Assessing the effect of climate natural variability in water resources evaluation impacted by climate change (pages 1061–1071)

摘要

Water resource assessment on climate change is crucial in water resource planning and management. This issue is becomingmore urgent with climate change intensifying. In the current research of climate change impact, climate natural variability(fluctuation) has seldom been studied separately. Many studies keep attributing all changes (e.g. runoff) to climate change, whichmay lead to wrong understanding of climate change impact assessment. Because of lack of long enough historical series, impactsof climate variability have been always avoided deliberately. Based on Latin hypercube sampling technique, a block samplingapproach was proposed for climate variability simulation in this study. The widely used time horizon (1961–1991) was definedas baseline period, and the runoff variation probability affected by climate natural variability was analysed. Allowing for sevenfuture climate projections in total of three GCMs (CSIRO, NCAR, and MPI) and three emission scenarios (A1B, A2, and B1),the impact of future climate change on water resources was estimated in terms of separating the contribution from climate naturalvariability. Based on the analysis of baseline period, for the future period from 2021 to 2051, the impact of climate naturalvariability may play a major part, whereas for the period from 2061 to 2091, climate change attributed to greenhouse gases maydominate the changing process. The results show that changes from climate variability possess a comparable magnitude, whichhighlights the importance to separate impacts of climate variability in assessing climate change, instead of attributing all changesto climate change solely. Copyright © 2012 John Wiley & Sons, Ltd.