TR(BR)-13/98-99 : Rainfall-runoff modelling of Baitarani river basin upto Anandapur using HEC-1

Abstract

A hydraulic simulation model, HEC-1 has been applied to Baitarani river for modelling hourly flows of the river at Anandapur gauging site. The model has been designed to simulate the response and flood events of a basin to precipitation events. The study area lies between the latitude 22° 15. to 21° 20 N and longitude 85° 10' to 86° 55' E and falls within the states of Orissa and Bihar. The river Baitarani drains an area of about 8570 sq. km upto the gauging site and length of the main river upto gauging site is about 232 km.

In the present study, the HEC-1 model has been successfully used for simulation of peak flood. Hourly discharge data, hourly and daily rainfall data were used for calibration and validation of the model for years 1991 to 1994. The model parameters such as time of concentration, storage coefficient, initial and constant loss rate parameters were optimised and fixed for the basin during calibration. Clark technique ft): unit hydrograph and empirical equation for base flow separation were utilised in the model. The simulation results show fairly good peak flood, stream volumes and hydrograph obtained by the calibrated model.