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Hot like hell - Droughts draining the life out
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Definition

A drought is a period of unusually persistant dry weather that persists long enough to cause serious problems such as crop damage and/or water supply shortages. The severity of the drought depends upon the degree of moisture deficiency, the duration, and the size and location of the affected area.

 

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A drought also can be defined as 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 and harm the local economy.


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. 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. Hunter-gatherer migrations in 9,500 BC Chile have been linked to the phenomenon, as has the exodus of early humans out of Africa and into the rest of the world around 135,000 years ago.

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.

 


There are actually four different ways that drought can be defined.

    Meteorological - a measure of departure of precipitation from normal. Due to climatic differences, what might be considered a drought in one location of the country may not be a drought in another location.Is brought about when there is a prolonged period with less than average precipitation. Meteorological drought usually precedes the other kinds of drought.    


Agricultural - refers to a situation where the amount of moisture in the soil no longer meets the needs of a particular crop.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.    

 


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Hydrological - occurs when surface and subsurface water supplies are below normal.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. Similar circumstances also place their largest lake, Balkhash, at risk of completely drying out.    

Socioeconomic - refers to the situation that occurs when physical water shortages begin to affect people.

  

Consequences

Because of their widespread occurance, droughts often produce economic impacts exceeding $1 billion. The costliest drought on record was the 1988 drought, which devastated crops in the Corn Belt, causing direct crop losses of $15 billion and much larger additional indirect economic impacts. There is nothing we can do to prevent droughts since they result from long-term shifts in storm tracks away from the affected region, or persistent wind patterns that reduce the flow of moisture into a region. Often, "blocking weather patterns" that feature persistent, stationary high-pressure regions over an affected area are observed with droughts.

Water is essential for all socio-economic development and for maintaining healthy ecosystems. As population increases and development calls for increased allocations of groundwater and surface water for the domestic, agriculture and industrial sectors, the pressure on water resources intensifies, leading to tensions, conflicts among users, and excessive pressure on the environment.

 

Aral_see_ship_on_the_field_effect_of_droughts

Scarcity often has its roots in water shortage, and it is in the arid and semiarid regions affected by droughts and wide climate variability, combined with population growth and economic development, that the problems of water scarcity are most acute.

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   
  • 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  
  • Shortages of water for industrial users   
  • Snake migration and increases in snakebites  
  • Social unrest   
  • War over natural resources, including water and food   
  • Wildfires, such as Australian bushfires, are more common during times of drought

   

Regions Lake Chad in a 2001 satellite image, with the actual lake in blue. The lake has shrunk by 95% since the 1960s. 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. 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.

 

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Approximately 2.4 billion people live in the drainage basin of the Himalayan rivers. 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.

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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. In 2005, parts of the Amazon basin experienced the worst drought in 100 years. 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. 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.
Historical_drought_map_over_USA

According to the WWF, the combination of climate change and deforestation increases the drying effect of dead trees that fuels forest fires. 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.


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. Australia could experience more severe droughts and they could become more frequent in the future, a government-commissioned report said on July 6, 2008. 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. East Africa currently faces its worst drought in decades, with crops and livestock destroyed. The U.N. World Food Programme recently said that nearly four million Kenyans urgently needed food.

  

Causes

One of the main causes wich can trigger the droughts is climate change and everything related with it : masive forest cutting, land usage, river or lakes drained to build or for agriculture usage. But as short term,droughts are caused by lack of rain over a long period of time and here we can take into consideration the previous statemnt related with climate change and man influence. If rain does occur it usually isn't enough for the ground to absorb before it is evaporated again. Plants and animals need water to survive, so if there is not enough water they will eventually die from thirst and dehydration. Water is one of the main ingredients in the food chain, for example: If a plant dies from lack of water then the animal that eats that plant will also die, the cycle will then continue to die out. Most droughts tend to occur during summer, as the weather is hot and water is quickly evaporated. Droughts can last for years in most extreme cases.

