1D-Flood Hazard Mapping and Analysis Using HEC-RAS Modelling, A case study of the Seti River, West Central Nepal

With jolts of climate change, dubious rainfall, melting of glaciers, Nepal in last couple of years has been liable to natural disasters spawning loss of lives, possessions and economic losses.Flooding, is a major issue in Nepal that needs to be prioritized calls for more action to study, analyze and prevent it.The Seti River has been periodically enduring flood events and much less thought has been given to it, though some studies has been conducted previously.This study is perpetrated to add effort towards it.The study uses long term precipitation for rainfall analysis using Hazen, California and Weibull while discharge to reckon flood frequency prediction employing Gumbel, Weibull and Log Pearsons Type III method.The HEC-RAS uses Gumbel flood values to produce one dimensional flood maps for return period of 2,10,50,100 years and Arc-GIS is used for hazard and risk analysis.The result unveils positive correlation between flood discharge, rainfall and inundation area over different return period with expected flood exceeding the channel capacity over the years.Installation of early warning system in rivers, potential dangerous glacial lakes and community-based disaster management has been suggested for preparedness, response and recovery from such catastrophes.