平坝区近61年汛期降水特征分析

An Analysis of the Characteristics of Precipitation for the Past Sixty-One Years in Pingba District

摘要: 利用1961~2021年平坝区逐月降水资料，采用趋势分析、线性回归、滑动平均、Morlet小波分析等方法分析了平坝区近61年各月降水和汛期(5~9月)降水变化特征。结果表明：平坝区年降水量的变异系数为17%，但是不同月份的降水量变异系数差异较大，近61年来平坝区汛期5月份降水量分布比较均匀，6~8月份降水量分布比较分散，其中9月份降水量最为分散。汛期降水总体呈上升趋势，且近61年来汛期降水基本集中在5、6、7月。在汛期5个月中，除5月、8月的平均降水量呈减少趋势外，其余各月均呈上升趋势。汛期降水周期性变化明显，存在着一个长周期22~24年的和10年以下的短周期，10年以下的短周期强度要明显低于长周期活动强度。

Abstract: Based on the monthly precipitation data of Pingba area from 1961 to 2021, the variation characteristics of monthly precipitation and flood season (May to September) precipitation in Pingba area in the past sixty-one years are analyzed by means of trend analysis, linear regression, moving average and Morlet wavelet analysis. The results show that the variation coefficient of the annual precipitation in Pingba district is 17%, but the variation coefficient of the precipitation in different months is quite different. In the past sixty-one years, the precipitation in May of the flood season in Pingba district is relatively uniform, and the precipitation in June to August is relatively scattered, of which the precipitation in September is the most dispersed. The precipitation in the flood season generally shows an upward trend, and the precipitation in the flood season in the past sixty-one years is mainly concentrated in May, June and July. In the five months of the flood season, the average precipitation in May and August showed a decreasing trend, while the average precipitation in other months showed an increasing trend. The periodic change of precipitation in flood season is obvious. There is a long period of 22~24 years and a short period of less than 10 years. The intensity of short period of less than 10 years is significantly lower than that of long period.