The initial space settings of suitable environments for plants strongly affect the mutual feedback evolution of the river landscape and terrestrial plants. Thus, based on the morphological characteristics of newly-defined systematic out-branching channels in nature, this study performs an effective simulation of the flow of a designed moderately curved bend with a single short branch. The practice-based channel curvatures and branch on–off conditions are controlled in ANSYS FLUENT. The results show that: (1) the core zone of the depth-averaged primary velocity excess is approximately inversely equivalent to the channel migration potential; (2) the existence of the branch can strongly promote the formation of a new core vorticity zone and the conflicting development of the inner-negative and outer-positive vorticity zone after the bifurcation site at the cross-sections; (3) the free-flowing branch can greatly diminish the downstream helical flow strength; overall, the variation tendency of the ratio of helical flow strength to discharge squared is immune to the small range of change in stable inflow; and (4) the downstream channel is a strongly erosive region with the branch outlet closed, judging by the shear stress distribution; otherwise, it is a deposition region. The findings lay the groundwork for harmonious optimization of branch and plant configurations in river-bend systems.

植物适宜环境的初始空间设置强烈影响河流景观与陆生植物的相互反馈演化。因此，基于自然界新定义的系统分支通道的形态特征，本研究对设计的具有单个短分支的适度弯曲弯道的流动进行了有效模拟。基于实践的通道曲率和分支开关条件在 ANSYS FLUENT 中进行控制。结果表明：（1）深度平均一次超速核心区与水道迁移势近似反等价；(2)分支的存在可以强烈促进新的核心涡度带的形成，以及截面处分岔点后内负外正涡度带的冲突发展；(3) 自由流动的分支可以大大降低下游的螺旋流动强度；总体而言，螺旋流强度与流量平方比的变化趋势不受稳定流入的小范围变化的影响；(4)下游河道为强侵蚀区，支流口封闭，从剪应力分布判断；否则为沉积区。这些发现为河弯系统中分支和植物配置的和谐优化奠定了基础。(3) 自由流动的分支可以大大降低下游的螺旋流动强度；总体而言，螺旋流强度与流量平方比的变化趋势不受稳定流入的小范围变化的影响；(4)下游河道为强侵蚀区，支流口封闭，从剪应力分布判断；否则为沉积区。这些发现为河弯系统中分支和植物配置的和谐优化奠定了基础。(3) 自由流动的分支可以大大降低下游的螺旋流动强度；总体而言，螺旋流强度与流量平方比的变化趋势不受稳定流入的小范围变化的影响；(4)下游河道为强侵蚀区，支流口封闭，从剪应力分布判断；否则为沉积区。这些发现为河弯系统中分支和植物配置的和谐优化奠定了基础。