Abstract : To investigate the distribution characteristics and causes of rainstorms in Qiannan Prefecture of Guizhou Province , based on torrential rain data observed by 195 regional stations at a high frequency in Qiannan Prefecture and high-precision gridded elevation data , we analyze the rainstorm events in Qiannan from 2015 to 2024 by means of statistical analysis , climatic tendency rate , linear regression , and ArcGIS methods . The results show that over the past decade , torrential rain events in Qiannan exhibited significant temporal heterogeneity , with an annual average of 738 station/times . The rainstorm frequency demonstrated a linear decreasing trend of 10 station/times per year , peaking at 1 033 station/times in 2020 and getting down to its lowest with 501 station/times in 2023 . The ten- day distributions of torrential rain and heavy rainstorm both displayed a single-peak pattern . Torrential rain peaked in mid-June , while heavy rainstorm peaked in late June . Torrential rain events from October to mid-April accounted for only 11% of the annual severe precipitation events , with no torrential rain recorded between late October and the next early March . Approximately 89% of annual torrential rain events were concentrated between May and September , with June being the peak period . Spatially , both torrential and heavy rainstorms showed higher frequency in southern part of Qiannan Prefecture . The low-lying areas in eastern Qiannan and the canyon zones in the west were the high-frequency centers of both torrential and heavy torrential rain . Mountainous areas in the southeast served as torrential rain centers but not heavy rainstorm centers . Topographically, high-frequency torrential rain centers were characterized by relatively low elevations and southward-opening funnel-shaped terrain . The lower altitudes in southern areas facilitated the convergence and energy accumulation of warm-moist air currents that were transported northward from oceanic sources , promoting the occurrence of torrential rain . This study reveals the distribution patterns of torrential rain in Qiannan Prefecture and the topographic features of the high-frequency centers of rainstorms , which could provide a scientific basis for enhancing forecasting capabilities and mitigating losses caused by torrential rain events .