Annual streamflow of Jinghe River basin in northern slope of Tianshan Mountains recorded by tree-ring during 1615—2007

Tree-ring width from northern slopes of Tianshan Mountains is of great potential for hydroclimate reconstruction. Tree-ring width data of Picea schrenkiana from two sites which are located at Jinghe River basin were collected and developed into tree-ring width chronologies. Correlation analysis between tree-ring width index and hydrometeorological factors indicates the potential of tree ring width for streamflow reconstruction, and the coefficient between tree-ring width standard chronology and streamflow from last September to current August in Jinghe River hydrological station is 0.612. A linear transfer function is established to reconstruct the annual streamflow during 1615—2007. There are 7 flood years and 11 drought years, and 13 consistent periods and 10 consistent periods during 1615—2007. Multi-taper method (MTM) spectral analysis revealed the cycles of 56.8 a, 6.9 a, 3.8 a, 3.4 a, 2.0—2.1 a above the 99% confidence level. The cycle of 6.9 a, which is accordant with ENSO, indicated the possible influence of large scale ocean-atmosphere pattern on the regional hydroclimate. Furthermore, the significant negative association (P<0.05) between Souther Oscillation Index (SOI) and reconstructed hydrological series also proved this teleconnection pattern. The drought and flood period in Jinghe River is well corresponding with that in Manasi River and Urumqi River, and the wet and dry period in Tianshan Mountains area and Yili region, which indicated the consistency of large-scale circulation background and driving climatic factors of hydroclimate change in northern slopes of Tianshan Mountains.