A Pakistan Army helicopter flies over the Garhi Khairoo, area near the new flood zone of Shahdakot, Pakistan on Sunday. The country's agricultural heartland has been devastated, with rice, corn and wheat crops destroyed by floods. Paula Bronstein / Getty Images

By Catharine Paddock, PhD, Medical News Today
25 Aug 2010 – 9:00 PDT As well as losing crops and farm animals directly as a result of flooding, the people of Pakistan could be facing longer term food shortages as canals overloaded in the second wave of flooding threaten to undermine the irrigation infrastructure that the country will rely on once the waters recede. The last three weeks have seen two flood surges along the Indus River, which starts in Tibet and flows through the whole length of Pakistan from north to south, to join the Arabian Sea near the port city of Karachi in Sindh. In an attempt to manage the flooding, particularly following the second wave, it appears that water is being diverted from the river into irrigation canals. In a Nature News report published on 20 August, James Dalton, an advisor for the International Union for Conservation of Nature Water Programme based in Switzerland, explained how the flood waves developed. He said that the enormous damage from the first surge was due to dry and hard ground, so the water from the first rains just ran off into the river without being soaked up. As the flood travelled south, the ground in the north gradually absorbed the water and soaked some of it up. But after it became saturated, the water from the continuing rains had nowhere to go but flood across the surface again. In the meantime, there is no respite from the rains, and meteorologists in Pakistan report that the waters from the first wave have merged with that of the second, with exceptionally high levels expected around the Kotri area, in Sindh, and that this will last until the end of the month. …

Pakistan Flood: Canals Overloaded In Second Wave Threaten Long Term Recovery