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Wednesday, October 1, 2014

rivers changing course .... and sea disappearing - the Aral Sea !!

A report not on Modi but based on Modis… !!

Lord Krishna was born in Mathura and Vasudevar carried Him in a basket over his head – it was raining heavily and river Yamuna was in spates.  When Vasudeva reached nearer, Yamuna parted – Vasudeva with child Krishna walked through and reached Gokul (Gokulam) ~ Thiruvayarpadi where Lord Krishna and Balarama grew up.  When we visit this holy place, people will show a place which is believed to be the place, where Vasudevar climbed up from Yamuna …….. you may not find the river there now. 

In Delhi, people say that Yamuna river once flowed closer to the Fort, but now it is a bit far ……..  rivers do change their courses due to various reasons. There have been reports that illegal  sand mining is adding to the plight of the Yamuna river in changing its  course  and also making  its riverbed unstable, thus disturbing the biodiversity of the region.  In recent times, Bihar has been affected badly by flooding in Kosi river and it was stated that the river reverting to its 250-year-old course rendered lakhs of people homeless in northern Bihar – and they say it is  a part of its natural evolution.  It is stated that  fast-flowing rivers are prone to silting up as they surge down the hills and spread out on the plains, allowing sand and suspended matter to deposit in their slower, wider depths. Over time, the deposits create resistance, forcing the river to move to an area of lower resistance. This is called changing course.

Miles away, a Sea is fast disappearing – not in shorter period – it has been happening for long, but the culmination is perhaps getting nearer now.  Aral Sea - the giant lake between Kazakhstan in the north and Uzbekistan in the south - has dried up completely, says NASA. In the early 1900s, the Aral Sea was the fourth largest lake in the world.  In the early 1960s, the Soviet government decided the two rivers that fed the Aral Sea, the Amu Darya in the south and the Syr Darya in the east, would be diverted to irrigate the desert, in an attempt to grow rice, melons, cereals, and cotton. Before the project, the Syr Darya and the Amu Darya rivers flowed down from the mountains, cut northwest through the Kyzylkum Desert, and finally pooled together in the lowest part of the basin making  the Aral Sea, once the fourth largest in the world.

Although irrigation made the desert bloom, it devastated the Aral Sea. The series of images from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite documents the changes. At the start of the series in 2000, the lake was already a fraction of its 1960 extent. The Northern Aral Sea (sometimes called the Small Aral Sea) had separated from the Southern (Large) Aral Sea. The Southern Aral Sea had split into eastern and western lobes that remained tenuously connected at both ends.  The Aral Sea was a lake lying between Kazakhstan (Aktobe and Kyzylorda provinces) in the north and Karakalpakstan, an autonomous region of Uzbekistan, in the south. The name roughly translates as "Sea of Islands", referring to about 1,534 islands that once dotted its waters; in Old Turkic aralmeans "island" and "thicket".
Photo credit : NASA

Aral Sea has been steadily shrinking since the 1960s after the rivers that fed it were diverted by Soviet irrigation projects. By 2007, it had declined to 10% of its original size, splitting into four lakes – the North Aral Sea, the eastern and western basins of the once far larger South Aral Sea, and one smaller lake between the North and South Aral Seas. By 2009, the southeastern lake had disappeared and the southwestern lake had retreated to a thin strip at the extreme west of the former southern sea; in subsequent years, occasional water flows have led to the southeastern lake sometimes being replenished to a small degree. The shrinking of the Aral Sea has been called "one of the planet's worst environmental disasters". The region's once-prosperous fishing industry has been essentially destroyed, bringing unemployment and economic hardship. The Aral Sea region is also heavily polluted, with consequent serious public health problems. The retreat of the sea has reportedly also caused local climate change, with summers becoming hotter and drier, and winters colder and longer.
The dried sea and the boats – pic credit : Daily Mail

Today, the vast lake - formed 5.5 million years ago in Central Asia - in the middle of the Kyzylkum desert has shrunk to a level where water is no more visible to the eyes, revealed a series of images from Nasa's Terra satellite. Experts predict the giant lake will disappear completely by 2020. Summer 2014 marked another milestone for the Aral Sea – for  the first time in modern history, the eastern basin of the South Aral Sea has completely dried. This image pair from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite shows the sea without its eastern lobe on August 19, 2014.  According to an expert,  the desiccation in 2014 occurred because there has been less rain and snow in the watershed that starts in the distant Pamir Mountains; this has greatly reduced water flow on the Amu Darya. In addition, huge amounts of river water continue to be withdrawn for irrigation. The Kok-Aral Dam across the Berg Strait—a channel that connects the northern Aral Sea with the southern part—played some role, but has not been a major factor this year, he said.

It makes a sad reading indeed

With regards – S. Sampathkumar

30th Sept. 2014

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