2003 年 9 巻 p. 7-12
Accurate estimations of flood discharge and sediment transportation are of significant importance in the management of river basin as a whole system. In the case of flood discharge measurements, rod floats has long been used since the Meiji era accepting its not enough accuracy. Recently, however, non-intrusive velocity measurement methods that utilize the Doppler effect by microwave or image analysis have come to be available. In this general description, several problems associated with the float method and stage-discharge relationships are firstly pointed out and field measurement results using floats and non-intrusive techniques are compared. Secondly the observation techniques of the sediment transport in mountainous areas are examined. Relation between flow rate and sediment discharge was shown at some time scales. In a stream with the step-pool, the sediment transportation depends on sediment storage in the channel.
