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Numerical Experiments of Vegetation Growth Effects on Bed Change Patterns

식생생장 영향을 고려한 하도변화에 대한 수치모의

Hyung Suk Kim1*
,
Moon Hyeong Park2
,
Hyo Seop Woo3
김 형석1*
,
박 문형2
,
우 효섭3
1Korea Institute of Civil Engineering and Building Technology, River and Coastal Research Division, Post doc. Researcher
2Korea Institute of Civil Engineering and Building Technology, River and Coastal Research Division, Senior Researcher
3Korea Institute of Civil Engineering and Building Technology, River and Coastal Research Division, Senior Research Fellow
1한국건설기술연구원, 하천해안연구실, 박사후연구원
2한국건설기술연구원, 하천해안연구실, 수석연구원
3한국건설기술연구원, 하천해안연구실, 선임연구위원
*교신저자. *Corresponding Author. 
2014. pp. 68-81
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Abstract

In this study, the numerical simulation regarding the process and characteristics of topography change due to the vegetation recruitment and growth was carried out by adding the vegetation growth model to two-dimensional flow and sediment transport models. The vegetation introduction and recruitment on the condition for developing an alternate bar reduced the bar migration. The vegetated area and channel width changes were more significantly influenced by changes in upstream discharge rather than the duration of low flow. When the upstream discharge decreased, the vegetation area increased and the channel width decreased. The vegetation introduction and recruitment on the condition for developing a braided channel significantly influenced the characteristics of topography changes. In the braided channel, vegetation reduced the braided index, and when the upstream discharge decreased significantly, the channel topography was changed from the braided channel to the single channel. The vegetation area decreased as the upstream discharge increased. The channel width decreased significantly after the vegetation was introduced and it also decreased as the upstream discharge decreased. It was confirmed through the numerical simulation that a decrease in flood discharge accelerated the vegetation introduction and recruitment in the channel and this allowed to confirm its influence on the characteristics of topography changes qualitatively.

Keywords
Flow and sediment transport model
Vegetation growth model
Alternate bar
Braided bar

본 연구에서는 2차원 흐름/유사이동 모형에 식생생장모형을 추가하여 하도의 식생 활착 및 성장에 의한 지형변화 과정과 특성을 수치모의 하였다. 교호사주가 발달하는 조건에서 식생 이입 및 활착은 사주의 이동을 감소시켰다. 식생면적 및 하폭의 변화는 저유량 지속시간보다 상류유량 변화에 더 크게 영향을 받았다. 상류유량이 감소하면 식생면적은 증가하고 하도 폭은 감소하였다. 망상하도가 발달하는 조건에서 하도내 식생 이입 및 활착은 지형변화 특성에 크게 영향을 미쳤다. 망도하도에서 식생은 망상의 수를 감소시키고 결국 상류유량이 크게 감소하면 하도지형을 망상하도에서 단일수로로 변화시켰다. 식생면적은 상류유량이 증가함에 따라 감소하였다. 하도폭은 식생 도입 후 급격히 줄어들었고 상류유량 감소와 함께 감소하였다. 수치모의를 이용하여 홍수량 감소가 하도 내의 식생 이입 및 활착을 가속시키고 이로 인해 하도변화 특성에 미치는 영향을 정성적으로 확인할 수 있음을 보였다.

키워드
흐름/유사이동 모형
식생생장모형
교호사주
망상하도
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Information
  • Publisher :Korean Society of Ecology and Infrastructure Engineering
  • Publisher(Ko) :응용생태공학회
  • Journal Title :Ecology and Resilient Infrastructure
  • Journal Title(Ko) :응용생태공학회 논문집
  • Volume : 1
  • No :2
  • Pages :68-81
  • DOI :https://doi.org/10.17820/eri.2014.1.2.068
Journal Informaiton Ecology and Resilient Infrastructure Ecology and Resilient Infrastructure
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