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Updated: Jun 10, 2026
12:44
Watershed Planning within a Quantitative Scenario Analysis Framework
Published on: July 24, 2016
Global hydrology modelling and uncertainty: running multiple ensembles with a campus grid
Simon N Gosling1, Dan Bretherton, Keith Haines
1Walker Institute for Climate System Research, Agriculture Building, University of Reading, Earley Gate, Reading RG6 6AR, UK. s.n.gosling@reading.ac.uk
Summary
Climate model uncertainties impact water resource predictions. This study uses a large ensemble of simulations to quantify climate change impacts on global river runoff and water stress, revealing key regional changes and increased global population risk.
Area of Science:
- Climate Science
- Hydrology
- Environmental Modeling
Background:
- Global climate models (GCMs) introduce structural uncertainty into climate change impact studies.
- This uncertainty propagates to impact estimates, necessitating comprehensive analysis for decision-makers.
- Computational demands often limit the exploration of climate model structural uncertainty.
Purpose of the Study:
- To present a large ensemble of global river runoff and water resource stress simulations to address climate model structural uncertainty.
- To reduce the computational time required for ensemble creation through high-throughput computing.
- To analyze regional runoff changes and global population risk under climate change.
Main Methods:
- Developed a 189-member ensemble of global river runoff and water resource stress simulations.
- Adapted a hydrological impacts model and utilized the University of Reading Campus Grid for high-throughput computing.
- Reduced ensemble creation time from 750 hours to 9 hours using optimized computing resources.
Main Results:
- Identified considerable uncertainty in regional runoff changes across different GCMs.
- Demonstrated reduced uncertainty in runoff changes for regions with significant increases (high northern latitudes, Central Asia) and decreases (Mediterranean).
- Confirmed a consensus that climate change will increase the percentage of the global population at risk to water resource stress.
Conclusions:
- A large ensemble approach effectively addresses climate model structural uncertainty in impact studies.
- Specific regions show more robust projections of runoff changes despite overall GCM variability.
- Climate change poses a significant and increasing threat to global water resource availability for a larger population.
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