#ISSS2016 Boulder

The Pakistan flooding, July-November 2010, caused ~2000 fatalities, displaced 20,000,000 inhabitants for weeks to many months, and was 7.5 on a duration-area affected-intensity scale that compares flood magnitudes on a global basis. Exceptional damage was inflicted on crops and cropland and on agriculture support systems such as canals and levees. Total economic impact reached 43 billion USD; 4,500,000 mainly agricultural workers lost their employment for 2010-2011. The catastrophic flood was associated with unusually intense but not unprecedented rainfall in the upland catchment. Most damage was caused by multiple failures of irrigation system levees, and by barrage-related backwater effects that initiated failures and led to avulsions (sudden changes in flow location). The meteorological events did not cause the catastrophe. Instead, the lack of planned accommodation to the river's high sediment load set the stage for super-elevation of the Indus above the surrounding terrain, dangerous levee failures, and channel avulsions. The dynamics of this remarkable event demonstrate that planning for major flow diversions is a necessary component of effective flood control along this and other avulsion-prone rivers. This disaster will serve as an example to discuss the ‘lessons learnt’ for all stakeholders.