基于Copula的不同气候区暴雨联合特征分析——以辽宁省为例

The characteristic analysis of rainstorm on different climate zones based on Copula function:take Liaoning Province as a case

选取纬度相近的宽甸、建平和营口站1955—2012年降水数据,引入Copula函数,对辽宁省不同气候类型区暴雨要素进行联合特征分析.结果表明:(1)暴雨单要素拟合中,广义极值分布比较通用,暴雨比和暴雨强度适合同时用于反映暴雨特征,暴雨日数只适用于反映半湿润山区的暴雨特征,暴雨量适用于反映半湿润平原区和半干旱区的暴雨特征;(2)不同地貌、不同气候区,联合暴雨多个要素的Copula函数的类型不尽相同,Clayton Copula函数适合用于联合反映半湿润山地区和半干旱区的暴雨,Frank Copula函数适合用于反映半湿润平原区的暴雨联合特征;(3)辽宁省暴雨的联合重现周期从东部半湿润的山区向西部半干旱区逐渐延长,而同现重现周期则从西部干旱区向东部半湿润山区延长,即二者表现出相反的趋势.

By selecting similar latitude meteorological data on Kuandian,Jianping,and Yingkou Stations from 1955 to 2012,we analyse the joint characteristic of rainstorm factors on different climate zones in Liaoning Province by introducing the copula function.The results show that：（1）In the fitting of rainstorm single elements,the generalized extreme value distribution is general,rainstorm intensity（I）and rainstorm contribution（R）suitable used to reflect the features rainstorm,rainstorm days（D50）is applicable only in the semi-humid mountain,rainstorm amount（P50）is applicable to reflect the features rainstorm in semi-humid plains area and semi-arid zone;（2）The Copula function for joint of rainstorm factors is different in Liaoning Province that have different physiognomy and different climate zones,Clayton Copula function is suitable to use in reflecting the features of joint rainstorm factors in semi-humid mountain and semi-arid areas,Frank Copula function is suitable to use in reflecting the features of joint rainstorm factors in semi-humid plains area;（3）Joint return period gradually extend form the eastern semi-humid mountain to the western semi-arid areas in Liaoning Province.Co-occurrenc return period show the opposite trend.It extend gradually from the western semi-arid areas to the eastern semi-humid mountain in Liaoning Province.