Global hydrology modelling and uncertainty: running multiple ensembles with a campus grid
- 13 September 2010
- journal article
- Published by The Royal Society in Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
- Vol. 368 (1926), 4005-4021
- https://doi.org/10.1098/rsta.2010.0164
Abstract
Uncertainties associated with the representation of various physical processes in global climate models (GCMs) mean that, when projections from GCMs are used in climate change impact studies, the uncertainty propagates through to the impact estimates. A complete treatment of this ‘climate model structural uncertainty’ is necessary so that decision-makers are presented with an uncertainty range around the impact estimates. This uncertainty is often underexplored owing to the human and computer processing time required to perform the numerous simulations. Here, we present a 189-member ensemble of global river runoff and water resource stress simulations that adequately address this uncertainty. Following several adaptations and modifications, the ensemble creation time has been reduced from 750 h on a typical single-processor personal computer to 9 h of high-throughput computing on the University of Reading Campus Grid. Here, we outline the changes that had to be made to the hydrological impacts model and to the Campus Grid, and present the main results. We show that, although there is considerable uncertainty in both the magnitude and the sign of regional runoff changes across different GCMs with climate change, there is much less uncertainty in runoff changes for regions that experience large runoff increases (e.g. the high northern latitudes and Central Asia) and large runoff decreases (e.g. the Mediterranean). Furthermore, there is consensus that the percentage of the global population at risk to water resource stress will increase with climate change.Keywords
This publication has 14 references indexed in Scilit:
- Impacts of climate change scenarios on runoff regimes in the southern AlpsPublished by Copernicus GmbH ,2009
- Storm tracking with remote data and distributed computingComputers & Geosciences, 2008
- Associations between elevated atmospheric temperature and human mortality: a critical review of the literatureClimatic Change, 2008
- Performance metrics for climate modelsJournal of Geophysical Research: Solid Earth, 2008
- Effect of GCM bias on downscaled precipitation and runoff projections for the Serpentine catchment, Western AustraliaInternational Journal of Climatology, 2007
- Uncertainty in predictions of the climate response to rising levels of greenhouse gasesNature, 2005
- Climate change and global water resources: SRES emissions and socio-economic scenariosGlobal Environmental Change, 2004
- Climate change impacts on runoff in Sweden-assessments by global climate models, dynamical downscaling and hydrological modellingClimate Research, 2001
- Global Water Resources: Vulnerability from Climate Change and Population GrowthScience, 2000
- Global land cover classifications at 8 km spatial resolution: The use of training data derived from Landsat imagery in decision tree classifiersInternational Journal of Remote Sensing, 1998