植生の流れ抵抗性に関する現地実験的研究

It is well known that condition of flow in a small open channel is largely influenced with state of the vegetations. However, the relation between vegetation and roughness of channel has not been throughly analysed. In order to find rational approach to the problem, some experiments have been carried out on the paddy field as the model of vegetation throughout the growth period.
This report deals with some of discussions on the characteristics of resistance against flow on the paddy field. It is essentially found that the main factor of resistance is rather the rice stump than the shear force on the bed and wall caused by viscosity of fluid. The authors induced the modified coefficent of resistance peculiar to the stump transformed as Eq. 13 and recoginzed that there was a relation between C_<mD> and Froude number as shown in Fig. 10. Although this experiment has not been enough to discuss in detail, some suggestions to the future studies are indicated.