基于Copula函数的淮河流域非平稳气象干旱特征研究  

Characterization of non-stationary meteorological drought in Huaihe River Basin based on Copula function

作　　者：王易 姚蕊 孙鹏 葛晨昊 WANG Yi;YAO Rui;SUN Peng;GE Chenhao(School of Geography and Tourism,Anhui Normal University,Wuhu 241002,Anhui,China;State Key Laboratory of Earth Surface Processes and Resource Response in the Yangze-Huaihe River Basin,Anhui Normal University,Wuhu 241002,Anhui,China;Engineering Technology Research Center of Resources Environment and GIS,Anhui Normal University,Wuhu 241002,Anhui,China)

机构地区：[1]安徽师范大学地理与旅游学院,安徽芜湖241002 [2]安徽师范大学江淮流域地表过程与区域响应安徽省重点实验室,安徽芜湖241002 [3]安徽师范大学资源环境与地理信息工程安徽省工程技术研究中心,安徽芜湖241002

出　　处：《水利水电技术(中英文)》2024年第11期26-38,共13页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(42271037);安徽省重点研究与开发计划项目(2022m07020011);安徽高校协同创新项目(GXXT-2021-048);安徽省自然科学基金优青项目(2108085Y13);国家级大学生创新创业训练计划项目(202310370041,202310370042,202310370044)。

摘　　要：【目的】淮河流域干旱时空变化显著,部分地区易发生严重干旱,研究其干旱特征对于该地区的农业生产、水资源管理以及生态保护等方面都具有重要的作用。【方法】对1980—2019年淮河流域195个气象站点月非平稳的标准化降水蒸散指数(NSPEI)数据进行分析研究该地区的气象干旱,并通过游程理论识别历史干旱事件提取出干旱历时、干旱烈度,而后对干旱历时和干旱烈度依次使用用单变量函数和多变量Copula函数进行分析。【结果】结果显示:淮河流域干旱事件主要表现为轻旱和中旱,分别占干旱事件总数的39%和47%,且主要分布在流域西北部和南部,极旱事件极少。Generalized Pareto函数在对干旱历时、干旱烈度的单变量分布拟合都为最合适,87个站点显示t-Copula函数为拟合效果最好的的联合分布函数。重现期在20a以上时,干旱历时和干旱烈度的空间分布特征大致相同,高值区为流域西南部。联合重现期和同现重现期概率空间分布随着重现期增长几乎不变,同现重现期高值区主要为流域南部和西部。【结论】结果表明:淮河流域的干旱事件以月内中旱、季内轻旱和季内中旱为主,极端干旱发生频率很低;随着重现期增大,干旱历时和干旱烈度的高值区主要分布在淮河流域西南部,因此该区域的干旱灾害风险最大;联合重现期和同现重现期的空间分布特征变化不显著,当重现期为100 a时西南部会发生干旱历时可达10.8个月,干旱烈度可达11.9的长历时高烈度的干旱事件。[Objective]The temporal and spatial variations of drought in the Huaihe River Basin are significant,with some areas prone to severe drought.Studying the characteristics of drought in this region is crucial for agricultural production,water resource management,and ecological protection.[Methods]Monthly non-stationary standardized precipitation evapotranspiration index(NSPEI)datum from 195 meteorological stations in the Huai River Basin from 1980 to 2019 were analyzed to study meteorological drought in the region.Historical drought events were identified using run theory,extracting drought duration and drought severity.These were then analyzed using univariate functions and multivariate Copula functions.[Results]The result show that drought events in the Huaihe River Basin are mainly characterized by mild and moderate drought,accounting for 39%and 47%of all drought events,respectively.These events are primarily distributed in the northwest and south of the basin,with extreme drought being rare.The Generalized Pareto function is the most suitable for fitting the univariate distribution of drought duration and drought severity,with 87 stations indicating that the t-Copula function is the best fit for the joint distribution.When the return period exceeds 20 years,the spatial distribution characteristics of drought duration and drought severity are found to be approximately the same,with high-value areas concentrated in the southwest of the basin.The spatial distribution of the joint return period and concurrent return period probabilities is observed to remain nearly unchanged as the return period increases,with high-value areas mainly located in the southern and western parts of the basin.[Conclusion]Drought events in the Huaihe River Basin are primarily characterized by moderate droughts within months,mild droughts within seasons,and moderate droughts within seasons,with the occurrence of extreme droughts being found to be very low.As the return period increases,the high-value areas for drought duration and drought

关 键 词：非平稳气象干旱 干旱特征 COPULA函数 淮河流域 气候变化 非平稳标准化降水蒸散指数(NSPEI) 水资源 极端干旱 

分 类 号：P429[天文地球—大气科学及气象学]