EDRO

Seeding Socioeconomic Avalanches! [Hacked by WordPress; filtered by Google!]

Archive for the ‘desertification’ Category

Could Sydney, Australia Be Buried by Dust Storms

Posted by edro on October 19, 2009

How Large Is Your Dust Storm?

On September 23, 2009 our colleagues at FEWW posted the following on their blog:

FEWW entry summarized a phenomenal dust storm which had started a day earlier ( September 22),  sweeping across Australia’s eastern states of New South Wales (NSW) and Queensland (Qld), reaching Sydney, the country’s largest city, and Brisbane.

The dust plume measured about 500 kilometres wide and at least 1,000 km long, covering dozens of communities, towns and cities in both states.

Recently, they posted details of another dust storm

They have now asked EDRO Moderators the following questions:

‘How much dust would it take, and under what circumstances could it make Sydney uninhabitable?’

Desertification of farmlands, villages and small communities have been commonly occurring throughout history. In recent times, countries like China have experienced accelerated rates of desertification. Up to 3 million km² of land in China have already desertified.  The country’s annual desertification rates have  more than doubled to 3,400 km²  since the 1970s (1,560 km²) and have increased by 62 percent compared with the 1980s (2,100 km²). Thousands of villages have been lost to encroaching deserts.

According to a report by the Secretariat of the United Nations Convention to Combat Desertification (UNCCD), “some 24,000 villages, 1,400 kilometres of railway lines, 30,000 kilometres of highways, and 50,000 kilometres of canals and waterways are subject to constant threats of desertification.”

“Dust-laden blasts have buried villages before blowing into cities and suffocating urban residents.”

Historic examples are abound about large cities in Africa, Asia, Near and middle East that were lost to desert.

Chilean town of Chaitén is one of the latest examples of a town lost to [human-enhanced] natural phenomena, namely lahar caused by volcanic ash deposits, and other pyroclastic materials.

Well, Could it Happen to Sydney, Australia?

The short answer is yes!

Given  copious supplies of dust [or sand,] sufficiently strong winds,  as well as extremes of climatic and atmospheric conditions conducive to precipitating large amounts of airborne dust on the ground, dust storms could bury any village, town or city in their path and make them partially or completely uninhabitable.

Under the said conditions, one or more dust storms blowing within a critical period of time, with wind forces lasting long enough to deposit significantly large amounts of dust over a critically large portion of the city could trigger a partial or total collapse of Sydney [or other cities in eastern Australia.]

How Much Dust?

Australia’s CSIRO estimated that the September 22-24 storm carried a record-breaking 16 million tons of dust from the deserts in the heart of Australia [The Lake Eyre Basin was reportedly the main region, where the dust came from.] Interestingly enough, the media boasted how the benevolent storms had dumped a million tons of iron-rich topsoil from Australia’s outback into the Tasman Sea and Pacific Ocean.

Most of the dust spread over a vast area precipitating on the continental Australia, Indian ocean to the west,  and Tasman Sea to the east, reaching as far as the North Island, New Zealand.

EDRO Team designed a basic model and, using the available data, ran  a few dozen simulations. The  simulations showed that the amount of dust needed to ‘bury’ central Sydney [an area about 100 km²,] so as to make the entire city mostly uninhabitable, would be about 10-12 times the dust blown off in the Septemeber 22-24 dust storm.

Notes:

  1. The simulations were based on optimally extreme climatic and atmospheric conditions conducive to precipitating large amounts of airborne dust in a relatively small area.
  2. Dust diameters of (i) less than 60 micrometer, and (ii) 62 – 65 micrometer, were used in the simulations.
  3. The maximum air particle concentration levels reached over 45,000 micrograms/m³ of air.
  4. As the air particle concentration levels rose above about 25,000 micrograms/m³ of air, the number of casualties dramatically increased.

Related Links:

Advertisements

Posted in australian coal, carbon-intensive economy, Chaitén town, climate change, collapsing cities, desertification, drought, ghost towns | Tagged: , , , , , , , , , | 3 Comments »

East Africa Driven to the Verge of Catastrophe

Posted by edro on October 6, 2009

Drought, Hunger and Destitution Are Driving East Africa to the Verge of Collapse

Severe drought threatens 23 million east Africans in seven countries

More than 23 million people in 7 countries in East Africa including the worst affected nations of Ethiopia, Kenya, Somalia and Uganda, face starvation amid a 2-year drought.

“The Ethiopian government puts the number in need at 5.3 million. Pastoralist communities in the country’s southern Borena area have been particularly hard hit by the lack of rain.” Reuters reported.

“Some 6.2 million Ethiopians hit by two-year recurrent drought are facing starvation and need emergency assistance,” a charity organization spokeswoman told Reuters.

India

Floods triggered by more than a week of heavy rains have left 2.5 million Indians homeless.The flooding, described as the worst in living memory, has killed more than 250 people in south India, in the states of Karnataka and Andhra Pradesh, and

More than five million people have taken shelter at temporary government relief centers.

