Development of evaluating method for the relationship between sedimentation, flood disturbance and river plant dynamics

这项研究是为了在河床、湿地和洪水干扰之间建立植物动力学的关系。选定了湿地、齐萨尼亚拉丁美洲，选定了碎石河、Eragrostis curvula和Phagmites。实地观测是通过在阿拉川河中游的碎石运动的阈值上激发了Eragrostis curvula的影响。在各种液压条件（颗粒直径、床坡度和水深）和生长条件（植物的菌落直径和密度）下，已估计使用受植物影响的植物区的梯度参数和计算的断裂速度的屏蔽参数。mean grain size （d50）和d84 （84%的grain weight） around the plants was evaluated by comparing friction vVelocity of the flow condition with the critical friction vVelocity of the diameter。《Eragrostis Cur的消除门槛》 ... More 在植物的拖拉机影响的Friction Velocity的情况下定义了一个vula，相当于D84的关键Friction Velocity。与HI （H·水深度， I·床斜率）有关的阈值条件和植物的拖动已被证实用于阿拉斯加河的洪水和吉野河的两股洪水。日本Phragmites在阿拉斯加河的中游流中的洪水分化对洪水、植物生产力和跑道扩展的影响被研究。《P.Japan的动态增长模型》已开发出考虑到干扰的影响，i. e。跑步者形态学和射击生产力在父母殖民地的差异。“在离父殖民地的距离上的生物质分布很好地被模型所代表。”为了分析洪水干扰间隔的影响，最大水位在三个洪水事件中计算和评估了P.Japonica的生境是否受限制或不受限制。在补充中，平均粒度直径的阈值Friction Velocity与洪水事件中的Friction Velocity进行了比较。Although the gravel movement possibility has a little different， tendency with the damaged situation of p.japonica， the clear relationship between the flood interval and the productivity in each hability in each hability is found. The analysis indicates the possibility to calculate the plant productivity under the effect of flood disturbance。Less（低）

The research was conducted to elucidate the relationship between plant dynamics on a gravel bed river or wetland and flood disturbance. For wetland, Zizania latifolia was selected and for gravel bed river, Eragrostis curvula and Phragmites japonica was selected.Field observation was conducted to elucidate the effect of Eragrostis curvula on the threshold of gravel movement at midstream of the Arakawa River. Under various hydraulic conditions (particle diameter, bed slope and water depth) and growth conditions (colony diameter and density of the plant), Shields parameter of the gravel in the plant-vegetated area was estimated using the drag characteristics of the plant and calculated friction velocity affected by the plant. Threshold of gravel movement of median grain size (d50) and d84 (84% of the grain weight) around the plants was evaluated by comparing friction velocity of the flow condition with the critical friction velocity of the diameter. The removal threshold of Eragrostis cur … More vula was defined at which the friction velocity affected by the plant's drag is equal to the critical friction velocity of d84. The threshold condition related to HI (H・water depth, I・bed slope) and the drag by plant was validated for a flood in the Arakawa River and for two floods in the Yoshino River.The effect of flood disturbance on the morphology of runners, plant productivity and runner-expansion characteristics of Phragmites japonica was investigated at midstream of the Arakawa River. The dynamic growth model of P. japonica was developed considering the effect of disturbance, i.e., the difference of runner morphology and shoot productivity in the parent colony. The aboveground biomass distribution along the distance from the parent colony was well represented by the model. For analyzing the effect of flood disturbance interval, maximum water levels at three flood events were calculated and evaluated whether the habitat of P. japonica were inundated or not. In addition, the threshold friction velocity of the average grain diameter was compared with the friction velocity at the flood event. Although the gravel movement possibility has a little different, tendency with the damaged situation of P. japonica, the clear relationship between the flood interval and the productivity in each habitat is found. The analysis indicates the possibility to calculate the plant productivity under the effect of flood disturbance. Less