Due to global climate change, the increasing frequency of extreme precipitation events poses severe challenges to socioeconomic development and ecological environmental security in the Yangtze River Delta (YRD) region. On the basis of high-resolution daily precipitation data from the YRD region for 1961–2022, the spatiotemporal evolution patterns of eight extreme precipitation indices defined by the ETCCDI are analyzed systematically. The results indicate that: (1) Over the past 62 years, extreme precipitation has exhibited a consistent and stable south-high–north-low spatial pattern in terms of frequency (R10mm and R20mm) and intensity (PRCPTOT, R95p, Rx1day, SDII), while in terms of duration, CDD shows a north-high–south-low distribution and CWD displays the opposite pattern. (2) From 1961 to 2022, extreme precipitation frequency and intensity increased significantly, with PRCPTOT and R95p rising at 3.18 mm/yr and 0.99 mm/yr, respectively, exhibiting a general south-high–north-low spatial pattern at the pixel scale. (3) All indices have experienced significant abrupt change years, with frequency indices primarily exhibiting change years during 1990–2005, and intensity indices mainly around 2008. (4) At the seasonal scale, extreme precipitation frequency, intensity, and duration peak in summer and reach their lowest in winter, with a dominant south-high–north-low spatial pattern. Trends indicate that frequency and intensity increase mainly in summer and winter, with the strongest enhancement in summer (PRCPTOT 2.66 mm/yr, R95p 0.81 mm/yr), while spring and autumn show unstable or regionally variable patterns. This study can provide decision-making support for addressing climate change and enhancing extreme weather risk management capabilities in the YRD region.
Gao et al. (Sun,) studied this question.