Development of a Rainfall-Runoff Model, its Calibration and Validation

In this study a rainfall-runoff model was developedbased on water balance equations. Input to the model isprecipitation and potential evapotranspiration (both onmonthly basis). Output from the model is the simulated runoffat the watershed outlet. Five parameters were adopted fordescription of the characteristics of drainage area. Theseparameters are estimated using the Downhill Simplex Method. Themodel was calibrated and tested for four watersheds.Statistical results showed that the model preformed well. Thecorrelation co-efficient between the simulated and measureddata was on the range of 77% to 93%. Copyright Kluwer Academic Publishers 2001