Statistical Comparisons of watershed scale response to climate change in selected basins across the United States

Earth Interactions
By: , and 

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Abstract

In an earlier global climate-change study, air temperature and precipitation data for the entire twenty-first century simulated from five general circulation models were used as input to precalibrated watershed models for 14 selected basins across the United States. Simulated daily streamflow and energy output from the watershed models were used to compute a range of statistics. With a side-by-side comparison of the statistical analyses for the 14 basins, regional climatic and hydrologic trends over the twenty-first century could be qualitatively identified. Low-flow statistics (95% exceedance, 7-day mean annual minimum, and summer mean monthly streamflow) decreased for almost all basins. Annual maximum daily streamflow also decreased in all the basins, except for all four basins in California and the Pacific Northwest. An analysis of the supply of available energy and water for the basins indicated that ratios of evaporation to precipitation and potential evapotranspiration to precipitation for most of the basins will increase. Probability density functions (PDFs) were developed to assess the uncertainty and multimodality in the impact of climate change on mean annual streamflow variability. Kolmogorov?Smirnov tests showed significant differences between the beginning and ending twenty-first-century PDFs for most of the basins, with the exception of four basins that are located in the western United States. Almost none of the basin PDFs were normally distributed, and two basins in the upper Midwest had PDFs that were extremely dispersed and skewed.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Statistical Comparisons of watershed scale response to climate change in selected basins across the United States
Series title Earth Interactions
DOI 10.1175/2010EI364.1
Volume 15
Issue 14
Year Published 2011
Language English
Publisher American Meteorological Society
Contributing office(s) Oregon Water Science Center
Description p. 1-26
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Earth Interactions
Country United States