An approach for prediction of flood hydrograph at outlet of an ungauged basin using modified dynamic wave model

ABSTRACT

Floods are the most disastrous natural hazards, but the prediction of flood hydrographs is hindered due to the lack of Hydro-meteorological data. This paper presents an approach for flood routing of the ungauged basin using rainfall-runoff and Dynamic wave models. Specifically, the SCS-CN rainfall-runoff model is employed to obtain the inflow and lateral inflow hydrographs of the ungauged sub-basins, and a Modified Dynamic Wave Model is employed to anticipate the flood hydrograph at the outlet of the ungauged basins. The Modified Dynamic Wave Model for the parabolic channel (MDWMP) has been numerically solved using an implicit finite difference scheme considering both continuity and momentum equations. The method is tested in hypothetically considered ungauged Kulsi River Basin, a mountainous basin in Northeastern India, and the results obtained are compared with the observed data at the outlet of the Kulsi Basin. The approach is validated by considering four parameters RMSE, Peak flow Error, Peak time Error, and Total Volume Error. A high degree of affinity (i.e. peak flow error below 6%) was observed between the predicted outflow hydrograph and the observed hydrograph, which verified the satisfactory applicability of the developed approach to anticipate the flood hydrograph of an ungauged basin.

KEYWORDS:

• Saint-venant equations
• hydraulic routing
• dynamic wave model
• finite difference

Acknowledgments

The authors are thankful to the faculty members of the Civil Engineering Department, Assam Engineering College, Guwahati, Assam. The authors also thank the National Institute of Hydrology (NIH, Guwahati) and Indian Meteorological Department (IMD, Guwahati) for providing necessary information and data.

Declarations

Funding: Not applicable.

Conflicts of interest: On behalf of all authors, the corresponding author states that there is no conflict of interest.

Availability of data and material: Not applicable.

Disclosure statement

No potential conflict of interest was reported by the authors.