Flood Hazard Assessment for the Tori Levee Breach of the Indus River Basin, Pakistan

Levee breaches are some of the most common hazards in world and cause loss lives, livelihoods, property destruction. During 2010 flood Pakistan, devastating breach occurred at Tori on right bank Indus River, downstream Guddu Barrage, which caused residual floods northern Sindh adjoining regions Balochistan province. In this study, 2D unsteady flow modeling performed for computed inundation by coupling a HEC-RAS (Hydrological Engineering Centre—River Analysis System) hydraulic model with remote sensing Geographic Information System techniques. The performance was judged comparing observed simulated water levels (stage) during peak seven different gauging stations located within River reach daily extents multi-day composites. quantitative values calibration validation showed good range difference from 0.13 to ?0.54 m between (stage), 84% match maximum area, 73.2% measure fit. overall averages these comparison were 57.12 75%, respectively. Furthermore, passed through breach, found be 4994.47 cumecs (about 15% flow) head stage 71.56 m. By using flows risk maps identified hazard zones according characteristics (depth, velocity, depth times arrival time, duration). All concluded fact that active plain uninhabitable under conditions.