ヨシの生長とガタ土堆積の相互作用およびヨシ生長抑制策の効果

抄録

The Ushizu river is a well mixed type and the upper tidal distance is approximately 12km from the river mouth. Mud sedimentation and the spread of Phragmites australis in the river bank form original scenery. However, they cause a river cross-section closure and the capacity degradation of river flowing.

This study is to clarify the characteristic growth of P. australis in the long term, the relation of habitat of P. australis and sedimentation, the trap of suspended matters and the effect of the shield plate that has an inhibiting effect on growth. As a result, the relationship between the waterside progress of P. australis and mud sedimentation is shown. Also, sedimentation is caused near the group edge of P. australis. In addition, the density of P. australis increased by cutting of it. This means that the cutting may cause more spread of P. australis. Finally, a new vegetation system to control the spreading of P. australis was suggested.