Pakistan Floods: Lessons Learnt

Firstly, the rise in the planetary temperature has reached a tipping point. We are now in a scary new era of extreme weather. We should therefore be doing everything we can and more to cut our greenhouse gas pollution. At best, we can slow the rise in heat and limit the maximum temperature level.

Secondly, we urgently need to step up efforts to protect ourselves from this new normal. We need to do all we can to stop weather disasters becoming catastrophes. This means increasing the resilience of our infrastructure, economies and communities. Greater resilience in Pakistan would include better emergency warning and evacuation systems, better flood protection for key infrastructure (schools and other community buildings that can serve as flood shelters) and plans to help communities recover once the waters recede.

The third and main point which we must acknowledge is the way we have (mis)managed the Indus - and countless other rivers around the world - for the past century. Although these policies have provided various short-term benefits, these have come at major long-term costs which we are now having to pay. We have ended small- and medium-scale flooding on many rivers through building dams and embankments, but in doing so we have greatly increased the scale of (and our vulnerability to) very big floods. Increasing resilience to floods in Pakistan, the US and just about everywhere else is going to require reversing our river management mistakes through restoring rivers and floodplains, including taking out embankments and dams.

In Pakistan, two of the world's biggest dams and a vast associated system of barrages and diversion canals have greatly reduced the amount of water and sediments carried by the Indus in most years. The most obvious consequence of this has been the destruction of the farmlands, fisheries and mangrove forests of the Indus Delta, one of the 20th century's great environmental disasters. Another consequence is that the river normally lacks sufficient flows to carry away the riverine sediments that are not trapped behind dams. Sediments that once would have been deposited onto the floodplain in normal floods are trapped within thousands of miles of embankments. These sediments build up on the riverbed, steadily reducing its capacity to handle large flows. When, inevitably, a major flood comes, the shrunken river channel, straight-jacketed within its embankments, can no longer hold the flow; the Indus then surges out over the densely populated floodplain.

According to Daanish Mustafa of King's College London in National Geographic, recalling the fable in which a man sells his soul to the devil in exchange for a life of luxury, ‘The major river engineering is basically a Faustian bargain'. Mustafa is a geographer who has studied the history of Pakistan's river management. Until a few decades ago, there were typically mild floods each summer: when the monsoon rainfall hits and when snowmelt from the Himalaya and Karakoram Mountains is at its peak. Because humans have sculpted the river and the surrounding natural floodplain and wetlands for farming and other needs, there are fewer floods. But when they hit, they are far worse.

Allowing the river to flood more regularly and naturally could help temper the floods and make them more tolerable, say Mustafa and other experts. Managing Pakistan's floods is a delicate balance between giving the river more room and building barriers to protect people and their land. As Mustafa explains, the unusual monsoon pattern behind the current catastrophe has been seen in a weaker form already several times in the past decade. The hydrological past is no longer a reliable guide to the hydrological future and we need to rethink our management of rivers to take account of this.

To read more about the failure of flood control and how we can reduce flood risks, visit the International Rivers website.

Source: Huffington Post, image: National Geographic