Abstract:
Floods are probably the most repeating, broad, grievous and frequently occurring natural hazards of the world. India is one of the most terrible flood-influenced nations. In India the Himalayan Rivers represent most extreme flood harm in the nation. The Kosi river in north Bihar, eastern India displays a challenge regarding long and repeating flood risk. In spite of a long history of flood control management in the basin for over five decades, the stream keeps on bringing a great deal of suffering through broad flooding. The fields of north Bihar are probably the most helpless regions in India, inclined to flooding. This Study addresses the flooding issue in the Kosi river basin and exhibits an in-depth investigation of flood hydrology. This study presents about the parameterization of hydrologic and hydraulic modelling for simulation of overflow and flood inundation zone mapping. SRTM-DEM of 90m pixel size is used to create the different maps (DEM) of Kosi Basin. Hydraulic and hydrological models such as SWAT model, SWAT-CUP along with HEC-RAS are utilized for runoff and flood inundation modelling. Average hydrological qualities of the Kosi waterway incorporate high discharge fluctuation, and high sediment motion. Yearly Peak discharge frequently surpasses the mean yearly flood and the low-lying regions of the alluvial fields are broadly immersed for seemingly endless amount of time after year.
Flood forecasting and warning, flood hazard mapping and flood risk zoning are very viable non-structural techniques in overseeing floods that diminishes the dangers and catastrophe of the floods. In perspective of this an effort has been made in the present study to simulate runoff and flood inundation for Kosi River Basin in Bihar, India. Results showed that for Kosi catchment, the observational runoff prediction model i.e. SWAT Model as presence of less data predicted discharge that can be considered in case of unavailability of accurate or sufficient data. The flood hazard map is approved with long term inundation maps and offers a practical answer for arranging mitigation measures in flood prone regions. The flood inundation for the Kosi River floodplain is completed utilizing HEC-RAS 1-D hydrodynamic model using steady flow as well as unsteady flow analysis shows give the results on which one can rely upon unless more accurate analysis is not happening.
