资源环境科技发展态势分析平台

A reconstruction of annual to multi-decadal precipitation based on ring-width of Cedrus deodara (Himalayan cedar or deodar) was carried out in the Lidder (Liddar) Valley, Kashmir Himalaya. A composite tree-ring chronology demonstrated a significant direct relationship with April-June precipitation. A modified version of point-by-point regression methodology was used to reconstruct April-June precipitation since 1723 C.E. This reconstruction accounts for 40% of the total variance of the actual precipitation in the calibration period. The reconstruction shows a prolonged decadal dry period between 1822 and 1887 C.E., the driest period in the reconstruction. The wettest period occurred during the early 19th century and latter part of the 20th century. Extreme dry and wet events have been identified in the reconstruction on the basis of percentile distribution. The reconstruction was compared with documented extreme flood, famines and drought events in Kashmir Valley occurring in those 288 years. The composite 500 mb height-anomaly maps suggest the prospect to study the long-term atmospheric circulation variability over the Kashmir Valley and surrounding region using tree-ring data. The impact of westerlies in the precipitation patterns was also evident in analysis of composite 500 mb height anomaly. Furthermore, the reconstruction was validated through comparison with independent records and spatial correlation with gridded precipitation and drought.