SACRAMENTO RIVER FLOW RECONSTRUCTED TO A.D. 869 FROM TREE RINGS¹

Abstract

A time series of annual flow of the Sacramento River, California, is reconstructed to A.D. 869 from tree rings for a long‐term perspective on hydrologic drought. Reconstructions derived by principal components regression of flow on time‐varying subsets of tree‐ring chronologies account for 64 to 81 percent of the flow variance in the 1906 to 1977 calibration period. A Monte Carlo analysis of reconstructed n‐year running means indicates that the gaged record contains examples of drought extremes for averaging periods of perhaps = 6 to 10 years, but not for longer and shorter averaging periods. For example, the estimated probability approaches 1.0 that the flow in A.D. 1580 was lower than the lowest single‐year gaged flow. The tree‐ring record also suggests that persistently high or low flows over 50‐year periods characterize some parts of the long‐term flow history. The results should contribute to sensible water resources planning for the Sacramento Basin and to the methodology of incorporating tree‐ring data in the assessment of the probability of hydrologic drought.

Holocene multidecadal and multicentennial droughts affecting Northern California and Nevada

“…To test Dd 18 O=Dt as an indicator of change in the hydrologic balance, we compared the lake-based drought time series with a tree-ring-based reconstruction of river discharge from the western flank of the northern Sierra Nevada and with ages of stumps of trees that had (Meko et al, 1999); solid areas indicate drought periods. D. Ages of tree stumps killed by rising lake waters (Lawrence and Lawrence, 1961, Stine 1990.…”

“…Vertical dashed lines indicate droughts that impacted more than one region. Northern Sierra discharge reconstruction from Meko et al (1998); southern Sierra precipitation reconstruction from Graumlich (1993); and northwestern New Mexico precipitation reconstruction from Grissino-Mayer (1996). illustrate such a negative excursion in d 18 O.…”

“…1) spawned renewed interest in the history and prehistory of such events. Recent tree-ring reconstructions, employing sophisticated statistical calibrations, have extended Sierra Nevada and Great Basin precipitation and discharge records back more than a 1000 yr (Graumlich, 1993;Hughes and Funkhouser, 1998;Meko et al, 1999) and AMS 14 C studies of stumps from Sierran lakes have highlighted severe droughts that terminated about 840 and 600 cal yr BP (Stine 1990(Stine , 1994.…”

A tree-ring-based reconstruction of the Yimin River annual runoff in the Hulun Buir region, Inner Mongolia, for the past 135 years

“…Similar responses are shown by the relationship between the annual runoff of the Yimin River and maximum temperature and seasonal/annual precipitation, as well as by the relationship between the regional tree-ring width chronology and these climatic factors (Table 2). For instance, the correlation coefficients associated with the April-September mean maximum temperature (T 4-9(max) ), the seasonal precipitation for April-September (P [4][5][6][7][8][9] ) and the annual precipitation from the previous August to the current July (P 8-7 ) were -0.406, 0.64 and 0.669, respectively, for the annual runoff of the Yimin River and -0.465, 0.381 and 0.619, respectively, for the RC. The similar correlation coefficients associated with P 4-9 (0.64) and calendar-year annual precipitation (P ann ) (0.674) for the annual runoff of the Yimin River indicated that the Yimin River annual runoff was dominated by the summer rainfall (one-half of the year) [28].…”

“…The statistical relationship between tree-ring index data and the hydroclimatic records of variables such as runoff and streamflow has been exploited to construct reconstructions that are hundreds of years in length for many parts of the world [5][6][7][8][9][10].…”