Author(s): Jisung Kim; Won Kim; Keuksoo Kim
Linked Author(s): Won Kim
Keywords: Upwind implicit; 1-D numerical model; Flow resistance
Abstract: Exchange of momentum caused by trees in floodplain plays a role as an additional flow resistance. For practical purpose, resistance of trees in floodplain is considered in composite roughness coefficient, a bulk parameter. Quantity of roughness coefficient is, however, hard to estimate. In this study, onedimensional upwind implicit scheme, which contains additional resistance term by trees, is developed to overcome the limitation of non-quantitative composite roughness coefficient mentioned above. Robust model, which provides stable and accurate result even in flow regime with high CFL number, is established by developed scheme. To evaluate the model, hydraulic experiments of single tree, tree colony and debris obstructing flow in the space between trees are conducted. Without roughness coefficient by subjective and iterative judgment, the scheme offers stable and accurate result for the three experiment cases. Proposed model can be used as an alternative to establish standards for planting trees in relatively wide rivers which offset two dimensional effect of flow.