Spatiotemporal variability of extreme precipitation at different time scales and quantitative analysis of associated driving teleconnection factors: Insights from Taihu Basin, China

The increasing frequency of extreme precipitation (EP) has become an important issue owing to its high degree of destruction. Studies on the spatiotemporal distribution of EP variability and its teleconnection with meteoro-logical factors are extremely important but lacking in the Taihu Lake basin (TLB). Based on the daily precipi-tation data from 50 hydrological stations in the TLB from 1965 to 2018, we introduced a new circular distribution method to statistically delineate the different flood seasons and assess the spatiotemporal evolution characteristics and future persistence of extreme precipitation indices (EPIs) at different time scales. In addition, geodetector was used to quantify the effects of interactions between meteorological factors on the EPIs changes. The results showed that the EP in the TLB tended to increase significantly (P < 0.05) over the past 54 years, with faster growth in the urban cluster in the northeastern part of the basin. The increase in intensity and maximum precipitation amount was dominant during the plum rain period (PRP), whereas the increase in the number of days of precipitation was dominant during the typhoon period (TP). The scaling exponents reveal that the increasing of EP had long-range correlation at different time scales. Furthermore, the influence of climate factors on EP was nonlinear, and the Western Pacific Subtropical High (WPSH) intensity were the climate factor that played a major role in the variability of the EPIs. The results of this study provide a reference for TLB and other monsoon coastal areas worldwide to cope with extreme climate and develop corresponding strategies.

Automated summary

This study investigated the spatiotemporal distribution of extreme precipitation (EP) and its relationship with meteorological factors in the Taihu Lake basin (TLB). The results showed that EP in the TLB has significantly increased over the past 54 years, with faster growth in the urban cluster in the northeastern part of the basin. The increase in intensity and maximum precipitation amount was dominant during the plum rain period, while the increase in the number of days of precipitation was dominant during the typhoon period. The study also found that the influence of climate factors on EP was nonlinear, with the intensity of the Western Pacific Subtropical High playing a major role. These findings provide valuable insights for the TLB and other monsoon coastal areas in dealing with extreme climate events.