Characteristics of extreme precipitation and its effects on soil and water retention in Sichuan, China under multiple climate change elements

• Wet and dry durations decrease in Sichuan Province, but the vast majority of Extreme precipitation indices will still rise in the future. • Daily precipitation intensity (SDII) was mutated in 2006, and water and soil retention changed accordingly in the preceding and following periods. • The dual-factor combinations NINO3.4 + AO and AO + Sunspot had the greatest impact on SDII. • Increases in the number of climatic elements do not always increase the impact on precipitation, but may also diminish it. During climate change, extreme precipitation events (EPEs) can negatively impact regional water supplies, agriculture, and soil and water conservation. While previous studies have focused on individual climate drivers or hydrological impacts, the simultaneous correlation among multiple climate factors, EPEs, and soil and water conservation capacity has rarely been examined. To address this, this study analyzed 60 years of daily precipitation data in Sichuan Province to investigate the spatial and temporal evolution of EPEs, identify mutation years and future trends. We examined how combinations of climate elements interact to affect EPEs over time and space, quantified their impacts and assessed corresponding shifts in soil and water conservation capacity before and after detected mutation years. Results show an upward trend in EPEs over the past 60 years in Sichuan Province, with notable spatial differences: the western region is becoming wetter, while the eastern region is becoming drier. Although annual precipitation shows no significant change, daily precipitation intensity rose sharply in 2006, leading to marked increases in soil and water retention, especially in eastern Sichuan. Moreover, combined climate drivers, particularly the Arctic Oscillation and sunspot activity, play a strong role in influencing EPE intensity, especially in southern Sichuan. This study provides insights into the impact of climatic factor combinations on EPEs and soil and water conservation, aiding regional water management and disaster prevention in the face of complex climate change.