Bastola, Satish and Murphy, Conor and Sweeney, John (2011) The role of hydrological modelling uncertainties in climate change impact assessments of Irish river catchments. Advances in Water Resources, 34. pp. 562-576. ISSN 0309-1708

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Abstract

This study attempts to assess the uncertainty in the hydrological impacts of climate change using a multi- model approach combining multiple emission scenarios, GCMs and conceptual rainfall–runoff models to quantify uncertainty in future impacts at the catchment scale. The uncertainties associated with hydro- logical models have traditionally been given less attention in impact assessments until relatively recently. In order to examine the role of hydrological model uncertainty (parameter and structural uncer- tainty) in climate change impact studies a multi-model approach based on the Generalised Likelihood Uncertainty Estimation (GLUE) and Bayesian Model Averaging (BMA) methods is presented. Six sets of regionalised climate scenarios derived from three GCMs, two emission scenarios, and four conceptual hydrological models were used within the GLUE framework to define the uncertainty envelop for future estimates of stream flow, while the GLUE output is also post processed using BMA, where the probability density function from each model at any given time is modelled by a gamma distribution with heteros- cedastic variance. The investigation on four Irish catchments shows that the role of hydrological model uncertainty is remarkably high and should therefore be routinely considered in impact studies. Although, the GLUE and BMA approaches used here differ fundamentally in their underlying philosophy and repre- sentation of error, both methods show comparable performance in terms of ensemble spread and predic- tive coverage. Moreover, the median prediction for future stream flow shows progressive increases of winter discharge and progressive decreases in summer discharge over the coming century.

Item Type:	Article
Keywords:	Climate change; Rainfall–runoff model; Uncertainty; GLUE; BMA; Ireland;
Academic Unit:	Faculty of Social Sciences > Geography Faculty of Social Sciences > Research Institutes > Irish Climate Analysis and Research Units, ICARUS
Item ID:	8897
Identification Number:	https://doi.org/10.1016/j.advwatres.2011.01.008
Depositing User:	Conor Murphy
Date Deposited:	13 Oct 2017 13:39
Journal or Publication Title:	Advances in Water Resources
Publisher:	Elsevier
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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