Journal of Korea Water Resources Association (한국수자원학회논문집)

Korea Water Resources Association (한국수자원학회)
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Experimental analysis of meandering channel development processes with floodplain vegetation

홍수터 식생에 의한 저수로 사행 발달과정 실험적 분석

  • Jang, Chang-Laea (Department of Civil Engineering, Korea National University of Transportation)
  • 장창래 (국립한국교통대학교 건설환경도시교통공학부 사회기반공학전공)
  • Received : 2023.10.29
  • Accepted : 2023.11.24
  • Published : 2023.12.31
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Abstract

This study investigates the impact of riparian vegetation in the floodplain on channel stability, changes in bend curvature, and meandering channel migration. In channels with riparian vegetation, over time, meander width remains relatively constant, but selective bank erosion leads to meander development and downstream movement. During this process, bank erosion and changes in the riverbed are not significant, and the channel maintains relatively constant conditions with reduced sediment discharge and minimal variability. As the density of vegetation increases, bank erosion rates decrease. The erosion rates along the riverbanks increase with the density of vegetation on the floodplain, thus affecting the development of meanders. This factor notably contributes to enhancing riverbank stability and influencing channel changes through floodplain vegetation. Bank erosion rates and dimensionless bend curvature are greatest when there is no riparian vegetation but decrease in conditions with vegetation. Furthermore, the relationship between lateral migration rate and dimensionless bend curvature is similar to that of bank erosion rates. Therefore, riparian vegetation enhances channel stability, influencing bank erosion, meander curvature, and meander migration.

본 연구에서는 실내실험을 수행하여 홍수터 식생에 의한 하안의 안정성, 만곡부의 곡률 변화, 사행의 발달과 이동을 정량적으로 분석하였다. 홍수터에 식생이 있는 하도는 시간이 증가하면서 사행의 하폭이 일정하게 유지하지만, 선택적인 하안침식에 의해 사행이 발달하고 하류로 이동하였다. 이러한 과정에서 하안침식과 사주의 변화가 크지 않으며, 저수로가 일정하게 유지되면서 유사유출량은 감소하고 변동성이 거의 없이 일정하게 유지되고 있다. 식생의 밀도가 증가함에 따라, 하안침식률이 감소하였다. 식생의 밀도가 증가함에 따라 하안침식률이 감소하였고, 사행의 발달에 영향을 주었다. 이는 홍수터 식생이 하안의 안정성을 증가시키고, 하도의 평면변화에 영향을 미치는 주요 인자 중의 하나임을 의미한다. 하안침식률과 무차원 곡률반경은 홍수터에 식생이 없는 조건에서 가장 크고, 식생이 있는 조건에서는 작다. 또한 상대 측방이동률과 무차원 곡률반경도 하안침식률과의 관계가 유사하는 특성을 보였다. 따라서 홍수터 식생은 하도의 안정성을 증가시켜서 하안침식과 사행의 발달뿐만 아니라, 사행의 곡률 변화와 이동에 영향을 준다.

Keywords

Acknowledgement

이 논문은 2023년도 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업(NRF-2021R1I1A3048276)과 2023년 한국교통대학교 산학협력단 지원을 받아 수행하였습니다. 실험을 수행하는데 많은 도움을 준 한국교통대학교 하천수리연구실 학생들에게 감사를 표합니다.

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