CS(AR)-16/98-99 : Daily rainfall-runoff modelling using a simple conceptual model for Gundlakama river in Andhra Pradesh

Abstract

Since 1990's, some new techniques are being applied more widely in solving analytical problems of rainfall-runoff modelling on the readily accessible personal computers. Utilizing the concepts of physics to describe the land phase of hydrological cycle in space and time and computing facilities available hydrological modelling is being made easy and simple. It is important to see that the number of parameters of the model is not so large that modelling the process becomes cumbersome. To make the modelling quick and effective, conceptual models with a few parameters are being preferred.

In this study, a simple 5-parameter model, based on the conceptual of probability distributed method as proposed by Moore (1985) is applied to simulate the daily runoff over a 9-year period of 1989 to 1997 at Tamavaram in Prakasam district of Andhra Pradesh on the Gundlakamma river. A program in Fortran 77 is developed to undertake automatic optimization of the model to simulate the observed flows using a proper objective function. From the calibration and validation of the modelling study, it is found that the model, though a five-parameter one, could respond properly to the rainfall and resulted in a reasonable by efficiency of 72.14% in calibration and 68.25% in validation