Pakistan floods: An anatomy of the Indus

"This monsoon season the upland areas of Pakistan received fantastic amounts of rainfall, with four months worth of rain falling in just a couple of days. Some areas in Northern Pakistan received more than three times their annual rainfall in a mere 36 hours. Under such extraordinary circumstances, floods were inevitable. What was somewhat preventable was the extent of human misery caused by the floods - particularly for the poor. And whilst the rains were the result of an extreme and unusual natural event, the planning of water resources could have been more thoughtful. "

ABC The Drum Unleashed - Pakistan floods: An anatomy of the Indus

"Pakistan floods: An anatomy of the Indus

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Kuntala Lahiri-Dutt
Kuntala Lahiri-Dutt

This monsoon season the upland areas of Pakistan received fantastic amounts of rainfall, with four months worth of rain falling in just a couple of days. Some areas in Northern Pakistan received more than three times their annual rainfall in a mere 36 hours. Under such extraordinary circumstances, floods were inevitable. What was somewhat preventable was the extent of human misery caused by the floods - particularly for the poor. And whilst the rains were the result of an extreme and unusual natural event, the planning of water resources could have been more thoughtful.

A pinch of geography would be useful. The Indian monsoon winds can be viewed as a giant sea-breeze with ocean moisture sucked in by rising hot air over the South Asian plains. It is also influenced by large scale weather patterns such as the jet stream. Located approximately on the Tibetan plateau it consists of warm equatorial air which, after rising and flowing pole-ward for about 10 to 15 kilometres, descends on the subtropical areas to flow back towards the equator. This jet stream wobbles north and south as it flows around the Northern Hemisphere, and as it shifts, it drags the weather systems along.

This year, meteorologists noticed a change in the normal behavior of the jet stream. In mid-July, the jet stream came to a halt as a consequence of the 'blocking' effect of Rossby Waves which were, for some reason, stronger than the jet stream. The blocking event coincided with the summer monsoon, which brought unusually heavy amounts of rain on the mountains that girdle the north of Pakistan. Gushing quickly down the tributaries into the Indus River the rain waters gave rise to floods of catastrophic proportions.

Thus, it was weather, certainly not climate change that was responsible for the Indus floods. Whether or not this blocking event, however, was a consequence of climate change, is something we just do not know yet. Scientific knowledge about the monsoons is still full of holes. In particular our knowledge about how the jet stream, the moisture-bearing clouds, and the highly erodible mountains all interact remains incomplete.

It was not just the rains that bear the full responsibility for the enormity of the floods in Indus valley. Rivers are essentially channels to drain out water. Being one of the largest rivers of the world, Indus should have been able to carry out the excess waters into the sea. Why couldn't the river flush out the excess waters? This is where human intervention - in terms of poor water resource planning and infrastructure development - played an important role in exacerbating the floods. To increase the area under irrigation, in recent decades more and more waters of the Indus River have been diverted into nearby farms. Many of these farms are owned by the richer farmers who have, with state support and over the years, built levees or embankments along the river to protect their farms from the occasional floods. These water infrastructures hold the key to understanding the mechanics of the Indus floods.

We tend to forget that the Himalayas is one of the youngest mountain ranges in the world and since it has undergone huge tectonic upheavals, it is extremely fragile, containing soft rocks that are highly susceptible to erosion during heavy rains. Rivers like the Indus that originate in the Himalayas bring down enormous quantities of sediments with the water. Engineers and water planners, experts who build these infrastructures, however, plan for only water. There is poor consideration for the sediment load that gets carried within the banks of the river channel. Each human interference into a natural river system has its consequence: when excessive amounts of water are drawn out of its channel, a river channel becomes less efficient and loses its ability to quickly move the water. When levees are built along the banks, the sediments get deposited on the river bed, which gradually rises above the surrounding plains. Not only does this enhance the flood risk, but with the levees standing as walls, it makes it difficult for the floodwater to return back into the channel once it has spilled over.

In the last few decades, however, the water and irrigation infrastructures over the Indus have increased in size and numbers, in an effort to contain the rain waters from where they rush down the hill slopes to 'protect' the habitations and farming lands located on the Indus plains. Indeed over two thirds of the Indus flow is diverted for irrigation. A number of tributaries, for example, join the Indus from the west. These are fast-flowing hill torrents that bring down huge quantities of silt during the monsoons. With funding from external development agencies, a series of barrages have been built along the hill slopes to prevent their waters reaching the Indus. Many of these barrages added waters to the already inflated Indus and contributed to further worsening of the flood situation.

What we see is that technology-based interventions do not affect the rich and the poor in the same way. The barrages certainly benefit the richer farmers who own the farming lands and who now harvest more than one crop. But when they fail, as they did in this year, these very barrages can plunge innumerable people's lives into utter distress. The political ecology of the water infrastructure is such that those who benefit from them are usually not those who suffer from the floods.

A popular view circulating in the media is that the loss of lives and livelihoods was due to the encroachment of the river bed by the poor. Indeed, just like the diaras and the charlands of Gangetic plains, a large number of indigenous communities lived in and around the Indus river bed - in the Kachha (or the fragile or wet land), the Baet (the doab or the mound between two permanent river branches) and the Pakka lands (or the firmer ground). Some of these communities are unrecognised containing no proof of identity as legal citizens of Pakistan. Over years of living with the river, these communities developed finely-tuned understanding of how the river behaves, how the floodwaters rise and fall, and which wrinkles on the land they flow through. With their lives at stake, over many generations of living and coping with the changing moods of the river, they had developed a close knowledge of the river's rise and fall and are always at high level of alertness. But, the extraordinary downpours, the sudden rise of the waters, the lack of warning and the unpredictable movements of rushing floodwaters through the breaches in the embankments have made all that irrelevant this year. In deep frustration, Imdad Khan, an old farmer of Baet Morjhangi, commented that: "The Sindhu broke its old agreements with us" (as quoted by Ahsan Wagha). The catastrophic inundations, however, were not only partially caused by human folly, which was not committed by the biraderi (clan/community) to which Imdad belongs, but of people who had never lived in the Indus valley.

Although in numbers of dead the disaster that has hit the nation is smaller than the Asian Tsunami, the scale of human suffering, particularly during the post-flood times, and the magnitude of the nearly impossible task of rebuilding innumerable livelihoods is far greater than it. If something good can at all come out of the enormous human tragedy that Pakistan has been confronted with, it should be a rethinking of river development and planning not only in that country, but all of South Asia.

Kuntala Lahiri-Dutt is a Fellow in Resource Management in Asia Pacific Program, Crawford Scool of Economics and Government at the College of Asia and the Pacific, The Australian National University."