基于非平稳GEV模型的雅鲁藏布江流域极端温度事件风险归因研究  

Study on Risk Attribution of Extreme Temperature Events in the Yarlung Zangbo River Basin Based on Nonstationary GEV Models

作　　者：韩清禹 刘伟 刘标胤 张勇 陈洁杰 吴永震 HAN Qingyu;LIU Wei;LIU Biaoyin;ZHANG Yong;CHEN Jiejie;WU Yongzhen(Huaneng Tibet Yarlung Zangbo Hydropower Development Investment Co.,Ltd.,Lhasa 850000,China)

机构地区：[1]华能西藏雅鲁藏布江水电开发投资有限公司,西藏拉萨850000

出　　处：《水文》2024年第5期106-112,共7页Journal of China Hydrology

摘　　要：气候变化和人类活动背景下雅鲁藏布江流域水文气象极值序列趋势性引发的非平稳特征影响了极值风险的时程演进特征。通过将人类活动、气候变化相关的物理驱动因子作为模型参数的协变量,构建动态的广义极值分布(GEV)模型,以雅鲁藏布江流域的极端日高温和低温序列为研究对象,定量评估以城市化为代表的人类活动因子和气候变化因子对于流域内极端高温和低温事件发生风险的影响。基于一种分步优化模型优选策略,很大程度上简化了最优非平稳GEV模型的优选过程。提出一种基于线性回归的斜率比较法实现了对人类活动和气候变化与极端温度事件风险的响应关系的归因与剥离。分析结果表明:雅鲁藏布江流域极端高温和极端低温序列呈现出5%显著水平的上升趋势。城市化为代表的人类活动对于该流域的极端高温事件发生风险产生了一定的弱化作用,气候变化相关的因子尤其是全球增温和局部增温效应是极端高温风险不断增加的主要驱动因素。Under the background of climate change and human activities,the non-stationary characteristics caused by the trend of hydrometeorological extreme value series in the the Yarlung Zangbo River Basin has imposed impact on the time-varying evolution characteristics of risk of extremes.This study constructed a dynamic generalized extreme value distribution(GEV) model by taking the physical driving factors related to human activities and climate change as the covariates of model parameters.Taking the extreme daily high temperature and low temperature series of the Yarlung Zangbo River Basin as the research object,this study quantitatively evaluated the impact of human activities and climate change factors represented by urbanization on the risk of extreme high temperature and low temperature events in the basin.Based on a phase-wise model optimization strategy,the optimization process of the optimal non-stationary GEV model was greatly simplified.This study proposed a slope comparison method based on linear regression to achieve attribution and stripping of the response relationship between human activities,climate change,and extreme temperature event risk.The analysis results show that the extreme high temperature and extreme low temperature sequences in Yarlung Zangbo River show a significant upward trend of 5%.The human activities represented by urbanization have brought a certain degree of mitigation to the risks posed by extreme high temperature events in the watershed.Climate change related factors,especially global warming and local warming effects,are the main driving factors for the continuous increase of extreme high temperature risks.

关 键 词：广义极值分布 非平稳 频率分析 极值事件 雅鲁藏布江 

分 类 号：P33[天文地球—水文科学] TV11[水利工程—水文学及水资源]