气候变化下雄安新区干旱风险研究

Research on drought risk in Xiong’an New Area under climate change

摘要

雄安新区地处华北平原中部，属于我国水资源相对匮乏的地区之一，研究其干旱特征演变形势，对雄安新区经济社会发展及水资源管理具有重要意义。利用1975—2018年31个气象站点的长系列气象监测数据和CanESM2气候模式数据，计算不同时间尺度下标准化降水指数SPI,并采用多种类型Copula函数，构建基于干旱特征表征的二维联合概率分布模型，分析雄安新区所在水资源二级区在气候变化影响下的干旱演变规律及风险状况。在月尺度和季节尺度上，水资源二级区轻旱、中旱和重旱发生频率的空间分布情况有所转移，整体变化不大，但特旱发生频率则存在显著的增加；在年尺度上中旱频率有所减小，而轻旱、重旱和特旱的发生频率增加显著，同时在空间分布特征有明显转移；Clayton Copula函数对雄安新区所处区域干旱历时和干旱程度的拟合效果最佳，二者的单变量重现期均位于联合重现期与同现重现期之间，随着重现期的增大至100 a时，干旱历时达到6.9个月，干旱程度达到7.4,但二者的同现重现期将超过200 a。结果表明：未来轻旱、重旱和特旱均在雄安新区及周边出现明显聚集现象，也意味着未来雄安新区的水资源承载安全风险有升高的可能性，但长历时高烈度的干旱事件出现概率相对较小。

Abstract

The Xiong'an New Area is located in the central part of the North China Plain, which is characterized as one of the regions in China with relatively scarce water resources. The evolution of its drought characteristics is deemed significant for the economic and social development of the Xiong'an New Area and effective water resource management. Long-term meteorological monitoring data from 31 weather stations from 1975 to 2018 and CanESM2 climate model data were utilized to calculate the Standardized Precipitation Index(SPI) across various time scales. Additionally, different types of Copula functions were employed to construct a two-dimensional joint probability distribution model based on the characterization of drought features. The aim was to analyze the drought evolution patterns and risk status in the secondary water resource zone where the Xiong'an New Area is located under the influence of climate change. At both monthly and seasonal scales, a spatial redistribution of the frequencies of mild, moderate, and severe droughts has been observed in the secondary water resource zone, although the overall changes remain minimal. In contrast, a significant increase in the frequency of extreme drought events has been recorded. On the annual scale, while a decrease in the frequency of moderate droughts has been noted, significant increases in the frequencies of mild, severe, and extreme droughts have been observed, along with notable shifts in their spatial distribution characteristics. The Clayton Copula function was found to provide the best fit for drought duration and intensity in the region. The univariate return periods for these variables are situated between the joint return period and the co-occurrence return period; as the return period extends to 100 years, a drought duration of 6.9 months and a drought intensity value of 7.4 have been reached, while the co-occurrence return period exceeds 200 years. The results indicate that a marked clustering of mild, severe, and extreme drought events is expected to occur in the Xiong'an New Area and its surrounding regions. This suggests an increased potential risk to the water resource carrying capacity in the future, while the probability of prolonged high-intensity drought events remains relatively low.

关键词

雄安新区 / 气候变化 / 干旱 / 联合概率分布

Key words

Xiong'an New Area / climate change / drought / joint probability distribution

Author summay

徐小婷(1991—), 女, 工程师, 硕士, 主要从事水文水资源分析、防汛抗旱研究。E-mail: [e-mail]