Author(s): Samhee Lee; Inrock Lee; Jung Won Lee; Won Jeong
Linked Author(s): Samhee LEE
Keywords: Sandbar bed material river vegetation river channel terrestrialization compound cross-section
Abstract: Major rivers in Korea, which are part of the Asian monsoon climate zone, have a large coefficient of flow fluctuation of about 200 to 700 (393 for the Hangang river which flows through Seoul), resulting in large seasonal changes in rainfall and runoff. As a result, the upper part of the sandbars is often not submerged at the median water level. Changes in land cover of rive channel were investigated in most of the national rivers managed by the nation. As a result, it was found that riparian vegetation has settled in high-berm areas, including non-submerged sandbars, which used to be naked land even at these water levels, and then gradually transitioned to forested areas, resulting in the growth of river compound cross-sections (high-berm areas) (e. g., 17 times in the Naeseongcheon River and 78% in the Cheongmicheon River in 10 years). The cause of this was confirmed to be the accelerated sedimentation of very fine particles of suspended sediment, which had not been considered in the analysis of river-bed fluctuation, due to slowed flow in the vegetation. This is defined as the phenomenon of ‘river channel terrestrialization’ which is the gradual transformation of a water body into a vegetated land area. As flood safety and aquatic ecological health deteriorate in areas with ‘river channel terrestrialization’, this study explored the evaluation techniques and management measures to prepare for them
Year: 2025