Characteristics and evolution of heat wave and extreme precipitation compound events in South China based on copula function

Abstract Compared to single events, compound extreme weather and climate events have the potential to exert more serious impacts on natural systems and human society, particularly in densely populated regions. Focusing on South China, this study identified heat wave–extreme precipitation compound events based on summer daily maximum temperature and precipitation data of 79 meteorological stations spanning 1970 to 2019. A two‐dimensional joint cumulative probability distribution function of heat wave intensity and extreme precipitation intensity was constructed using the copula function, and the return periods of different types of compound events were analyzed to evaluate their occurrence characteristics. The results indicate that the average heatwave intensity and extreme precipitation intensity increased at rates of 0.1°C per decade and 4.1 mm per decade, respectively. A two‐dimensional joint analysis of heatwave and extreme precipitation intensities was performed, with the Gaussian copula function identified as the most appropriate model. In recent years compound events have exhibited higher frequencies, stronger intensities, wider spatial distributions, and significantly shorter return periods compared to earlier periods. Moreover, under similar conditions of heatwave and extreme precipitation, the Pearl River Delta and northern mountainous regions are more prone to the occurrence of compound events.