Figure 5. Observational data of typhoon events.
2.3.5 Management Practices
2.3.5.1 Subdivision of the Management Area
To explore the management strategy of sediment in the catchment area, this study divided the catchment area into multiple subdivisions to facilitate the determination of essential areas within it. Catchment area division was based on two concepts—the establishment of a depressionless flow direction (Jenson & Domingue, 1988) and the establishment of gridded cumulative discharge (O’Callaghan & Mark, 1984). After the threshold values of each subdivision were determined, the division of the catchment area would automatically be conducted. Based on this principle, the Chenyulan River catchment area could be divided into 269 subdivisions (Figure 6).