Title: Hydrological impacts of climate change on the future streamflow of three unregulated catchments of the Australian hydrologic reference stations

Authors: Hashim Isam Jameel Al-Safi; Priyantha Ranjan Sarukkalige

Addresses: Department of Civil Engineering, Curtin University, Perth 6102, Australia; Department of Irrigation and Drainage Techniques, Technical Institute of Shatrah, Southern Technical University, Dhi Qar, Iraq ' Department of Civil Engineering, Curtin University, Perth 6102, Australia

Abstract: A physically-based distributed hydrological model (BTOPMC) is adopted to assess the impact of climate-change on the hydrological-behaviour of three-contributing catchments of the Australian hydrologic reference stations (HRSs). Both historical and future streamflow trends are compared and discussed. Firstly, the BTOPMC-model was calibrated and validated based on the observed hydro-meteorological data from the three-catchments. The calibrated BTOPMC-model was then forced with the downscaled future climate signals from a multi-model ensemble of eight-GCMs of the CMIP5 under the RCP4.5 and RCP8.5 scenarios to simulate the future daily streamflow at the three-HRSs for the mid (2046-2065) and late (2080-2099) of the 21st-century. Nearly all GCMs predict a reduction-tendency in mean-annual rainfall and an increase in temperature and potential-evapotranspiration across the studied catchments. The mean annual-streamflow also shows reductiontendencies during the future-periods ranged between 26%-53% at Dingo-Road HRS, 10%-25% at Haystack-HRS and 6%-33% at Coggan-HRS relative to the control-run.

Keywords: climate change; hydrologic reference stations; HRSs; physically-based simulation modelling; BTOPMC model; CMIP5; Australia.

DOI: 10.1504/IJHST.2019.102420

International Journal of Hydrology Science and Technology, 2019 Vol.9 No.4, pp.366 - 398

Received: 07 Oct 2017
Accepted: 30 Dec 2017

Published online: 18 Sep 2019 *

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