半干旱草原内陆河流域复合干热气候特征及其植被响应  

Characteristics of Compound Dry-Heat Events and the Vegetation Responses in an Inland River Basin of a Semi-arid Steppe

作　　者：张仪萱 王怡璇 刘廷玺[1,2,3] 段利民 时淑悦[1] 刘婷 ZHANG Yixuan;WANG Yixuan;LIU Tingxi;DUAN Limin;SHI Shuyue;LIU Ting(The College of Water Conservancy and Civil Engineering,Inner Mongolia Agricultural University,Hohhot 010018,China;Inner Mongolia Key Laboratory of Ecohydrology and High-Efficient Utilization of Water Resources,Hohhot 010018,China;Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reaches of the Yellow River,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,内蒙古呼和浩特010018 [2]内蒙古自治区生态水文与水资源高效利用重点实验室,内蒙古呼和浩特010018 [3]黄河流域内蒙古段水资源与水环境综合治理协同创新中心,内蒙古呼和浩特010018

出　　处：《中国草地学报》2025年第2期8-20,共13页Chinese Journal of Grassland

基　　金：国家自然科学基金项目(51939006,52269005,U23A-2001);内蒙古自治区高校青年科技英才项目(NJYT 22037);内蒙古农业大学青年教师科研能力提升专项(BR220104);教育部创新团队发展计划项目(IRT17R60);科技部重点领域科技创新团队项目(2015RA4013);内蒙古自治区科技领军人才团队项目(2022LJRCO007);内蒙古自治区教育厅一流学科科研专项项目(YLXKZX-NND-010)。

摘　　要：随着全球气候变化的加剧,复合干热事件的发生频率明显增加,对植物生长和生态系统造成了显著影响。评估复合干热事件的严重程度,并探究植被对其的响应关系,有利于深化对极端气候事件潜在危害的认识并制定有效的缓解和适应措施。本文基于Copula函数联合标准化降水指数(Standardized precipitation index,SPI)和标准化温度指数(Standardized temperature index,STI),构建了标准化复合干热事件指数(Standardized composite dry-heat index,SCDHI),分析了锡林河流域1982—2020年植被快速生长期(6—8月)干旱和高温的变化特征,探究了流域复合干热事件的演变规律及植被响应。结果表明:Frank-Copula函数对SPI与STI联合分布的拟合效果最优,SCDHI可以模拟干旱和高温间的依赖关系,具有标准化干旱指数所具备的多尺度时空可比、统计意义明确等特点;流域旱情的逐年变化较为平稳,而高温事件呈显著持续上升趋势,流域气候总体呈暖干化特征,复合干热事件在7、8月有轻微加重的趋势;发生干热事件(SPI<-1.0且STI>1.0)的同现重现期约为10年;此外,植被对极端气候的敏感性与生长阶段有关,处于稳定生长期的植被对气候变化的抵抗力较高。With the rapid climate change,the occurrence of compound dry-heat events has increased,leading to significant impacts on plant growth and ecosystem.Therefore,assessing the severity of compound dry-heat events and its impacts on vegetation growth are crucial for understanding the hazards of extreme climate and for developing effective mitigation and adaptation strategies.In this study,the Copula function was used to propose the standardized compound dry-heat events index(SCDHI)based on the cumulative joint probability of the standardized precipitation index(SPI)and the standardized temperature index(STI).Evolution of the compound dry-heat events and corresponding vegetation responses in Xilin river basin were investigated based on the analysis of drought and high temperature dynamics during rapid growth stages(June to August)from 1982 to 2020.The results showed that the Frank-Copula was the most appropriate distribution function for combining SPI and STI.The SCDHI was well-fitted for quantifying the dependency of drought and high temperatures when displaying multi-scale spatiotemporal comparability and clear statistical significances.Changes of the drought conditions in the basin maintained basically stationary,while the high temperature events showed a significant upward trend.The climate of the basin generally tended to be warming and drying,with a slight aggravation of compound dry-heat events in July and August.The cooccurrence return period of the dry-heat events defined as SPI<−1.0 and STI>1.0 was about 10 years.Moreover,the sensitivity of vegetation to extreme climate conditions was closely related to the growth stage.Grassland vegetation had higher resistance to climate change in stable growth stage.

关 键 词：干旱 高温 复合事件 COPULA函数 草原植被 内陆河流域 

分 类 号：S812[农业科学—草业科学]