Title: Evaluation of the impact of climate change on water resources and droughts frequency and severity in a small-scale international catchment in the Iberian Peninsula

Authors: José Moyano; Mirta Dimas; Antonio Jiménez-Álvarez; Luis Miguel Barranco; Carlos Ruiz del Portal; Adrián Rico

Addresses: Hydrology Unit, Centre of Hydrographic Studies of the Centre for Studies and Experimentation of Public Works, Madrid, 28005, Spain ' Hydrology Unit, Centre of Hydrographic Studies of the Centre for Studies and Experimentation of Public Works, Madrid, 28005, Spain ' Hydrology Unit, Centre of Hydrographic Studies of the Centre for Studies and Experimentation of Public Works, Madrid, 28005, Spain ' Hydrological Planning Unit, Centre of Hydrographic Studies of the Centre for Studies and Experimentation of Public Works, Madrid, 28005, Spain ' Hydrological Planning Office, Miño-Sil River Basin Authority, Ourense, 32003, Spain ' Hydrological Planning Office, Miño-Sil River Basin Authority, Ourense, 32003, Spain

Abstract: An evaluation of the potential effect of climate change on water resources and droughts has been performed in a small-scale international region in NW of the Iberian Peninsula. Twenty EURO-CORDEX climate projections were used for three future periods (2010-2040, 2040-2070 and 2070-2100) under RCP4.5 and RCP8.5. The bias of the climate projections was analysed and corrected using quantile mapping (QM) technique. A distributed model at a spatial resolution of 500 m was used for the hydrological simulation. The ensemble of projections simulated a reduction in runoff of -8.7% in RCP4.5 and -15.8% in RCP8.5 by the end of the century. High discrepancies between projections, due to the uncertainties of the process, cause differences within the river basin, but reductions in runoff are generalised all over the territory by 2100. The frequency and severity of droughts, estimated through a probabilistic approach, are likely to increase by the end of the century.

Keywords: climate change impact; hydrologic simulation; bias correction; water resources; droughts; international river basin management; drought frequency estimation; drought severity estimation.

DOI: 10.1504/IJW.2023.133996

International Journal of Water, 2023 Vol.15 No.3, pp.207 - 231

Received: 16 May 2023
Accepted: 04 Jun 2023
Published online: 09 Oct 2023 *