Millions of hectares of cropland, including sugarcane plantations have been flooded by torrential rains, prompting worries about a fall in sugar output in Karnataka, one of the country’s top three producers.

Philippines

An estimated one million people have been severely affected after Tropical Storm Ketsana (locally known as Ondoy) triggered epic flooding in the Philippines.

The storm brought in sever rains and caused the worst flooding in living memory, leaving 80 to 90 percent of Manila completely submerged in floodwater. The official death toll stands at about 300, with another 50 or so missing. The worst problems in the affected areas are

  • Access to Food and medicine
  • Disruptions in the supply of power and telecommunications
  • Shortages of drinking water
  • Sanitation concerns and threat of supply shortages

Cambodia

Meanwhile, 60,000 people have been affected as a result of flooding and landslides caused by storm Ketsana, with about 20 deaths including a pregnant woman and up to 100 injuries including 20  serious cases and up to 50,000 hectares of crops and rice fields destroyed by flood waters.

According to a report by  an aid organization, some 1,519 houses, 55 public buildings, 160 irrigation systems, channels, dams, embankments, 40 km of roads  and 3 bridges were damaged, or destroyed, causing major disruptions throughout the flooded areas.

Related Links:

          Posted in Andhra Pradesh flooding, Borena drought, Cambodia flooding, desertification, food shortages, hunger in east africa, Karnataka flooding, Karnataka sugar output, Ketsana death toll, ketsana land slides, Manila flooding, mud slides, Ondoy storm, Tropical Storm Ketsana | Tagged: , , , , , , , , | 1 Comment »

          One Step Away From Collapse

          Posted by edro on February 17, 2009

          Civilizations are and have always been just a step away from collapse

          According to the following news item, generation-long droughts in Indochina led to the collapse of Angkor, an advanced civilization that occupied the modern-day Cambodia, about 700 years ago.

          Another long spell of drought in the mid-18th century caused the collapse of all kingdoms in Southeast Asia including Laos, Thailand and Vietnam.

          Killer droughts recorded on tree rings

          fokienia-hodginsii

          Fokienia hodginsii can reach 30 m in height and up to 2.2 m in diameter on flat land. © Andrei Kuznetsov [Large-scale logging has resulted in the species disappearing or becoming scarce in parts of its range, notably in northern Viet Nam and southern China. 2008 IUCN Red List of Threatened Species.]

          Researchers from the United States and Japan have discovered  details of generation-long  droughts in Indochina going as far back as 700 years by studying tree ring core samples from Fokienia hodginsii, a rare species of ancient conifers that grows in Vietnam’s cloud forests, Reuters reported.

          They discovered two persistent drought periods  in the early 1400s, which coincided with the collapse of the large and wealthy Angkor civilization in what is now Cambodia.

          “There was a very significant multi-decadal drought in the early 1400s with the worst drought year being 1417,” said Brendan Buckley of the Tree Ring Laboratory at the Lamont-Doherty Earth Observatory in the United States.

          A third major drought lasting at least 30 years occurred in the mid-18th century, said Buckley, who worked with Masaki Sano and Tatsuo Sweda of Ehime University of Japan studying the tree rings of Fokienia.

          “All of the kingdoms in Southeast Asia collapsed, in Thailand, Vietnam and Laos between 1750-80,” he said.

          “The research is helping unravel the complexity of the annual monsoon that usually begins during March-May and on which millions rely to grow crops, particularly rice in the Mekong Delta. It could also help understand how climate change could affect the densely populated region and its economies.” Reuters reported.

          “Buckley said the chronology constructed from  36 conifer trees found in a national park near Dalat showed a strong correlation between dry spells and the El Nino weather pattern that typically brings drought to Southeast Asia and eastern Australia.”

          “It’s an amazing site, really, so it’s a real breakthrough in tropical tree ring studies,” he said.

          “Fokienia is an exceptional tree species because of the way it grows and responds to drought,” he said, adding the data was corroborated with a lot of historical records, such as ancient lanna palm leaf texts from Thailand and accounts of foreign merchants, plus tree-ring data from teak trees in Thailand.

          “What the Fokienia trees are most keenly tuned into is the length of the monsoon. Longer the monsoon, the trees grow more.”

          D2 —> D4 =  Collapse of a Civilization

          The relationship is simple:

          • No water =  Drought
          • Too much water =  Floods [Deluge]
          • Drought and Deluge =   NO Crops [food]
          • No Crops = Famine
          • Famine = Divergence + Displacement + Death + Disease [leading to more death]
          • D2 —> D4 =  Collapse of  Civilization

          Related Links:

          W: 510, I: 1; L: 4

          Posted in 4D, desertification, El Nino, famine, Loss of topsoil, monsoon | Tagged: , , , , , , , , | 1 Comment »