Dead-Sea-Salt-Evaporation_

These types of droughts effect outback properties and can devastate crops and livestock. However, many crops are effected. If a farmer has lost his crop due to drought then he will get no money to pay for the next seasonal crop. Where do Droughts occur? Droughts usually occur in hot dry areas of land. In most cases the area is dry because there is very minimal rainfall. The rain that does fall will be quickly absorbed into the ground or blown away by the dry air flow that moves along the ground. Therefore the land is very dry and not many things can live there. Australia and USA are the most variable rainfall climates in the world. Over the long term we have about three good years and three bad years out of ten.


These fluctuations have many causes, but the strongest is the climate phenomenon called the Southern Oscillation. This is a major air pressure shift between the Asian and east Pacific regions - its best-known extreme is El Nino. In recent years, the Bureau of Meteorology's greater understanding of El Nino has improved its ability to predict seasonal rainfall and help authorities and individuals with early drought warnings. More information: About El Nino and La Nina

livestock_droughts

Ancient Meso-American civilizations of the Mayans and Aztecs likely amplified droughts in the Yucatan and southern Mexico by clearing rainforests to make room for pastures and farmland. Generally, rainfall is related to the amount of water vapor in the atmosphere, combined with the upward forcing of the air mass containing that water vapor. 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 Nino-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. Another climate oscillation known as the North Atlantic Oscillation has been tied to droughts in northeast Spain.

Human activity can directly trigger exacerbating factors such as over farming, excessive irrigation, deforestation, and erosion adversely impact the ability of the land to capture and hold water. 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 throughout the world, and especially in developing nations. Overall, global warming will result in increased world rainfall. 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.

    

What can be done to prevent or diminuate the effect of droughts

Understand the causes of long-lived droughts, such as in the 1930s Dust Bowl period. Improve drought monitoring ability, including estimates of soil moisture and snow water storage. Determine the relationships between droughts and changes in greenhouse gases, aerosols, and land use. Ameliorate the effects of droughts by seeding trees Control excesive forest cut land usage ,etc

   

Intersting facts

For the continental U.S., the most extensive U.S. drought in the modern observational record occurred from 1933 to 1938, the "Dust Bowl" period. In July 1934, 80% of the U.S. was gripped by moderate or greater drought, and nearly two-thirds (63%) was experiencing severe to extreme drought. During 1953-1957, severe drought covered up to one half of the country

In History - Famine and droughts in Biblical events

Drought was the most common cause of famines mentioned in the Bible. Drought caused famines in the time of Abraham (Genesis 12:10 ), Isaac (Genesis 26:1 ), Joseph (Genesis 41:27 ), and the judges (Ruth 1:1 ). Drought and famine also plagued the Israelites in the days of David (2 Samuel 21:1 ), Elijah (1 Kings 18:2 ), Elisha (2 Kings 4:38 ), Haggai (Haggai 1:11 ), and Nehemiah (Nehemiah 5:3 ). At times the coming of droughts and famines was predicted by prophets (2 Kings 8:1 ; Isaiah 3:1 ; Jeremiah 14:12 ; Acts 11:28 ). Other natural forces also caused famines: locusts, wind, hail, and mildew (Joel 1:4 ; Amos 4:9 ; Haggai 2:17 ). The Israelites also experienced famines caused by enemies. Occasionally oppressors destroyed or confiscated food (Deuteronomy 28:33 ,Deuteronomy 28:33,28:51 ; Isaiah 1:7 ). The siege of cities also resulted in famine, such as the siege of Samaria by Ben-hadad (2 Kings 6:24-25 ) and the siege of Jerusalem by Nebuchadnezzar (2 Kings 25:2-3 ).

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.[10] Hunter-gatherer migrations in 9,500 BC Chile have been linked to the phenomenon, as has the exodus of early humans out of Africa and into the rest of the world around 135,000 years ago.

 

Drought-_

The Biblical references to famine therefore ring a familiar bell and the misery that it would have brought in those times can be easily imagined. Drought occurs over a region when the rainfall has been inadequate or has not been received at the proper time. The Hebrew word for ‘drought’ is ‘choreb’ which also means heat and dryness. There are only six references to drought in the Bible. The Bible, however, refers to famine in different contexts as many as 85 times in the Old Testament and 10 times in the New Testament. The Hebrew words for ‘famine’ are ‘raab’ and ‘rabown’ and the Greek word is ‘limos’, which also mean dearth, scarcity of food and hunger.


