Paper No. JAWRA-07-0180-P of the Journal of the American Water Resources Association (JAWRA). Discussions are open until June 1, 2009.
Spatial Distribution of Water Supply in the Coterminous United States1
Article first published online: 29 OCT 2008
© 2008 American Water Resources Association. No claim to original U.S. government works
JAWRA Journal of the American Water Resources Association
Volume 44, Issue 6, pages 1474–1487, December 2008
How to Cite
Brown, T. C., Hobbins, M. T. and Ramirez, J. A. (2008), Spatial Distribution of Water Supply in the Coterminous United States. JAWRA Journal of the American Water Resources Association, 44: 1474–1487. doi: 10.1111/j.1752-1688.2008.00252.x
- Issue published online: 1 DEC 2008
- Article first published online: 29 OCT 2008
- Received December 19, 2007; accepted April 10, 2008.
- water supply;
Abstract: Available water supply across the contiguous 48 states was estimated as precipitation minus evapotranspiration using data for the period 1953-1994. Precipitation estimates were taken from the Parameter-Elevation Regressions on Independent Slopes Model (PRISM). Evapotranspiration was estimated using two models, the Advection-Aridity model and the Zhang model. The evapotranspiration models were calibrated using precipitation and runoff data for 655 hydrologically undisturbed basins, and then tested using estimates of natural runoff for the 18 water resource regions (WRR) of the 48 contiguous states. The final water supply coverage reflects a mixture of outputs from the two evapotranspiration models. Political, administrative, and land cover boundaries were mapped over the coverage of mean annual water supply. Across the entire study area, we find that 53% of the water supply originates on forested land, which covers only 29% of the surface area, and that 24% originates on federal lands, including 18% on national forests and grasslands alone. Forests and federal lands are even more important in the West (the 11 western contiguous states), where 65% of the water supply originates on forested land and 66% on federal lands, with national forests and grasslands contributing 51%.