Jhoukou River is one of the branches of the Laonong River which consists of slate,and its most featured fluvial form is ingrown meander. Because of the strong erosion along the Jhoukou River, there are some indications of channel migration under the long time scale. This study used different SPOT satellite images and aerial photos of two different versions to count the landslide ratio and draw the channel centerline, including typhoon Herb (1996), typhoon Bilis (2000), typhoon Toraji (2001), typhoon Mindulle (2004), and typhoon Haitang (2005). We also calculated annual sediment discharge from 1989 to 2005, to explore the relationships between the sediment discharge and earth surface processes, such as landslides, debris flow, and rainfall. The result shows the landslide ratio of the five typhoon events is between 1.0% and 3.96%, and Haitang typhoon was the highest one. In this study area, landslide areas are increasing year by year, indicating erosion is becoming stronger. However, the fluvial mean curvature value changed from 1.84 in 1980 to 1.86 in 2001 under the time scale of decades, but there was no channel migration of the Jhoukou River. This implies the earth surface processes do not affect meandering forms over a short period.
Key Words : Landslide, sediment discharge, meander, channel migration.