海河流域近现代降水量变化若干特征

Characteristics of precipitation variations in Haihe River Basin in modern times

根据器测资料、代用资料和文献资料,综合分析海河流域1956 年以来、1880 年以来和1736年以来降水量变化的主要特征,探讨影响降水多年代尺度变化的可能机制.结果表明：淤海河流域平均年降水量距平百分率在1956-2013 年表现出较明显下降趋势,每10 a 下降速率为2郾6%,但在1880-2012 年期间下降趋势很弱;于1736-2012 年,海河流域平均年降水量距平百分率未表现出任何长期趋势变化,1956 年以来和1880 年以来的趋势性减少现象也不再显得异常,但存在-系列年代到多年代尺度振动;盂20 世纪40 年代后期到60 年代早期是1736 年以来最湿润阶段,但20世纪初以来几次持续性干旱,包括1997-2003 年的严重干旱,在1736 年以来历史上并非罕见,1826-1843 年曾出现持续时间最长的严重干旱;榆海河流域平均年降水量具有准周期性振动特点,较明显的准周期包括2 -7 a、11 a、22 -23 a、33 a 和63-65 a;虞20 世纪60 年代后期以来海河流域降水的趋势性减少,是区域气候63 -65a 自然低频周期性振动的组成部分,预计未来几十年整个流域降水量总体上将呈增多趋势,并可能在2035-2040 年达到峰值区间.

Based on observed data, substitutive data, and scientific literature, this paper analyzes the main characteristics of precipitation variations over the last 60 years, 130 years, and 280 years and discusses the possible mechanism influencing precipitation variations on multi-decadal scales. Results showed the following: ( 1 ) The average annual precipitation anomaly percentage in the Haihe River Basin exhibited a decreasing trend during the period from 1956 to 2013, with a rate of decrease of 2.6% per 10 years, but the decreasing trend was weak during the period from 1880 to 2012. (2) During the period from 1736 to 2012, the average annual precipitation anomaly percentage in the Haihe River Basin did not show a significant long-term trend. A reduction in the trend of the average annual precipitation anomaly percentage in the Haihe River Basin appears to be a normal, but the fluctuation still existed on decadal and multi-decadal scales. (3) The period from the late 1940s to the early 1960s had the wettest climate conditions of the last 280 years. There have been several periods of persistent drought since the beginning of the 20th century, including the severe one, which has not been rare over the last 280 years, during the period from 1997 to 2003. The longest period of severe drought occurred from 1826 to 1843. (4) The average annual precipitation in the Haihe River Basin showed a characteristic of quasi-periodical fluctuation, and the relatively significant quasi-periods of fluctuation were 2 to 7 years, 11 years, 22 to 23 years, 33 years, and 63 to 65 years. (5) The reduction in the tendency of the precipitation in the Haihe River Basin after 1960s was a component of the natural low-frequency periodical fluctuation over 63 to 65 years in the regional climate. It is predicted that the annual precipitation in the Haihe River basin will increase over the next few decades, and it will probably reach its peak value during the period from 2035 to 2040.