Reconstruction and Analysis of Heavy Rainfall /Rainstorm Events in Northern China over the Past 650 Years

Frequent rainstorm events in North China pose significant threats to both natural ecosystems and socio-economic systems. Based on historical documents including local gazetteers and archives, combined with instrumental records since the Republican era, this study systematically reconstructs the chronology of rainstorm events, extreme rainstorm sequences, and typhoon-induced rainstorm sequences in North China from 1368 to 2024, and further analyzes their spatiotemporal evolution patterns and driving mechanisms. First, following the principle of uniformitarianism, identification criteria for historical rainstorm events were established and validated through comparison with modern instrumental records. The reconstructed rainstorm chronology reveals significant variations across interannual, interdecadal, intra-annual, and spatial scales. Second, using the percentile threshold method, extreme rainstorm event clusters with a 30% occurrence probability from 1470 to 2024 were extracted. Further analysis indicates distinct spatial distributions of extreme rainstorms between cold and warm periods: during cold periods, rainstorm locations shifted northward and westward, primarily concentrated on the windward slopes of the Yanshan and Taihang Mountains. Extreme rainstorm events show positive correlation with typhoon frequency and exhibit significantly higher occurrence probability during La Niña decay years compared to El Niño decay years. Finally, based on identification methods for typhoon-induced rainstorms, typhoon rainstorm event clusters were further extracted. The study finds higher frequency of typhoon rainstorms during warm periods, with increased occurrence in relatively dry years. Unlike extreme rainstorms, typhoon rainstorms show similar occurrence probability during La Niña years and subsequent years, suggesting different driving mechanisms. This research reveals the evolutionary characteristics of rainstorm events in North China across different temporal scales and climatic backgrounds, providing scientific basis for understanding their formation mechanisms and for disaster prevention and mitigation.