The Bible tells about several instances of widespread and severe famines, some of them having lasted over three, three and a half, or even as many as seven years at a stretch. Moreover, many of the famines were inflicted by God himself on unrepentant people as a punishment for their sins. Not only that, famines came in combination with other plagues. So the magnitude of ruin, death and desolation would have been unimaginable. This is how God had made sure that no one would escape his wrath by any chance:

He that is far away will die of the plague, and he that is near will fall by the sword, and he that survives and is spared will die of famine. So will I spend my wrath upon them.1 - 1 Ezekiel 6:12


Positive beneffits of droughts

Dead sea salt and Potash (Potasium) extraction.


Dead_sea_ecological_disaster_1960_-_2007

Dead_Sea

Usage of solar pannels and solar energy.

 

Animal reaction
Some animals react in starnge ways when drought occur. Most of the animals try to migrate to other areas, some of them stays and are quite adapted to this hostile environmental such as "Australian Water Holding Frog (Cyclorana platycephala)" who burrow itself into deep mud. Australian water holding frogs live in dry grasslands and deserts where there is less than 12 inches (30 cm) of rain a year. When rain comes the frogs have the ability to soak up water so they swell like a balloon. The frogs than use their powerful webbed feet to dig deep into the mud. The frogs will create a cacoon around them up to 3 feet (1 m) under the ground. Here they rest until the nest rain comes, which can be months or even years!

Australian_Water_Holding_Frog_(Cyclorana_platycephala)


Some fishes can do it to , like the "lungfish" who adapt to long period of drought by going deep into mud (which can solidify after)and covering himself with a "mucus" to keep him wet.He breath air, and he can stay deep underground until next rain which can happen in couple of years.


Queensland_Lungfish_(Neoceratodus_forsteri)


Another interesting animal is thorny lizzard or thorny devil who has specific methods to rezist on high temperature and capture any drop of moisture.This lizzard eats ants and small insects and take the necessary water from them.Aditionally in the morning the lizzard can capture the tinny droplets out water from dew trough her skin.


Thorny_lizzard_devil_Australia


Snakes can react in a different way.The drought is making snakes far more active - three people have died in Australia during a long period of drought. A 16-year-old schoolboy from Sydney had a heart attack, and died a short time later, after being attacked by an Eastern Brown snake, which injects a lethal venom and is one of the world's most dangerous reptiles.

Thorny_lizzard_devil_Australia

Hotest and dryest areas on Earth

The Atacama Desert in South America, west of the Andes mountains it is according to NASA, National Geographic and many other publications, the driest desert in the world

Hottest point on earth ever recorded  57.8 °C (136.0 °F)'Aziziya, Libya 13 September 1922. However, that reading is controversial and even would not be, does mean that ‘Aziziya is the hottest place on Earth; that title belongs to Dallol, Ethiopia, where the mean temperature is 34.4°C (94°F). If the record was not the actual temperature, then the hottest temperature is 56.7°C (134°F) which has been recorded in 1913 in Death Valley, California in the United States.

 

   

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Sources
http://www.fao.org/nr/water/issues/scarcity.html
http://www.noaawatch.gov/themes/droughts.php
http://www.drought.gov/portal/server.pt/community/drought_indicators/us_drought_monitor
http://www.readyforsyth.org
http://www.un.org/apps/news/story.asp?NewsID=39996&Cr=tuvalu&Cr1=
http://atoc.colorado.edu/~seand/headinacloud/wp-content/uploads/2007/10/figure2.jpg
http://www.usgs.gov/
http://environmental.lilithezine.com/Australian-Drought.html
http://www.eoearth.org/article/Abiotic_factor?topic=49461
http://www.geosociety.org/news/pr/05-01.htm
http://news.nationalgeographic.com/news/2002/10/1024_021024_ChileAtacama.html
http://biblemet.files.wordpress.com/2010/03/kelkar-bible-meteorology-13-famine-drought.pdf
http://www.studylight.org/dic/hbd/view.cgi?number=T2014
http://edtech2.boisestate.edu/olienr/502/virtualtour/waterholding.html
     
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