Subtropical areas are often struck by typhoons. The sediment disasters that accompany typhoons severely affect the environment. However, sediment yield (SY) data usually lack integrity. This study used long-term daily river discharge and SY data to establish a runoff–SY rating curve (Q–Qs rating curve) and used it to estimate the SY of typhoon events. In addition, based on the curve number, this study analyzed the relationship between the potential maximum retention (S) and SY; the results showed that different amounts of cumulative rainfall correspond to different S–SY functions; thus, the potential maximum erosion (A) of the catchment area could be estimated using this characteristic. For a sediment management strategy, this study took subdivisions as a unit and incorporated the potential maximum erosion (A) and slope to establish a map indicating the spatial distribution of sediment disaster risks. To determine the priority areas for management, the relationship between the cumulative number of subdivisions and landslide rate could be used to determine the areas with high potential, which can serve as a reference for related management research.