastewater (sewage) that has been treated and purified for reuse.
• Transvasement - Building canals or redirecting rivers as massive attempts at irrigation in drought-prone areas.

See also[link]

• Climate change
• Collapse: How Societies Choose to Fail or Succeed
• FEMA
• Food security
• Permanent wilting point
• Topsoil
• United Nations Convention to Combat Desertification
• Water conflict
• Water crisis

Regional:

• Amazon Rainforest drought
• Droughts and famines in Russia and USSR
• Drought in Australia, Exceptional Circumstances relief payments
• Drought in the United Kingdom
• Drought in the United States
• Maya collapse
• Sahel drought

References[link]

Wikimedia Commons has media related to: Drought

External links[link]

Look up drought in Wiktionary, the free dictionary.

Wikinews has related news: Drought

Wikibooks has more on the topic of Drought

• Water scarcity from FAO Water (Food and Agriculture Organization of the United Nations)
• US Drought Monitor Current U.S. drought conditions
• US Economic Costs of Drought NOAA Economics
• Catastrophic drought is coming back, Brian M. Fagan lecture for the Long Now Foundation (MP3)

Vienna Teng
Teng performing at Joe's Pub in 2007.
Background information
Birth name	Cynthia Yih Shih[1][2] (Chinese: 史逸欣; pinyin: Shǐ Yìxīn)
Born	(1978-10-03) October 3, 1978 (age 33) Saratoga, California, U.S.
Genres	Folk, pop, indie folk, chamber pop
Occupations	Singer-Songwriter
Instruments	Vocals, piano, guitar
Years active	2003–present
Labels	Virt, Rounder
Website	viennateng.com

Cynthia Yih Shih (b. October 3, 1978, Saratoga, California), better known by her stage name Vienna Teng, is a Taiwanese American pianist and singer-songwriter based in Ann Arbor, Michigan. Teng has released four studio albums: Waking Hour (2002), Warm Strangers (2004), Dreaming Through the Noise (2006), and Inland Territory (2009). She has also released one live album, The Moment Always Vanishing (2009), on which she is double-billed with her percussionist, Alex Wong.

Teng's musical style incorporates folk, pop, classical piano, and a cappella. She uses piano as her primary instrument and writes lyrics with emotion, narrative, and personal history.

Career[link]

Teng performing at the Independent in San Francisco

Teng took her stage name "Vienna" from the capital city of Austria. A native of Saratoga, California, she began playing classical piano at age 5. While pursuing a degree in computer science at Stanford University, Teng joined the Stanford Harmonics, a student-run a cappella group.^[3] She began recording her compositions at the studios in Stanford's Center for Computer Research in Music and Acoustics (CCRMA), intending to distribute her music on campus. Many of these recordings were eventually released in her debut album Waking Hour. After graduating in 2000, Teng worked as a software engineer for Cisco Systems in San Jose, but she continued to write music and perform in her free time. In 2002, Teng signed with Virt Records and quit Cisco Systems to focus on her musical career.

Teng's first major national exposure was on National Public Radio's Weekend Edition in January 2003, followed shortly thereafter by CBS's Late Show with David Letterman. She has since made appearances on the CBS Saturday Early Show, CNN's NewsNight with Aaron Brown and The Wayne Brady Show, and opened concerts for Joan Baez, Shawn Colvin, Joan Osborne, India.Arie, Brandi Carlile, Sarah Harmer and Marc Cohn. Her first album, Waking Hour, peaked at #5 on the Amazon.com bestseller list; her second album, Warm Strangers, reached as high as #2.^[4][5] In 2006, Teng signed with Zoë/Rounder.^[6]

Teng performing at Joe's Pub in 2007.

From December 2006 to early 2007, she toured extensively in the United States to promote the release of her third album, Dreaming Through the Noise. Teng co-headlined with Duncan Sheik and opened for Madeleine Peyroux. She began the Green Caravan Tour in April 2007, accompanied by cellist Marika Hughes, violinist Dina Maccabee, and percussionist Alex Wong, along with opening acts such as David Berkeley and Jenny Owen Youngs. In 2008, she relocated from California to New York City, and performed in Central Park on Earth Day at the Green Apple Festival.

Her fourth album, Inland Territory, won the ninth annual Independent Music Awards Vox Pop vote for best Folk/Singer-Songwriter Album.^[7]

In 2010, Teng announced to her fans that she had been accepted into the Erb Institute for Global Sustainable Enterprise at the University of Michigan. Through the program, she will receive an MBA from the Ross School of Business and an MS from the School of Natural Resources and Environment. Teng continues to perform and compose music, although she does not tour as frequently as she had before enrolling.

Cultural influence on music[link]

Although nearly all of Teng's recordings are in English, Warm Strangers features a hidden cover of "Green Island Serenade," a 1950's Taiwanese classic by Teresa Teng performed in Mandarin Chinese. Teng has also stated live that the lyrics to "Grandmother Song" from Inland Territory are nearly a verbatim translation of a lecture Teng received from her Mandarin-speaking grandmother, voicing her disapproval of Teng's career choice.

Discography[link]

• 2001: Waking Hour – self-produced
• 2002: Waking Hour – Virt Records
• 2004: Warm Strangers – Virt Records
• 2006: Dreaming Through the Noise – Zoë/Rounder
• 2009: Inland Territory – Zoë/Rounder
• 2009: The Moment Always Vanishing – self-produced live album; recorded at Joe's Pub in New York City on December 20, 2009

References[link]

External links[link]

Wikimedia Commons has media related to: Vienna Teng

• "Vienna Teng Biography". Virt Records. Archived from the original on March 22, 2006. http://web.archive.org/web/20060322201137/http://www.virtrecords.com/viennateng/bio.html. 
• Biography at official website
• Vienna Teng's official YouTube channel
• Vienna Teng's Twitter page
• v1.ViennaTeng.com – Vienna Teng's first website (2000–2004)
• WarmStrangers.com-Unofficial fansite with song anecdotes, a list of unreleased tracks, and a database of live performances.
• Vienna Teng collection at the Internet Archive's live music archive
• Paradigm interview – August 2007 interview with Vienna Teng. Located under "Music."
• Collectedsounds.com – Interview in which Vienna Teng discusses her musical history and influences.
• Vienna Teng interview (September 2007) with asiaXpress.com
• Kaplan, Shari (November 27, 2002). "Saratoga Style: Talented local musician plays at Blue Rock Shoot". Saratoga News (Saratoga, California). http://www.community-newspapers.com/archives/saratoganews/20021127/sn-style1.shtml.