Nash IUH Model Parameters Estimation using Method of Moments and C Programming

Abstract

Parameter estimation of any model remains a very challenging problem since last few decades due to its non-convexity and ill-conditioning. The non-convexity of the parameter estimation problem usually resolved by using suitable global optimization methods while ill-conditioning and over fitting problems can be reduced with the help of regularization techniques. Nowadays, application of efficient advanced computing techniques and robust optimization algorithm are applied in model calibration, but none of them provide a unique value of parameter. Nash proposed the instantaneous unit hydrograph is often used in flood forecasting and rainfall-runoff. The success of Nash instantaneous unit hydrograph model is highly depended on the accuracy of its parameters ‘n’ and ‘k’ estimation. The present study was undertaken to estimate the parameters ‘n’ and ‘k’ of Nash conceptual model using moments methods and C programming from excess rainfall hyetograph and direct runoff hydrograph.