Downstream Flood Peak Improvement Modeling for a River System Incorporating Ungauged Subbasins

Abstract

Floods cause enormous economic damage and human suffering needing control measures to reduce the impacts of flood in vulnerable areas. The present study focuses on evaluating the peak flow rate reduction at a potential downstream damage station in a river system. Downstream flood flow simulation model for a river system incorporating flows from gauged and ungauged sub basins is used to estimate the flow rate at the damage site. The model is applied to Barak river system, India with potential downstream damage station, Annapurnaghat. Three flood events are used in the study. Flow contributions from the ungauged sub basins during the selected flood events are estimated by applying GIUH approach. The model is applied to evaluate improvements in the downstream peak flow rate at Annapurnaghat for flow control measures at various upstream catchments in the river system. The study reveals that controlling flows from all major intervening catchments a safe flow close to danger level at downstream station Annapurnaghat can be maintained.