近60年济南市降水量变化特征分析

Analysis on the Characteristics of Precipitation Changes in Recent 60 Years in Ji'nan City

摘要:

为查明济南市降水量变化特征和趋势，采用累积距平分析、MannKendall法、集合经验模态分解（EEMD）等方法对1956—2018年济南市降水量进行综合分析。结果表明，济南市降水量呈上升的变化趋势，倾斜率为8.35mm/10a，其中1956—1961年、1967—1972年和1981—1993年为降水偏少时期，1962—1966年、1973—1980年和1994—2018年为降水偏多时期，1961年和1990年发生过2次降水由偏少到偏多的突变，预测未来济南市降水量仍然以偏多为主；济南市降水量存在2.62a，5.73a，10.50a和36.50a的周期分量，其中5.73a分量通过了95%的置信区间检验，周期性显著，对降水量贡献率为48.73%；济南市降水量整体呈现先减少后增多的变化趋势，且后期的升高幅度小于前期的下降幅度。

Abstract:

Precipitation is an important source of spring water supply in Ji'nan city, and plays a decisive role in spring water gushing. In order to find out the characteristics and trends of precipitation change, cumulative anomaly analysis, Mann-Kendall method and ensemble empirical mode decomposition (EEMD) method are used to analyze the precipitation in Ji'nan City from 1956 to 2018. It is showed that the precipitation has an upward trend with an inclination of 8.35mm/10a. 1956—1961, 1967—1972 and 1981—1993 are the period of less precipitation, while 1962—1966, 1973—1980 and 1994—2018 are the period of more precipitation. There are two abrupt changes in precipitation from less to more in 1961 and 1990, which predict that the precipitation in Ji'nan would still be more in the future. The precipitation of Ji'nan city has periodic components of 2.62a, 5.73a, 10.50a and 36.50a，the 5.73a component passes the 95% confidence interval test, the periodicity is significant, and the contribution rate to precipitation is 48.73%. Overall, precipitation in Ji'nan city shows a trend of decreasing first and then increasing. The increasing trend in the later period is smaller than that in the previous period.