1951—2017年松花江流域连续性极端降水事件时间趋势特征分析

连续性极端降水事件是松花江流域洪涝灾害的重要原因.基于1951—2017年松花江流域41个气象站点降水数据,采用泊松回归方法进行时间趋势分析.结果表明:松花江流域连续性极端降水事件在第90百分位阈值下、第99百分位阈值下一次回归结果显著,呈现增加趋势,指数化系数为1.006841、1.037159;3个子流域在不同百分比阈值下通过检验,均呈现出增加趋势,松花江干流流域在第99百分位阈值下一次回归结果显著,指数化系数为1.050931,嫩江流域在第90百分位阈值下、第95百分位阈值下一次回归结果显著,指数化系数为1.0050186233、1.0058413365,第二松花江流域在第95百分位阈值下一次回归结果显著,指数化系数为1.007653;各站点回归结果差异较大,第90百分位阈值下9个站点通过检验,趋势特征为:4个站点增加,4个站点减少,1个站点先减少后增加,第95百分位阈值下7个站点通过检验,趋势特征为:2个站点增加,3个站点减少,1个站点先减少后增加,1个站点先增加后减少,第99百分位阈值下仅有1个站点通过检验,呈现增加的趋势.

Time Trend Analysis of Continuous Extreme Precipitation Events in Songhua River Basin from 1951 to 2017

Continuous extreme precipitation event is an important reason for the flood disaster in Songhua River Basin. Based on the precipitation data of 41 meteorological stations in the Songhua River Basin from 1951 to 2017, the Poisson regression method was used to analyze the time trend. The results show that the regression results of Songhua River Basin under the 90th percentile threshold and the 99th percentile threshold are significant, showing an increasing trend, and the indexation coefficient is 1.006841 and 1.037159; the three sub basins pass the test under different percentile thresholds, showing an increasing trend, and the main stream basin of Songhua River has a significant regression results under the 99th percentile threshold, and the indexation coefficient is 1.050931, the regression results of Nenjiang River Basin under the 90th percentile threshold and 95th percentile threshold are significant, the indexation coefficient is 1.0050186233 and 1.0058413365, and the regression results of the second Songhua River Basin under the 95th percentile threshold are significant, the indexation coefficient is 1.007653; the regression results of each station are significant, and 9 stations under the 90th percentile threshold pass the test, the trend features are: 4 sites increased, 4 sites decreased, 1 site decreased first and then increased, 7 sites passed the test under the 95th percentile threshold, the trend features are: 2 sites increased, 3 sites decreased, 1 site decreased first and then increased, 1 site increased and then decreased, only 1 site passed the test under the 95th percentile threshold, showing an increasing trend.