Empirical approach to develop synthetic unit hydrographs for ungauged Dhamani basin, Maharashtra (India)

Abstract

The study aims to develop average representative unit hydrograph for Dhamani basin from the chosen storms. The best average representative unit hydrograph with minimum root mean square error is determined using leave one out cross validation method. The study further deals with empirical synthesis of unit hydrograph using Snyder's method, Mitchell's equation and Commons' method. A simple and rapid empirical approach of involving Buckingham pi theorem method is used to determine synthetic unit hydrograph parameters for the representative basin. The results attained by this approach are compared with the other synthetic methods. It is observed that, the peak discharge computed using Buckingham pi theorem method shows a good estimate with minimum percentage error (3.661%). The shape of the hydrograph gives good fit to the observed unit hydrograph amongst the other methods as it shows minimum deviation. This method offers a reasonable approach of determining peak discharge and shape of the hydrograph.