1961-2017年成都市降水变化特征分析

本文选取1961—2017年成都市月降水量数据,利用线性回归分析、Mann-Kendall突变分析和EEMD周期分析等数理统计方法,研究了成都市近57年降水量的变化特征,为其水资源检测、评估和气象灾害防治提供一定的理论依据和基础。结果表明,成都市近57年平均年降水量为892.6 mm,呈逐渐下降的趋势且无突变现象发生,以3年和5年的年际周期振荡变化为主。降水主要集中在夏、秋两季,累计降水量超过年降水量的80%,其中夏季降水量呈减少趋势,不存在突变,包含2年和7年的周期;秋季降水量存在2个突变点,变化周期以准3年和11年为主。春季降水量占全年降水量的16%,有多个突变点,存在2年和9年的周期。冬季降水量仅占3%,呈缓慢上升趋势,存在多个突变点,周期为2年和准6年。

Precipitation Change Trends and Characteristics of Chengdu in 1961-2017

Based on the precipitation data of Chengdu from 1961 to 2017, the characteristics of the change were analyzed by linear regression analysis, Mann-Kendall rank statistic method and EEMD analysis. Its results provide some theoretical foundation for the detection, evaluation and meteorological disaster of water resources. The results show that the average annual precipitation in Chengdu was 892.6mm in the past 57 years, and it exhibited a decreasing trend with no mutation. And the inter-annual oscillations were 3year and 5year. Precipitation was concentrated in summer and autumn with the cumulative precipitation accounting for more than 80%. The summer precipitation was in a decreasing trend with no mutation , containing the periods of 2year and 7year. The precipitation had two mutation points in autumn, and the periodic change were mainly the inter-annual oscillations of quasi 3year and 11year. The spring precipitation accounted for 16% of the annual precipitation with the periods of 2year and 9year, and mutation occurred in 1973. The winter precipitation only accounted for 3%, exhibiting a slow increasing trend with multiple mutation points. And the oscillations periods were 2year and quasi 6year.