Causation and avoidance of catastrophic flooding along the Indus River, Pakistan

[摘要] The catastrophic flood of 2010 along the Indus River began inJuly with unusually intense but not unprecedented rainfall in the upland catchment.During four months, close to 2,000 fatalities occurred and ~20,000,000 inhabitantswere displaced. The meteorological events triggered but did not cause this “natural”disaster. Analysis of multi-temporal remote sensing and topography instead indicatesthat most damage was caused by dam and barrage-related backwater effects, reducedwater and sediment conveyance capacity, and multiple failures of irrigation systemlevees. The numerous failures extended from upstream areas, where some record dischargesoccurred, to downstream reaches and the delta, where peak discharges were not extreme.In Sindh, Pakistan, two major river avulsions (sudden changes in flow location)occurred. At one of these (the northern avulsion), Indus water flooded ~8,000 km2of agricultural land to depths of 1–3 m; part of the river flowed 50–100 km westof its pre-flood location. The avulsion was caused by breaching of the Tori Bund,an artificial levee upstream of Sukkur Barrage, on 6–7 August, two days before arrivalof the first flood crest and long before attainment of peak river flow at Chacharan,100 km upstream, on 24 August. The early breach, during the rising stages of theflood, permitted much of the incoming flood wave to feed the avulsion over a sustainedperiod.

[学科分类] 地质学

[关键词] Fire safety;fatal fires;smoke alarms