9645 - Laserfiche WebLink

Home Browse Search

W05415 WOODHOUSE ET AL.: UPDATED COLORADO RIVER RECONSTRUCTIONS W05415 . ~ -L 1668, 1776-1783, and 1873-1883). Overall, these analy- ses demonstrate that severe, sustained droughts are a defining feature of Upper Colorado River hydroclimate. Flows in the Upper Colorado are also shown to be nonsta- tionary over decadal and longer timescales, making short- term records inappropriate for most plamling and forecast applications. [53] Although our results differ in some respects from those of Stockton and Jacoby [1976], the underlying messages are the same. The long-term perspective provided by tree ring reconstructions points to looming conflict between water demand and supply in the upper Colorado River basin. This suggestion has even greater relevance today. Demands on the Colorado River over the past decades have risen to meet or exceed average water avail- ability. Any variations or shifts in climate can have a significant impact on the system [Harding et a/., 1995; Christensen et aI., 2004]. The sensitivity of the Colorado River system became abundantly clear with the onset of the recent drought. Though the southern portion of the Upper Colorado, as well as many areas in the Lower Basin, gained a measure of drought relief in the winter of 2004-2005, major reservoirs on the Colorado River remained far below capacity in 200S. In the future, predicted climatic changes, including a shift in the ratio of snowfall to rainfall and earlier snowmelt and nmoff [Cayan et al., 200 I; Stevvart et al., 2004], will likely compound the strain on water resour- ces throughout the entire Colorado River Basin. [54] Many such climatic changes may have already begun in the western United States [Mote et a!., 2005], and rising temperatures will also increase demands for irrigation and hydropower generation. Proxy reconstructions can aid in planning for these scenarios by providing insights into the range of natural variability and a means to explore extreme climatic events and persistent climatic changes that are poorly captured in observational records. Reconstructions of annual streamflow for large rivers are particularly useful in that they integrate climatic variability over large regions, provide essential data for water managers, and complement existing reconstructions of seasonal climate variability [e.g., Cook et aI., 2004]. In concert with information on projected future changes, information on long-ternl variability must guide planning for drought management and economic development in the basin if we are to adequately face the social, legal and environmental challenges that coming decades will undoubtedly present. [55] Acknowledgments. S. T Gray was funded by the U.S. Geolog- ical Survey and Wyoming Water Development Commission. D. M. Meko was funded by a grant from the Arizona Board of Regents Technology and Research Initiative Fund. C. A. Woodhouse received funding from the NOAA Office of Global Programs Climate Change Data and Detection program (grant GC02-046). We greatly appreciate the comments of Edward Cook and two anonymous reviewers. We also thank Jeff Lukas, Mark Losleben, Margot Kaye, Gary Bolton, Kurt Chowanski, Stephen Jackson, Julio Betancourt, and RG. Eddy for field and laboratory assistance in tree ring chronology data collections and chronology development and James Prairie (USBRl for providing the estimates of natural flow for Colorado River basin gauges used in the calibrations. References Cayan, D. R., and R. H. Webb (1992), EI Nino/Southern Oscillation and streamflow in the western United States, in EI Nino: Historical and Paleoclimatic Aspects of the South em Oscillation, edited by H. F. Diaz and V. Markgraf, pp. 29-68, Cambridge Univ. Press, New York. Cayan, D. R., M. D. Dettinger, H. F. Diaz, and N. E. Graham (1998), Decadal variability of precipitation over western North America, J Clim., 11, 3148-3166. Cayan. D. R., K. T. Redmond, and L. G. Riddle (1999), ENSO and hydrologic extremes in the western United States, J Clim., 12,2881- 2893. Cayan, D. R., S. A. Kammerdiener, M. D. Dettinger, J. M. Caprio, and D. H. Peterson (200 I), Changes in the onset of spring in the western United States, Bull. Am. Meteorol. Soc.. 82, 399-415. Christensen, N. S., A. W Wood, N. Voisin, D. P. Lettenmaier, and R. N. Palmer (2004), Effects of climate change on the hydrology and water resources of tbe Colorado River Basin, Clim. Change. 