Evaluation of Sediment Yield and Risk Management of Sediment Disaster
With the Natural Resources Conservation Service-Curve Number Method
Abstract
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.