松花江流域极端气象水文要素分析

Analysis of Extreme Meteorological and Hydrological Elements in Songhua River Basin

利用松花江流域1961—2018年逐日降水及逐日径流数据资料,基于11个极端降水指标和5个极端径流指标,采用趋势分析法、Mann-kendall非参数检验方法、Mann-kendall突变检验法、克里金插值法、皮尔逊相关系数等方法分析了松花江流域极端降水及极端径流事件的变化特征、地区性差异和规律,同时分析了极端降水和极端径流事件间的关联性。结果表明:除持续干期指数(Consecutive dry days,CDD)和降水强度指数(Simple daily intensity index,SDII)外,其余指数多年平均值均呈现出第二松花江流域为高值区,松花江干流流域次之,嫩江流域为低值区,各极端降水指数的空间趋势分布和突变年份也体现出区域差异性;各极端径流指数的变化趋势和突变年份分别相近,且都呈微弱变化趋势;在不同时间尺度下,极端降水与极端径流事件的相关系数均通过99%显著性检验,由于松花江流域汇流速度较慢,当时间尺度为30天时极端降水与极端径流事件表现出最为显著的关联性。

Using the daily precipitation and daily runoff data in the songhua river basin during 1961~2018,based on the 11 extreme precipitation index and five extreme runoff indicators,taking the trend analysis method,Mann-Kendall nonparametric test methods,Mann-Kendall mutation test,kriging interpolation method,Pearson correlation coefficient and other methods,this paper analyzed the change characteristics and regional differences of extreme precipitation and extreme runoff events in songhua river basin and,at the same time,analyzed the correlation between the extreme precipitation and extreme runoff events.The results show that,except the CDD and SDII indexes in the continuous dry period,the perennial average values of the other indexes all show that the songhua River basin is the high-value region,the songhua River main stream basin is the second-highest value region,and the Nenjiang River basin is the low-value region.The spatial trend distribution and abrupt transition years of each extreme precipitation index also reflect regional differences.The variation trend of each extreme runoff index was similar to that of the abrupt change year,and all showed a slight variation trend.Under different time scales,the correlation coefficients of extreme precipitation and extreme runoff events all passed the 99%significance test.Due to the slow confluence of the Songhua River Basin,extreme precipitation and extreme runoff events show the most significant correlation when the time scale is 30 days.