1736年以来南京逐季降水量的重建及变化特征

基于清代雨雪档案和现代气象观测资料,利用自然降水入渗试验结果及雨雪分寸与降水量统计关系,重建南京1736~2006年逐季和年降水量。分析显示:(1) 18世纪春、冬季为多雨期,秋季为少雨期;19世纪秋、冬季和全年为多雨期,春季为少雨期;20世纪上半叶,4季和全年均为少雨期;自20世纪末期始夏季和全年进入多雨期。(2) 年降水变化存在2~5 a周期,经历1851~1860年和1893~1894年两次突变。研究结果与区域内其他旱涝等级或降水量序列有较好可比性。绝大多数粮食欠收年对应于降水异常年,生长期为干旱异常的欠收年数量多于为洪涝异常的欠收年。

Reconstruction and Analysis of Seasonal Precipitation in Nanjing Since 1736

Based on the Yu-Xue-Fen-Cun (ancient rainfall and sownfall data) archives in the Qing Dynasty and modern meteorological observations, this paper reconstructed seasonal and annual precipitation from 1736 to 2006 in Nanjing. The conclusions indicated: (1) In the 18th century, Nanjing received more precipitation during the spring and winter, while the autumn was in less precipitation period. In the 19th century, the autumn, winter and annual precipitation was relatively more, while the spring was in less precipitation period. During the first half of the 20th century, there was relatively less precipitation in all seasons. From the end of the 20th century on, the summer and annual turned into rainy period. (2) The annual precipitation had 2-5 yr cycles and abrupt changes during 1851-1860 and 1893-1894. These reconstructions were well consistent with other drought/flood or precipitation series in the region. Moreover, most of poor harvests occurred in the abnormal precipitation years, in which the proportion of years with less precipitation was higher.