基于Copula函数的唐乃亥与兰州站径流相依关系及演变分析OA

The Tangnaihai and Lanzhou stations are two major control hydrological stations in the Yellow River Basin.Quantitative analysis of the dependence and evolution of monthly runoff between these two stations provides critical support for the operation of water storage and com-pensation projects and the joint scheduling of water resources in the basin.Taking the implementation of the Yellow River Flood Control Oper-ation Scheme in 2015 as a temporal breakpoint,monthly runoff data from 2005 to 2024 are divided into two periods:Ta(2005-2014)and Tb(2015-2024).Copula functions are constructed for each period to quantitatively calculate probabilities under wet and dry conditions.The re-sults indicate that:The conditional probabilities of wet and dry states in both periods are consistently significantly higher than the correspond-ing joint probabilities,revealing that the Tangnaihai Station exerts a distinct driving effect on runoff variations at the Lanzhou Station.Com-pared with the Ta period,the joint probabilities of wet and dry states in the Tb period increase by 5.84％and 7.27％,respectively,while the conditional probabilities increase by 17.46％and 15.73％.This suggests that the synchronization of extreme states and the runoff dependence between the two stations have strengthened following the implementation of the Scheme.The findings elucidate the wet-dry dependence of monthly runoff between the two stations and quantitatively assess the reshaping effect of artificial interventions on hydrological synchronization.