清水江流域近60a降水变化特征分析

Analysis of Precipitation Variation Characteristics in Qingshui River Basin in Recent 60 Years

摘要: 通过对清水江流域内11个国家级气象站1962~2021年近60a降水气象资料，采用M-K突变检验、小波分析等方法对年降水量和汛期降水量进行时空变化特征分析，得出清水江流域多年平均降水量为1235.2 mm，降水量主要集中在汛期4~9月，占年降水量的74.9%。多雨区位于流域上游和下游，少雨区位于中游。汛期4~9月降水量各月分布不均，6月份最多，9月份最少。近60a年平均降水量和汛期降水量变化趋势不显著，存在减少和增加交替趋势，没有发生突变。年降水量和汛期降水量周期及振荡时间尺度基本一致，主要存在15~35a和2~3a的准周期，降水量存在少–多–少–多–少–多3次少多交替振荡的周期变化过程，比较显著的周期为24a和2a。

Abstract: Based on the precipitation data of the 11 basic weather station in Qingshui River Basin form 1962 to 2021, the M-K mutation test and wavelet analysis were used to analyze the temporal and spatial variation characteristics of annual precipitation and flood season precipitation. The results show that the average annual precipitation in the Qingshui River Basin is 1235.2 mm, and the precipitation is mainly concentrated in the flood season from April to September, accounting for 74.9% of the annual precipitation. The rainy areas are located in the upstream and downstream of the basin, and the less rain areas are located in the midstream. Precipitation is unevenly distributed from April to September in flood season, with the maximum in June and the minimum in September. In the past 60 years, the variation trend of annual average precipitation and flood season precipitation was not significant, and there was an alternating trend of decrease and increase, without mutation. The period and oscillation time scale of annual precipitation and precipitation in flood season are basically the same, and there are mainly quasi-periods of 15~35a and 2~3a. The precipitation has a periodic variation process of less-more-less-more-less-more three times less-more alternating oscillation, and the relatively significant periods are 24a and 2a.