淮河流域极端气候事件非平稳特征研究

Non-stationary Characteristics of Extreme Climate Events:A Case Study of Huaihe River Basin

气候变化和人类活动导致极端气候事件呈现非平稳性,传统的平稳性分析方法已不能正确揭示气候极值的真实时空分布规律。利用淮河流域1960-2018年日值气温和降水数据,对极端气候事件指数平稳性特征进行判定,采用非平稳广义极值分布(GEV)和广义帕累托分布(GPD)解读极端气候事件的空间分布特征。主要结果为:①低温极值中,超门限最低气温(Tmingpd)和1日最低气温(Tnn)表现出显著增加趋势,变化幅度分别为0.16 d/a和0.04℃/a。超门限最高气温(Tmaxgpd)、1日最高气温(Txx)、超门限降水(Pregpd)和1日最大降水量(Rx1day)均表现为不显著变化;②不同的平稳性检验方法会导致气候极值序列存在一定的平稳性差异,总体上Tmingpd和Tnn在淮河流域表现为非平稳性,Pregpd和Rx1day表现为平稳性,Tmaxgpd和Txx表现相对复杂,平稳性和非平稳性同时存在;③低温极值(Tnn、Tmingpd)30年重现水平从南向北变化,反应纬度地带性规律;高温极值(Txx、Tmaxgpd)从东部向西部减少,反应海洋对陆地气温的调节作用;降水极值(Rx1day、Pregpd)30年重现水平从东南向西北递降,反应东亚季风的逐步减弱。该研究可以进一步提高对极端气候事件时空规律的科学认识,为流域水资源管理和区域防灾减灾提供科学依据与理论支撑。

Climate change and human activities have caused extreme climate events to be non-stationary,and traditional stationarity analysis is unable to correctly reveal the true spatiotemporal variability.The daily temperature and precipitation data of 1960-2018 from 70 stations is used to calculate climate extremes commonly used in the Huaihe River Basin.Additionally,the non-stationary generalized extreme value distribution(GEV)and generalized Pareto distribution(GPD)model are used to interpret spatial distribution of return level.The main results are as follows:①The low temperature extremes(Tmingpd and Tnn)shows a significant increasing trend,with a change magnitudes of 0.16 d/a and 0.04℃/a,respectively.Other climate extremes(Tmaxgpd,Txx,Pregpd and Rx1day)all show no significant changes.②Different stationarity test will lead to a certain difference in stationarity results for a time series.In general,Tmingpd and Tnn are non-stationary,Preggpd and Rx1day are stationary,and Tmaxgpd and Txx are relatively complex with stationary and non-stationarity exist at the same time in the Huaihe River Basin;③ The 30-year return level of low temperature extremes(Tnn,Tmingpd)change from south to north,reflectingthe influence of latitude zonality. The high temperature extremes(Txx,Tmaxgpd)decreases from the east to the west,reflecting the thermalregulation of the ocean. The precipitation extremes(Rx1day,Pregpd)gradually decrease from southeast to northwest,reflecting the gradualweakening of the East Asian monsoon. The research can further improve the scientific understanding of the spatial and temporal distributionof extreme climate events,and provide scientific basis and theoretical support for water resources management and regional disaster preventionand mitigation in the Huaihe River Basin.