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2024 Vol.57, Issue 12 Preview Page

Research Article

Numerical simulations of bed morphology under fixed channel width confinement

수치모형을 이용한 고정된 하폭변화에 따른 하상변동 특성 분석

Hyeok-Cheol Shina
,
Yong-Jun Kwonb
,
Moonhyung Parkc
,
Yonguk Ryud
,
Hyung-Suk Kime*
신 혁철a
,
권 용준b
,
박 문형c
,
류 용욱d
,
김 형석e*
aMaster Student, Department of Civil and Environmental Engineering, Kunsan National University, Gunsan, Korea
bPh.D. Student, Department of Civil and Environmental Engineering, Kunsan National University, Gunsan, Korea
cResearch Fellow, Department of Hydro Science and Engineering Research, Korea Institute of Civil Engineering and Building Technology, Goyang, Korea
dAssistant Professor, Department of Civil Engineering, Chonnam National University, Gwangju, Korea
eAssociate Professor, Department of Civil Engineering, Kunsan National University, Gunsan, Korea
a국립군산대학교 토목환경공학부 석사과정
b국립군산대학교 토목환경공학부 박사과정
c한국건설기술연구원 수자원하천연구본부 연구위원
d전남대학교 토목공학과 조교수
e국립군산대학교 토목공학과 부교수
*Corresponding Author
31 December 2024. pp. 1133-1143
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Abstract

The installation of hydraulic structures for river restoration projects typically involves assessments focused on flow and water level whereas the river morphological characteristics are not considered. This study employs a two-dimensional numerical model to analyze morphological changes under varying channel width confinements. The results indicate that as the channel width increases, the wetted width and active width decrease. In braided channels, the active width shows approximately 20~40% of the total wetted width. When the dimensionless stream power decreases below a critical threshold, the transition from a single-thread channel to a braided river is marked by a sharp increase in the Braiding Index (BI) and Active Braiding Index (ABI), leading to a more complex channel structure. The numerical results agree with findings from previous studies. Changes in channel width significantly influence river morphology and stability. These findings provide essential insights for supporting channel width adjustments in river restoration and management practices.

Keywords
River restoration
Numerical simulation
Active width
Braiding index
Active braiding index

하천복원 시 수공구조물이 설치되는 경우 대부분 유수의 흐름에 대한 검토 및 평가가 수행되고 있으며, 하천의 지형적 특성은 충분히 고려되지 않고 있다. 본 연구에서는 2차원 수치모형을 이용하여 하폭이 제한된 조건에서 하폭의 변화에 따른 하도의 변화 및 특성을 수치모의하여 분석하였다. 하폭이 증가하면 습윤폭(wetted width)과 활성폭(active width)이 감소하며, 망상하천에서는 전체 습윤폭의 약 20~40% 범위를 유지하는 활성폭 비율이 나타났다. 무차원 유수력(dimensionless stream power)이 특정 값 이하로 감소할 경우, 단일 수로에서 망상하천으로 전환되는 과정에서 BI (Braiding Index)와 ABI (Active Braiding Index)가 급격히 증가하며 하도의 구조가 복잡해지는 양상이 나타났다. 수치해석 결과로 도출된 여러 매개변수 변화 특성은 기존 연구와 부합하는 것으로 나타났다. 이는 하천의 하폭 변화가 하천의 형태와 안정성에 중요한 영향을 미치며, 하천 복원 및 관리 과정에서 하폭 조정의 필요성을 뒷받침하는 근거로 활용될 수 있다.

키워드
하천복원
수치해석
활성폭
Braiding index
Active braiding index
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Information
  • Publisher :KOREA WATER RESOURECES ASSOCIATION
  • Publisher(Ko) :한국수자원학회
  • Journal Title :Journal of Korea Water Resources Association
  • Journal Title(Ko) :한국수자원학회 논문집
  • Volume : 57
  • No :12
  • Pages :1133-1143
  • Received Date : 2024-11-25
  • Revised Date : 2024-12-07
  • Accepted Date : 2024-12-09
  • DOI :https://doi.org/10.3741/JKWRA.2024.57.12.1133
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