中文摘要：

利用时空统计技术,对早期根据历史文献中旱涝状况描述而重建的过去1000年干湿变化数据进行插补,建立了相对完整的关中平原过去1000年旱涝等级数据集;在此基础上辨识了关中平原干湿变化的阶段性特征和极端事件;并通过对重建序列进行小波分析和集合经验模态分解的手段,检测了干湿变化的年际-年代际-百年际尺度的周期,进而统计诊断了周期特征与气候驱动因子的关系.结果表明：过去1000年关中平原的干湿变化主要分为3个阶段,960～1150年气候由湿转干,1151～1800年气候由干转湿,1801年以后气候再次由湿转干;17世纪和19～20世纪是极端旱涝事件的频发期,约每2年发生一次.关中平原的干湿变化具有3～7 a的年际变化周期,准10 a,准30 a和准70 a的年代际变化周期,以及100 a尺度的世纪周期.El Ni？o事件发生的当年或者第2年,关中平原气候偏干;太平洋年代际振荡与干湿变化在1435年之前呈正相关,之后则呈反相关关系;太阳活动的极大期与气候干旱相对应.

英文摘要：

In this study, spatial-temporal statistical technologies were utilized to interpolate a dryness and wetness grade dataset, which was reconstructed from previous Chinese historical documents, but with significant data gaps in the past 1000 years, and a complete grade dataset of dryness and wetness was developed for Guanzhong Plain including seven sites at Linfen, Changzhi, Xi＇an, Fengxiang, Luoyang, Nanyang and Hanzhong. The probit model was used to interpolate the missing values at the spatial scale depending on the highest variance explanation between neighbouring stations, and the Markov chain model was used to interpolate the temporal series depending on the known features of the dataset from 1470 to 2010. On the basis of this dataset, long-term variation features and extreme drought and flood events in the Guanzhong Plain were identified. By means of wavelet analysis and ensemble empirical mode decomposition methods, the main cycles of interannual-interdecadal-centennial scales of dryness and wetness variations were detected and the relationships between periodicity and driving forces were analyzed. Results indicated that the dry-wet change of the Guanzhong Plain has had three stages in the past 1000 years, that is, the climate changed from wet to dry in 960–1150, then from dry to wet in 1151–1800, and again from wet to dry after 1801. On the half-centennial time scale, five wet periods in 960–1000, 1151–1200, 1251–1300, 1351–1400 and 1651–1900, and five dry periods in 1001–1150, 1201–1250, 1301–1350, 1401–1650 and after 1901 were identified. Extreme drought and flood events occurred with high frequency in the 17 th and 19th–20th centuries, about once every two years. Extreme drought events lasting 5 years occurred in 1070–1089, 1212–1216, 1327–1331, 1431–1445, 1481–1491, 1634–1641, 1688–1692, 1714–1722, 1875–1878, 1925–1931 and 1993–1997. Extreme flood events lasting 5 years occurred in 981–985, 1647–1653, 1658–1664, 1676–1680, 1725–1730, 1848–1854