DAM BREACH ANALYSIS AND PARAMETER SENSITIVITY ANALYSIS ALONG A RIVER REACH USING HECRAS

A dam break is a low-probability, high risk catastrophe event that extremely destructive and has substantial negative socio-economic impact on downstream nearby areas. Simulating breach analyzing flood propagation from those events vital for identifying minimizing the risks associated of location. This study intended to anlayse effect overtopping failure two scenario (a) base-case (scenario with average value parameters their range) (b) worst case (the largest geometry, shortest formation time highest peak outflow magnitude). Further, hydrodyanmic modelling perfomed investigate sensitivity analysis (local global) five (dam elevation, width, time, weir coefficient, trigger elevation) in proposed hydropower project located Nepal. Aeronautical Reconnaissance Coverage Geographic Information System (ArcGIS), Hydraulic Engineering Center River Analysis (HEC-RAS) OriginPro 2022b are utilized analyse parameter sensitivity.
 Generation hydrograph shows devasting innudation 1047 househols 50.83 kilometers roads. The velocty was recorded as 15.16 m/s 20.85 base respectively. minimum depth maximum flooding location found be 24.51 m 73.6 47.43 106.75 case. Due backwater at Bheri river, flow 14 km reduces significantly 124852.57 m3/s 244204.41 From local sensitivty it been that, elevation more sensitive triggering less hydrograph. Whereas, width seems TFE least using Monte Carlo Simulation gloal sensitivity.