Effect of scenario assumptions on climate change risk estimates in a water resource system

摘要

ABSTRACT: The common approach in evaluating the impacts of climate change on a water resource system begins with downscaling general circulation model (GCM) projections, estimating resultant streamflow via a hydrological model, and assessing impacts with a water resource system model. An alternative methodology, described as ‘decision scaling,’ links a bottom-up approach with climate information including GCM projections through a decision analysis framework. One advantage of this approach is that the effects of different assumptions related to the processing of climate simulations can be directly characterized. This paper demonstrates the usefulness of the decision-scaling methodology by examining how probability distribution function choice influences the modeling of climate-change-impact uncertainty, and how, in turn, this affects projections of water supply systems. The approach is demonstrated in an analysis of the risk of climate change impacts on a large water supply system located in central Massachusetts, USA.