| Bamboo has been used to protect levees widely because their stems are connected by rhizomes and this features strong resistance against erosion during floods. However, interaction between flood and bamboo vegetation has not been paid attention as much as other species such as willow and pseudoacacia.We have surveyed succession process of bamboo vegetation in a gravel-sand bar of the Naka River, Ibaraki prefecture. We have tried to elucidate the expansion and decrease of vegetation area by considering the effect of sediment deposition and erosion process caused by floods. Since bamboo stems are densely populated within vegetation area, their foundation are hardly destroyed Expansion process of bamboo vegetation is made by extending rhizomes to nearby area when sand is deposited. Since bamboohas strong resistance to flow, sand deposition is intensive within vegetation. This causes deposition of slit and clay behind them leading to the decay of their favorite environment by themselves. |
