Evolution Characteristics of Meteorological Drought under Future Climate Change in the Middle Reaches of the Yellow River Basin Based on the Copula Function

Against the background of global warming and frequent extreme precipitation events, changes in drought characteristics middle reaches Yellow River Basin (YRMB) have been particularly pronounced recent years. Under new situation, it is necessary to further our understanding risk basin its response mechanisms climate change. In this study, YRMB was utilized as research area. Based on (P) potential evapotranspiration (PET) data under four emission scenarios (historical future), five timescales (SPEI-1, SPEI-3, SPEI-6, SPEI-9, SPEI-12) SPEI indices were estimated study. Drought events identified using run-length theory, spatial distribution values frequency, duration, intensity, severity also examined. preferred copula function, two-dimensional joint variables established, return period historical (1901–2014) future (2022–2100 SSP245 SSP585 scenarios) periods calculated. The results show that index increasing tends be more humid. scenarios, frequency long durations, high intensities, or severe may higher. univariate always higher than period, but lower co-occurrence both types can used assess range estimations future. provide support for spatiotemporal improving accuracy decision making.