62, 337-363. Conover, W. (1980), Practical Nonparametric Statistics, 2nd ed., John Wiley. Hoboken. N. J. Cook, E. R. (1985), A time series approach to tree-ring standardization, Ph.D. dissertation, Univ. of Ariz., Tucson. Cook, E. R., and K. Briffa (I990), A comparison of some tree-ring stan- dardization methods, in Methods ofDendrocbronologv: Applications in the Environmental Sciences, edited by E. R. Cook and L. A. Kairiukstis, pp. 153-162. Springer, New York. Cook. E. R., K. Briffa, S. Shiyatov, and V. Mazepa (1990), Tree-ring standardization and growth-trend estimation, in Methods of Dendro- chronologv: Applications in tbe Environmental Sciences, edited by E. R. Cook and L. A. Kairiukstis, pp. 104-123. Springer, New York. Cook, E. R., C. A. Woodhouse, C. M. Eakin, D. M. Meko, and D. W Stahle (2004), Long-tern] aridity changes in the western United States, Science, 306,1015-1018. Enfield, D. B., A. M. Mestas-Nunez, and P. 1. Trimble (2001), Tbe Atlantic multidecadal oscillation and its relation to rainfall and river flows in the continental U.S.. Geophys. Res. Left.. 28, 2077-2080. Fritts, H. C. (1976), Tree Rings and Climate. Elsevier, New York. Fritts, H. C., J. Guiot, and G. A. Gordon (1990), Verification, in Methods of Dendrochronology: Applications in the Environmental Sciences, edited by E. R. Cook and L. A. Kairiukstis, pp. 178 -185, Springer, New York. Fulp, T (2005), How low can it go?, Southwest Hydro!., 4. 16-17. Goodman, P. H. (1996), NevProp software, version 3, users' manual, Univ. of Nev., Reno. (http://brain.cs.unr.edu/publicationslNevPropManual.pdf) Gray, S. T, S. T Jackson, and 1. L. Betancourt (2004), Tree-ring based reconstructions of interannual to decadal-scale precipitation variability for northeastem Utah, J Am. Water Resow: Assoc., 40, 947-960. Haan, C. T. (2002), Statistical Methods in Hvdrology, 2nd ed., Iowa State Univ. Press, Ames. Harding, B. L., T B. Sangoyomi, and E. A. Payton (1995), rmpacts of severe sustained drought in Colorado River water resources, Water Re- sour. Bull., 316, 815-824. Hidalgo, H. G., and J. A. Dracup (2003), ENS 0 and PDO effects on hydroclimatic variability in the Upper Colorado River Basin, J Hvdro- meteorol., 4, 5-23. Hidalgo, H. G., T C. Piechota, and 1. A. Dracup (2000), Alternative prin- cipal components regression procedures for dendrohydrologic recon- structions, Water Resour. Res., 36,3241-3249. Hoeding, M., and A. Kumar (2003), The perfect ocean for drought, Science, 299, 691- 694. Mann, M. E., and 1. Lees (1996), Robust estimation of background noise and signal detection in climatic time series, Clim. Change, 33,409-445. Mardia, K., 1. Kent, and J. Bibby (1979), Multivariate Analysis, Elsevier, New York. McCabe, G. 1., M. A. Palecki, and J. L. Betancourt (2004), Pacific and Atlantic Ocean influences on l11ultidecadal drought frequency in the United States, Proc. Natl. Acad. Sci. U.S.A., /Of, 4136-4141. Michaelsen, 1. (1987), Cross-validation in statistical climate forecast mod- els, J Clim. Appl. Meteoml., 26, 1589- 1600. Meko, D. M., C. W Stockton, and W. R. Boggess (1995), The tree-ring record of severe sustained drought, Water Resour. Bull., 31, 789-801. Mote, P. W.. A. F. Hamlet, M. R. Clark, and D. P. Lettenmaier (2005), Declining mountain snowpack in western North America, Bull. Am. Meteorol. Soc., 86. 39-49. Rencher, A. c., and F. C. Pun (1980), rnflation of R2 in best subset regres- sion, Technometrics, 22, 49-53. Snedecor, G. w., and W. G. Cochran (1989), Statistical Methods, 8th rev. ed., rowa State Univ. Press, Ames. Stahle, D. W, E. R. Cook, M. K. Cleaveland, M. D. Therrell, D. M. Meko, H. D. Grissino-Mayer, E. Watson, and B. H. Luckman (2000), Tree-ring 15 of 16