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

Authors: Akshay R. Thorvat; Jayantilal N. Patel

Addresses: Civil Engineering Department, S.V. National Institute of Technology, Surat-395007, Gujarat, India ' Civil Engineering Department, S.V. National Institute of Technology, Surat-395007, Gujarat, 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.

Keywords: Buckingham pi theorem; design floods; dimensional analysis; isolated storms; leave one out cross validation; peak discharge; root mean square error; RMSE; single event method; synthetic unit hydrographs; SUH; time to peak; ungauged basins; India; flood prediction; hydrology; flooding.

DOI: 10.1504/IJHST.2016.077396

International Journal of Hydrology Science and Technology, 2016 Vol.6 No.3, pp.266 - 284

Received: 30 Jul 2015
Accepted: 24 Nov 2015
Published online: 29 Jun 2016 *

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