The Application of a Statistical Downscaling Process to Derive 21^st Century River Flow Predictions Using a Global Climate Simulation

Technical Report · Thu Aug 22 04:00:00 EDT 2013

DOI:https://doi.org/10.2172/1091096· OSTI ID:1091096

Werth, D. ^[1]; Chen, K. F. ^[1]

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1. Savannah River Site (SRS), Aiken, SC (United States)

The ability of water managers to maintain adequate supplies in coming decades depends, in part, on future weather conditions, as climate change has the potential to alter river flows from their current values, possibly rendering them unable to meet demand. Reliable climate projections are therefore critical to predicting the future water supply for the United States. These projections cannot be provided solely by global climate models (GCMs), however, as their resolution is too coarse to resolve the small-scale climate changes that can affect hydrology, and hence water supply, at regional to local scales. A process is needed to ‘downscale’ the GCM results to the smaller scales and feed this into a surface hydrology model to help determine the ability of rivers to provide adequate flow to meet future needs. We apply a statistical downscaling to GCM projections of precipitation and temperature through the use of a scaling method. This technique involves the correction of the cumulative distribution functions (CDFs) of the GCM-derived temperature and precipitation results for the 20^th century, and the application of the same correction to 21^st century GCM projections. This is done for three meteorological stations located within the Coosa River basin in northern Georgia, and is used to calculate future river flow statistics for the upper Coosa River. Results are compared to the historical Coosa River flow upstream from Georgia Power Company’s Hammond coal-fired power plant and to flows calculated with the original, unscaled GCM results to determine the impact of potential changes in meteorology on future flows.

• Research Organization: Savannah River Site (SRS), Aiken, SC (United States)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program
• DOE Contract Number: AC09-08SR22470
• OSTI ID: 1091096
• Report Number(s): SRNL--STI-2013-00265
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
climate
downscaling
hydrology