Multi-Century Tree-Ring Reconstructions of Colorado Streamflow for Water Resource Planning

Water resource management requires knowledge of the natural variability in streamflow over multiple time scales. Reconstructions of streamflow derived from moisture-sensitive trees extend, in both time and magnitude, the variability provided by relatively short gage records. In this study, we present a network of 14 annual streamflow reconstructions, 300–600 years long, for gages in the Upper Colorado and South Platte River basins in Colorado generated from new and existing tree-ring chronologies. Gages for the reconstruction were selected on the basis of their importance to two of the largest Colorado Front Range water providers, who provided the natural flow data for the calibration with tree-ring data. The reconstruction models explain 63–76% of the variance in the gage records and capture low flows particularly well. Analyses of the reconstructions indicate that the 20th century gage record does not fully represent the range of streamflow characteristics seen in the prior two to five centuries. Multi-year drought events more severe than the 1950s drought have occurred, notably in the 19th century, and the distribution of extreme low flow years is markedly uneven over the past three centuries. When the 14 reconstructions are grouped into Upper Colorado, northern South Platte, and southern South Platte regional flow reconstructions, the three time series show a high degree of coherence, but also time-varying divergences that may reflect the differential influence of climatic features operating in the western U.S. These reconstructions are currently being used by water managers to assess the reliability of water supply systems under a broader range of conditions than indicated by the gage records alone.

[1]  J. Michaelsen.  Cross-Validation in Statistical Climate Forecast Models , 1987 .

[2]  Malcolm K. Hughes,et al.  SACRAMENTO RIVER FLOW RECONSTRUCTED TO A.D. 869 FROM TREE RINGS 1 , 2001 .

[3]  Edward R. Cook,et al.  Paleoclimatic Analogs to Twentieth-Century Moisture Regimes Across the United States , 2003 .

[4]  Harold C. Fritts,et al.  The International Tree-Ring Data Bank: an enhanced global database serving the global scientific community , 1997 .

[5]  Daniel R. Cayan,et al.  Interannual Climate Variability and Snowpack in the Western United States , 1996 .

[6]  Harold C. Fritts,et al.  Tree Rings and Climate. , 1978 .

[7]  Ghita Ionescu.  Lukás , 1970 .

[8]  C. Woodhouse.  A TREE‐RING RECONSTRUCTION OF STREAMFLOW FOR THE COLORADO FRONT RANGE 1 , 2001 .

[9]  Edward R. Cook,et al.  A time series analysis approach to tree-ring standardization , 1985 .

[10]  G. Müller,et al.  The Scientific Basis , 1995 .

[11]  M. Dettinger,et al.  Changes in Snowmelt Runoff Timing in Western North America under a `Business as Usual' Climate Change Scenario , 2004 .

[12]  M. Dettinger,et al.  Large-Scale Atmospheric Forcing of Recent Trends toward Early Snowmelt Runoff in California , 1995 .

[13]  Peter M. Brown,et al.  DROUGHT IN THE WESTERN GREAT PLAINS , 1845 – 56 Impacts and Implications , 2022 .

[14]  J. King,et al.  Upper Yellowstone River Flow and Teleconnections with Pacific Basin Climate Variability during the Past Three Centuries , 2003 .

[15]  E. West.  The Way to the West: Essays on the Central Plains , 1997 .

[16]  D. Lettenmaier,et al.  The Effects of Climate Change on the Hydrology and Water Resources of the Colorado River Basin , 2004 .

[17]  J. Houghton,et al.  Climate change 2001 : the scientific basis , 2001 .

[18]  D. Easterling,et al.  The twentieth‐century pluvial in the western United States , 2005 .

[19]  Charles W. Stockton,et al.  Reconstructed Stream Flow for the Salt and Verde Rivers From Tree‐Ring Data , 1981 .

[20]  D. Meko,et al.  TREE-RING RECONSTRUCTION OF UPPER GILA RWER DISCHARGE1 , 1995 .

[21]  T. Wigley,et al.  On the Average Value of Correlated Time Series, with Applications in Dendroclimatology and Hydrometeorology , 1984 .

[22]  M. Stokes,et al.  An Introduction to Tree-Ring Dating , 1996 .

[23]  Daniel R. Cayan,et al.  Climatic Fluctuations and the Timing of West Coast Streamflow , 1992 .

[24]  E. Cook,et al.  Methods of Dendrochronology - Applications in the Environmental Sciences , 1991 .

[25]  Lewis,et al.  Water and Climate in the Western United States , 2006 .

[26]  K. Trenberth,et al.  Modern Global Climate Change , 2003, Science.

[27]  E. Cook,et al.  Drought Reconstructions for the Continental United States , 1999 .

[28]  M. Dettinger,et al.  Changes in the Onset of Spring in the Western United States , 2001 .

[29]  Robert Tibshirani,et al.  An Introduction to the Bootstrap , 1994 .

[30]  Martyn P. Clark,et al.  Historical effects of El Nino and La Nina events on the seasonal evolution of the montane snowpack in the Columbia and Colorado River Basins , 2001 .

[31]  Warren M. Washington,et al.  The Effects of Climate Change on Water Resources in the West: Introduction and Overview , 2004 .