How well do terrestrial biosphere models simulate coarse-scale runoff in the contiguous United States?
- Northern Arizona Univ., Flagstaff, AZ (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Univ. of Colorado, Boulder, CO (United States)
- United States Department of Agriculture (USDA) Forest Service, Portland, OR (United States). Pacific Northwest Research Station
- Montana State Univ., Bozeman, MT (United States)
- United States Department of Agriculture (USDA) Forest Service, Knoxville, TN (United States). Southern Research Station
- Auburn Univ., AL (United States)
- Univ. of Maryland, College Park, MD (United States)
Significant changes in the water cycle are expected under current global environmental change. Robust assessment of present-day water cycle dynamics at continental to global scales is confounded by shortcomings in the observed record. Modeled assessments also yield conflicting results which are linked to differences in model structure and simulation protocol. Here we compare simulated gridded (1 spatial resolution) runoff from six terrestrial biosphere models (TBMs), seven reanalysis products, and one gridded surface station product in the contiguous United States (CONUS) from 2001 to 2005. We evaluate the consistency of these 14 estimates with stream gauge data, both as depleted flow and corrected for net withdrawals (2005 only), at the CONUS and water resource region scale, as well as examining similarity across TBMs and reanalysis products at the grid cell scale. Mean runoff across all simulated products and regions varies widely (range: 71 to 356 mm yr(-1)) relative to observed continental-scale runoff (209 or 280 mm yr(-1) when corrected for net withdrawals). Across all 14 products 8 exhibit Nash-Sutcliffe efficiency values in excess of 0.8 and three are within 10% of the observed value. Region-level mismatch exhibits a weak pattern of overestimation in western and underestimation in eastern regions although two products are systematically biased across all regions and largely scales with water use. Although gridded composite TBM and reanalysis runoff show some regional similarities, individual product values are highly variable. At the coarse scales used here we find that progress in better constraining simulated runoff requires standardized forcing data and the explicit incorporation of human effects (e.g., water withdrawals by source, fire, and land use change). (C) 2015 Elsevier B.V. All rights reserved.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Grant/Contract Number:
- AC05-00OR22725; FG02-06ER64317; MTU050516Z14
- OSTI ID:
- 1335319
- Alternate ID(s):
- OSTI ID: 1249857
- Journal Information:
- Ecological Modelling, Vol. 303; ISSN 0304-3800
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Contribution of environmental forcings to US runoff changes for the period 1950–2010
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journal | May 2018 |
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