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Posts tagged Drought

Drought in the Amazon Delta Region and Effects on Global Warming – June 2nd, 2013

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June 2nd, 2013 Category: Climate Change, Image of the day, Rivers, Sediments

Brazil – June 1st, 2013

An increased frequency of droughts in the Amazon, particularly the delta region (visible here), such as the ones that occurred in 2005 and 2010, threatens to turn the world’s largest tropical forest from a sponge that absorbs greenhouse gases into a source of them, causing accelerating global warming. This is because the trees normally absorbing carbon dioxide as they grow, helping to cool the planet, release these gases when they die and rot.

The 2010 drought caused a reduction of rainfall in an area of 3 million square kilometres of forest – far more than the 1.9 million square kilometres affected in 2005. Because of this, the Amazon forest will no longer absorb in 2010 and 2011 its usual volume of 1.5 billion tons of carbon dioxide from the atmosphere. Moreover, the dead and dying trees will release 5 billion tons of gas over the next year, causing the cumulative impact to reach 8 billion tons.

Emissions caused by the two droughts were probably sufficient to cancel all of the carbon absorbed by the Amazon forest in the last ten years. If such events occur more frequently, the Amazon forest would reach a point where, from a valuable store of carbon reducing the speed of climate change, it would change into a large source of greenhouse gases, which could accelerate global warming (click here for more information).

Drought and Low Water Levels in the Mississippi River, USA

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April 30th, 2013 Category: Climate Change, Rivers

USA – April 29th, 2013

For months along the Mississippi River here, the withering drought has caused record-breaking low water levels that have threatened to shut down traffic on the world’s largest navigable inland waterway.

The river has remained open  for shipping from Missouri to Illinois due to dredging, blasting and scraping away of rock obstructions along the riverbed, effectively lowering the bottom of the channel by two feet. Despite the success in keeping the Mississippi open, the effects of the low water can be seen up and down the river, both in reduced barge traffic and in the disarray caused by receding waters.

Fires and Dust in Drought-Stricken West Africa

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March 21st, 2012 Category: Dust Storms, Fires

Dust Over West Africa - March 19th, 2012

Dust and smoke mix together over West Africa, creating a hazy veil that obscures much of the ground below. Click here for previous images of the fires and here for previous images of the dust storm.

The presence of both fires and a dust storm are indicative of the very dry conditions plaguing the region. According to Oxfam, urgent action is needed to stop drought in West Africa’s Sahel region turning into a humanitarian disaster affecting 13 million people.

Drought Continues to Afflict Amazon, Brazil

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November 19th, 2010 Category: Climate Change, Vegetation Index

Brazil - November 16th, 2010

In a one-year period the Amazon region has gone through the biggest flood and now the worst drought. Scientists have expressed surprise, saying that they were expecting these extremes would only happen every 50 years.

This FAPAR image focuses on the Amazon Rainforest in Brazil. Here, the vegetation index is highest to the west (rusty red), and good to the east (green), with some areas of low photosynthetic activity (yellow).

The fact that these extreme events are so close may indicate changes in the climate, not only here in Amazonas region of Brazil visible here, but also in the south of Brazil, since the Amazon influences the rains there as well. Deforestation, therefore, affects this entire system.

This drought directly affects the lives of people who live along the rivers. These people depend on the river for transportation, meals, and end up isolated because of the drought. In some areas in the middle of the Amazon basin, people have no water to drink, reported Greenpeace.

Lake Mead on the Nevada-Arizona Border, USA – August 14th, 2009

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August 14th, 2009 Category: Climate Change, Image of the day, Lakes

Utah, USA - July 26th, 2009

Utah, USA - July 26th, 2009

The contours of the Nevada and Arizona landscape around Lake Mead and the Colorado River appear quite sharp in this orthorectified image. Filled by water impounded by the Hoover Dam, Lake Mead is the largest reservoir in the USA.

However, the combination of a huge demand for Lake Mead’s water and climate change has resulted in a 100 foot drop in this large lakes’s water level since 2000. Although that may not seem to be a great deal of water loss, it is important to remember that the vast reservoir is wide at the top but narrow at the bottom. This means that the 10% drop in depth actually represents a 50% loss in volume.

This huge loss happened in just nine years – The lake went form 96 percent capacity to roughly 43 percent, as of May 2009. The US Bureau of Reclamation predicts that water levels will drop another 14 feet over the summer.

Last year, researchers at the University of California San Diego concluded that if climate change goes uncurbed and water use is not reduced, Lake Mead could dry up by the year 2021.