基于二维Copula函数的梅江上游干支流洪水遭遇特征分析OA

Under the influence of global climate change and human activities,the spatiotemporal heterogeneity of flood events in the Meijiang River Basin has intensified,with significantly increased risks of flood encounters between its mainstream and tributaries,posing severe threats to flood control safety in Meizhou City.As a frequent flood-prone area in southeastern coastal China,the upper Meijiang River's flood evolution patterns and encounter characteristics are crucial for optimizing basin-wide flood control strategies and risk management.This study analyzed annual maximum discharge sequences(1985-2024)from three hydrological stations in the upper Meijiang River(Jianshan,Hezikou,and Shuikou(II)),employing Kendall correlation coefficients and two-dimensional Copula functions to investigate flood characteristic evolution and spatiotemporal patterns of mainstream-tributary flood encounters.Key findings include:① The Meijiang mainstream floods are predominantly influenced by the Qinjiang River.By identifying optimal marginal distributions for hydrological stations and combining Kendall correlation coefficients with AIC criteria,joint distribution functions and return period contour maps were constructed.The increasingly steep contours between Shuikou(II)and Jianshan stations reveal enhanced synchrony,confirming greater Qinjiang River impacts on the mainstream.② Inter-tributary influences vary with flood extremity:Significant asynchronous characteristics emerge under low return periods,while extreme events exhibit strong positive correlations and synchronous linear growth patterns.