The transportation and production of sediments are closely related to changes in river morphology. Based on the balance of sediments, this study establishes two major indexes, the
sediment generation index IP and the sedimentation transportation index IR. In this study, we examined the impact of Typhoon Morakot and Typhoon Fanapi on the generation and transportation of sediment in Kao-Ping River in southern Taiwan. For both indexes, we selected a number of control factors, such as topography, rainfall, river morphology, landslide, etc., for the GIS multi-variable
analyses. The results revealed a huge amount of sediment generated and accumulated during Typhoon Morakot. For Typhoon Fanapi two years later, it suggests sediment accumulation is limited at the downstream areas and the transportation of sediment is becoming more balanced. However, there are still tremendous amounts of sediment in the river banks that possess hazard potential and need to be
treated.
Key Words : GIS, sediments generation, sedimentation transportation, control factor analysis.