“…The statistical parameters of GEV‐NS models are described as a function of time or other physical covariates. Thus, how to estimate the NS design precipitation with a prescribed return period under NS condition is one of the core questions (Acero et al, 2017; Acero, Parey, García, & Dacunha‐Castelle, 2018; Jiang, Xiong, Yan, Dong, & Xu, 2019; Salas & Obeysekera, 2014; Yan, Xiong, Guo, et al, 2017). According to the design concepts under ST condition, the annual design precipitation associated with a given return period varies over time.…”