Special essay: Pakistan floods

[shrd]

SEPTEMBER 6, 2010
by Kuntala Lahiri-Dutt (Australian National University)
There are many questions emerging from the recent floods in Pakistan, ranging from attempts to understand the atmospheric phenomena behind the downpours to the search for where ultimate responsibility lies for the ensuing human calamity. This short essay investigates some of those questions.
A pinch of geography is necessary to explain why Pakistan received such an extraordinary amount of rain during this rainy season. The Indian monsoon can be understood as a giant sea-breeze, with ocean moisture sucked in by rising hot air over the South Asian plains. It is influenced by large scale weather patterns such as the jet stream in the northern hemisphere, which this year came to a halt as a consequence of Rossby Waves, powerful spinning wind currents created by the earth’s rotation. Such unusual occurrences – called ‘blocking events’ – have taken place in the past, and have resulted in unusual weather phenomena. This year, as the jet stream became stationary, unusually hot summers led to the breakout of wildfires in Western Russia, and unprecedented rains poured down the slopes of the Western Himalayas. The blocking event coincided with the summer monsoon, which brought unusually heavy amounts of rain on the mountains that girdle the north of Pakistan.
The intensity of the localized rainfall was fantastic – four months worth of rainfall had fallen in just a couple of days. Some areas in Northern Pakistan received more than three times their annual rainfall in a matter of 36 hours. Gushing quickly down the tributaries into the Indus River, the rainwaters gave rise to floods of catastrophic proportions. Given the immensity of the downpours, some flooding was inevitable. Yet rivers are essentially channels to drain out water; being one of the largest rivers of the world, the Indus should have been able to carry out the excess waters into the Arabian Sea which it joins near Karachi. Why could the river not flush out the excess waters? This is where human intervention – in terms of water resource planning and infrastructure development – played an important role in the floods.
To increase the area under irrigation in Pakistan, more and more of the waters of the Indus River have been diverted in recent decades 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. It is not only the Pakistani government but local councils and water resource planning authorities in all the countries in South Asia which have supported such ‘straight-jacketing’ of rivers. Yet 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, the levees standing as walls also make it difficult for the floodwater to return back into the channel once it has spilled over.
In the last few decades, water and irrigation infrastructure within the Indus system has increased in size and number. Indeed, over two thirds of the Indus flow is now diverted for irrigation. A number of tributaries also join the Indus from the west. These are fast-flowing hill torrents that bring down huge quantities of silt during the monsoons (because the Himalayas is one of the youngest mountain ranges in the world, rivers that originate there like the Indus bring down enormous quantities of sediments in the form of sand, silt and clay). With funding from the Asian Development Bank and the World Bank, a series of barrages have been built along the hill slopes to prevent their waters from reaching the Indus. When many of these barrages failed, they added waters to the already inflated Indus and contributed to further worsening of the flood situation.
Besides the frozen jet stream that caused the unusual rains, then, it is the water infrastructure on the Indus River and its tributaries that are to blame for the scale of human impact of the floods in Pakistan. One can safely say that the floods were partly ‘anthropogenic’ in that they were caused by careless planning of water resources. Engineers and water planners have often given insufficient consideration to the sediment load that gets carried within the banks of the river channel, and through the interventions of their infrastructure they exacerbated this year’s flood. They created a false sense of security amongst the rural peasants, whose lives and livelihoods were washed away in the floods.
Water planning as it has been practised in Pakistan certainly carries benefits for some segments of the rural communities, specifically those rich farmers who own the farming lands. When key pieces of infrastructure such as barrages fail, however, innumerable people’s lives can be plunged 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; although the water resource planning is done in the name of improving the lot of the poor, it is they who suffer most when the technology fails.
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 entire South Asia. No one could have possibly predicted or prevented the floods. It was by all measures an unusual natural event exacerbated by human folly in terms of water resource planning and development. One can, however, certainly ensure that the magnitude of its after-effects was within human ability to deal with. Unfortunately the Pakistani government is poorly equipped to deal with the human aftermath. This is where all of us as individuals can play a role. We still have the time to help the flood-affected people, and assist them to rebuild their lives