کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4577295 | 1630005 | 2012 | 10 صفحه PDF | دانلود رایگان |
SummaryStreamflow variability on timescales of decades to centuries becomes increasingly important as water managers grapple with shortages imposed by increasing demand and limited supply, and possibly exacerbated by climate change.
► Two applications of dendrochronology to the study of flow variability are illustrated for an existing 1244-yr reconstruction of annual flows of the Colorado River at Lees Ferry, Arizona, USA: (1) identification and climatological interpretation of rare flow events, and (2) assessment of vulnerability of water-supply systems to climatic variability.
► Analysis centers on a sustained drought of the mid-1100s characterized by persistent low flows on both the Colorado and Sacramento Rivers.
► Analysis of geopotential height anomalies during modern joint-droughts suggests more than one mode of circulation might accompany joint-drought in the two basins.
► Monte Carlo simulation is used to demonstrate that a drought as severe as that in the 1100s on the Colorado River might be expected about once in every 4–6 centuries by chance alone given the time-series properties of the modern gaged flows. Application of a river-management model suggests a mid-1100s-style drought, were it to occur today, would drop reservoir levels in Lake Mead to dead-pool within a few decades.
► Uncertainty presents challenges to accurately quantifying severe sustained droughts from streamflow reconstructions, especially early in the tree-ring record.
► Corroboration by multiple proxy records is essential.
► Future improvements are likely to require a combination of methodological advancements and expanded basic data.
Research highlights
► The mid-1100s is a model for devastating hydrologic drought in the western US.
► Exact simulations highlight the risk of drought on the Colorado River.
► Persistent drought on the Colorado River could arise from today’s climate variability.
► Recurrence of medieval-period drought would rapidly lower Lake Mead to dead pool.
Journal: Journal of Hydrology - Volumes 412–413, 4 January 2012, Pages 200–209