Applicability of HEC-RAS & GFMS tool for 1D water surface elevation/flood modeling of the river: a Case Study of River Yamuna at Allahabad (Sangam), India

Abstract

Floods always have been a natural disasters and it is very difficult to stop flood destruction and apply required preventive measures without any pre-prediction. Remote sensing and GIS tool like Global flood monitoring system (GFMS) and HEC-RAS model provide the idea to analyze the flood analysis and their potential. The purpose of this study was to model the water surface elevation (WSE) of river Yamuna at district Allahabad near Sangam area, Uttar Pradesh, India by using the one of the latest flood monitoring tool (GFMS) which provides near real time discharge value of various streams of the world. In this study three stations were selected for calibration of the model, at present these stations are also being used by various government organizations of India for river stage monitoring. HEC-RAS modeling was carried out for determine flood events or WSE/HFL (High Flood Level) of the year 1978 and 2001–2014. After that, the modeled output data was compared with real observed data and no significance difference in most of the cases was observed. The findings of HEC-RAS modeling indicate that applicability of this model can play the effective role to predict flood potential and identify the WSE in future for making the plan for any city situated near the river. In this regard, WSE level for upcoming 100, 500 and 1000 years was estimated by Gumbel’s distribution method and found maximum stage 89.367, 90.568 and 92.268 m, respectively, above from mean sea level. Further, this study indicates that a larger area nearby the study area falls in highly risky zone and plan for safety management is needed. This methodology can be used for urban planning and disaster management for various cities situated near the rivers in the world.