On the event-based extreme precipitation in the Xiangjiang River Basin, China: temporal-spatial distribution and future trends

An in-depth understanding of event-based extreme precipitation (EEP), emphasizing precipitation process, can help to prevent the risk posed by regional high-intensity and persistent precipitation. The concept of time distribution pattern (TDP) is used to distinguish EEPs, which classifies EEPs according to the occurrence time of extreme precipitation. Furthermore, TDP1,2,3 is that the distribution of daily precipitation above the threshold is in the first half, in the second half, and both the first half and second half of EEP, respectively. We analyze temporal characteristics, spatial distribution, future trends of EEP, and the contribution rate of urbanization to EEP in this study. EEP thresholds exhibit a latitudinal gradient from central to northern and southern regions except for Nanyue Station (NY). TDP1 and TDP2 account for more than 60% among the total of EEPs. However, TDP3 is the dominant precipitation type observed at each station from the perspective of precipitation, intensity, duration, especially, in summer. EEP is less and TDP is unstable in autumn and winter. In general, there is an increasing trend in EEP and it is predicted that the trend of EEP will continue to rise. Moreover, the contribution rate of urbanization to EEP varies significantly, with a more pronounced inhibitory effect observed. The inhibitory effect of urbanization on the frequency and duration of TDP3 reached 60.83% and 72.77%, respectively. However, it is more significant on the extreme nature of TDP1 under urbanization, with a positive contribution rate of 9.63% and 21.83% to precipitation and intensity of TDP1, respectively. The results conclude that the higher the level of urbanization, the more pronounced the extreme trend of TDP1 becomes.