Numerical Approach for Channel Flood Routing in an Ungauged Basin: a Case Study in Kulsi River Basin, India

Flood is the most devastating and frequent disaster in North-East India, resulting in loss of human life and damage of properties. Its deleterious effects can be minimized by appropriate modeling, analysis, and management methods. Such modeling and analyzing techniques are hindered in flood prediction in an ungauged basin due to the lack of hydro-meteorological data. The main objective of this work is to develop a numerical approach for flood routing in an ungauged basin using the rainfall-runoff model and the flood routing models (Muskingum approach, Cunge-Muskingum model, KWM, VPKWM, DWFRM, and MDWMP). The Geographic Information System software has been used to extract the geographical information of the study area. The SCS-CN rainfall-runoff model is employed to obtain the inflow, and lateral inflow hydrographs of the ungauged sub-basins and the routing models are employed to anticipate the flood hydrograph at the outlet of the ungauged basin. The modeling approach is employed to the Kulsi River Basin, India, hypothetically considered an ungauged basin, and the results obtained from the various routing models are compared with the observed data at the outlet of the basin. The performance of the flood routing models is validated by considering nine statical parameters, i.e., RMSE, E-peak, peak flow time error, E-volume, MAE, R-squared, RE, NSE, and KGE. The results reveal that out of all the abovementioned models, MDWMP shows better performance as far as the predictions in ungauged basin is concerned. The Muskingum approach (MA) and DWFRM routing models can also suitably be used in prediction of flood hydrograph at the downstream of an ungauged basin in less gauged river basin reaches.