The recent floods in Pakistan's Indus Valley are of truly Biblical proportions.
The UN estimates that the humanitarian crisis is now larger than the combined effects of the three worst natural disasters to strike in the past decade.
"Rivers just can't cope with all that water in such a short time. It was five times, maybe 10 times, more than normal” Rajiv Sinha, Indian Institute of Technology
These include the Asian tsunami and the major earthquakes that devastated Kashmir and Haiti.
The headline figure of 1,700 killed masks the real scale of the disaster that has displaced 14 million people.
As I write, the southern city of Hyderabad, with a population of 1.5 million, stands on the brink of inundation as peak floodwaters surge downstream.
Scientists have described this catastrophe as a once-in-a-century flood.
But could climate change mean that floods of this magnitude, or even bigger, become a more regular occurrence?
The "Great Mother"
The Indus is one of the world's great rivers.
From its headwaters in the Himalayas of Tibet, it flows north-west through India before turning sharply south across Pakistan. It finally discharges into the Arabian Sea, a journey of some 3,200km (2,000 miles).
Although some of its water comes from melting Himalayan glaciers, the vast majority is dumped by the summer monsoon.
As torrential rain sweeps in from the Indian Ocean, floods are triggered almost annually.
Geologists are working round the clock to better understand the ancient flood history of the Indus River.
Such history lessons will help to better predict its erratic behaviour and "plan for our own uncertain future", said Professor Peter Clift of Aberdeen University, an expert on the Indus River.
His team recently used makeshift "rigs" to drill down into the sands and mud of the Indus floodplain. By precisely dating layers of flood-deposited sand, they were able to work out past changes in river flow.
Their results were startling.
"Monsoon intensity is somewhat sensitive to the surface temperature of the Indian Ocean" Professor Martin Gibling Dalhousie University
During a warm period 6,000 years ago, the Indus was a monster river, more powerful and more prone to flooding than today.
Then, 4,000 years ago, as the climate cooled, a large part of it simply dried up. Deserts appeared whether mighty torrents once flowed.
Professor Clift believes that this failure of the Indus may have triggered the collapse of the great Harappan civilisation.
The city ruins of Mohenjo-daro, a relict of this lost culture, date from the time when the rivers ran dry.
But what caused these thousand-year cycles of Indus drought and flood?
Source: BBC
The UN estimates that the humanitarian crisis is now larger than the combined effects of the three worst natural disasters to strike in the past decade.
"Rivers just can't cope with all that water in such a short time. It was five times, maybe 10 times, more than normal” Rajiv Sinha, Indian Institute of Technology
These include the Asian tsunami and the major earthquakes that devastated Kashmir and Haiti.
The headline figure of 1,700 killed masks the real scale of the disaster that has displaced 14 million people.
As I write, the southern city of Hyderabad, with a population of 1.5 million, stands on the brink of inundation as peak floodwaters surge downstream.
Scientists have described this catastrophe as a once-in-a-century flood.
But could climate change mean that floods of this magnitude, or even bigger, become a more regular occurrence?
The "Great Mother"
The Indus is one of the world's great rivers.
From its headwaters in the Himalayas of Tibet, it flows north-west through India before turning sharply south across Pakistan. It finally discharges into the Arabian Sea, a journey of some 3,200km (2,000 miles).
Although some of its water comes from melting Himalayan glaciers, the vast majority is dumped by the summer monsoon.
As torrential rain sweeps in from the Indian Ocean, floods are triggered almost annually.
Geologists are working round the clock to better understand the ancient flood history of the Indus River.
Such history lessons will help to better predict its erratic behaviour and "plan for our own uncertain future", said Professor Peter Clift of Aberdeen University, an expert on the Indus River.
His team recently used makeshift "rigs" to drill down into the sands and mud of the Indus floodplain. By precisely dating layers of flood-deposited sand, they were able to work out past changes in river flow.
Their results were startling.
"Monsoon intensity is somewhat sensitive to the surface temperature of the Indian Ocean" Professor Martin Gibling Dalhousie University
During a warm period 6,000 years ago, the Indus was a monster river, more powerful and more prone to flooding than today.
Then, 4,000 years ago, as the climate cooled, a large part of it simply dried up. Deserts appeared whether mighty torrents once flowed.
Professor Clift believes that this failure of the Indus may have triggered the collapse of the great Harappan civilisation.
The city ruins of Mohenjo-daro, a relict of this lost culture, date from the time when the rivers ran dry.
But what caused these thousand-year cycles of Indus drought and flood?
Source: BBC


Millions of people have been displaced by the floods
Satellite images show flood waters swelling the Lower Indus river; flow through the Sukkur barrage has exceeded what it was built to withstand
Pakistan has experienced one of the most intense monsoons in decades
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