CR 68:49-58 (2016)  -  DOI: https://doi.org/10.3354/cr01368

ABSTRACT: In most cases, precipitation and drought records in central Asia extend only a few decades, hampering the detection of long-term decadal- to centennial-scale cycles and trends. However, long-term precipitation and drought series can be developed using tree-ring data, which offers researchers the ability to extend limited instrumental precipitation and drought data back several centuries. Water scarcity is the primary limiting factor in the sustainable development of Urumqi, the largest city in arid central Asia. In this study, a regional tree-ring chronology from Picea schrenkiana is used to reconstruct previous July-current June total precipitation for the Urumqi region and place the gauged precipitation (1957–2008) in a long-term, multi-century context. The precipitation reconstruction explains 52.1% of the actual precipitation variance during the common period (1957–2008) and contains a strong regional drought signal for the Tien Shan region. This reconstruction successfully captured the wetting trend that occurred from the 1980s to the 2000s and generally agreed with dry periods previously estimated from tree-ring records obtained from the surrounding areas. Moreover, a wavelet coherence analysis shows that significant common oscillations (11.5 and 60 yr) have occurred and suggests that precipitation variations across the Urumqi region were related to different climatic forcing mechanisms (i.e. solar activities and the NAO). Our precipitation reconstruction provides a long-term perspective on current wet and dry events in Urumqi, helps guide expectations of future variability, aids in sustainable water resource management and provides scenarios to address climate change planning.

KEY WORDS: Dendrochronology · Annual precipitation reconstruction · Urumqi · NAO · Solar activity